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RxMan
11-10-2004, 06:56 AM
My first few tries at carrier landings went very well, since then I have completely lost control of my approach. I began wondering if prop pitch could/should be used (esp in US planes) instead of throttle to control speed on approach. Any ideas on thsi?

WTE_Snowhawk
11-10-2004, 07:07 AM
On final pilots do what are referred to as PUFF checks,
Prop fully fine
Undercarriage down and locked
Flaps identified and down
Flaps open (cowl flaps that is)
I suppose in this situation we'd add an "A" for the arrestor hook, and make them PUFFA checks.
As you can see, prop fully fine is the first on the list, so the short answer to your question is no, don't use pitch to control airspeed. the reason we want it fully fine (100%) is so that we have maximum RPM at low speed in the event of a missed approach resulting in a go-around.
Throttle controls rate of descent, attitude controls airspeed.
If you're having trouble judging when you need throttle, open your canopy and adjust your seat, makes landing much easier as you can usually see the carrier over your nose 'till short final.
Of course, you can use pitch if you want on final, no one's stopping you, I'm just letting you know how us real pilots do it. Mind, I've never had to land on a carrier... http://forums.ubi.com/images/smilies/blink.gif

fabianfred
11-10-2004, 07:31 AM
I have been using prop pitch to help slow me down for all my landings since FB came out....

you can still use it to slow down, then put back to fine before hitting the deck...

one is supposed to slam the throttle fully open as one hits the deck, just in case it don't catch

Xnomad
11-10-2004, 07:46 AM
I find lowering the prop pitch helps me slow down a great deal faster than waiting for the plane to lose momentum by itself. I usually lower it to 50% and then play with the throttle. From what I understand lowering the pitch in real life wouldn't do this it would just decrease the resistance of the prop. Leaving it at 100% should in theory make the prop brake the plane like a car's engine can brake a car when you let go of the accelarator however, this doesn't happen in the game and lowering the pitch seems to slow the plane down. I might be wrong but that's what I've heard and I'm not a real pilot.

Also if I'm too fast on final approach then I'll shove it down to 0% until I'm in the glide scope at the right speed and then I put it on 50% again.

Viking-S
11-10-2004, 08:05 AM
Was a thread the other day with this site (http://home.att.net/~ww2aviation/Bentwings.html) in it! Some good info on carrier landing and take of. Might be different in game.

MOhz
11-10-2004, 08:20 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by WTE_Snowhawk:
On final pilots do what are referred to as PUFF checks,
Prop fully fine
Undercarriage down and locked
Flaps identified and down
Flaps open (cowl flaps that is)
I suppose in this situation we'd add an "A" for the arrestor hook, and make them PUFFA checks.
As you can see, prop fully fine is the first on the list, so the short answer to your question is no, don't use pitch to control airspeed. the reason we want it fully fine (100%) is so that we have maximum RPM at low speed in the event of a missed approach resulting in a go-around.
Throttle controls rate of descent, attitude controls airspeed.
If you're having trouble judging when you need throttle, open your canopy and adjust your seat, makes landing much easier as you can usually see the carrier over your nose 'till short final.
Of course, you can use pitch if you want on final, no one's stopping you, I'm just letting you know how us real pilots do it. Mind, I've never had to land on a carrier... http://forums.ubi.com/images/smilies/blink.gif <HR></BLOCKQUOTE>

hullo dude, i dunno if you are new, but this is the world of IL2 so dont think that just because the real pilots used PUFF, that it works that way in IL2, but still nice info!

GvSAP_Wingnut
11-10-2004, 08:43 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by MOhz:
hullo dude, i dunno if you are new, but this is the world of IL2 so dont think that just because the real pilots used PUFF, that it works that way in IL2, but still nice info! <HR></BLOCKQUOTE>

Are you serious? He just described the ABC's of a proper approach.

