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R_Target
03-24-2009, 05:34 PM
I ran across this a few years ago, and realized I'd never seen it posted here, so here we go:

"A few years ago, the Society of Experimental Test Pilots ran a flight test
comparison of the F6F-5, FG-1D (Goodyear F4U), P-47D-40 and P-51D. Chief
test pilot was John Ellis of Kal-Aero. Other pilots also participated.

The three radial jobs had versions of the R-2800 that produced appx. 2,000
hp, so differences in performance can be reasonably attributed to the
airframe (and prop). The P-51 had a V-1650-9 Merlin rated at appx. 1,500
hp.

The P-47 had a Curtiss Electric constant-speed four-blade prop.
The FG-1 and F6F both had Hamilton Standard three-bladed constant speed
props (so only the airframe made the difference between these two).
The P-51 had a Hamilton Standard Hydromatic four-bladed constant speed
prop.

Because of the age of the aircraft, structural loads were kept to 6g max.
Engines were fueled with 100LL, which limited MP by four inches on the
radials. Power was limited to maximum continuous settings (except for
take-off & climb to 10,000 ft., when military power was used),
superchargers were limited to low range. Altitude did not exceed 10,000
ft (so bomber escort altitudes were not reached).

Some of the findings:

CLIMB brake release to 10,000 ft.
Hellcat quickest at 4min 15 seconds, followed by the FG-1 at 4min 44 sec.
However, the F6F required 100 lbs of continuous right rudder making it
very tiring to operate. The P-47 trailed the FG-1 by a few seconds. The
P-51 came in last.

LEVEL ACCELERATION at 10,000 ft. using METO to max attainable speed
P-51 accelerated from 110 KIAS to 242 KIAS in 133 seconds.
P-47 accelerated from 105 KIAS to 223 KIAS in 130 seconds.
F6F accelerated from 100 KIAS to 220 KIAS in 115 seconds.
FG-1 accelerated from 100 KIAS to 230 KIAS in 162 seconds.

STALL normal (straight and level decelerating at 1 kt/sec.) and
accelerated (constant 3g turn decelerating at 1 kt/sec.)
Aerodynamic warning:
Best--P-47, with buffet 5 kt above stall.
Worst--P-51, no buffet or other warning.
FG-1 and F6F buffeted 2 kts above stall.
Decreasing aileron effectiveness and increasing longitudinal stick forces
were noticeable in all except the FG-1.
Height loss, accelerated stall:
Best--P-47, 100 ft.
Worst--P-51, 500 ft.
FG-1 and F6F both 150 ft.

Behavior during accelrated stall:
Most predictable and controllable: P-47 and F6F. Both could be flown at
will into the pre-stall buffet, which at no time was heavy enough to
present problems with tracking, and held at maximum usable lift
coefficient with ease. Sideslip became noticeable as wing heaviness
correctible with rudder. There was little tendency to depart controlled
flight.
The FG-1 suffered severe airframe buffet shortly before the stall, but at
the stall there was a strong g-break and rapid right wing drop--no matter
which direction the turn. Careful left rudder could prevent wing drop,
but then at the stall the aircraft became very unpredictable, bucking and
porpoising, with a tendency to a sudden departure.
The P-51 gave no warning whatsoever of an accelerated stall. At the
stall, the aircraft departed with complete loss of control, achieving
270-degree of roll before recovery. Departure was accompanied by violent
aileron snatch strong enough to rip the control stick from the hand.
In short, the P-51 suffered from a Part I deficiency.

SUSTAINED TURN PERFORMANCE at METO at 10,000 ft.
The F6F out-turned the other three by a conclusive margin (1g). The other
three were all about the same.
Corner speeds of all were very close to the maximum level flight speed,
implying very rapid energy loss when turning at the structural limit.
The F6F was in light airframe buffet at 6g at Vmax; the P-47 experienced
light buffet at 4.8g. The FG-1 and P-51 were buffet-free up to 6g.

MANEUVERING STABILITY stick forces/g at Vmax
FG-1--5 lbs/g (too light)
P-47--7.5 lbs/g (ideal)
F6F--12.5 lbs/g (barely acceptable)
P-51--over 20 lbs/g (excessive)

STATIC LATERAL DIRECTION STABILITY steady heading sideslips
All aircraft except the P-47 exhibited moderate or greater adverse aileron
yaw. Worst was the F6F, followed by the FG-1 and the P-51.

ROLL PERFORMANCE
1g 360-degree right (left slower--F6F worst, P-51 best)
FG-1--81 deg./sec.
F6F--78 deg./sec.
P-51--75 deg./sec.
P-47--74 deg./sec.
3g 180 degree right (left slower--P-51 and F6F best, FG-1 worst)
P-47--66 deg./sec.
FG-1--58 deg./sec.
P-51--55 deg./sec.
F6F--48 deg./sec.

DIVING ACCELERATION 30 deg. dive from 10,000 ft., 5,000 ft. begin pull-up,
level off at 4,000 ft.
Aircraft P-51 P-47 FG-1 F6F

Start Speed 110 kts 100 kts 100 kts 120 kts
Max Speed 350 kts 348 kts 315 kts 350 kts
Time 23 secs 32 secs 28 secs 25 secs
All aircraft except the P-47 needed retrimming during the dive.

AGILITY
g capture of 3g target, held for 5 seconds.
G capture and hold was easiest in the P-47, predictable and accurate. F6F
overshot the target by 0.2g. P-51 and FG-1 both overshot by 0.5g

Heading Change Time (180 deg at METO, 220 KIAS at 10,000 ft.)
FG-1--8.5 sec P-47--9.7 sec F6F--9.9 sec P-51--10.0 sec

AIR-TO-AIR TRACKING 210 KIAS at 10,000 ft. (straight & level into a 3g
turn to the left building to 4g followed by a hard reversal into a 4g
right turn.)
FG-1 best, followed by P-47, F6F and, trailing badly, the P-51. Lateral
corrections in the P-51 were difficult thanks to the very high stick
forces. During one run-thru, an effort at a longitudinal tracking
correction that put 4.5g on the plane led to a sudden departure and spin.
Poor forward visibility in all aircraft (P-47 wost, FG-1 best) made
air-to-air tracking difficult. Depressed sight-line aiming difficult to
impossible.

AIR-TO-GROUND TRACKING (90-degree roll into a 30-degree dive from 200 KIAS
at 5,000 ft. into a 3.5g right rolling pullout to a 90-degree heading
change initiated at 2,500 ft.)
The P-47 was far and away the best, accelerating 125 kts in the dive, no
retrimming required, with crisp control response. Accurate target
tracking very easy. FG-1 next best. 100 kt. acceleration. Agressive
lateral corrections required. P-51 similar to FG-1 in acceleration and
control response, but with heavier stick forces. F6F also accelerated 100
kts., but stick forces increased 20 lbs and rudder forces became so high
they interfered with accurate target tracking.

THROTTLE & PROPELLER RESPONSE
MP response instantaneous. Hamilton Standard propeller response quick and
positive. Curtiss electric prop (on P-47) sluggish in response, delaying
RPM change by 3 seconds in a change from 2,000 rpm (cruise) and 2,550 rpm
(METO).
Radial engines required pilot to manage cowl and cooler flap settings.
Merlin engine had automatic control of oil and coolant radiator flaps.

-------
So, if you've read down this far, what's your pick for best? Is there
really a best? I'll put my $2 on the P-47, with the reservation that, if
I knew I was going to do a lot of air-to-air against very maneuverable
aircraft, I would switch my pick to the F6F."

Viper2005_
03-24-2009, 06:32 PM
Interesting, but note that the V-1650-9 was not fitted to the P-51D. It was the engine for the P-51H.

The V-1650-9A was a modified version of the -9 engine with external installation features identical to the -7 so that it could be retrofitted to additional P-51Ds.

However, it certainly wasn't intended to be a 1500 bhp engine in service.

It was actually rated as follows:

Combat:
1930 bhp/3000 rpm/10100 feet in MS gear
1630 bhp/3000 rpm/23500 feet in FS gear

Takeoff:
1830 bhp/3000 rpm

All of the above were achieved at +25 psi boost (81" Hg if you prefer).

Cruise:
2700 rpm, +8 psi

Of course, you can't operate at +25 psi boost using 100LL fuel...

