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gothkrieger
02-17-2011, 03:07 PM
When flying the Bf109G I seem to accelerate very slowly from 350 to 450 mph. I am flying fairly level if not level. This seems to happen at both low and high altitude. Finding it hard to catch up with some Russian aircraft as a result. No problem getting up to speed in a dive, LOL. Flying clean, no flaps and the like happening. Any tips?

WTE_Galway
02-17-2011, 03:51 PM
Keep the ball centered.

Some people play with manual prop pitch but no idea if it really helps.

VW-IceFire
02-17-2011, 04:39 PM
I'm wondering if this is IAS/TAS confusion? If so don't worry ... it's happened to most of us http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

There's two types of airspeed... indicated air speed (IAS) and true air speed (TAS). The in cockpit gauges on the Bf109 will give IAS in kilometers per hour. The speedbar (red text on the bottom left) will also give speed in IAS in whatever units you prefer. I assume you've changed your speed bar to read in MPH.

IAS is the speed at which air is passing outside of the aircraft. Briefly... it's important to the handling of the aircraft. TAS is the actual speed you're traveling at. At 0 meters (or sealevel) both IAS and TAS are identical. As you climb the two values diverge and at extreme high altitudes the numbers will be significantly different.

If you go into virtual cockpit mode the number there will give the true air speed or TAS in kilometers per hour.

So if you read in a book that the Bf109K-4 can reach 450mph (I forget the exact number) you'll need to do the conversion which is 724 kph and you'll have to realize that this speed will only be reached at one ideal altitude. Performance varies depending on the altitude.

Typically Russian planes are not as fast as German aircraft, however, at low altitudes Russian planes tend to be equal or occasionally faster than German planes. This is only a general rule of thumb and does not apply to all cases.

Which Bf109 are you flying and which Russian aircraft are you flying against? The performance varies quite a bit between all of the different versions. Naturally http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

M_Gunz
02-17-2011, 08:38 PM
Are you sure that you are reading MPH and not KPH? Especially if you are reading Indicated Air Speed!

AFAIK there never was a 109G that could run 450 MPH TAS level without diving first.


At 0 meters (or sealevel) both IAS and TAS are identical. <== only true at standard temperature, is that 15 C?

On a hot day the air is thinner even at SL and IAS will read low. Also your prop won't get as much thrust nor your wings as much lift. But on a cold day it's the opposite. Pilots have told me in the summer you can see the difference literally day and night in how long your takeoff run is with the same load to get the same IAS.

That's why when running 'tests' the map and time make a difference with Crimea noon being the closest stock map to standard atmosphere.

WTE_Galway
02-17-2011, 08:51 PM
Originally posted by M_Gunz:
Pilots have told me in the summer you can see the difference literally day and night in how long your takeoff run is with the same load to get the same IAS.


oh you can get bet your grandmother on that one http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

It is a classic problem in places like New Guinea. A fuel/passenger load that will see you safely airborne at 5.00 am from a short runway at 5000 feet can see you off the end of the same runway and into the trees if you try the same thing at 2 pm on a hot summer day.

Sadly tragic Density Altitude related air incidents are common. here is a link to a report on just one such incident:

http://www.aopa.org/asf/epilot_acc/lax07fa258.html


Distressing video but something all pilots should be continually aware of.



When preflight planning, it’s important to remember that high density altitude not only increases required runway length, but also can have a dramatic effect on rate of climb. Making matters worse, true airspeed increases with density altitude (relative to indicated airspeed), which means the airplane’s groundspeed will be higher than normal. Together, these factors can make it extremely difficult to outclimb obstructions or rising terrain that, under normal circumstances, would present no problem. Tricky crosswinds are an added concern, further degrading climb performance and decreasing the stability of an airplane that may already be on the verge of stalling.

gothkrieger
02-17-2011, 09:42 PM
Ok, I will pay attention to the exact aircraft and speeds and I will get back with better stats on what is going on.

Erkki_M
02-18-2011, 12:03 AM
Originally posted by gothkrieger:
When flying the Bf109G I seem to accelerate very slowly from 350 to 450 mph. I am flying fairly level if not level. This seems to happen at both low and high altitude. Finding it hard to catch up with some Russian aircraft as a result. No problem getting up to speed in a dive, LOL. Flying clean, no flaps and the like happening. Any tips?

If you play the stock game and Bf 109 G-6 / G-6_late, its a known "borked" plane. It wasnt the best of 109s IRL, but nowhere as good as G-2 where it should be. Too much mass, probably.

Its top speeds are OK though... Are you playing single player? Beware that engine overheat doesnt apply to the AI and it always flies perfectly trimmed.