SKULLS Virga
11-10-2004, 09:04 AM
"hullo dude, i dunno if you are new, but this is the world of IL2 so dont think that just because the real pilots used PUFF, that it works that way in IL2, but still nice info!"

Wrong.....again.

x6BL_Brando
11-10-2004, 09:18 AM
Along with the PUFF checks, the other best advice is get slow farther away! In other words, think a bit more carefully about the approach and don't look for shortcuts to slow you down. That said, sideslipping - wing over, opposite rudder - is a good way to lose some alt without biting so much into distance travelled.

mortoma
11-10-2004, 09:23 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by MOhz:
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by WTE_Snowhawk:
On final pilots do what are referred to as PUFF checks,
Prop fully fine
Undercarriage down and locked
Flaps identified and down
Flaps open (cowl flaps that is)
I suppose in this situation we'd add an "A" for the arrestor hook, and make them PUFFA checks.
As you can see, prop fully fine is the first on the list, so the short answer to your question is no, don't use pitch to control airspeed. the reason we want it fully fine (100%) is so that we have maximum RPM at low speed in the event of a missed approach resulting in a go-around.
Throttle controls rate of descent, attitude controls airspeed.
If you're having trouble judging when you need throttle, open your canopy and adjust your seat, makes landing much easier as you can usually see the carrier over your nose 'till short final.
Of course, you can use pitch if you want on final, no one's stopping you, I'm just letting you know how us real pilots do it. Mind, I've never had to land on a carrier... http://forums.ubi.com/images/smilies/blink.gif <HR></BLOCKQUOTE>

hullo dude, i dunno if you are new, but this is the world of IL2 so dont think that just because the real pilots used PUFF, that it works that way in IL2, but still nice info! <HR></BLOCKQUOTE>Well it is knda both ways, in the game, lowering your prop pitch does help you slow down, which it wouldn't in real life. So in the game it's not such a bad idea. However the going to full fine again just before you land is still the best procedure, in both real life and the game. So in real life pilots would be on full fine pitch from the get-go, once entering the landing pattern. In the game, maybe ok to slow down by coarsening the prop pitch but still the best idea to go full fine on final approach. It gives you the highest RPM/HP both in RL and in the game.

WTE_DuStA
11-10-2004, 07:59 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by MOhz:
hullo dude, i dunno if you are new, but this is the world of IL2 so dont think that just because the real pilots used PUFF, that it works that way in IL2, but still nice info! <HR></BLOCKQUOTE>

well hello dude. Not sure if your aware but this is a flight sim and modelled on real life aircraft and vehicles so...... one would assume that adopting real life procedures for things would then make it easier for you to land in game. What snowhawk was typed is exactly what the majority of us in WTE do as running a quick checklist before landing prevents a crash on landing.

tHeBaLrOgRoCkS
11-10-2004, 08:15 PM
Hmm that does make me curious? Will prolly get my butt kicked for this but if Prop pitch is not supposed to slow you down then why the hell dont we see as many bloody whines about that as we do about FMs/DM's and sodding 50'cals?

I am genuinely curious about this as it would seem to be a far groser mis-representation of the simulated enviroment than wether a fricken bar in the cockpit obscures your view?

If there is a thread on this issue? And if its been done to death then kindly point it out to me cos if you guys out there that whine about all the other **** are keeping schtum about this particular issue then I am never gona take you seriously again!!

This is one of those elevator trim on a slider deals aint it LOL

IL2-chuter
11-11-2004, 01:24 AM
On constant speed props you're not setting the prop pitch to 100%, you're setting the prop pitch governor to 100% (max power) rpm. As soon as you get enough throttle to achieve 100% rpm the governor increases the pitch -from off the fine pitch stop- to increase blade drag to stop the accelleration of the engine past the desired rpm, and constantly adjusts as necessary to maintain set rpm value. At idle thtottle the prop is going to be on the fine pitch stop for lack off adequate oil pressure (electric prop uneffected).

