Stationary CV, no head wind: who can take off?

[Shortround6]

and don't forget Doolittle getting the first B-25 off in under 500 feet without a catapult

See: http://www.zenoswarbirdvideos.com/Images/B-25/B25TOC&LC.pdf

Take off distances for a hard runway at sea level vary from 1000ft to 4600ft depending on wind and weight (load).
Just because army planes were able to take-off from carriers on occasions doesn't mean that they had full combat capability when doing so. (full tanks, full ammo, or full under wing loads).

 

[herman1rg]

I saw some early footage of a bi plane taking off from a carrier into a strong wind, the ship sailed on underneath the plane which just rose vertically into the air.

Have you got a link for that?

 

[JoeB]

Take off distances for a hard runway at sea level vary from 1000ft to 4600ft depending on wind and weight (load).
Just because army planes were able to take-off from carriers on occasions doesn't mean that they had full combat capability when doing so. (full tanks, full ammo, or full under wing loads).

In general yes, but the B-25's in Doolittle Raid were at a pretty high weight, had various items of equipment removed, but more fuel added. OTOH they had a quite high wind over deck, launched in an area of typically high winds, and in the videos you can see it's a rough sea, with Hornet adding to it by steaming at high speed into the wind. Plus, there was special training, though some of the planes nearly stalled and crashed. A much higher than normal risk was accepted for that mission, all around. However the USN conducted regular carrier qualification trials for the PBJ (ie B-25) later in the war.

In case of Army fighters taking off from carriers, P-40's, P-39's and P-47's all did it, but takeoffs from escort carriers were catapult shots, and in general the intention was just to ferry the a/c to nearby bases on land. P-40's flew off from Ranger on three ferry missions to Africa. On the first USN Bu Air predicted a P-40E would need 280' of deck against a 25kt wind. Ranger's CO conducted his own tests before the mission and found it took 390'; and in the first actual fly off in May 1942 off Ghana (to ferry the a/c on across Africa) some of the Army pilots barely made it though actual wind over deck was 35kt. The Army pilots hadn't had any special training; this would clearly make a difference, too. The P-40's flew off Ranger with 100 gals of fuel and half ammo.

Of course, 700+ RAF Hurricanes and Spitfires flew off RN carriers (and USS Wasp) to supply fighters to Malta prior to late '42 when they started flying all the way from Gibraltar. Again though that was with significant wind over deck, and special measures (like mounting wooden chocks to hold a Spit's flaps half open, allowed to fall out by fully deploying then closing them after takeoff). Those a/c had (usually non-jettisonable) long range tanks though often no ammo. In a couple of cases mechanical aborts managed to land back aboard without arrester gear, which was also feasible for typical WWII fighters, again assuming fairly big carrier with clear deck, goodly amount of wind over deck, and a reasonably skilled and/or lucky pilot.

Joe

 

[renrich]

I believe also that land based Hurricanes landed successfully on a British carrier during the campaign in Norway. However, few, if any, aircraft designed initially for land based use during WW2 could really be made into rivals for the aircraft purpose built to be carrier borne.

 

[davebender]

The Spitfire was a relatively light aircraft with a relatively high power to weight ratio. That helps a lot.
Spitfire Vb
Supermarine Spitfire - Wikipedia, the free encyclopedia
6,622 lbs Loaded Weight.
.22 hp / lb

As opposed to this monster which weighed twice as much and had a lower power to weight ratio yet still managed to take off from a CV.
F6F-5 Hellcat.
Grumman F6F Hellcat - Wikipedia, the free encyclopedia
12,598 lbs Loaded Weight.
.16 hp / lb.

How about this aircraft which weighed 3 times as much as a Spitfire, had half the power to weight ratio yet still managed to leave the deck.
TBF Avenger
Grumman TBF Avenger - Wikipedia, the free encyclopedia
17,893 lbs Loaded Weight.
.11 hp / lb.

 

[Shortround6]

The Spitfire was a relatively light aircraft with a relatively high power to weight ratio. That helps a lot.
Spitfire Vb
Supermarine Spitfire - Wikipedia, the free encyclopedia
6,622 lbs Loaded Weight.
.22 hp / lb

Wickipedia:
"Powerplant: 1× Rolls-Royce Merlin 45 supercharged V12 engine, 1,470 hp (1,096 kW) at 9,250 ft (2,820 m)"

If your aircraft carrier was at 9250ft above sea level that might be the correct power figure. then again it might be the combat power rating and not the take -off rating.
Most engines used in Spitfire MK Vs had a take off rating of 1230hp using 12lb of boost.

Other things that affect take-off are the wing loading, the actual co-efficient of lift of the wing (that includes such things as the airfoil and aspect ratio and the actual incidence of the wing at take off speeds among other things) and the contribution of the flaps.

there have also been Navy planes that were allowed higher take-off weights from land than from carriers.