The 100LL limit generally accepted for the Merlin is about +18 psi boost (ie 67" Hg). So the P-51 loses a lot more than 4" Hg by virtue of its fuel...

<span class="ev_code_red">Reference:</span>
Harvey-Bailey, A. 1995. THE MERLIN IN PERSPECTIVE - the combat years. 4th edition. Derby: Rolls-Royce Heritage Trust.

Urufu_Shinjiro
03-24-2009, 08:02 PM
Wow, very interesting, wish there was more of this sort of thing.

R_Target
03-24-2009, 08:03 PM
Interesting, but note that the V-1650-9 was not fitted to the P-51D. It was the engine for the P-51H.

Indeed, it's not a 1650-7. R.Gruenhagen's Mustang lists 1380hp/3000rpm/61" for takeoff, as does Graham White, and 1500hp/3000rpm/61" at 16,000ft for 1650-9/-9A.

The P-51 may or may not be more handicapped than the radials, but I'm more interested in the handling and maneuvering comparisons . http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Stiletto-
03-24-2009, 08:31 PM
It would be interesting to know how much fuel were in the tanks. Also, I don't know how much thought you can put into these tests, these are hardly frontline factory aircraft 60 some years after they were made. I am sure the pilot is good but if he has had more experience in some of the airframe than others, that is going to change the results as well.

VW-IceFire
03-24-2009, 08:39 PM
Just reading through the stall section makes that Mustang they tested sound a fair bit like the Mustang we have in behavior. I always thought the sudden departure was sort of off...one of those weird bugs...but apparently the behavior is right.

Lots of other tidbits in there. Thanks for sharing!

Viper2005_
03-24-2009, 09:26 PM
Early laminar flow aerofoils will tend to give you an absolutely horrible stall.

You can infer from the P-51's stick force per g that it didn't have any fuel in its rear tank (if it was still even fitted).

jamesblonde1979
03-25-2009, 12:53 AM
STATIC LATERAL DIRECTION STABILITY steady heading sideslips
All aircraft except the P-47 exhibited moderate or greater adverse aileron
yaw. Worst was the F6F, followed by the FG-1 and the P-51.


Well, well, well. The truth comes out

eindecker
03-25-2009, 06:04 PM
A fair number of airworthy P-51Ds are fitted with V-1650-9s.
The USAF surplussed a mountain of spares in the late 1950s.
Airworthy P-51Hs have always been rare and the majority
of the spares went to boat racers and to
keep P-51D and P-51Ks in the air.
For those who do not know, a P-51K is a P-51D with an Areoproducts
prop in place of the Hamilton Standard. They are otherwise exactly the same.

Eindecker

R_Target
03-25-2009, 06:31 PM
Originally posted by jamesblonde1979:
Well, well, well. The truth comes out

I'm not sure I follow you. Was someone concealing this?

b2spirita
03-25-2009, 06:38 PM
Originally posted by R_Target:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by jamesblonde1979:
Well, well, well. The truth comes out

I'm not sure I follow you. Was someone concealing this? </div></BLOCKQUOTE>

The oleg conspiracy, be sure.

VW-IceFire
03-25-2009, 07:38 PM
Originally posted by R_Target:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by jamesblonde1979:
Well, well, well. The truth comes out

I'm not sure I follow you. Was someone concealing this? </div></BLOCKQUOTE>
There was considerable moaning in another memorable thread about how the American planes were nerfed by Oleg...and how he introduced serious lateral stability issues to US planes whereas in real life they were so very stable. Maybe the degree to which this is a problem is different...but again it seems like reality scores another one.

Its got to also be peoples configurations. I've managed to work out the stability issues by tweaking my control setup. I may be gaming the game but I don't think WWII birds were setup to be as sensitive as our joysticks are to the flight model.

M_Gunz
03-25-2009, 08:12 PM
It probably helps to be ~in~ the plane and not fixated on the sight in relation to a target, too.
IOW, virtual-PIO only makes things worse.

I would like to see what Viper makes of that particular segment of the report.

BTW, does anybody else get the feeling that Maddox Games has a software wind tunnel to use on the models?
Framerate is not a crucial factor with those.

M_Gunz
03-25-2009, 08:15 PM
Originally posted by VW-IceFire:
There was considerable moaning in another memorable thread about how the American planes were nerfed by Oleg...

Another THREAD??

Has there been an entire month since AEP came out when there was not? Or even two actual real weeks? (as opposed to....)

R_Target
03-25-2009, 08:56 PM
Originally posted by VW-IceFire:
There was considerable moaning in another memorable thread about how the American planes were nerfed by Oleg...and how he introduced serious lateral stability issues to US planes whereas in real life they were so very stable. Maybe the degree to which this is a problem is different...but again it seems like reality scores another one.

I never had much of a problem with lateral(rocking wings)stability. Adverse yaw, afaik, happens to all planes with ailerons; and can be minimized with proper rudder technique. The biggest complaint in IL2 was always directional stability, or more properly, directional damping, aka "wobbles". My personal opinion is that it's a bit excessive on the F6F and the F4U. As far as the big conspiracy goes, I don't pay it much mind.


Its got to also be peoples configurations. I've managed to work out the stability issues by tweaking my control setup. I may be gaming the game but I don't think WWII birds were setup to be as sensitive as our joysticks are to the flight model.

I went through a period of trying all the different approaches, but really I think finding a set of input sensitivities that you can deal with and getting used to it makes more of a difference.

Buzzsaw-
03-25-2009, 09:42 PM
Salute

Making comparisons with 60 year old warbirds flown at lower than allowable G's and lower than max. engine ratings and expecting to get a match with the real combat aircraft performance is complete nonsense.

None of these aircraft were being flown as they were in WWII.

The Mustang in this test does not behave as per the normal at all, particularly in the reference to its control forces being high. The real Mustang was noted for its light control forces. (except elevator when compared to the VERY light Spitfire elevator) This aircraft sounds like it has been setup incorrectly or has had previous damage.

You want a comparison, read this comparison between actual aircraft of the period:

>>>>

INTRODUCTION

1. According to Air Ministry instructions, and A.D.G.B. letter reference ADGB/S.32179/Air Trg. Dated 28th December 1943, Tactical trials have been completed on the Mustang III. Aircraft No. FZ.107 was delivered on 26.12.43, and was checked and weighted as for operational load (total 10,100lbs). For descriptive purposes chief comparisons have been made with Spitfire IX No. BS.552 (clipped wings and a fairly old aircraft), Spitfire IX No. JL.359, normal wings, fitted with S.U. pump carburetor. Brief comparative trials were carried out against Tempest V. No. JN.737 Spitfire XIV No. RB.141, Focke Wulf 190 No. PM.679 and Me.109G No. RN.228.

BRIEF DESCRIPTION

2. The Mustang III is a high altitude long-range single seater fighter, armed with four .5” Browning’s in the wings. It is fitted with a V-1650-3 engine (i.e. Packard built Rolls Royce Merlin 61 type), of approximately 1550h.p. It can carry two long-range tanks or two 500lbs. bombs under the wings. In appearance it differs from the Mustang 1 in that it has a different type of engine, four blade airscrew, air intake immediately under the airscrew hub, a deeper fuselage behind the wings housing all the radiators and oil coolers, and a slightly larger fin and rudder. It is a very clean looking aeroplane.

Cockpit
3. The pilot’s cockpit is similar to the Mustang 1. It has been “cleaned up” considerably. Of particular note are: -

(i) The only undercarriage-warning device is a red light by the gun site, which lights when the wheels are unlocked. (There is no light when the wheels are locked up or down.)

(ii) The cockpit, and in particular the instruments, are of American design and consequently seem oddly placed to a British pilot.

(iii) When the engine is started and the mixture lever placed in “Normal”, the locking unit must be tightened, otherwise the pitch control may creep back on take off.

(iv) The tail wheel only becomes castoring when the stick is pushed right forward.

(v) It should be impossible to retract the undercarriage when the weight of the aircraft is on the wheels.

(vi) There are three trimming wheels for all control surfaces.

(vii) The flap angle is pre-selected by the control lever in the cockpit. There is a safety stop, which need only be used when carrying the 120-gallon long-range tanks (i.e. does not apply when carrying normal 62.5 gallon long-range tanks). This is to prevent lowering the flaps more than 30 deg.

