JATO

JATO (acronym for jet-assisted take-off), is a type of assisted take-off for helping overloaded aircraft into the air by providing additional thrust in the form of small rockets. The term JATO is used interchangeably with the (more specific) term RATO, for rocket-assisted take-off (or, in RAF parlance, RATOG for rocket-assisted take-off gear).

Early experiments using rockets to boost gliders into the air were conducted in Germany in the 1920s (Lippisch Ente), and later both the Royal Air Force and the Luftwaffe introduced such systems in World War II. The British system used fairly large solid fuel rockets to shoot planes (typically the Hawker Hurricane) off a small ramp fitted to the fronts of merchant ships, known in service as Catapult armed merchantmen (or CAM Ships), in order to provide some cover against German maritime patrol planes. After firing, the rocket was released from the back of the plane to fall into the water and sink. The task done, the pilot would fly to friendly territory if possible or parachute from the plane, hopefully to be picked up by one of the escort vessels. Over two years the system was only employed nine times to attack German aircraft with eight kills recorded for the loss of a single pilot.

The Luftwaffe also used the technique with both liquid-fueled units made by the Walter firm and BMW — and solid fuel, themselves made both by the Schmidding and WASAG firms — as both firmly-attached and jettisonable rocket motors, to get airborne more quickly and with shorter takeoff runs. These were used to boost the takeoff performance of their medium bombers, and the enormous Gigant, Messerschmitt Me 321 glider, conceived in 1940 for the invasion of Britain, and used to supply the Russian front. The enormous Me 321s originally had air tow assistance from up to three Messerschmitt Bf 110 heavy fighters in a so-called Troika-Schlepp arrangement into the air with loads that would have made the takeoff run too long otherwise, but with much attendant risk of aerial collision from the trio of vee-formation Bf 110s involved in a simultaneous towplane function. This became especially important late in the war when the lengths of usable runways were severely curtailed due to the results of Allied bombing. Their system typically used jettisonable, self-contained Walter HWK 109-500 or -501 Starthilfe ("takeoff-help") liquid-fuel monopropellant rocket engines driven by chemical decomposition of "T-Stoff", essentially almost pure hydrogen peroxide, with a Z-Stoff catalytic compound.

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