Ever since the Wright brothers used a falling weight from a tower to accelerate some of their early aircraft on takeoff when winds alone were not enough, the need to apply external energy to achieve flying speed has been recognized and pursued in different ways. The Wright’s device was an early form of a catapult, a system much-modified and used by aircraft carriers still.
But another takeoff booster found favor because it could be attached to many types of aircraft and did not require a modified runway or takeoff surface. Commonly known as JATO, for jet-assisted takeoff, it is also called RATO for rocket-assisted takeoff. You get the idea from either acronym — a special thruster helps accelerate the aircraft to give it flying speed more quickly.
The applications for JATO appealed to aeronautical planners. In Germany, the huge Me 321 transport, fully loaded, lumbered along too slowly for too long to achieve takeoff in the usable length of the airfield unless add-on rocket boosters could accelerate the beast. Seaplanes could get unstuck from the surface of the water more quickly.
And C-130 Hercules transports could operate from short or high-altitude airstrips with the boost provided by attachable JATO bottles.
The dawn of JATO coincided with World War II. While many aircraft were tested for JATO compatibility, it was not commonly used on most of them.
The British made limited use of a rocket bottle attached to a Hawker Hurricane, mounted on some convoy freighters and launched at the sight of German anti-convoy bombers. The spent booster rocket fell to the sea, and the Hurricane could hopefully fly to land or ditch nearby so its pilot could be rescued by the convoy.
The notoriously slow acceleration of early jet engines gave the designers of Boeing’s revolutionary swept-wing B-47 Stratojet cause to employ JATO to help heavy B-47s quickly reach flying speed. Early B-47s were built with an internal JATO system with 18 nozzles pointing aft; others used 30 or more attachable external rockets that could be dropped when spent.
Boeing also made provision for JATO use with the 727 trijet airliner, a feature that could be important in high altitude airfields with high density altitude.
During the Cold War, the United States tried creative ways to keep a nuclear reaction force viable in Europe in the face of a possible Soviet strike that could render runways unserviceable. The American answer was ZELMAL — Zero-length launch, mat landing.
It started with tests at Edwards Air Force Base with a trailer-mounted F-84 Thunderjet propelled to flight speed by a large booster rocket. Presuming runways would be unusable, the modified F-84 was intended to land, wheels up, on a portable rubber mat. The ZEL part worked; MAL, not so much, with a test F-84 bouncing off the mat and onto the ground beyond in a filmed test.
The concept matured with the potential to launch a nuclear-armed F-100 Super Sabre with a rocket booster from a standing start — just the ZEL portion. This time, the plan called for the F-100 pilot to deliver a nuclear weapon on target and then fly back to friendly territory and bail out.
West Germany explored ZEL with an F-104G tested at Edwards AFB and the Soviets tried it with the MiG-19. But ZEL remained an exhilarating test, not an operational reality.
The availability of missiles and V/STOL aircraft helped make ZEL obsolete. Improvements in engine performance generally reduced the need for JATO in other operations.
For many years, the U.S. Navy Blue Angels’ support aircraft, a C-130, made a spectacular JATO-assisted takeoff during team performances at air shows. But as the last stockpile of JATO bottles was depleted, the JATO demonstrations concluded in 2009.
More JATO Photos
Also, great article and I really enjoyed the photos!
IIRC JATO was offered by Beech on the Model 18, and QueenAir for a while.
A rocket was also installed on early Swearingen Metroliners to enable a sufficient single-engine climb gradient during gear retraction, as the Garrett engines used didn’t have enough power. Airplanes so equipped (Metro 1’s and some II’s) had a slightly larger tail cone.
As higher powered Garretts became available, the systems were deactivated. A friend that flew the early planes said that the one time he tried to fire the bottle (en route to maintenance) it didn’t work anyway…:)
Good times…
Here is a photo of a Navion with a JATO. Previously I found an advertisement where the company in San Diego was going to market these to the public pending approval by the defense department. That never happened as the defense department deemed it a threat to National Security. The were also testing it on the Ercoupe in the pictures if I remember correctly.
https://www.flickr.com/photos/sdasmarchives/5684470557
In the 80’s At Airborne Express (ABX) we operated two DC9-30 freighters with JATO. They were armed according to takeoff data requirements to be used between V1 and 400′ AGL so as to allow a higher TOGW while meeting second segment climb requirements at higher elevation airports like DEN.