4. The control column is well placed and of the stick variety. It is pivoted in both directions at its base.

5. No “misting up” was encountered during the trials, including flying at and diving from heights up to 35,000 feet.

FLYING CHARACTERISTICS

6. The Mustang III is very similar to fly and land as the Mustang 1. It is therefore delightfully easy to handle. It is as easy to fly as a Spitfire IX with the exception that the rudder is needed whenever changing bank (in order to prevent skid, and to prevent the sight from swinging off). This soon becomes automatic. The engine feels very smooth.

Flying controls
7. These are well balanced and positive, especially at high speeds. In comparison with the Spitfire IX : -

(a) The rudder is heavier. It is far more effective as only a small amount of re-trimming is necessary at high speeds (over 400mph I.A.S.) to keep the aircraft straight. There is no lateral wander.

(b) The ailerons feel lighter, especially over small movements and in general flying. There appears, however, to be a cushioning effect when full aileron is applied. This is because considerably more stick force is necessary when a quick change of bank is desired.

(c) The elevators are considerably heavier. They are not tiring, partly because the change of trim with speed is less.

Formation Flying
8. Because the aircraft is clean, one would expect station keeping to be difficult, but engine response is so steady that formation flying is very easy.

Low Flying
9. The view forwards and downwards over the leading edge of the wing is the same as the Mustang 1, and therefore better than the Spitfire IX. This helps to make the aircraft easy to low fly. It was not, however, built for low flying operations, and to improve its air to air combat the Unit is advising a certain harmonization which will make the aircraft difficult for ground attack.

Night Flying
10. Normal flying at night is quite straightforward. The exhaust glow does not seriously inconvenience the pilot. A different type of exhaust stub would be necessary for night fighting.

11. Apart from certain cockpit lighting troubles listed below, the take off and landing is also quite straightforward. Use of the floodlight is recommended rather than an airfield floodlight, as considerable cockpit dazzle results when using the latter. To prevent exhaust glare on landing, an engine-assisted approach right to the ground is recommended. With a small modification, blinkers could be fitted to the aircraft where a dusk or night landing is anticipated. It is considered that the disadvantage that would be suffered in day combat, would outweigh this luxury.

(a) Undercarriage warning light is lethal. Unless the British type instrument is fitted, this light must be covered over.

(b) The cockpit lighting when suitably manipulated is adequate

Compressibility Speeds
12. Because the Mustang III increases speed so rapidly in the dive, it is not difficult to enter compressibility range at high altitudes (approaching the speed of sound). This can only be done in a dive. The maximum permissible airspeeds at various heights are: -

I.A.S HEIGHT
298mph at 35,000ft
336mph " 30,000ft
376mph " 25,000ft
422mph " 20,000ft
468mph " 15,000ft
520mph " 10,000ft
574mph " 5,000ft

13. The following is a summary of the R.A.E’s instructions (Report No. Aero.1906). Should the speeds at height be exceeded by any type of aircraft. In the dive, the nose may suddenly tend to drop. On no account must the trimming wheel be used to prevent it doing so, but only backward pressure on the stick. When the aircraft has reached a lower altitude where the speed of sound is greater, the aircraft will come out of the compressibility range and behave normally, being pulled out of the dive. Had the trimming wheel been used to prevent the nose dropping when in the compressibility range, there would have been a very sudden nose up tendency on coming out of the compressibility range. The result of such a sudden change of trim is liable to cause structural failure.

TACTICAL COMPARISON WITH SPITFIRE IX

14. A very close comparison can be made because the engines are of very similar design and capacity. The tactical differences are caused chiefly by the fact that the Mustang III is a much cleaner aircraft, is slightly heavier, and has a higher wing loading than the Spitfire IX (43.8lbs. per sq.ft of the Mustang III. against 31 lbs. Per sq.ft)

Endurance
15. The Mustang III with maximum fuel load has between 1.5 and 1.75 the range of a Spitfire IX with maximum fuel load. The fuel and oil capacities are 154 gallons and 11.2 gallons respectively, as opposed to 85 gallons 7.5 gallons of the Spitfire IX, both without long-range tanks. With long range tanks, the Mustang can carry a total of 279 gallons of petrol ( 2 62.5 gall. long range tanks) as opposed to the Spitfire IX’s maximum of 177 gallons ( 1 90 gall. “Slipper tank”).

16. The fuel consumption at similar boost and rev settings is approximately the same for the two aircraft, but the Mustang is approximately 20 mph faster in level flight. Therefore if the ranges are compared directly according to the fuel capacities of the two aircraft when the long-range tanks are fitted, the Mustang will still have something in hand.

Speeds
17. The official speed curves are not yet available. This units speeds runs have therefore not been confirmed. They show, however, that in general for the same engine settings the Mustang III is always 20-30mph faster in level flight at all heights. This is also true for the maximum engine setting of 3,000 rpm 67”hg(+18lbs) or what ever is available, depending on the height. The best performance heights are similar, being between 10,000ft and 15,000ft and between 25,000ft and 32,000ft.

Climbs
18. The Mustang III has a considerably lower rate of climb at full power at all heights. (In a formation take off, Spitfire IX maintains formation with 5lbs less boost). At other engine settings and 175mph the 2 aircraft have a similar climb. The Mustang has, however, a better zoom climb in that it can dive 5,000ft or more and regain its original altitude at a greater speed. It needs less increase of power to regain its previous altitude and speed.

Dives
19. The Mustang III pulls away very rapidly in a slight dive. At the same revs the Spitfire IX requires from 4 to 6lb more boost to remain in formation.

Turning Circle
20. The Mustang is always out-turned by the Spitfire IX. Use of flaps on the Mustang does not appear to improve the turning circle. There is adequate warning of the high-speed stall in the form of elevator buffeting, followed by tail buffeting.

Rate of Roll
21. Although the ailerons feel light, the Mustang III cannot roll as quickly as the Spitfire IX at normal speeds. The ailerons stiffen up only slightly at high speeds and the rates of roll become the same at about 400mph.

Search
22. The all-round view from the pilot’s cockpit is the same as the Mustang 1, therefore generally inferior to the Spitfire IX, but better forwards and downwards on either side of the fuselage. A sliding hood has been designed and is being fitted to service Mustangs. This makes its rear view at least equal to, if not better than the Spitfire IX.

Sighting View and Firepower
23. The aircraft is fitted with an American 70mph sight. A bracket for the G.M.2 sight has been designed and is fitted to most aircraft. If it is not fitted, a universal adaptor as shown at Appendix “B” (not included here) can be made and fitted by the squadron. Due to the fact that it is most unlikely that the aircraft will be used against ground targets, the highest possible setting for the guns and sights has been chosen to produce the maximum amount of sighting view over the nose. This gives a vertical view of 180mph cruising speed, increasing to an unrestricted view at approximately 45 deg to the vertical, with guns ¾ cocked from aircraft datum. This is considerably better than the Spitfire IX. The guns are cocked up about 2 deg above the aircrafts cruising line of flight. The fire-power consists of four .5 Browning’s in the wings. This is very little compared with the Spitfire.

Armour
24. Armour plating on the Mustang III is provided for the pilot by means of two plate located behind the pilots seat. One 5/16“ thick extends from just below the bottom of the seat to a point just level with the pilots shoulders. The other 7/16” thick is attached to the top of this plate and affords protection to the pilot’s head. Otherwise protection is provided by the ¼” armour plate fire-wall, the engine, and the 1 ½” armour plate glass windshield. ¼” armour plate is also located immediately forward of the coolant tank on the forward end of the engine. There is no armour plate on the fuel tanks, but the tanks themselves are self-sealing.

BRIEF TACTICAL COMPARISON WITH SPITFIRE XIV

Maximum Endurance
25. By comparison the Spitfire XIV has no endurance.

Maximum speed
26. There is practically nothing to choose in maximum speed.

Maximum climb
27. The Spitfire XIV is very much better.

Dive
28. As for the Spitfire IX. The Mustang pulls away; but less markedly.

Turning Circle
29. The Spitfire XIV is better.

Rate of Roll
30. Advantage tends to be with the Spitfire XIV.

Conclusion
31. With the exception of endurance, no conclusions should be drawn, as these two aircraft should never be enemies. The choice is a matter of taste.

BRIEF TACTICAL COMPARISON WITH TEMPEST V

Maximum endurance
32. By comparison, the Tempest V has no endurance.

