Aces High Bulletin Board
General Forums => Aces High General Discussion => Topic started by: F4UDOA on December 29, 2000, 11:22:00 AM
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I will just use F4U data since I have the most of it, but I am sure other birds are the same.
Try taking off from CV with a F4U 100% fuel and Ammo no flaps. Relatively simple. Now try it with full flaps and the takeoff run becomes more difficult. It actually is harder using flaps than without?? According to the Pilots manual full flaps should lower stall speed from 96MPH to 76MPH(At 11,300LBS). And with a 40mph head wind to fly into that should be a pretty short takeoff run. Same for the HellKitty too.
It would seem that all birds don't quite stall at the right speed with full flap deflection. The 38 probably suffers the worst because it has the most to gain with the Fowler flaps. However getting an accurate weight for the P-38L fully loaded is near impossible.
Just some food for thought. From the manuals.
Takeoff run
F4U-1D 11,700LBS.
0knots headwind 680FT <==Short
45knots headwind 120FT <==real short
P-38L 17,400lbs
0Knots headwind 1030FT
45knts headwind 300FT
Ever wonder why the P-38 didn't fly off carrier decks??
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What could it do for the USN that the Corsair couldn't? Considering that B-25's were launched from the Hornet... I don't think take-off run was an issue.
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I have a devil of a time getting a -1D off the deck with 75% fuel, 1k eggs, and rockets. Been using 3 notches of flaps (-1C lifts off just fine in that config). Guess I'll have to try full flaps on the next -1D sortie (http://bbs.hitechcreations.com/smf/Smileys/default/biggrin.gif)
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The part about the 38's being launched from the deck was just a joke. The short takeoff run was necessary for the fast carriers and times where there was no headwind or if the carrier was disabled and unable to create a headwind. A B-25 probably has better wing loading than a P-38 depending on the load.
My point is really to show that the flaps do not significantly reduce stall. Just tested F6F-5. Stalls about the same as F4U and P38. All three are too high with flaps.
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The F4U1c will take off with FULL ammo, fuel, 2k of Bombs, and Full rocket load WITHOUT any Flaps being deployed. The F4U1d will not take off under ANY conditions with the above mentioned FULL loadout i.e flaps or no flaps. I have not tried the F6F so can't comment on that one yet. Also I have yet to make a successful trap with either the F4U1d or the TBM (this may however be my poor skill level) but I do find that the F4U1c can be trapped at ANY reasonable attempt EVEN if slightly over speed and FORCED to the deck, no so with the F4U 1d, F6F, or the TBM which seem to explode after I have caught the arresting cable (too fast maybe???). Since I have NO first hand experience with ANY of these planes I can only ask if this is a correct depiction since I have NO actual facts with which to base any comment (other than the game itself)
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I actually have an easier time getting a full F4u-1d up than a full 1c. I use 2 notches on both, haven't had too much trouble (though I do swoop pretty low coming off the carrier).
Landing I've found the 1d and 1c both pretty tough handling coming in rough, but f6f is a deader easy if you bounce it hard.
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Jim read my carrier takeoffs in the Help forum.
I regularly take off with 100% fuel, 2 1k bombs and rckts in the 1D with full flaps and wep. She'll drop 20 ft comin off the deck but she flies (http://bbs.hitechcreations.com/smf/Smileys/default/wink.gif)
S!
Rocket
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I get off the deck with 2 notches flaps, and wep, in 1D with 1k's and rckts..
Try not droppin flaps til the aircraft has accelerated abit.
AKskurj
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Your not supposed to use full flaps on takeoff.
Full flaps put them down almost vertically, and act more like airbrakes than lifting surfaces in that setting. They're used to slow down steep aproaches for landings.
Try it will half flaps.
Hans.
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Looks like these guys are using full flaps to takeoff...
(http://www.warbirdsresourcegroup.org/NARG/images/hellcat11.jpg)
(http://www.warbirdsresourcegroup.org/NARG/images/hellcat5.jpg)
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Gents,
In the pilots manual for "emergency takeoffs" it say "In case of short field or runway, lower flaps full down. Make a normal takeoff run with nose high".