The concept of an idling prop (fine pitch) inducing drag has been covered here previously . . .

Not much mention has been made of the FULL FEATHER electric props on the German single engine fighters. This could be an interesting feature when deadstick over enemy territory . . .


http://forums.ubi.com/images/smilies/16x16_smiley-indifferent.gif

tHeBaLrOgRoCkS
11-11-2004, 03:28 PM
Hmm cheers musta slipped through without me noticing I will investigate further. course would help if the bloody search engine didn't have a habit of timeing out on me lol

tHeBaLrOgRoCkS
11-11-2004, 03:57 PM
Yeah I had seen threads on prop pitch before but hadn't picked up on the fact that it wasn't being moddeld correctly I guess I really should check into Olegs ready room now even if its like living in a vineyard. Thanks for setting me straight.

BAT-TURN here I come mwuahahaha

WTE_Snowhawk
11-12-2004, 02:48 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>
hullo dude, i dunno if you are new, but this is the world of IL2 so dont think that just because the real pilots used PUFF, that it works that way in IL2, but still nice info!
<HR></BLOCKQUOTE>

This statement has been more than adequately refuted by Wingnut, Brando and DuStA.

If you are the type of person who enjoys the type of suspension of disbelief and immersion that using real world techniques provide, then Brando is right on the money when he says this:
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Along with the PUFF checks, the other best advice is get slow farther away! In other words, think a bit more carefully about the approach and don't look for shortcuts to slow you down. That said, sideslipping - wing over, opposite rudder - is a good way to lose some alt without biting so much into distance travelled.
<HR></BLOCKQUOTE>
If you are one of those people who would like to use real world best practices to make your gaming more enjoyable, here's a basic principle. Become a pro-active pilot. Think ahead. Fly smoothly. Unless you've got an engine failure or a bandit has you in his sights or such similar circumstance, let me suggest that you relax, and let the plane slow down by itself.
If you are one of those people and would like more real world stuff, just let me know and I'll start a thread.

lindyman
11-12-2004, 05:31 AM
I guess it can be different on different planes, but I've been told to make sure the cooling flaps are closed already in cruise, then on descent and then tripple check on final, as having them open when the engine is on idle is likely to shock cool it, and you really don't want that. It might not damage it right away, but you've severely shortened its lifetime.

If you need to go around, open the trottle and open the cooling flaps.
_
/Bjorn.

Tully__
11-12-2004, 05:49 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by RxMan:
My first few tries at carrier landings went very well, since then I have completely lost control of my approach. I began wondering if prop pitch could/should be used (esp in US planes) instead of throttle to control speed on approach. Any ideas on thsi? <HR></BLOCKQUOTE>
Assuming you're entering the pattern at a reasonably slow speed, leave rpm setting at 100% (prop pitch), use pitch angle to control speed and throttle to control glide slope angle.

For more info, check out the carrier qualifications page (http://www.blacksheep214.com/cq/cq.htm) on the BSS site. It describes a correct pattern for carrier landings.

Tully__
11-12-2004, 06:05 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by tHeBaLrOgRoCkS:
Yeah I had seen threads on prop pitch before but hadn't picked up on the fact that it wasn't being moddeld correctly I guess I really should check into Olegs ready room now even if its like living in a vineyard. Thanks for setting me straight.

BAT-TURN here I come mwuahahaha <HR></BLOCKQUOTE>

Not only prop pitch, mixture too. In real life the pilots of the multi engine radials often ran wide open throttle and used mixture to control power settings as soon after takeoff as they reached a safe altitude to come off max power settings. For more information on this, check out John Deakin's Pelican's Perch (http://www.avweb.com/news/columns/182146-1.html) column at AVWeb.