Maximum speed
33. The Tempest V is 15-20mph faster up to 15,000ft. There is then no choice until 24,000ft when the Mustang rapidly pulls ahead, being about 30mph faster at 30,000ft.

Maximum climb
34. These compare directly with the results of the speed tests. At similar performance height, the Tempest has the better zoom climb.

Dive
35. The Tempest tends to pull away.

Turning circle
36. The Tempest is not quite as good.

Rate of Roll
37. The Tempest is not so good. This attribute of the Tempest V may be improved upon in later aircraft.

Conclusions
38. The Mustang has endurance and general performance above 24,000ft. Conclusions should not be drawn below this height, but the Tempest has a better speed and climb below 10,000ft.

BRIEF COMPARISON WITH FW. 190 (BMW.801D)

Maximum speed
39. The FW.190 is nearly 50mph slower at all heights, increasing to 70mph above 28,000ft. It is anticipated that the new FW.190 (DB.603) might be slightly faster below 27,000ft but slower above that height.

Climb
40. There appears to be little to choose in the maximum rate of climb. It is anticipated that the Mustang III will have a better maximum climb than the new FW.190 (DB.603). The Mustang is considerably faster at all heights in a zoom climb.

Dive
41. The Mustang can always out-dive the FW.190.

Turning circle
42. Again there is not much to choose. The Mustang is slightly better. When evading an enemy aircraft with a steep turn, a pilot will always out-turn the attacking aircraft initially because of the difference in speeds. It is therefore still a worthwhile maneuver with the Mustang III when attacked.

Rate of Roll
43. Not even a Mustang III approaches the FW.190.

Conclusions
44. In the attack, a high speed should be maintained or regained in order to regain height initiative. The FW.190 could not evade by diving alone. In defense a steep turn followed by a full throttle dive should increase the range before regaining height and course. Dog-fighting is not altogether recommended. Do not attempt to climb away without at least 250mph showing initially. Unfortunately, there is not enough information on the new FW.190 (DB603) for any positive recommendations to be made.

BRIEF COMPARISON WITH Me.109G

Maximum Speed
45. The Mustang III is faster at all heights. Its best heights, by comparison, are below 16,000ft (30mph faster approx) and above 25,000ft (30mph increasing to 50mph at 30,000ft).

Maximum climb
46. This is rather similar. The Mustang is very slightly better above 25,000ft but worse below 20,000ft.

Zoom Climb
47. Unfortunately the Me. 109G appears to have a very good high-speed climb, making the aircraft very similar in a zoom climb.

Dive
48. On the other hand in defense the Mustang can still increase the range in a prolonged dive.

Turning Circle
49. The Mustang III is greatly superior.

Rate of Roll
50. Not much to choose. In defense (in a tight spot) a rapid change of direction will throw the Me.109G’s sight off. This is because the 109G’s maximum roll is embarrassing (slots keep opening)

Conclusions
51. In attack, the Mustang can always catch the Me.109G, except in any sort of climb (unless there is a high overtaking speed). In defense, a steep turn should be the first maneuver, followed if necessary, by a dive (below 20,000ft). A high-speed climb will unfortunately not increase the range. If above 25,000ft. keep above by climbing or all out level.

COMBAT PERFORMANCE WITH LONG-RANGE TANKS

Speed
52. There is a serious loss of speed of 40-50mph at all engine settings and heights. It is still, however, still faster than the FW.190 (BMW.801D) above 25,000ft. Although slower than the Me.109G.

Climb
53. The rate of climb is greatly reduced. It is out climbed by the FW.190 (BMW.801D), and definitely out stripped by the Me.109G.

Zoom Climb
54. The Mustang III is still good in the zoom climb (attack), but is still out stripped (defense), if being followed all the way by the FW.190 (BMW.801D), and definitely out stripped by the Me.109G.

Dive
55. So long as the tanks are fairly full, the Mustang still beats the FW.190 (BMW.801D) and the Me.109G in a power dive.

Turning Circle
56. The tanks do not make quite so much difference as one might expect. The Mustang III can at least turn as tightly as the FW.190 (BMW.801D) without stalling out and therefore definitely more tightly than the Me.109G.

Rate of Roll
57. General handling and rate of roll are very little affected.

Conclusions
58. The performance of the Mustang III is greatly reduced when carrying drop-tanks. Halfhearted attacks could still be evaded by a steep turn, but determined attacks would be difficult to avoid without loosing height. It is still a good attacking aircraft especially if it has the advantage of height.

<<<<

Note the Mustang dive speeds, far higher permissible speeds allowed than ANY German prop plane. The warning is there to avoid problems with trimming, but assuming the pilots read that advisory and followed it, there are no issues with structural strength.`

Note the many instances which contradict the Warbirds test. For example, the fact the British test notes there is plenty of warning of stall from elevator and tail buffeting.

The Mustang outturns the 109G, and note this model is the G2.

Note the Tempest is the early test model, not the finalized version.

This Mustang III (P-51B/C) is running only 67 inches of boost, not 80 inches as the game's Mustang III is. The Game's P-51B and C run only 61 inches of boost, a boost level which was only in use back in the continental U.S. All aircraft which flew overseas had uprated boost limits on 130 octane to 67 inches, and later with 150 octane this went to 80 inches.

I'd trust the wartime British Test pilots, running the aircraft at full boost and at full G loads sooner than modern day pilots gingerly running 60 year old planes through limited tests.

BigKahuna_GS
03-26-2009, 12:54 AM
Some of the findings:

CLIMB brake release to 10,000 ft.
Hellcat quickest at 4min 15 seconds, followed by the FG-1 at 4min 44 sec.

LEVEL ACCELERATION at 10,000 ft. using METO to max attainable speed
F6F accelerated from 100 KIAS to 220 KIAS in 115 seconds.
FG-1 accelerated from 100 KIAS to 230 KIAS in 162 seconds.



Very interesting reading.

This surprised me-

<span class="ev_code_YELLOW">AIR-TO-AIR TRACKING 210 KIAS at 10,000 ft</span>. (straight & level into a 3g
turn to the left building to 4g followed by a hard reversal into a 4g
right turn.)

<span class="ev_code_YELLOW">FG-1 best</span>, followed by P-47, F6F and, trailing badly, the P-51.

Poor forward visibility in all aircraft (P-47 worst, <span class="ev_code_YELLOW">FG-1 best</span>) made
air-to-air tracking difficult. Depressed sight-line aiming difficult to impossible.

Thought the Hellcat would be best.
According to Corsair pilots the long nose was not an issue during flight/combat and really no longer than the nose on a P51, P47 or D9.


The top of the page goes against all US Navy war time testing F4U vs F6F

http://us.geocities.com/slakergmb/1318f6f0.gif

http://us.geocities.com/slakergmb/1378f6f0.gif



------------------------------------------------------------------------------------------------
Ice-Fire
There was considerable moaning in another memorable thread about how the American planes were nerfed by Oleg...and how he introduced serious lateral stability issues to US planes whereas in real life they were so very stable. Maybe the degree to which this is a problem is different...but again it seems like reality scores another one.

-------------------------------------------------------------------------------------------------


I think you are confusing the real complaint of the "wobbles".
If the wobbles are someones attempt at lateral instability modeling I just don't know.


STATIC LATERAL DIRECTION STABILITY steady heading sideslips
All aircraft except the P-47 exhibited moderate or greater adverse aileron
yaw.<span class="ev_code_YELLOW"> Worst was the F6F</span>, followed by the FG-1 and the P-51.

So the F6F was the most unstable here ?

I had my buddy who is a commercial pilot for Skywest Airlines and has an acrobatic rating (he also teaches acrobatics) read this. Basically his take was that if put an airplane in a bank the wing with the airleron that is down will create more lift & drag and the wing with the airleron that is up will produce less lift resulting in adverse yaw.

He also said the thicker the wing equals more drag and the larger the airleron could also produce more drag. All common sense.

My first thought was wouldn't you simply correct adverse yaw with rudder input (yes) but there is no mention of it in the test. Also the Zero has both a thick wing and very large airlerons how would it do in this test?

There is only 4 aircraft in this test. I think it would be more interesting to compare twenty fighters from all sides to compare lateral instability and get a greater perspective.

Interesting read just the same.