There was never an actual JATO firing required.
I wanna see the ercoupe with JATO!
[Hangar Flying] JATO-powered Ercoupe
That was the link I clicked on! Come on Guys!
Me too! Where is the JATO Ercoupe?
In the early ’70s I flew right seat in Howard 500, a rare beast. It carried 2 JATO bottles to use if needed if an engine was lost. On the glare shield we had two large red buttons (one for each engine). In an emergency mashing the button would shut off fuel to the engine, activate the fire suppression system within the cowl, maybe a few other things, including arming the JATO bottle on that side, did not ignite it though.
Thankfully we never had to use it. Soon after we got the plane the FAA had us remove the system.
When I was 6 years old in 1955 my father worked for Boeing Aircraft in Wichita, Kansas. That year he volunteered to work on a team that went from airbase to airbase modifying the B-47’s. My father took the family with him. We lived in a mobile home and I went to a different first grade school at each airbase while the team made their modifications.
Years later I asked him what modifications they made. He told me they added the JATO system to the existing B-47’s. He went on to say that the big draw-back to the JATO system was that the weight of the JATO’s left on board the aircraft was excessive, so the engineers went back to the drawing board and devised a way to jettison the spent JATO’s after take-off. Then they discovered a problem with jettisoning the spent rockets. The aerodynamics of the jet caused the jettisoned rockets to flip up and damage the tail of the bomber. Therefore, the JATO system was abandoned.
My father spent most of his career working for Boeing in Wichita. One of his co-workers had been at Boeing since the post-WWII era. Apparently, there were some amazing stories from the early days of the JATO modification work in Wichita. My dad’s friend described nearly burning the tail off of their testbed aircraft on one of the early flights.
Once ignited, there was no way to shut off a JATO bottle. They burned until the fuel was expended.
My favorite story was about when a bunch of the Boeing workers took a JATO bottle to the local oval racetrack and attached it to a car. This was someone’s bright idea to set a new lap record.
My dad’s friend was volunteered to be the driver. After barely surviving the experience without crashing the car, he was thronged by onlookers. They thought his run was the most amazing spectacle ever. He told them he had never been so terrified in his entire life (and he had survived Pearl Harbor). As soon as the JATO bottle ignited all he could think about was trying to maintain directional control of the car so that it didn’t launch straight into the stands. They asked how much throttle he used, and he replied that he had both feet on the brake immediately following ignition. Absolutely crazy.
I believe this article, and some of the comments, incorrectly interchange the terms JATO and RATO.
Most of the examples given, including the historic Ercoupe flight, were, in fact, Rocket Assist Take Off (RATO), not JATO (Jet Assist Take Off).
More than a matter of semantics.
Despite all the bottles in essence being what we now typically call rockets, they were collectively referred to as JATO. None of them were ever truly jet powered in the truest sense of what we now call a jet engine. Let’s not forget the earliest examples of JATO were used on propeller driven aircraft before the average pilot even knew what a jet engine was, and perhaps the first JATO were named as such due to the hot jet of gases that came out of the JATO bottle.
There was also an Ercoupe which had a JATO bottle fitted to it. That must have been a wild ride indeed. Under the theory that if some is good, more is better, a few more JATO bottles would likely have resulted in the world’s only swept-wing Ercoupe. I’d sit this one out and watch from a safe distance . . .
Fred good article, but don’t forget the general aviation connection in that the first JATO flight in the US was on an Ercoupe in 1941.
The concept of JATO started as a USAAC study conducted with CalTech’ Jet Propulsion Laboratory (then known a GALCIT)to develop a method for shortening take off distance. The first aircraft on which a solid rocket was tested was an Ercoupe. Testing occured at March Field in 1941.
The reason for using an Ercoupe was the construction of the fuselage. Very strong little plane and very stable with a high degree of dihedral. Great plane!