ddsflyer
11-12-2004, 10:31 AM
Actually the flight model in IL2 for prop pitch is backward from what it should be. In flying real aircraft, when landing you place the prop in its highest RPM setting (fine pitch) on short final. The flat blades act as a flat plate airbrake and slow you down quickly when power is pulled off. My own plane, A Beech Baron 58 drops like a stone if I pull off all the power with the prop levers fully forward on final. I have to keep power on all the way down until in the flare. With the prop(s) at low RPM (coarse pitch) there is less drag when power is reduced (think of it as partial feathering of the prop(s)) and the plane slows much less. The action and function of constant speed variable pitch propellers is poorly understood by most lay people. Complicating the fact is that many WWII aircraft used electric propellers (like the Curtiss Electric) which act differently from hydraulic (like Hamilton Standard) props.

And by the way, it is a GUMP check, not PUFF. Gas, Undercarriage, Mixture, Prop.

tttiger
11-12-2004, 11:21 AM
Since PF came out, I've gone back and re-watched the training films for the new planes at Zeno's WarBirds. As most of you know, these are the real WWII training films for the planes.

http://www.zenoswarbirdvideos.com/main.html

NONE of them shows any of the Navy planes landing with cowl flaps open. They all say to open the cowl flaps once down to keep the cylinder head temperatures down.

Whatever the last F in PUFF is, I don't think it's Cowl Flaps Open.

Otherwise, this is a good check list. Thanks!

BTW, if you haven't watched the training films at Zeno's, take a look at them. Lots of good info.

ttt

tHeBaLrOgRoCkS
11-12-2004, 11:56 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Tully__:
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by tHeBaLrOgRoCkS:
Yeah I had seen threads on prop pitch before but hadn't picked up on the fact that it wasn't being moddeld correctly I guess I really should check into Olegs ready room now even if its like living in a vineyard. Thanks for setting me straight.

BAT-TURN here I come mwuahahaha <HR></BLOCKQUOTE>

Not only prop pitch, mixture too. In real life the pilots of the multi engine radials often ran wide open throttle and used mixture to control power settings as soon after takeoff as they reached a safe altitude to come off max power settings. For more information on this, check out John Deakin's http://www.avweb.com/news/columns/182146-1.html column at AVWeb. <HR></BLOCKQUOTE>

Cheers Tully http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif Yeah I had read a thread in Pacific forum that also has some good links on prop pitch and I think after fooling around with it I have got a fairley good grasp of how it applies in IL2 although if you asked me to explaine it it would probably cause my frontal lobe to leak outta my nose http://forums.ubi.com/images/smilies/blink.gif. The reason I started messing with prop pitch in the first place is that I read 'First light' by Geophrey Wellum and I am sure that in one of the chapters he mentions that they would use prop pitch settings to Fine tune position when in close formation? At least I think it was in that book it may have been somewhere else but I am sure I read it somewhere (I will check back).

I think the only way to realy get your head around it is to map the control too your mouse wheel or some similar variable slider and just fook about with it (my current bird of choice for this has been the pony NT) whack that baby up and down a few times and you will soon start to see how it applies. Using the rocker on my saitek has enabled me to perform some interesting low speed energy fights with the ai in QMB(not the best enviroment I know but I would prolly get eaten alive pulling this shiot online).

Wether I will employ this configuration on a regular basis I am not sure as I find the rocker a little uncomfotable after a period of time and I may swap the rocker over to throttle and the throttle over to prop pitch? Hell I may even stick another joystick in and use its throttle to control pitch? Arrrgh I wish watteville lived next door to me I could really use a custom throttle quadrant right now heheh guess I will have to make it myself.

Any way thanks for the links and info I shall continue to experiment.

´²оÑ€н¸º¸ лобо²о³о сÑ"µºл? ¿Ñ€оÑ"ÑŒ!!

http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif


P.S when I just pressed ' a minit ago some sort of word search bar appeard its stopped now but did some one enable Moderator tools gloabaly again ?