-

jamesblonde1979
03-26-2009, 01:48 AM
Originally posted by R_Target:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by jamesblonde1979:
Well, well, well. The truth comes out

I'm not sure I follow you. Was someone concealing this? </div></BLOCKQUOTE>

It's pretty simple.

Better pilots have a lighter touch, they report an aircraft as being stable whilst ham-fisted rookies think it wobbles like buggery.

QED

M_Gunz
03-26-2009, 07:04 AM
And unless you have FFB, you don't feel stick forces in IL2 which should make a big difference.
Easy to get PIO.
I'm not sure how much FFB helps though, how well it works in this system.

R_Target
03-26-2009, 10:15 AM
Originally posted by 609IAP_Kahuna:
The top of the page goes against all US Navy war time testing F4U vs F6F

F4U vs F6F at similar weight and power should have similar ROC and TTC. Acceleration's not that far apart either. Note that the Corsair is 10 knots faster even though the time is longer.


This surprised me-

<span class="ev_code_YELLOW">AIR-TO-AIR TRACKING 210 KIAS at 10,000 ft</span>. (straight & level into a 3g
turn to the left building to 4g followed by a hard reversal into a 4g
right turn.)

<span class="ev_code_YELLOW">FG-1 best</span>, followed by P-47, F6F and, trailing badly, the P-51.

Poor forward visibility in all aircraft (P-47 worst, <span class="ev_code_YELLOW">FG-1 best</span>) made
air-to-air tracking difficult. Depressed sight-line aiming difficult to impossible.

Thought the Hellcat would be best.
According to Corsair pilots the long nose was not an issue during flight/combat and really no longer than the nose on a P51, P47 or D9.

It looks like the 47 and the Navy planes were close and the 51 wasn't. The forward visibility thing seems anomalous, as most of my reading confirms that F6F forward view was superior to the other three planes.


STATIC LATERAL DIRECTION STABILITY steady heading sideslips
All aircraft except the P-47 exhibited moderate or greater adverse aileron
yaw.<span class="ev_code_YELLOW"> Worst was the F6F</span>, followed by the FG-1 and the P-51.

So the F6F was the most unstable here ?

It appears that that's what they're saying. NACA testing indicates the F6F has positive static lateral stability, although the adverse yaw is noted. I don't have a problem with how this is modeled in IL2.


There is only 4 aircraft in this test. I think it would be more interesting to compare twenty fighters from all sides to compare lateral instability and get a greater perspective.

I think they should've narrowed the focus to just the radials. Fewer variables.

BigKahuna_GS
03-27-2009, 09:33 AM
F4U vs F6F at similar weight and power should have similar ROC and TTC. Acceleration's not that far apart either. Note that the Corsair is 10 knots faster even though the time is longer.


Hya R_Target,

The Official Navy test I posted indicates the F6F was inferior to the F4U at the same power
ratings in ROC & TTC. There was no contest between the 2 aircraft when the Dash 4 apppeared.

In America's Hundred Thousand the flight tests in acceleration posted in the book indicated the Corsair handily beat the Hellcat in acceleration tests. I also think the Corsair had the cleaner air frame drag wise.

I havent seen any test with overboosting between these aircraft. This Corsair is only at 65"MP where as the P47 was over boosted at 70"MP. When 145grade fuel was available on carriers there
overboosting of Corsairs for kamikaze intercepts. This was before the Dash-4 models.
435mph at 18,000ft

http://us.geocities.com/slakergmb/24360700.jpg

BigKahuna_GS
03-27-2009, 09:34 AM
http://us.geocities.com/slakergmb/23d60700.jpg

R_Target
03-27-2009, 01:24 PM
Originally posted by 609IAP_Kahuna:
Hya R_Target,

The Official Navy test I posted indicates the F6F was inferior to the F4U at the same power
ratings in ROC & TTC.

That comparison chart is drawn from the "Standard Aircraft Characteristics" for each respective type. Francis Dean dates the F6F document to 1949, several years after termination of Hellcat production. As such, I don't consider it an accurate representation of wartime performance. I have several wartime tests for ROC and TTC at Military Power, and in comparison with the Corsair, there's really little to choose from between the two. Additionally, some wartime production testing has higher ROC and top speed for the F6F at Military Power than "SAC" lists for Combat Power.

Another problem with USN F6F "SAC" is that TTC at WEP in the fully loaded, clean condition(usually "Combat") is not given, only TTC at WEP with external tank; or the "Fighter" loading condition. In a like-for-like comparison, F4U-1D vs F6F-5 in the "Fighter" condition at WEP power, TTC to 10,000ft and 20,000ft are identical, and this with the Hellcat weighing 500lbs more than the Corsair.

Unfortunately, I haven't been able to find wartime F6F testing at standard production WEP rating (60"MAP).

Do you have ROC and TTC for F4U at 65"MAP? I do have a doc of an F6F being tested at higher than standard WEP, which was not implemented to my knowledge. Comparison of results would be interesting.


There was no contest between the 2 aircraft when the Dash 4 apppeared.

A suitable comparison would be to the XF6F-6, which used the same engine and prop as the F4U-4. The speed differential would probably be about the same though, as XF6F-6 topped out at 419mph. Of course there was no F6F-6 production as the F8F-1 took over as the fleet defense fighter, inaugurating the second half of the Corsair's career as an attack plane.


In America's Hundred Thousand the flight tests in acceleration posted in the book indicated the Corsair handily beat the Hellcat in acceleration tests.

This was a Dash-4 versus an F6F-5, again not a like-for-like comparison of technological contemporaries. On that same page, the F4U-1 is listed as having poorer acceleration than the F6F-5, but again it's not a like-for-like comparison as Dean lists the Corsair at Military and the Hellcat at Combat powers. There are a lot of these frustrating situations in AHT, but I guess he did what he could with the information he could find.


I also think the Corsair had the cleaner air frame drag wise.

Hellcat has more drag for sure, probably because of greater frontal area and bigger wings.

BigKahuna_GS
03-27-2009, 02:52 PM
S!

------------------------------------------------------------------------------------------------
That comparison chart is drawn from the "Standard Aircraft Characteristics" for each respective type. Francis Dean dates the F6F document to 1949, several years after termination of Hellcat production. As such, I don't consider it an accurate representation of wartime performance. I have several wartime tests for ROC and TTC at Military Power, and in comparison with the Corsair, there's really little to choose from between the two. Additionally, some wartime production testing has higher ROC and top speed for the F6F at Military Power than "SAC" lists for Combat Power.

Another problem with USN F6F "SAC" is that TTC S!

at WEP in the fully loaded, clean condition(usually "Combat") is not given, only TTC at WEP with external tank; or the "Fighter" loading condition. In a like-for-like comparison, F4U-1D vs F6F-5 in the "Fighter" condition at WEP power, TTC to 10,000ft and 20,000ft are identical, and this with the Hellcat weighing 500lbs more than the Corsair.
-----------------------------------------------------------------------------------------------



http://home.comcast.net/~markw4/index1.html (http://home.comcast.net/%7Emarkw4/index1.html)

In the wartime fly off between the F4U1-D, F6F-3 and 190A5 January 1944

The Corsair was superior to the F6F in all catogories ROF, TTC, & Acceleration.
Something to note as well, the Corsair had the wrong propeller and the pilot had accidently
ran these tests in auto-lean not auto rich which caused premature overheating problems and reduced power. This flight test stated that the Corsair performance would have increased had the new propeller type been installed.

I realize this was F6F-3 but it looks like it had some work done being fitted with the latest
performance propeller.

--

As for Dean's book, I am at work and just going off of memory (a flawed memory)http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Did Dean say which F4U-1 model was used in the acceleration tests?

My dad flew both of these planes and while he loved how easy the Hellcat was to fly,
he also thought the Corsair was significantly faster, had a better climb & roll rate.

R_Target
03-27-2009, 05:18 PM
Originally posted by 609IAP_Kahuna:
In the wartime fly off between the F4U1-D, F6F-3 and 190A5 January 1944, the Corsair was superior to the F6F in all categories ROF, TTC, & Acceleration.

Yes, the Hog is noted as "slightly superior" in the relevant categories.


Something to note as well, the Corsair had the wrong propeller and the pilot had accidently
ran these tests in auto-lean not auto rich which caused premature overheating problems and reduced power. This flight test stated that the Corsair performance would have increased had the new propeller type been installed.
I realize this was F6F-3 but it looks like it had some work done being fitted with the latest
performance propeller.

