aircraft minimum take off distance for carriers

[mike siggins]

does any one know the shortest distance a fighter could get off the deck

 

[tyrodtom]

The aircraft carrier turns into the wind, and is moving itself too.
A 10 knot headwind, and the 15-20 knots of the carrier would significantly affect takeoff distance, as would what particular fighter we're talking about.
Also it's takeoff weight has a big affect also, air temperature, etc.
A lot of variables.

 

[beitou]

Off hand have a look and see what the take off distance for the first B25s to launch on the Mitchell raid were, they must have been pretty tight. Opps you did say fighters, sorry Friday night and beer. Or the first experiments from gun turrets in ww1, they must have been in the 10s of feet.

 

[swampyankee]

Minimum? Zero, obviously. There have been VTOL fighters in service, like the Sea Harrier in the Falklands. They could take off vertically, although whether or not they ever did so is a separate question.

 

[beitou]

Minimum? Zero, obviously. There have been VTOL fighters in service, like the Sea Harrier in the Falklands. They could take off vertically, although whether or not they ever did so is a separate question.

Sea Harrier undoubtably did take off vertically in exercises and trials from carriers and "through deck cruisers" but not in the Falklands. Ski jump take off and vertical landings.

 

[Shortround6]

Off hand have a look and see what the take off distance for the first B25s to launch on the Mitchell raid were, they must have been pretty tight. Opps you did say fighters, sorry Friday night and beer. Or the first experiments from gun turrets in ww1, they must have been in the 10s of feet.

Something like a Sopwith Pup, Put pilot in cockpit, head into the wind and untie it..........don't forget to start engine

Wingloading of about 5 lbs per sq ft.

 

[N4521U]

Better get airborne before the enf of the deck!

 

[swampyankee]

Better get airborne before the enf of the deck!

The plane will be airborne after the end of the deck, but it may not remain so for very long.

 

[mike siggins]

I just remember hearing of p47s and p51 having a long run to get off the ground

 

[Shortround6]

They do. See:

12,500lb P-47 with 40mph head wind needs 900ft of runway/flightdeck at 0 degrees C. Now if you leave 100-150 gallons of fuel out and don't put in any mg ammo (or even leave some of the guns out) you may get it down to 700ft or less and get the deck cargo (stripped P-47s) ashore where they can be rearmed and fully fueled. Please note that they can trade 50-70 ft of altitude for more distance to get up to flying speed when taking off the carrier deck.

Getting of the carrier deck in "ferry" mode in no way implies that the airplane could operate from a carrier in combat mode.

Thanks to Zeno's http://www.zenoswarbirdvideos.com/ for the chart.

 

[nuuumannn]

Harriers never took off vertically with a warload for a few reasons. There were restrictions on the load that could be carried vertically due to limited fuel and also water methanol. The earlier Harriers had a 50 lt water meth tank aft of the engine, which its contents were injected into the turbine section to expand the gases escaping the hot section. This was essential during vertical operations. There was also erosion from jet blast that damaged external stores and a heavier load could be carried by a rolling take-off. On vertical landing, Harriers were expected to release their external load before doing so to avoid incidents and it also reduced landing weight.

Regarding Pups etc; Frederick Rutland demonstrated that he could get a Sopwith Pup airborne from a standstill on a cruiser's flying off platform in less than 15 feet. The Royal Navy installed fixed flying off platforms on cruisers' forward superstructure, then on the main gun turrets of capital warships, which enabled aircraft to get airborne whilst the ship was heading in a particular direction, by rotating the turret into wind. Bernard Smart shot down a Zeppelin flying a Pup from the platform of the cruiser HMS Yarmouth, the first to be so converted. There was also destroyers that towed lighters with flying off platforms, in 1918 Stuart Culley shot down a Zeppelin in a Camel after launching from a towed lighter behind the destroyer HMS Redoubt. Again, the length of run was around 15 feet with the destroyer doing high 20s kts.

 

[yulzari]

There are recorded instances of Swordfish having difficulty catching up with a fast fleet carrier in a high headwind so the minimum take off distance would be nil. In fact, on a platform above the deck wind shear, it could, in principle, take off backwards were the carrier at maximum speed and the wind at gale force so the answer to your question could be a negative distance.

With a lightly loaded Swordfish you essentially have a 3 man 2 tonne kite.

Seriously though, you have to start with which aeroplane, what load, what headwind speed and what carrier speed to make a calculation. Now factor in the frequency and amplitude of deck pitching, height of swell and at what point in that pitching you release the aeroplane. So sometimes a given carrier could get a Lancaster off the deck and sometimes it would be hard put to get a Gladiator into the air. Hence the Admiralty specified minimum acceptable conditions to the manufacturers who could then make their designs take off in such circumstances.

Imagine a seaborne runway which has a mild swell with short wave length. If you begin the take off just as the runway is downhill all the way you will arrive at the end with extra speed and still able to climb above the sea rising in front of you. Now imagine the same with a very heavy long swell. Set off at under the same circumstances and you still leave the runway at extra speed but, sadly, fly straight into the wall of water in front of the vessel.

Another set of circumstances is the reverse, so you arrive at the end of the deck at slower speed (as you have climbed uphill) but the sea is far below you. This lets you continue to accelerate to flying speed after you have dropped off the deck at too low a speed to even maintain height. Or, sadly, not if your acceleration is too slow.