M_Gunz
02-18-2011, 12:49 AM
Originally posted by gothkrieger:
Ok, I will pay attention to the exact aircraft and speeds and I will get back with better stats on what is going on.

Speed _and_ altitude if you're going by the speedbar or instrument panel. Also to know if you have the speedbar set to kilometers per hour, miles per hour or knots as you can change that. 300 kph is abut 186 mph, big difference, conversion factor I use is 1.609 km per mile though quick-think is 100 kph is about 62 mph (check on a dual-scale speedometer). A lot of players used to mph in flight sims have gotten caught out thinking that "300 is fast". It's hard to re-train what was learned deeply too. 300 kph is for many of these planes just one hard turn above stall and spin!

The higher you fly the lower your IAS will be. Pay attention to that IAS as way up there you can't get away with as much. Your IAS tells you how much G's your wings can pull but your TAS says how tight or wide your turn will be at the same G-force, or how high your zoom should get you and just how accelerated that accelerated stall you might get into will be.

hrobert25
08-08-2011, 08:14 AM
Dear all,

I am actually not replying to the thread, but adding a question. Gothkrieger says he's flying fairly level, well, me with my Bf109 I am very far from flying level (you can now already guess I am a beginner).

My plane is all the time increasing the altitude and I need to constantly push the joystick forwards. As soon as I release the joystick, the plane starts climbing again.

I read through the manual, play around with the speed, propeler pitch etc. etc. and I just don't find the proper combination. Anyone of you could please tell me what I do wrong or tell me for a given altitude what the proper combination of settings is? Any replies will be much appreciated.

Cheers,
Robert

berg417448
08-08-2011, 08:18 AM
Are you trimming the elevator?

TipsyTed
08-08-2011, 08:33 AM
hrobert25, at what speed does that happen? Full throttle, full speed? If that's so, use elevator trim like berg said. Otherwise check your joystick calibration.

Kettenhunde
08-08-2011, 11:51 AM
At 0 meters (or sealevel) both IAS and TAS are identical.

CAS, EAS and TAS are equal depending on which type of altitude you are referencing.

IAS contains position error for installation and will vary accordingly.


only true at standard temperature, is that 15 C?

It is equal under other types of atmospheric conditions. It just depends on what altitude you are referencing.

True altitude they are not going to be equal. Indicated altitude they will be close if the altimeter settings are the same. The main variable will be instrumentation error.

There are five categories of errors relating to pressure altimeters. They are the mechanical error, the scale error, installation/position error, reversal error, and hysteresis error

At sea level density altitude and pressure altitude, it is always equal.

hrobert25
08-08-2011, 03:14 PM
Thank you for the replies. I am still going up and down, but slower. So it looks like trimming the elevator is the solution. http://forums.ubi.com/images/smilies/25.gif

This is really complicated. Anyone in Brussels/Belgium who offers private courses in IL2? http://forums.ubi.com/images/smilies/16x16_smiley-happy.gif

Cheers,
Robert

horseback
08-08-2011, 05:38 PM
Trimming a 109 is relatively easy in Il-2 '46. A little practice, and you'll be fine.

Try flying the game's version of the Mustang or P-38 afterwards though, and then come back and tell me how the USAAF ever survived the spring of 1944.

cheers

horseback

hrobert25
08-09-2011, 03:49 AM
He he, nice one horseback. http://forums.ubi.com/images/smilies/clap.gif

I am flying my Bf109 in IL2 Forgotten Battles, but I guess that doesn't make a big difference.

Yeah, with some practice that Saitek X52 will step by step justify the purchase. http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

megalopsuche
08-09-2011, 12:40 PM
If the OP is flying against the AI, then it's no surprise that he can't catch anything.

horseback
08-09-2011, 04:55 PM
Originally posted by hrobert25:
He he, nice one horseback. http://forums.ubi.com/images/smilies/clap.gif

I am flying my Bf109 in IL2 Forgotten Battles, but I guess that doesn't make a big difference.

Yeah, with some practice that Saitek X52 will step by step justify the purchase. http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif With the X52, you have enough hatswitches to dedicate one to trim; with my CH Products CombatStick, I have the POV hat assigned to nose up & down trim plus the left & right rudder trim (think compass points—North is nose down trim, South is nose up, and West & East are Left & right rudder trim respectively).

Keep in mind that in this game, trim is delayed by a few seconds, so click in your trim in little bits until you develop a ‘feel’ for a given aircraft. Button trim (as opposed to axis trim) is added or subtracted in 5% increments, so it may not be as precise as the trim on a slider, but it will get you in the ballpark.

cheers

horseback