65010-A was the standard F6F propeller blade.


As for Dean's book, I am at work and just going off of memory (a flawed memory)http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif
Did Dean say which F4U-1 model was used in the acceleration tests?

It just says "F4U-1" and "2000hp" which would be Military Power; the F6F-5 says "2250hp", which would be Combat Power.


My dad flew both of these planes and while he loved how easy the Hellcat was to fly,
he also thought the Corsair was significantly faster, had a better climb & roll rate.

Cool! http://forums.ubi.com/images/smilies/25.gif Depending on the model of Corsair, it could have slightly to much better climb than F6F. It appears the F6F-3 in the Fw190 tests was not equipped with the spring-tab ailerons of the F6F-5 which closed the gap considerably between the F4U and F6F. Corsair is usually tested slightly to considerably faster than Hellcat.

Grumman test-pilot Corky Meyer flew a Corsair that the Navy had provided to Grumman:


Performance almost equal

Except for the Corsair being 20 knots faster than the Hellcat in the main, sea-level, supercharger stage, both fighters had almost exactly the same speed at the low and high blower stages from 5,000 feet altitude up to service ceiling! In essence, they had the same performance. Our formation flights showed that both airplanes (with similar power settings) were in closely stabilized formation at all altitudes tested above 5,000 feet Sometimes, the Corsair would slowly gain a lead of 100 to 200 feet after five minutes of stabilized power flight, and sometimes, the Hellcat would do the same. Considering that both airplanes had the same engine, propeller, gross weight, wingspan, etc., they should have had about the same performance. We did notice that during these runs, the Corsair always had about a 20-knot indicated airspeed (IAS) advantage! We didn't realize just how embarrassing it would be to solve that dilemma.

The reason the Corsair was faster in the main stage blower was that its engine and carburetor were provided with ram air coming in directly from the forward-facing wing duct, whereas the Hellcat had the carburetor air coming in from the accessory compartment of the fuselage just behind the engine, with no ram air effect Our airplane was getting carburetor air at the same pressure as it would have were it motionless on the ground, and the Corsair was getting carburetor air supercharged by the speed of the airplane giving it more power (speed) in the main stage blower. In both aircraft, however, the designs were similar in that they provided ram air to the low and high blower stages. Our engineering department defended its position because taking the warmer air for the main stage blower would prevent inadvertent carburetor icing engine failures. Many Wildcats that had ram air in the main stage like the Corsair were lost because pilots failed to take precautions in time to avert this type of disaster. The Hellcat design was reviewed and approved by the Navy. I had had a carburetor icing accident during final approach on my first flight in a Wildcat a few months previously; it resulted in my first deadstick landing and a vertical ground loop. I therefore heartily agreed with the Navy's decision.

IAS performance equalized-the hard way

After noting the 20 knots indicated airspeed difference that had caused all the "lower performance" ruckus for our Hellcat, we eagerly decided to change the airspeed system so that it would read evenly with the Corsair when they were in formation. We had taken a lot of flak from all who had flown both airplanes (but not in formation) and, therefore, everybody 'mew' that the Hellcat was inferior in high-speed performance. We liked our simple and less complicated airspeed system with the static and dynamic orifices on the same boom, but we decided to go whole hog and put the static orifice on the fuselage (like the Corsair) to tailor the system to read 20 knots higher. We tried several orifice locations to get the required reading. After I had done a thorough testing of the final system over the entire flight envelope-or so I thought-I proudly flew the airplane to the Naval Air Test Center at Patuxent, Maryland for an evaluation. We soon found out that we had not purloined the Corsair airspeed system design thoroughly enough.

BigKahuna_GS
03-27-2009, 09:03 PM
S!


Yes, the Hog is noted as "slightly superior" in the relevant categories.


I always wonderd how well the Hog would of done in this flight test with the right prop
and running on auto-rich not auto-lean.



-------------------------------------------------------------------------------------------------
Grumman test-pilot Corky Meyer flew a Corsair that the Navy had provided to Grumman:
-------------------------------------------------------------------------------------------------


I always enjoyed reading Corky Meyers articles.
Did you see the flight test he did with the P38L & P47 and the dive recovery flaps?
Evidently the Bearcat was to be fitted with dive recovery flaps so he test flew a 38L & P47 to see how well the dive recovery flaps operated.

"My last Jug flight-a brand-new P-47M"

In October, 1944-a little more than a year later-at the Joint Army/Navy Fighter Conference at the Naval Air Test Center, Patuxent River, Maryland, I had a chance to evaluate this just-off-the-production line, pristine model of the jug to see which development miracles had been installed since my flights in the P-47B. By this time, the P-47 had not only run up an outstanding score of enemy aircraft shot down but had also gained a reputation as a great fighter-bomber. It had a lot going for it as a user-friendly destructive weapon. I was soon to find out why.

I was interested in evaluating three developments now in the P-47M. It had the new 360-degree-vision bubble canopy; it could climb to 40,000 feet without stopping to "rest" above 30,000 feet; and it had dive-recovery flaps to cure its former uncontrollable compressibility diving with no recovery possibility.

The beautifully laid out cockpit had changed little and I felt right at home in it, but now I had a pressurized oxygen mask to use.

P-47M service coiling

With the additional power and the increase in cowl-flap cooling, the P-47M went promptly to 40,000 feet with all of the engine instruments below their limits and very little need to coordinate the throttle and supercharger handles. During my checkout, I was told that the turbo-supercharger now had automatic altitude compensation and a governor to prevent it from over-speeding. What an asset this would have been for training, and especially in combat, had it been available for early P-47 squadron pilots. No blue fingernails on this climb.

Diving the P-47M-no longer a deathtrap

I had heard that Republic test pilot Parker Dupouy-another decorated AVG ace I had met at Republic in 1943-had <span class="ev_code_YELLOW">dived the P-47 vertically to its maximum Mach number of .868 and made a very successful dive recovery-flap pullout.</span> His dive also disproved several USAAC combat pilot's reports that they had dived the jug supersonic. Dupouy's dive was 61mph faster than the P-47's compressibility entry Mach number. To be sure of their operational availability, I checked out the extension and retraction of the dive-recovery flaps several times during the climb. I then fearlessly pushed over into a 60-degree dive and ran the combined Mach number/airspeed indicator rapidly up to .80-well past its compressibility limit Mach number. The stick expectedly became immovable, and the aircraft rapidly pitched nose-down. <span class="ev_code_YELLOW">Extending the dive recovery flaps provided an instant drag increase and a stick-free 4G pullout </span> that brought the aircraft back below its airspeed limit within a few easy seconds.


To give the reader <span class="ev_code_YELLOW">the combat value of the new dive recovery flaps that had been installed on Thunderbolts and Lightnings to allow steep diving attacks, Maj. Johannes Steinhoff's comments in his book, "The Final Hours" </span> about fighting them in the Luftwaffe's new Messerschmitt 262 jet fighter are pertinent. He relates: "The black dots in the cruelly black sky were Thunderbolts. <span class="ev_code_YELLOW">The Thunderbolts-American fighters we learned to fear because of their extraordinary ability to attack in a nose dive-had spotted easy prey, as they promptly pointed their noses to the ground.</span> Fahrmann [Steinhoff's wingman] tried to get his aircraft into the shelter of the cloud cover that spread out below him." <span class="ev_code_YELLOW">Even in his much faster jet fighter, Fahrmann was shot down by the Thunderbolts.</span>

Another of Steinhoff's comments: "The Lightnings made for the ground in tight spirals. No use trying to follow them; the Messerschmitt 262 didn't have dive brakes. It was agony every time; losing height without picking up so much speed, my aircraft became uncontrollable."

My dive-recovery-flaps evaluation reports in the P-47M and the P-38L Lightning (which I also flew at the Conference) inspired Grumman engineers to install dive-recovery brakes on the XF8F-1 Bearcat and XF7F-1 Tigercat. I have always wondered why the Navy refused to install them on the Hellcat to reduce the accident rate caused by that fighter's being so easily dived into compressibility. Too many Navy pilots were fatally injured diving the Hellcat beyond its Mach-number limit.

The pilot sits "outside" in the P-47M

The bubble canopy was the greatest improvement for a fighter pilot since the invention of the synchronized, forward-firing machine gun in WW I. Its unlimited visibility, especially to the rear, was unbelievable. One could get used to it immediately on the ground and especially in air combat.

