F4U Takeoff problem
 

Hi, I've been reading some topics on this but I can't find anything conclusive.

Basically, I used to fly the F4U when I started playing IL-2 and had no problems with it. I've returned to the game recently (4.11.1) and wanted to practice carrier take off (single mission - USN - F4U takeoff 1) and I can't seem to get the thing off no matter what. I don't remember having this problem before.

In my opinion the carrier in the training mission seems a bit short. I'm having trouble taking off without ordnance and I don't even want to think what it would look like if I tried with ordnance. :confused:

I'm attaching 2 of my attempts just so you get the picture of the problem and maybe tell me what's wrong.

Thanks in advance.

*Update.

I managed to take off with F4U-D variant, barely. Lowering fuel amount also helps with F4U-A. Still it seems strange I'm having so much trouble taking off the F4U-A with a full tank without ordnance.

Any thoughts?

I can take off with F4U-A with 100% fuel as well. Its close, but also AI cannot make it better. Didn't check your track, but did you use mixture 120%?

But indeed the CVEs are a bit short. Maybe we should change it.
Not sure, if Corsairs ever started on light carriers...

Thanks for the reply. In the training mission, the AI from the other carrier takes off but seems to be as close as half a meter from water at one point. I simply cannot hold the stick so perfectly still.

If someone has the time, please attach .trk of your take off in training mission "carrier take off 1" for the F4U-A with 100% fuel.

They didn't. Only Wildcats and Avengers operated from CVE's in any quantity. It's not possible to take off from a stationary CVE with a Corsair. I haven't tried with 10% fuel but even then I doubt it.

Probably should be changed... I can do that! :)

I envy you Caspar. I can do it myself, but with rather strange trim settings:

Aileron 6-8 notches right
Rudder 6-8 notches right
Elevator 25-30 notches up (!)

This way it flyes off from itself, and only minimal stick input is needed after takeoff, but still it's a bit odd historically.

During the war, Corsairs, Hellcats, even Spitfires, P-40s and P-47s were all flown off of CVE type carriers with full combat loads by average service pilots on several occasions without the aid of catapults. Taking off wasn't the problem; landing on a shorter, slower, more unstable CVE deck was a distinct problem.

By every account, the Wildcat was one of the hardest aircraft to take off from a carrier--the F4F-4 and FM-1 models were especially somewhat underpowered, and the darned things were so torque-y on top of those narrow landing gear that almost anything after that must have seemed like a piece of cake by comparison. Certainly, the late-war carrier fighters should have more than enough power and lift to clear even a short carrier deck easily with a normal combat load.

I think that there's either something 'off' in the acceleration & takeoff modeling or that the 'correct' procedure for the Player to achieve the desired results is not well known or understood.

cheers

horseback

If I'm not mistaken, those were all much larger than the one class of CVE that we have from Pacific Fighters.

The Wildcat may have been a bit of a handful but it was still the aircraft of choice for these tiny pocket carriers. At the battle of Leyte Gulf it was a few Wildcats and Avengers from the CVE's of Taffy 3 that held back a much larger force. There was no Hellcat or Corsair employed from these carriers.

I don't think F4U-s ever took off from CVE as it seems the corsair is much too heavy for such a short deck. I may not a best pilot tactically, but I know how to make smooth maneuvers with the plane, and it isn't helping.

The best I got with the 1A model is takeoff with 70% fuel. But I can take off from a moving carrier with the 1D every time without a hitch as its a bit more powerful.

If any Corsairs launched from a CVE it would have been one of the larger ones for sure...

I'll modify the training missions and submit to TD for approval. Those missions were setup with, I think anyways, very little understanding of Pacific flight ops, and certainly CVE's wouldn't be used for Corsair flight training...

..and they were made in times, where Corsairs FMs where still quite optimistic.
And maybe they should be some challenge indeed - if you learn how to start from a CVE, then you will do it from a CV with a smile. ;-)

However, further tips for take of with F4U from CVE:

1. Use tailwheel lock so you don't have to use much rudder in the beginning of the acceleration

2. Push stick forward to early lift the tail (keep calm and sensilbe, when it happens)

3. Open flaps shortly before leaving the deck and maybe open them to landing config (ground lift effect will happen over the water, at the deck the flaps only slow you down)

4. Its normal that you sink lower after leaving the deck, so don't over-react trying to pulling too high - at that point you need speed more than height (paradox, I know)

5. Close radiators and cockpit and set mixture to 120% - every little bit can help!

:)

Thanks, just one last question since we're at it. What exactly does the 120% mixture setting do?

I always thought it simply pumped more fuel that wasn't used but cooled the engine. Does it also develop more power? When should I use it generally?

