2006-08-12 03:15:32 · 34 answers · asked by Anonymous in Cars & Transportation ➔ Aircraft
What's the point? it weighs more than 250 tons!
2006-08-13 02:13:07 · answer #1 · answered by Anonymous · 1⤊ 0⤋
It depends upon what you mean by "push start" As has been said in several of the other answers you can not push start a jet on the ground.
But if you have a jet plane that has stalled engines I suppose you could call putting the jet into a dive "push starting" a jet engine.
The principle of the jet engine is to use compressor fans to push air through the engine adding fuel and spark along the way. When the fuel ignites the expansion of the gases powers additional turbin blades which turns into thrust to push the plane forward.
When a jet plane stalls an engine it is usually because it has been in a steep climb and lost much of the feed of air into the engine. By putting the jet into a steep dive the engines get "ram" effect of air being pushed into the engine without the compressor fans doing the job.
So the answer to your question is, yes you could "push start" a jet plane but you would have to be a 40000 feet at the start of the push.
Of course if you are at 40000 feet and loose your engines you best hope the pilot knows his stuff.
2006-08-12 03:36:36 · answer #2 · answered by Waldo 2 · 3⤊ 0⤋
Even if you could it seems like a bad idea, if you have a prop plane you can stand to the side and give it the push to start it. If your trying to do this on a jumbo jet you are inside the engine housing and when it starts would be sucked through. Or if your one of the people actually pushing the plane when the engine comes on you get blown away.
Seems like a bad idea, and I doubt the engineering allows it on a jumbo jet doesn't seem like it would work since a turbine would operate considerably different than a prop I would assume.
2006-08-12 03:21:47 · answer #3 · answered by Kevin S 3 · 0⤊ 0⤋
The nearest you'd come to push starting a jumbo or indeed any jet aircraft is by doing a crossbleed start, which is usually done when the aircrafts Auxilary Power Unit is not working. This basically means that there's no air or electrics to start the aircraft, so you need a ground power unit for electrics and an air cart to get the pressure in the engine up so the turbines start spinning. You'd then use the electrics and air from the running engine to start the next engine.
2006-08-12 20:36:06 · answer #4 · answered by Ray KS 3 · 0⤊ 0⤋
Any other pilots or mechanics, please correct me if I am wrong... This is as simple as I can explain it... When starting a jet engine, the pilot uses bleed air from either a ground APU (auxiliary power unit) or the aircraft's APU to spin the rotors and the fan of the engine. When the engine reaches a certain speed (rpm), fuel is then added into the combustion chamber and ignited. In theory, if you were able to pull the aircraft through the air at a speed where the wind blowing through the engine would spin it fast enough, it may be possible to "push (pull) start a jet engine.
2006-08-12 03:24:46 · answer #5 · answered by jb14022 1 · 1⤊ 0⤋
No. The engines are started with comporessed air that turn a turbine. The turbines must spin very fast before ignition of the air/fuel will result in the engine starting. If you push the Jumbo you will not get enough air flowing though the turbines to creat the required engine speed.
2006-08-12 22:53:35 · answer #6 · answered by Anonymous · 0⤊ 0⤋
JB14022 is quite correct, you can "push start" a jet engine by the aircraft's air speed pushing air through the engine, causing the engine to windmill. The correct term is called an airstart.
These are used probably hundreds of times a year by civil and military jets, after a flameout. And yes a Quantas 747 used this method after suffering flameouts on all 4 engines, after flying through through a cloud of volcanic ash.
They were down to about 6000 feet by the time they got all four turning and burning, so it was fresh underwear all round on that flight deck.
2006-08-12 06:59:34 · answer #7 · answered by Anonymous · 0⤊ 0⤋
like the finest solutions, jumbo jets do no longer use gas, they use kerosene, a more cost-effective and a lot less subtle product compared to gas. Jet engines can run on something that burns and creates warm gases, like bio fuels AND gas (besides the undeniable fact that they could truly no longer). besides the undeniable fact that, different gas elements boost the probabilities of an engine flame out (the position the engine's flame holder receives positioned out and the engine stops generating thrust), and would create unexpected upkeep complications. Jet gas is the optimal gas source for jet airplane right now and it isn't going different elements of gas will be used contained in the close to destiny.
2016-11-24 21:34:25 · answer #8 · answered by kinnu 4 · 0⤊ 0⤋
No. You can push start a car because the wheels transfer their motion to the engine via gearbox thus obviating the start mechanism.
In any Jet plane, there is no conection between wheels and engines, and so, it cannot be push-started.
2006-08-12 18:07:46 · answer #9 · answered by Pablo 6 · 0⤊ 0⤋
As many have indicated, turbofan engines can be re-started in flight following a flameout or precautionary shutdown, when no fire or apparent damage has occurred.
The air moving through the engine turns the fan/compressors, thereby allowing it to be re-started.
They can not be push started though.
2006-08-12 19:18:56 · answer #10 · answered by d_robertson744 2 · 0⤊ 0⤋
With reference to the reply from Tinkicker0 - I believe it was a British Airways 747, and they managed to restart only 3 engines. I think it was in 1982.
Look online for the official report of this incident - very interesting reading!
Also, the captain's initial announcement to the passengers was something like 'Ladies and gentlemen, we have a slight problem at the moment.... we are doing our best to fix it......I will come back to you shortly.....'
Also, take a look at www.aaib.gov.uk
2006-08-13 02:29:12 · answer #11 · answered by aarcue 3 · 0⤊ 0⤋