A Republic test pilot warned me that the bubble canopy had one unacceptable characteristic they had not yet cured: if the pilot pushed the rudder over to half deflection with the landing gear and flaps down, the rudder forces would decrease to zero and, without further pilot input, the rudder would go to full deflection and make the aircraft fly very much sideways. It also took a very powerful push on the opposite rudder pedal to get the aircraft back to a straight flight path. I was most interested in this phenomenon. We had noted the same problem in the XF8F-1 Bearcat in early flights, but we hadn't found the solution for it. In a carrier aircraft, such a lack of rudder control is absolutely unacceptable. My check demonstrated this yaw phenomenon very clearly.

I learned a lot from this flight, but I was to learn the solution to the bubble-canopy directional problem during my next flight in the P-51D Mustang with its new bubble canopy. <span class="ev_code_YELLOW">North American engineers had installed a fairly large triangular dorsal fin on the top of the rear fuselage and the fin leading edge; this eliminated the yaw problem from the bubble canopy completely.</span>


Conclusions

The Thunderbolt was available in large numbers from 1942 until 1945. It had very few drawbacks. Its heavy wing loading meant that pilots needed more flight hours to understand its effects on flight characteristics, but it offered superb evasive diving tactics after dive recovery flaps had been installed. It was continually developed with improvements to its turbo control and its performance, and its external store-carrying capability was increased. Its structure had a highly respected history of bringing back its pilots and a much lower combat loss rate per sortie than the P-38 and P-51. Its flight characteristics-trainer-like stall characteristics in the combat and landing configurations-gave its pilots early confidence. It handled many roles and missions with fabulous destructive capability. Its combat record was superb.

Epilog

Because of the wartime pressure to get the Hellcat into mass-production, <span class="ev_code_YELLOW">the XF6F-2 turbo-supercharged Hellcat did not fly until January 1944. By this time, the Navy had realized that it didn't need a very high-altitude fighter in the Pacific. </span> Therefore, the XF6F-2 was reworked and delivered as a standard F6F-3.

Author's note: I was assisted with this article by aviation historian Warren Bodie's book, "Republic's P-47 Thunderbolt." I recommend this excellent book for further information on the P-47's impressive participation in all theaters of WW II.

----

In 1943, I experienced compressibility in a Hellcat; I wonder how many of those P-38 pilots in the pursuit of the enemy dived too steeply-well beyond the critical Mach limit and into compressibility-in the heat of combat and disappeared into oblivion. At the Joint Army/Navy Fighter Conference on October 16, 1944, <span class="ev_code_YELLOW">I tested the P-38L dive-recovery flap well in excess of its 0.65 Mach-number limit. Upon actuation, they instantly provided a smooth, 4G recovery without pilot effort. </span> Immediately after I evaluated these "jewels," they were installed on all Grumman 17817-1 Bearcat fighters.

Where the aircraft really came into its own was in performing stalls. The counter-rotating propellers kept the aircraft pointing straight ahead, so there was no torque effect to require rudder input as the speed decreased. Stalls demonstrated a good, early buffet warning, and no wing dropping occurred at the stall, even with small, pilot-applied aileron and rudder inputs to try to irritate its lateral and/or directional attitudes near the stall. It was even more impressive to me when I performed single-engine stalls with one engine either windmilling or feathered. With one of the P-38's dual fins and rudders always in the slipstream of a live engine, a stall could be performed with little or no wing drop. It was a pilot's dream under the trying conditions of a single-engine approach and landing.

Probably the most amazing P-38 flight characteristic was that it had such uniform and gentle landing-pattern stalls and accelerated stalls during very tight combat turns from its cruise-type high aspect ratio wing planform. I estimated that its span-to-chord ratio was about 7:1. Most fighters have a stubbier wing than the P-38. I also believe that its counterrotating propellers had a bit to do with this phenomenon. The P-38 wing was a designer's dream and a pilot's delight.

Once it was fully developed, the P-38 inspired universal loyalty and praise from its pilots. The dive-recovery flaps had eliminated its compressibility problems at high dive speeds. Control-wheel forces had been reduced by 80 percent, and the hydraulically boosted ailerons had doubled rolling performance. Its exhilarating high-speed performance could then be used without complications. Despite its stodgy transport-style control column and its much less than perfect cockpit visibility, the P-38 was any pilot's must-have fighter.

CONCLUSIONS

When P-38 production lines began delivering the 7,494 P-38H, J and L models in April 1943, the P-38's assets greatly eclipsed its deficits, as Axis pilots around the world soon found out-to their fatal amazement.

--

R_Target
03-28-2009, 10:46 AM
I know, I have the book. http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

You can get about half of the articles online though.

Boone Guyton's book is a must for Hog fans too.

M_Gunz
03-28-2009, 01:08 PM
In the Roaring Glory P-47 video Jeff Ethel described the P-47 flying as if on rails, his words, his demonstration.
But then that was a P-47 with Jeff Ethel at the controls.

One big characteristic of the older arcadish flight sims is that they you be an Expert Pilot by design.
IRL it was never so.

BigKahuna_GS
03-30-2009, 11:31 AM
I know, I have the book.

What's the name of Corky's book?

There's an old interview of Pappy Boyington comparing the F4U vs F6F
It's been a long time since I've seen it or read it.

Basically it is how the Marines always get the hand me downs of unwanted and discarded items from their Big Brothers the US Navy.
Boyington thought as many early on did that the Marines would be recieving Hellcats and Corsairs would be on the carriers. That
was until the Corsairs had problems during carrier trials.

Evidently Boyington and several other Marines had flown both aircraft compared notes and they all agreed that the Marines for
once were getting the "hotter" aircraft in the F4U. In other words the Navy's loss was their gain.



-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
In the Roaring Glory P-47 video Jeff Ethel described the P-47 flying as if on rails, his words, his demonstration.
But then that was a P-47 with Jeff Ethel at the controls.
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



I have this series it is very good. I sent several to 1c. I like Ethell the best because he goes into more detail on the pre-flight walk arounds
and starting procedures. Ethell also does more manuevering rolls, turns, dives while flying. The P38 & P47 segments are my favorite.

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M_Gunz
03-30-2009, 12:10 PM
I just wonder what evaluation would have come about had the same planes been flown through remote control like a sim?
Something with camera and servos to a person at a desk on the ground.

I know that the models don't match the real planes except to within 5% (at 400mph, 5% is 20mph) but I see a bigger gap
between expert in cockpit to player at PC in the interface and usually an even bigger one in player ability.

R_Target
03-30-2009, 12:45 PM
Originally posted by 609IAP_Kahuna:
What's the name of Corky's book?

There's an old interview of Pappy Boyington comparing the F4U vs F6F
It's been a long time since I've seen it or read it.

Basically it is how the Marines always get the hand me downs of unwanted and discarded items from their Big Brothers the US Navy.
Boyington thought as many early on did that the Marines would be recieving Hellcats and Corsairs would be on the carriers. That
was until the Corsairs had problems during carrier trials.

Evidently Boyington and several other Marines had flown both aircraft compared notes and they all agreed that the Marines for
once were getting the "hotter" aircraft in the F4U. In other words the Navy's loss was their gain.

The book's called Corky Meyer's Flight Journal (http://www.amazon.com/Corky-Meyers-Flight-Journal-Corwin/dp/1580070930/ref=sr_1_1?ie=UTF8&s=books&qid=1238438018&sr=8-1).

Yeah, USMC pilots were the fortunate beneficiaries of continuing development problems in the F4U. At least, as far as USN higher-ups were concerned there were still problems. Tom Blackburn goes into detail in his book about VF-17 and Vought technicians solving the Corsair's problems in Summer 1943. By then though, the decision had been made. Blackburn proved his point in November 1943 when VF-17 pilots re-installed their tailhooks and executed flawless carrier landings on Bunker Hill and Essex while flying carrier CAP during the attacks on Rabaul.

Apparently USMC pilots looked on with some consternation as Blackburn had his pilots making flare-out carrier type landings even on dusty Solomons airstrips. http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif

BigKahuna_GS
04-07-2009, 10:24 AM
Yeah, USMC pilots were the fortunate beneficiaries of continuing development problems in the F4U. At least, as far as USN higher-ups were concerned there were still problems. Tom Blackburn goes into detail in his book about VF-17 and Vought technicians solving the Corsair's problems in Summer 1943. By then though, the decision had been made. Blackburn proved his point in November 1943 when VF-17 pilots re-installed their tailhooks and executed flawless carrier landings on Bunker Hill and Essex while flying carrier CAP during the attacks on Rabaul.