 

[Shortround6]

In general yes, but the B-25's in Doolittle Raid were at a pretty high weight, had various items of equipment removed, but more fuel added. OTOH they had a quite high wind over deck, launched in an area of typically high winds, and in the videos you can see it's a rough sea, with Hornet adding to it by steaming at high speed into the wind. Plus, there was special training, though some of the planes nearly stalled and crashed. A much higher than normal risk was accepted for that mission, all around. However the USN conducted regular carrier qualification trials for the PBJ (ie B-25) later in the war.

there is also the advantage of taking off a number of feet above sea level and being able to trade hight for flying speed. taking off as bow pitches up may help, leaving the bow as it pitches down may not be so good.

In case of Army fighters taking off from carriers, P-40's, P-39's and P-47's all did it, but takeoffs from escort carriers were catapult shots, and in general the intention was just to ferry the a/c to nearby bases on land........ The P-40's flew off Ranger with 100 gals of fuel and half ammo.

Joe

Thank you, that is what I was getting at. The Army ferry mission were not evidence that Army planes could actually perform the same missions from a carrier deck that navy planes could.

 

[fastmongrel]

The topic is a stationary carrier no headwind a lot of aircraft being talked about here are going to really struggle taking off with no wind in less than a 1,000 feet. A biplane could probably get off a WWII flight deck with no wind, aircraft like a P40, Hellcat or a Spit are going to need the entire flight deck and probably a bit more to have a chance.

 

[renrich]

I have read that the TBF, TBM, called the Turkey, was a jewel as far as operating off a carrier. Easy to land and launch. An interesting stat is: Hellcats flew 62240 action sorties from carriers during WW2 and had 321 operational losses and 829 losses on other flights. The Turkey flew 35564 action sorties with 231 operational losses and 339 losses on other flights.

Kind of hard to be sure but it appears that the Turkey was just as safe to operate from carriers as the Hellcat which is counterintuitve.

 

[RCAFson]

I have read that the TBF, TBM, called the Turkey, was a jewel as far as operating off a carrier. Easy to land and launch. An interesting stat is: Hellcats flew 62240 action sorties from carriers during WW2 and had 321 operational losses and 829 losses on other flights. The Turkey flew 35564 action sorties with 231 operational losses and 339 losses on other flights.

Kind of hard to be sure but it appears that the Turkey was just as safe to operate from carriers as the Hellcat which is counterintuitve.

i'm just reading, They gave me a Seafire, by Crosley and he states that a fully loaded Avenger could just barely TO from a 30knot carrier and a 700ft run in windless conditions, without catapult assist.

BTW the data cards at: WWII Aircraft Performance
give the TO run for 20 and 40 knots of effective wind and here a couple of samples:
http://www.spitfireperformance.com/seafirel2cads.jpg
http://www.wwiiaircraftperformance.org/f4u/f4u-1-ads.jpg

 

[renrich]

That sounds reasonable since a fully loaded Avenger weighed a lot and a carrier seldom was called on to make 30 knots and many could not and there were seldom windless conditions at sea.Does not change the fact that the Avenger had the reputation for being a relatively easy AC to operate off of carriers.

 

[davebender]

Other things that affect take-off are the wing loading, the actual co-efficient of lift of the wing (that includes such things as the airfoil and aspect ratio and the actual incidence of the wing at take off speeds among other things) and the contribution of the flaps.

I agree. However there's something to be said for raw power. The Me-109G10 with DB605DC engine weighed 6,834 lbs (loaded) and had 2,000 hp at take off. .29 hp / lb is probably the best power to weight ratio for any WWII era piston engine aircraft. I suspect a skillful pilot could get a Me-109G10 into the air with a very short take off run if he had to.

 

[parsifal]

A stationary carrier suggest to me, no head of steam. no wind at all at sea is an extremely rare occurrence, though it does happen. Except for light aircraft,, choppers and VSTOL aircraft there are no a/c I know of that could manage those sought of conditions. Even with no wind and no catapult most aircraft would struggle.

With a catapult bu no wind it becomes a lot easier, but most a/c would need to take of lightened loads

 

[Shortround6]

I agree. However there's something to be said for raw power. The Me-109G10 with DB605DC engine weighed 6,834 lbs (loaded) and had 2,000 hp at take off. .29 hp / lb is probably the best power to weight ratio for any WWII era piston engine aircraft. I suspect a skillful pilot could get a Me-109G10 into the air with a very short take off run if he had to.

And a Fieseler Storch had a a power to weight ratio of 0.086.

 

[davebender]

With a catapult bu no wind it becomes a lot easier, but most a/c would need to take of lightened loads

That depends on the catapult. Catapult ships operated by Lufthansa during the 1930s were pretty slow. I think they steamed slowly during aircraft recovery and launch only because it was impossible to anchor in mid Atlantic.

History of Air Cargo and Airmail ... - Google Books

The great K6 catapult manufactured by Heinkel was installed in the bows of the ship. It was 40 meters long and capable of launching in two seconds a 14 ton seaplane, with all its engine roaring, at an an initial velocity of 95 mph, by means of a compressed air pump at a pressure of 160 atmospheres.