WTE_Snowhawk
11-12-2004, 02:13 PM
ddsflyer said:
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>
And by the way, it is a GUMP check, not PUFF. Gas, Undercarriage, Mixture, Prop.
<HR></BLOCKQUOTE>
S` DDS
Different schools teach different techniques, that does not make mine right and yours wrong, they are simply different, which is totally fine and to be expected, since I learned to fly in Australia, and you learned to fly elsewhere I assume. http://forums.ubi.com/images/smilies/25.gif
We also do checks on downwind, called BUMFISH;
Brakes, Undercarriage, Mixture, Fuel, Instruments, Switches, Harnesses & Hatches.
A bit long winded, but this type of attention to detail is probably a good indication as to why there are so few GA accidents down here.
As for what the navy did, I told you guys, I've never had to land on a carrier, and never flown a warbird. The hottest thing I've flown is a Brand spankin' new cessna 182, or a Beechcraft Debonnair http://forums.ubi.com/images/smilies/35.gif , so the second F is indeed for cowl flaps in a PUFF check, obvioulsy the navy did not use PUFF. Coming from U.S., they probably used something more like GUMP. (run Forrest, RUN!) http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif
What I would love to do is find out how both USN and IJN conducted their approaches. What their actual procedures were, because I am 99% sure that they did them differently from what most of us have learned, and differently from each other as well. Out of all you boys stateside one of you must know of someone who flew in the war, perhaps one of you could find out and keep this post going with new information?
Any Japanese people out there know of any WWII pilots?
S`

XyZspineZyX
11-12-2004, 03:52 PM
can't flaps be used to slow down?
maybe gear down as well?
and a little bit of nose up, before entering the glidepath?
I mean it is not an airstrip where one can flare halfway along the length of the strip before touching down. All this slowing down thing, has to be down before entering anything even remotely the break.
I use a 95% pitch, cowl wide open, apply full flap on final keeping the VSI in level and don't seem to have too much trouble with a wave off.

Throttle up or down for height and flaps for speed control.

LStarosta
11-12-2004, 03:58 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Vagueout:
can't flaps be used to slow down?
maybe gear down as well?
and a little bit of nose up, before entering the glidepath?
I mean it is not an airstrip where one can flare halfway along the length of the strip before touching down. All this slowing down thing, has to be down before entering anything even remotely the break.
I use a 95% pitch, cowl wide open, apply full flap on final keeping the VSI in level and don't seem to have too much trouble with a wave off.

Throttle up or down for height and flaps for speed control. <HR></BLOCKQUOTE>

Gear down for a landing? You don't say! http://forums.ubi.com/images/smilies/mockface.gif http://forums.ubi.com/images/smilies/16x16_smiley-happy.gif

ZG77_Lignite
11-12-2004, 05:32 PM
'Prop Pitch' is such a hugely misleading term as it is used in FB/PF that it really messes a lot of people up. So, even though it was already mentioned once above, I'll mention it again (because it is critically important to the concept):

In FB/PF, 'Prop Pitch' is a generic term that generally relates to what your engine is doing, in most cases it has nothing to do with the actual pitch angle of the prop. In most every US, IJN/IJAF, RAF, and most other aircraft, 'Prop Pitch' refers directly to Engine RPM (and has nothing to do with prop pitch). In these aircraft with constant speed props, the pilot has no direct control over the prop itself, he merely selects the desired Engine RPM and the prop automatically adjusts itself to best efficiency for that speed/power combination.

XyZspineZyX
11-12-2004, 08:40 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by LStarosta:
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Vagueout:
can't flaps be used to slow down?
maybe gear down as well?
and a little bit of nose up, before entering the glidepath?
I mean it is not an airstrip where one can flare halfway along the length of the strip before touching down. All this slowing down thing, has to be down before entering anything even remotely the break.
I use a 95% pitch, cowl wide open, apply full flap on final keeping the VSI in level and don't seem to have too much trouble with a wave off.