Also it says in section C. of the standard check for all flights.
Flaps settings.-For normal operation it is recommended that a setting of 20Degrees be used for take off. Actually, any flap flap setting for 0 to 50degrees(full flap) may be used, the higher settings giving shorter takeoff ground distance. Take-offs with flaps up are easily accomplished with a small increase in run, dispensing with a small inconvenience of retracting the flaps after take-off. In addition the rate of climb immediately after take-off with flaps deflected is inferior to that with flaps up. Takeoffs with high flap setting and at full flap should be made only when it is necessary to obtain the shortest possible ground run. and after more experience with settings increased gradual from the recommended setting of 20degrees. When high flap setting is used the elevator tab should be set slightly tail heavy(about 1degree).
Sounds like full flap is the easy way to go.
However in AH it appears to be exactly the opposite with full flap increasing the take-off run instead of decreasing it. Also the appropriate stall speeds at reduced weight or with flap deflection.
BTW, this is not an F4U rant. I simply have more information for it than any other. The same would be true of the F6F-5, TBM, P-38 and P-51, or any other A/C that had flaps designed for the purpose of maneuvering or to decrease take-off run.
I know HTC has this info. It is just a matter of confirming the issue and verifying the data. Then when they find the time...
Thanks
F4UDOA
If anyone has a copy of the F6F pilots manual I would luv to see a copy of the weight and stall chart in the back.
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Did some testing offline.
First empty no problems
Then two 500lbs bombs no problems
Then all test with
100% fuel two 1000lbs bombs. auto take-off
No WEP
F4U-1D no flaps gear hit water. A/C ditched
F4U-1D full flaps gear hit water. A/C ditched
F4U-1C no flaps barely made it.
F4U-1C Full flap gear hit water A/C ditched
F6F-5 No flap made it.
F6F-5 Full flap, gear hit water A/C ditched.
So essentially The flaps make it harder to take off in a short run. The opposite of what is expected.
Here is a pic or two for your viewing pleasure.
(http://www.vought.com/photos/images/0426_079.jpg)
(http://www.vought.com/photos/images/0426_073.jpg)
(http://www.vought.com/photos/images/1109_04.jpg)
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Punt...
Pyro, any comment??
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Here's my comment...I load the F4U-1D up with 2x1k bombs and rockets, full fuel, give her WEP while holding brakes on, then let her go...just as I get to the end of the deck, I employ 1 notch of flaps, then gear up. No problems.
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F4UDOA one thing about full flap takeoffs is that you are lifting of WAY back on the drag curve , the means yes you CAN get her into the air (most probably in ground effect) but that doesn't necessarily mean you can actually accelerate to flying speed in this configuration.
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I was having problems with the Hogs flaps, but I have the hang of it now.
F4U-1C
Full Load: Full Flaps, Brakes on and run the throt up...punch the WEP and release the Brake simultaneously. Let her sink 5ft or so off the end before giving back force on the stick, and get the gear up fast. Run the flaps up as it steady's out.
The lighter the load, the less flap I use.
Launching with 1 DT and Rockets only takes 1 notch of flap and it barely sinks 3 feet off the end.
If I am not mistaken, if the bird is to light, or you use the emergency short takeoff procedure, you will have to hold the tail down as the airflow off the bottom of the flaps will tend to force it up and the nose down in turn.
This should also make the light bird harder to fly (more spoungey) since it will lift off before the airspeed is sufficient for normal aileron control.
I'm not sure how the calculated length of the AH deck, from the point of spawn, compares to the figures above, but it does feel like the run is longer than the numbers.
SkViper
Proud "C" Dweeb! :^)
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I'm not really having trouble getting off the deck. I'm just trying to show that the flaps aren't having the expected effect on take-off run and stall speeds according to the manuals for multiple A/C.
What I think is the telling test is the F4U-1C. I used auto-takeoff no flap or WEP, 2 1,000lbs bombs and it lifted off. When I lowered full flap it crashed into the water. Basically I would expect the flaps to reduce the take-off run by almost two thirds. 680 to 120FT.
It is possible that the drag is modeled to high relative to the lift provided by them. Just a guess as to what is the cause. I was just hoping to hear from Pyro on the subject.
