F4U Takeoff problem

[Plane-Eater]

Originally Posted by horseback

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.

[horseback]

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

Originally Posted by JtD

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.

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.

[JtD]

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...

[OREL_Erichos]

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.

Originally Posted by JtD

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...

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

[Bolelas]

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.

[RPS69]

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.