Apparently USMC pilots looked on with some consternation as Blackburn had his pilots making flare-out carrier type landings even on dusty Solomons airstrips.



I have the Corsair (and several other Corsair books) book by Barret Tillman and he goes into VF-17 operations extensively. Then there was the Brits who solved the Corsair carrier problem immediately. Once a bureaucracy like the Navy makes a decision ......it's easier to move a mountain. I have been meaning to buy Blackburn's book. It's too bad that Grumman didn't come out with the F8F sooner there was a real need.

A great 1-2 punch Bearcats intercepting kamikazes and Corsairs in the F/A mode. I think the carrier fleet should of and could of increased the number of fighters on board with this combination. With dual function fighters like the Corsair either active in the fighter screen mode or attack mode and able to carry as much ordinance as a Helldiver a scenario like this could be possible. If only the Skyraider had come on sooner as well.......

R_Target
04-07-2009, 01:59 PM
Originally posted by 609IAP_Kahuna:
I have the Corsair (and several other Corsair books) book by Barret Tillman and he goes into VF-17 operations extensively. Then there was the Brits who solved the Corsair carrier problem immediately. Once a bureaucracy like the Navy makes a decision ......it's easier to move a mountain. I have been meaning to buy Blackburn's book.

As I mentioned above, the technical problems (seat height, wing leading edge spoiler, gear oleos, tailhook) were in development before the RN operated Corsairs from carriers. Cutting the wingtips off was a RN modification however. More info is in (F4U test pilot) Boone Guyton's book. It would be great if somebody unearths the Spring 1944 USN F4U carrier suitability trials (or re-trials) to see if they used the "curving" approach. They certainly confirmed that Blackburn was right, as the trials went flawlessly with 100+ landings.


A great 1-2 punch Bearcats intercepting kamikazes and Corsairs in the F/A mode. I think the carrier fleet should of and could of increased the number of fighters on board with this combination. With dual function fighters like the Corsair either active in the fighter screen mode or attack mode and able to carry as much ordinance as a Helldiver a scenario like this could be possible. If only the Skyraider had come on sooner as well.......

This was already underway with the expansion of VF strength, then division of VF into VF/VBF supplemented by VMF and reduction in numbers of VT/VB in 1945.

M_Gunz
04-07-2009, 04:28 PM
Which was more accurate in bomb delivery, Helldiver or Corsair?
Which was more likely to hit a moving ship, not counting getting to the target?
By 1945, post-Leyte Gulf, there wasn't much threat from the Japanese Navy was there?

horseback
04-07-2009, 07:34 PM
Actually, there wasn't that much difference in dive bombing accuracy between the Helldiver and the F4U-1D, and although the designed bombers were more accurate you didn't have to worry about rear gunners going on strike (there were rumblings from many of these as the war neared its end about the risks of attacking a target of questionable value).

This was why as the war neared Japanese waters, carrier air groups moved the VFB squadron concept, using Hellcats and Corsairs instead of Helldivers (which weren't all that popular anyway) for the bombing and scout squadron functions, supplemented by the Avengers for surface/ground targets, and giving the flexibility of lots of extra fighters when the task group was under attack.

Kahuna's right about the Tillman books about the F4F, F4U, F6F, and SBD; they are wonderful resources of historical record as well as technical information. Tillman did most of his research in the late 60s and early 70s, before many of the major players passed away, so you get some very interesting first hand accounts scattered throughout.

cheers

horseback

BigKahuna_GS
04-07-2009, 09:56 PM
As I mentioned above, the technical problems (seat height, wing leading edge spoiler, gear oleos, tailhook) were in development before the RN operated Corsairs from carriers. Cutting the wingtips off was a RN modification however


Rgr that. What I meant was that the Royal Navy's approach to the problem was to "just fly
the damn plane". The reason for the trim job was due to hanger vertical clearance. The RN
needed the Corsairs now and did not want to wait, any technical improvements could be made
along the way.



------------------------------------------------------------------------------------------------
Horseback-This was why as the war neared Japanese waters, carrier air groups moved the VFB squadron concept, using Hellcats and Corsairs instead of Helldivers (which weren't all that popular anyway) for the bombing and scout squadron functions, supplemented by the Avengers for surface/ground targets, and giving the flexibility of lots of extra fighters when the task group was under attack.
------------------------------------------------------------------------------------------------



As a former SBD pilot my dad flight tested "The Beast" Helldiver. After flying a docile, agile, fun little aircraft in the SBD, most pilots really really disliked this large bulky pig of a plane on roller skates.

I realize carrier air groups finally moved to the VBF concept in '45. My point was more rhetorical in that the Navy had experienced kamikaze attacks in '44 and knew they fought
a serious sucidal enemy that fought to the death. The japanese had several thousand of one
way human smart bombs being prepared ready to wreak havok on the fleet.

I think the Navy should of made the VBF squadrons much sooner than they did instead it was
more reactionary to severe loses in personnel, damaged and destroyed warships.

Now imagine how effective these VBF Squadrons would of been with Bearcats & Corsairs.
The lone main attack aircraft being the Skyraider. What could have been.

--------------



Here's a little bio on my dad.

Click on this link:


Enlisted Naval Aviation Pilots (http://books.google.com/books?id=PMSahgM2tWkC&pg=PA103&lpg=PA103&dq=enlisted+pilot+william+e+bateman&source=bl&ots=_QYDUtk2M5&sig=Q6AUk_HytpPc2izOJQ0OzeofmIA&hl=en&ei=PgXcSdSdLI7OMoqEhdoN&sa=X&oi=book_result&ct=result&resnum=4)


(top right corner)

Unfortunately they left some info out such as Midway, the entire South Pacific tour, Corsair Sqdns & F9F Panther Sqdns in Korea. Since he was an enlisted man he went thru the “Flying Sergeants Program” similar to what Chuck Yeager went thru to become a pilot since he had not attended college. He was a division flight leader as a technical Sergeant and later he would become a production test pilot. Then again I never knew my dad was stationed in Japan.


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R_Target
04-07-2009, 10:16 PM
Originally posted by 609IAP_Kahuna:
Rgr that. What I meant was that the Royal Navy's approach to the problem was to "just fly
the damn plane". The reason for the trim job was due to hanger vertical clearance. The RN
needed the Corsairs now and did not want to wait, any technical improvements could be made
along the way.

Ah, I see. Yes, they did get on with it, but not without some trepidation and considerable operational losses themselves. The RN pilots eventually grew pretty fond of their Corsairs despite the hairy reputation. If you don't have it already, I highly recommend Norman Hanson's Carrier Pilot. He flew with 1833 Squadron from Illustrious in 44/45, and has a lot to say about the F4U. It's probably one of the better flying memoirs I've read, as Hanson has a real flair for writing, and a first-rate humorous approach.

Kettenhunde
04-08-2009, 10:58 AM
Our formation flights showed that both airplanes (with similar power settings) were in closely stabilized formation at all altitudes tested above 5,000 feet Sometimes, the Corsair would slowly gain a lead of 100 to 200 feet after five minutes of stabilized power flight, and sometimes, the Hellcat would do the same. Considering that both airplanes had the same engine, propeller, gross weight, wingspan, etc., they should have had about the same performance. We did notice that during these runs, the Corsair always had about a 20-knot indicated airspeed (IAS) advantage!

This passage is very noteworthy and applicable to any discussion of aircraft performance referencing paper graphs. It demonstrates the futility of comparing on paper performance derived under differing compressible flow theory.

http://img154.imageshack.us/img154/760/correctiondifferences.jpg (http://img154.imageshack.us/my.php?image=correctiondifferences.jpg)


All the best,

Crumpp

Bremspropeller
04-08-2009, 11:10 AM
Looks like Buzzaw's theory of laminar-flow profiles' decent stall-characteristics got a little blow here http://forums.ubi.com/images/smilies/59.gif


I've said it before:

Gimme a P-47 or respectively a Corsair over a P-51 or an F6F any day the week. http://forums.ubi.com/images/smilies/metal.gif