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I think using auto-takeoff invalidates your tests F4DOA. The auto-takeoff is basically auto-climb. The aircraft will try to reach a pre-set speed that is the best climb speed for that aircraft at sea level in a clean configuration. A heavy craft with full flaps will dive into the ocean before it reaches that clean speed.
When you deploy your flaps, you should decrease you auto-speed setting to match. The tough part would be finding the best climb speed at sea level for each flap and weight configuration. I think it might be better to just try and do it manually.
I think it would be easier to just test stall speed in various configurations. I think that would prove your point without the complications. Maybe a heavy Hog with full gas at various flap settings. For example get 'em all flying along at 500 feet and find the minimum speed at which level flight can be maintained for each flap position.
<S> for doing the tests. You went about this in a very professional manner, and I hope others can learn something from it.
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Lephturn - Chief Trainer
A member of The Flying Pigs http://www.flyingpigs.com (http://www.flyingpigs.com)
"A pig is a jolly companion, Boar, sow, barrow, or gilt --
A pig is a pal, who'll boost your morale, Though mountains may topple and tilt.
When they've blackballed, bamboozled, and burned you, When they've turned on you, Tory and Whig,
Though you may be thrown over by Tabby and Rover, You'll never go wrong with a pig, a pig,
You'll never go wrong with a pig!" -- Thomas Pynchon, "Gravity's Rainbow"
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Lephturn,
Hmm? I didn't think that auto climb would have that affect during take-off? Thanks for the heads up.
I will re-test manually and see if I can lift off sooner.
BTW I still think the stall speeds with flaps are too high with flaps base on level 1G stalls on some birds being around 75mph with flaps and stalling near 100mph in AH. Just feels like it should be lower, especially on the carrier birds.
Anyway thanks for the compliment on the testing. Would you like cash or a check?
I'll make it out to the Lephturn historical society (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
Thanks
F4UDOA
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(http://www.vought.com/photos/images/0426_079.jpg)
look at the rudder deflection needed!
(http://bbs.hitechcreations.com/smf/Smileys/default/biggrin.gif)
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Re-tested manually.
I am able to get F4U-1D of deck with full load fuel, rockets and 2X 1K bomb's. But the same take off run is required. Guess I am looking for shorter take-off as described in the manual. Am I knit picking? I do fly knit you know, guess I can't help myself. Stall speeds are still off.
Citabria,
I know you luv this picture. A P-38 being escorted by F4U's. Hehe
(http://www.vought.com/photos/images/0426_063.jpg)
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That a Photo-recon P-38 (F-5) of some sorts? Note the glass nose cone on the under wing "tank"
-Westy
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Cool F4DOA. (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
Posting a nice little chart of test results for different flap configurations and the resulting 1G stall speeds would be awesome. If something is obviously not right, I'm sure it's something Pyro would look at. Why don't you post a methodology and lets see if we can recruit some more folks to do the tests. I'm willing to help. If it will help, I'll try to work up a test methodology tonight and check out the Jug.
You can save the cheque and buy me a beer at the next con. (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
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Lephturn - Chief Trainer
A member of The Flying Pigs http://www.flyingpigs.com (http://www.flyingpigs.com)
"A pig is a jolly companion, Boar, sow, barrow, or gilt --
A pig is a pal, who'll boost your morale, Though mountains may topple and tilt.
When they've blackballed, bamboozled, and burned you, When they've turned on you, Tory and Whig,
Though you may be thrown over by Tabby and Rover, You'll never go wrong with a pig, a pig,
You'll never go wrong with a pig!" -- Thomas Pynchon, "Gravity's Rainbow"
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I'm with westy.. I wonder who was escorting whom (http://bbs.hitechcreations.com/smf/Smileys/default/wink.gif)
AKDejaVu
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Originally posted by Westy:
That a Photo-recon P-38 (F-5) of some sorts? Note the glass nose cone on the under wing "tank"
-Westy
I'm guessing that's why the engine nacelle has "Information Please" painted on it.
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Considering there appears to be no guns mounted in the nose of the P-38 I think it's fair to say that it is the one being escorted, Hehe.