Throttle up or down for height and flaps for speed control. <HR></BLOCKQUOTE>

Gear down for a landing? You don't say! http://forums.ubi.com/images/smilies/mockface.gif http://forums.ubi.com/images/smilies/16x16_smiley-happy.gif <HR></BLOCKQUOTE>

ya cheeky bugga.....read that as gear down to help slow down

Smokin256
11-12-2004, 11:20 PM
In the "early" days of FB during previous discussions about prop pitch several of us did extensive testing of the airbrake effect of 0% power & 100% p.p. (high rpm) vs. 0% p.p. (low rpm). At that time we found that the planes do slow down faster at high rpm than they do at low rpm as they should. I just did some quick tests in AEP & they still do. (don't have PF yet.)

Test 1; LaGG3 steady cruise at 3,000 meters, 400kph & 100% prop pitch. Cut throttle & maintain exactly 3,000 meters altitude & time how long it takes to slow down from 400kph to 300kph. Then do the same test but cut the throttle & set 0% prop pitch.

Results; 100% prop pitch 25 seconds, 0% prop pitch 35 seconds.

Test 2; Stuka Ju87-D3 Steady cruise at 3,000 meters, 300kph & 100% prop pitch. same drill & time how long it takes to slow from 300kph to 200kph.

Results; 100% prop pitch 30 seconds, 0% prop pitch 40 seconds.

At the time it was pretty much decided that there should be a greater difference but it's the best the game engine can do. & I think that's why you don't hear much about it anymore.

I think that the reason people think they're slowing down more when at low rpm is because the way the game handles engine sounds. This is the only place where I believe the game could use more complexity in the sound engine not less. It needs to change the pitch of the engine sounds with rpm as it does now and it needs to change the volume of the engine sounds with power settings . I think that would eliminate a lot of the confusion in this situation. And add a lot to the immersion level. But then again, if you lower the engine volume then you have the problem of "radar sound". In order for that system to work there would need to be a more substantial penalty (in loss of speed) for closing your throttle as there would be in real life.

I guess We'll just have to hope this stuff will be sorted out in BoB. The Problem is, we need to convince the community that it's important. Currently we have one thread that's kind of discussing prop pitch problems on the various boards. We have probably twenty threads discussing the reletive merits of the Shiny water! http://forums.ubi.com/groupee_common/emoticons/icon_rolleyes.gif .

Enough rambling from me for now!

Cheers.....Smokin256

Smokin256
11-13-2004, 12:01 AM
Correction, I guess there's two threads discussing Prop pitch problems. I just checked in Crashs' thread in the Pacific Fighters forum & found that there's actually a great discussion going on in there. I just assumed it had devolved into more silliness so I hadn't checked lately. There's hope yet!

Cheers.......Smokin256

tHeBaLrOgRoCkS
11-13-2004, 09:20 AM
RGR that
Prop pitch and sound engine filed under 'things I should whine about in 2006'

Heavy_Weather
11-13-2004, 09:28 AM
i thought it was a Puff-Diddy check not a Forest Gump check. wtf http://forums.ubi.com/images/smilies/59.gif

SithSpeeder
11-13-2004, 01:50 PM
Smokin--

Can you try your test using 50% pp? Empirically, it seems that the midrange seems to give me better braking.

I've forgot and done takeoffs with 0% pp before.