Well, let's start with a comparison to the TBF, which usually operated off those CVEs with the Wildcat; powered by an R-2600 generating about 1,900 horses vs the 2,000+ hp R-2800 which powered the Corsair and Hellcat. The Avenger's empty weight is 2,000 lbs heavier than the Corsair's, and it was usually heavily loaded with fuel and bombs, rockets or torpedoes on takeoff. A fully internally laden Avenger carried about 16,500 lbs with a wing area of 490 square ft; a loaded clean Corsair weighed in at 10,500 lbs with a wing area of 314 square ft, which works out to less than one pound (less than .5 kg) difference in weight per square foot of wing area with an extra 5-10% of takeoff power

I think that we should also remember that CVEs were the primary means of supplying replacement aircraft to deployed carrier task groups in the last 18 months or so of the Pacific war; they routinely flew replacement Corsairs, Hellcats, Helldivers and Avengers from the jeep carriers to the fast big carriers when the big boys started running short of aircraft before their combat tour was over. It was (and is still) actually far easier to take off from a smaller deck than it was to land.

They put Wildcats on those little carriers for two reasons: they could more safely land on those smaller decks and they took up less space while still capable of performing the necessary light CAP, escort and ground attack functions, not because they could take off from them more easily.

cheers

horseback

That's not right.

That's not physics.

It may be how to make a flight sim, but it isn't what would happen in the real world. In the real world, you would get surface effect over any non-porous surface (i.e. not a net with air below it, but you wouldn't try to land on that anyway).

To my knowledge, it only cools. It doesn't appear to increase power output or fuel consumption. I use it to run the engine cool at sea level.

I think flaps do generate lift on the carrier deck, too. But they also create drag -slowing you down a little. As you dont need lift on the carrier deck, you don't get any advantage from extending flaps early. As you can't extend them in an instant you need to compromise between drag and lift flaps create - and extend them on the way to the deck edge.

Exactly.

Don't try my tips in real life! :D

The obvious solution here is to implement deck catapults the same way the ships had (and depended on) them in real life... :)

Makes sense... do you know if there were any operational requirements for takeoff? I mean, I can get a Corsair off the deck of even the tiny CVE's in a Corsair so long as their is sufficient speed. Presumably they had some requirements for turning into the wind?

In terms of the training missions... an Essex class still represents the most typical carrier ops for a Corsair. Especially if you wanted to train with any kind of ordinance under wing.

ANY (intentional and authorized) carrier takeoff or landing was done with the flattop steaming full speed into the wind; the bigger carriers not only boasted a bigger deck (and remember that you actually only used about half the deck to either take off or land), but they were usually one of the fastest ships in any given task force. Today, a nuclear carrier is capable of a higher sustained speed than any other ship in the surface fleet, so the requirement remains in effect.

The jeep carriers were not nearly as fast, so the prevailing wind became more critical for aircraft operating off of them; into the wind, the aircraft's airspeed is that much higher while it is moving that much slower plus the deck's speed relative to the deck. That gives you a higher safety margin when landing on a postage stamp. Fortunately the Pacific usually has a lot of wind blowing about; I spent three years on a Fast Frigate out of Pearl, and I can remember only about three or four days at sea that I could describe as windless. A carrier going 25-30 knots into a 15 knot wind (which is about average, as I recall) subtracts 40+ knots from the speed you need to get into the air and adds that 40+ knots to your margin when you land.

Before the jet operations of the late forties-early fifties, catapult takeoffs were fairly rare (and I don't think that the escort carriers even had catapults). 'Cat' shots are kind of stressful on the old airframe, especially the sorts we had back in the day, so Air Group Commanders were not eager to add any additional risks to their pilots and aircraft. Jarring stuff loose is a lot less critical when you land, but banging and shaking your aircraft around on takeoff was rightly considered just asking for trouble.

cheers

horseback

Not entirely. CVEs absolutely had deck catapults, same as the fleet carriers; deck catapult usage was much higher on the CVEs because of their lower top speed. With a max gross weight TBM, a short deck with planes spotted over half of it, and limited speed into the wind, the CVE TBMs lived and died off the cats.

Fleet carrier usage was low early in the war (less than 75 total for 41 and 42 according to Carrier Airpower by Freidman), but was up towards 40% of all launches by the end of the war, especially as naval air assets increasingly began focusing on ground support with heavier ordnance loads.

The lighter F4Fs, SBDs, and even the F6Fs could reliably launch without them, but catapults were used frequently to carrier launch P-40s, P-47s, and even P-51s during major coastal assaults - I've seen footage of both Warhawks and Thunderbolts being cat-launched during Operation Torch in the Med.

I know for a fact that once F4Us began operating regularly off the fleet carriers later in the war and were commonly carrying 2+ tons of bombs plus a belly tank, cat shots were often used for the first planes spotted on the deck until enough room was clear for the rest to make running launches. Same for TBFs topped off with fuel, HVARs, and a full bomb bay.