Also the wind conditions that might let a heavy aeroplane lift off a small carrier are likely to be the same ones that would wash aeroplane, flight and groundcrew straight off the deck.

A practical extreme minimum is the turret platforms referred to above or the destroyer towed lighters that the RNAS used to launch 2F1 Sopwith Camels in the North Sea in 1918. The opposite extreme are super carrier decks nearly a 1/4 mile long and powerful steam catapults.

 

[Jabberwocky]

As already indicated, take-off roll depended on quite a few variables: Headwind and carrier speed, air temperature, aircraft weight/load out and flap setting are the main ones I can think of.

For example: According to the USN, an F6F-5 at 12,750 lb will need roughly 300 ft to take off into a 25 knot (29 mph/45 kph) headwind. With no headwind, it will need about 650 ft. On land, it will need about 800 ft.

For lighter aircraft, the difference is even greater. An F4F-4 will need about 250 ft with a 25 knot headwind, but 680 ft with no headwind. With full flaps, the same aircraft will only need about 215 ft into the headwind, and about 630 ft wihout.

The Fleet Air Arm's F6F's data sheets show how much weight and headwind can affect take-off distance.

F6F-5 at 11,800 lbs:
40 knot headwind: 180 ft
30 knot: 300 ft
20 knot: 435 ft

F6F-5 at 13,200 lbs:
40 knot headwind: 295 ft
30 knot: 450 ft
20 knot: 630 ft

Just from some quick research, the shortest take-off roll I've seen for a fighter is for the Seafire Mk II, with 140 ft into a 40 knot headwind, or 225 ft at 30 knots or 330 ft at 20 knots.

I've seen the F8F quoted as 150 ft take-off roll, but without any indication of wind/loading conditions.

 

[fastmongrel]

Cant find any figures but I have seen a video on youtube of Zeros taking off. It looked a very short run the tailwheel was off the ground in what looked like about 2 aircraft lengths and the main wheels in about another 2 or 3 aircraft lengths so I am guessing 120 to 150 ft.

 

[Greyman]

More data sheet figures ...

Fulmar II
20-kt wind = 420 feet
30-kt wind = 260 feet

Sea Hurricane
20-kt wind = 400 feet
30-kt wind = 270 feet

Seafire Ib
20-kt wind = 410 feet
30-kt wind = 275 feet
40-kt wind = 170 feet

Seafire IIc (merlin 45)
20-kt wind = 410 feet
30-kt wind = 280 feet
40-kt wind = 170 feet

Seafire IIc (merlin 32)
20-kt wind = 330 feet
30-kt wind = 225 feet
40-kt wind = 140 feet

Seafire III (merlin 55)
20-kt wind = 375 feet
30-kt wind = 260 feet
40-kt wind = 160 feet

Seafire III (merlin 55m)
20-kt wind = 330 feet
30-kt wind = 230 feet
40-kt wind = 140 feet

Firefly I
20-kt wind = 490 feet
30-kt wind = 330 feet
40-kt wind = 195 feet

Firefly III
20-kt wind = 425 feet
30-kt wind = 290 feet
40-kt wind = 180 feet

 

[swampyankee]

The OP asked the shortest distance a fighter could get off a carrier (?) deck; certainly a VTOL fighter, like the Sea Harrier could take off in zero-distance, and probably did do so during flight testing. So could some of the early biplanes, which could have stall speeds as low as 25 or 30 knots, so they could take off vertically from a fast ship, like HMS Furious or USS Lexington, especially if the ship is heading into any kind of a wind.

Whether any of these aircraft could do so in a militarily useful condition is a second question. As mentioned above, RN practice was that Sea Harriers would make a rolling take-off.

 

[beitou]

Out of intrest does anyone know the distance the first Doolitle raider had to get airborne?

 

[FLYBOYJ]

Out of intrest does anyone know the distance the first Doolitle raider had to get airborne?

Under 450'

 

[nuuumannn]

So could some of the early biplanes, which could have stall speeds as low as 25 or 30 knots, so they could take off vertically from a fast ship, like HMS Furious or USS Lexington, especially if the ship is heading into any kind of a wind.

In theory, yes, I guess so. During Rutland's initial proving flights using Pups firstly from the seaplane tender Manxman on 27 June 1917, his report claims an airspeed over the deck of 19 knots, the deck space being 15 ft 6 in, of which he did not comment how much of this he used. From the cruiser HMS Yarmouth's foc'sle deck on 28th June the airspeed was 26 knots and Rutland covered 14 ft 9 in of deck before he lifted off - 4 ft 6 in from the end of the deck.

As for vertical take-off operations, it was decided from very early on during concept testing using P.1127s that rolling take-off were better for reasons mentioned earlier, despite the recognition of the flexibility of a vertical take off. The P.1127 test bed carried out its first rolling take offs in October 1961. The first P.1127 to go to sea went in February 1963 aboard the carrier Ark Royal and vertical take-offs were carried out, this was in support of the navy's proposed P.1154 supersonic V/TOL aircraft that was eventually cancelled, but these were demo flights only. The ski ramp idea for ships was first proposed in 1972 and in 1977 Harriers were carrying out trials using the ski-ramp. Operationally, Sea Harriers did not carry out vertical take-offs, nor did/do Marine Corps AV-8s.

 

[VBF-13]

The height of the decks makes a difference, too. Watch the pictures. The less wind in their face, the more they're inclined to drop. Some of the accidents in Lake Michigan happened for that precise reason. The bigger the carrier, the more room for error.