* _54th_Speeder *

WTE_Snowhawk
11-13-2004, 08:22 PM
On page 1 Lindyman said this:
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>
I've been told to make sure the cooling flaps are closed already in cruise, then on descent and then tripple check on final, as having them open when the engine is on idle is likely to shock cool it, and you really don't want that. It might not damage it right away, but you've severely shortened its lifetime.
<HR></BLOCKQUOTE>
I didn't want to reply to this until I spoke to my CFI, so I asked about PUFF checks again, I specifically asked why on final, and asked if there was a risk of "Shock Cooling" the engine. He replied to me with questions, as is his style. Bugger always makes me think.
Anyway, his questions were these:
"when's the latest time that you close the trottle to idle in the circuit"
A: When turning base
"What is your average airspeed on final when you open cowl flaps"
A: Depends on plane, but about 70-80 Knots
"How long has your engine had to cool while throttle has been closed?"
A: Not sure really, maybe 60-120 seconds?
Then he started to talk.
We open cowl flaps so that we don't cook the engine in the event of a go-around, or a touch and go. We don't worry about flash cooling the engine because we're at a low indicated airspeed on short final, and the engine has been cooling gradually since turning base at least. (with faster planes, you reduce power earlier in the circuit, allowing more time for cooling at high indicated airspeed)
Again, it's about flying smoothly and thinking ahead.
Anyway, that's part two of why cowl flaps, but we were talking about pitch.
re-read ZG77_Lignite's post, he's correct about the pitch control having no direct effect on the pitch of the propeller. It really should be called "Governor control" But it isn't so don't worry.
for the layman the point is, High RPM = 100% setting, low RPM = 0% setting, and you want high RPM for a go around. (try taking off from full stop with 0% selected you'll see why.)
If you want to learn more about CSU's (constant speed units, or variable pitch propellers) search for info on the internet. It's quite an ingenious system.

Tully__
11-13-2004, 08:49 PM
Can anyone point to an incident where an aicraft engine problem was unequivocably proven to be caused by "shock cooling"?

Smokin256
11-13-2004, 10:24 PM
SithSpeeder, I ran the tests at 100%, 50% and 0% & times seem to fall right about in the middle. It's hard to tell for sure because the test is not exact. so much depends on maintaining exactly 3,000 meters altitude & that's really hard to do. At least with my stick. http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif At least I'm sure there isn't a great increase in deceleration at 50% prop pitch.

Cheers.......Smokin256

SithSpeeder
11-13-2004, 10:46 PM
Snowhawk said:
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>(try taking off from full stop with 0% selected you'll see why.) <HR></BLOCKQUOTE>

But I had said:
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR> I've forgot and done takeoffs with 0% pp before. <HR></BLOCKQUOTE>

It works fine to me. Not quite as well, but not shabbily, either.

YMMV

* _54th_Speeder *

SKULLS Virga
11-13-2004, 11:22 PM
"Can anyone point to an incident where an aicraft engine problem was unequivocably proven to be caused by "shock cooling"?"

Shock cooling is usually more of something that would be found sometime after the flight - cracked cylinders and exhaust manifolds.

"c. Gradual Descents. Gradual descents from high altitudes should be planned in
advance to prevent excessive engine cooling and provide passenger comfort. The
manufacturer's recommendations found in the Airplane Flight Manual should be
complied with, especially regarding descent power settings to avoid stress on
the engines. Although most jets can descend rapidly at idle power, many
turboprop and light twin airplanes require some power to avoid excessive engine
cooling, cold shock, and metal fatigue. ATC does not always take aircraft type
into consideration when issuing descent instructions. It is the pilot's
responsibility to fly the airplane in the safest manner possible. Cabin rates
of descent are particularly important and should generally not exceed 500 or 600
feet per minute. Before landing, cabin pressure should be equal to ambient
pressure or inner ear injury can result. If delays occur en route, descents
should be adjusted accordingly."

This from the F.A.A.'s website in an advisory circular here:

http://www.faa.gov/fsdo/orl/files/advcir/AC61-107.TXT

There is some difference in opinions on if or how much damage shock cooling does to an engine.

swingman
11-14-2004, 03:28 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by WTE_Snowhawk:
I didn't want to reply to this until I spoke to my CFI, so I asked about PUFF checks again...
<HR></BLOCKQUOTE>

Aparently, there's more than one idea regarding their usage. I was just echoing what I was told by my FI.

Oh... It seems like my fingers remembered the passwd of my old ID http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif Good!
_
/Bjorn.