EDIT: here's a Navy article from 1995 that mentions CVLs and CVEs relying heavily on deck catapults, and how Army fighters were commonly used off them for resupply deliveries: http://www.history.navy.mil/download/ww2-36.pdf
Also - this page confirms what I suspected, all Casablanca CVEs (which were a huge portion of all produced US / RN CVEs) had a deck catapult: http://www.ww2pacific.com/notecve.html

http://www.navsource.org/archives/03/009.htm indicates the Bogue class had a deck catapult as well; I'm not sure if they were standard or not, but the lead ship (CVE-9) had one, so I suspect they all did as it was carried on to the Casablanca class.

First, thanks for the head's up on the availibity of catapults on the CVEs; I had read Tillman's book on the Wildcat and he specifically mentioned that the first CVEs, which were converted merchantmen (in the case of the RN's first escort carrier, I believe that it was a converted German Merchant ship), and there was little mention of cats after that. I have also just finished the memoirs of an Avenger pilot, and cannot for the life of me recall him mentioning that they ever used catapults, which means that it was so common that it never occurred to him to bring it up, or that it was so rare...

However, I think cat shots were used for special cases; most flight ops were CAPs and recon patrols where takeoffs would not be made from a crowded flight deck. Even for big raids, the SBDs and Turkeys would take off first, because they were slower and had more endurance than the fighters, which more often than not were there to protect the bombers and torpeckers, so their load was just drop tanks and bullets most of the time. They didn't need the cats unless they were grossly overloaded or at the front of a very crowded deck, as in the late war scenario where they finally figured out that fighter-bombers were just as effective as Helldivers and had the added advantage of not having a whiny rear gunner weighing them down.

Having said all that, I still believe that the part about Air Bosses not wanting their planes shot off the deck with a catapult is valid; do you remember in the movie The Bridges Over Toko-Ri where the carrier uses the props from the Corsairs and Skyraiders parked on the flight deck to help maneuver the ship into port? The CAG was beside himself over the wear and tear on his planes' engines (James Michener, who wrote the original book, took that from personal observation) and complains bitterly to the Captain of the ship, whose primary concern is getting into his docking space more quickly, not whether one of the aircraft's engines was going to wear out that much sooner and cr@p out on some young man over the Korean hinterlands.

cheers

horseback

It works like the Fw190 erhöhte notleistung system in that it uses additional fuel evaporation to cool the compressed air in the intake manifold to allow a current unstable, or even higher, boost pressure. (Water -along with its required antifreeze - works better as it doesn't upset the mixture ratio.) The Germans found that simply spraying MW50 into the supercharger, with no change in throttle or supercharger settings, was good for a 4% increase in power while simultaneously reducing temps.

It was a reference to in game mechanics, not real life. In real life it does far more and has a much bigger impact than in game.

But to add to your real life info, the anti-freeze component is combustible so an WM injection does change the mixture ratio, even if not to the extend added fuel does...we could go on, but this is about F4U take offs in game.

Fw 190 erhöhte Notleistung does evaporate fuel in the intake manifold. The aircraft used direct fuel injection, and to my knowledge, fuel did not mix with air until it entered the cylinder. In fact, all erhöhte Notleistung did was to release pressure from a control chamber in the Kommandogerät so part of it were tricked into believing that there was less boost in the engine than there actually was. Fuel injection was stepped up to maintain mixture...again we could go on...

Hi,
I tested take off today and with 100% fuel, 120% mixture, settings trims - rudder to the right and elevator up, I was able take off with F4U-1A two times from three attempts. But this carrier is very short for Corsair, that`s true, with bombs and rockets hmm ... problem.

I not sure I follow the " ... erhöhte Notleistung does evaporate fuel in the intake manifold" to " ... direct fuel injection ... " and then back to " ... all erhöhte Notleistung did ... " ... (was to trick the Kommandogerät) into believing that there was less boost (you mean more, right?) ... " implying, maybe, that the cylinder injectors were adding the additional fuel?.

The erhöhte Notleistung system injected fuel through a single dedicated injector into the left air intake upstream of the supercharger at the rate of about 14.5 gallons per hour. Total fuel consumption could be 185 gph (full throttle can be 146 gph). I could ... well ... lol

Yeah, I get the game/reality point. I should try harder to focus on the game part. The game tries really, really hard :grin:

Dont know if this was mentioned here, but, on the take-off run on the carrier, and little after, never use ailerons, as any change on the wings will make them stall. We have to compensate only with rudder. After gaining speed we can go back to ailerons.

Frankly, the easy way is to use the catapult. If you happen to be on the first position of a flight, all afore mentioned tactics will fail, even without a heavy load.