Can airplanes fly with engines shut off at high altitudes?

Answer 1

Yes! Most aircraft can continue to fly without engines. The Space Shuttle is an excellent example. Every re-entry is unpowered; it quite literally glides in from outer space without any power at all.

Nearly every aircraft has a glide ratio. (The F-4 fighter is a notable exception; it's a sewer cover without power.) For example, a 747 Jumbo Jet has a glide ratio of 15:1. This means that without power, it can travel 15 miles for every mile of altitiude so at typical cruise altitude of 35,000 feet (a bit over 6 1/2 miles) it can travel about 99 miles. By comparison, the Space Shuttle's glide ratio is a measly 1:1 and we manage to get it on the ground safely every time; the two Space Shuttles lost to date had nothing to do with glide issues.

So, if you should find yourself in a 747 over the Continental US that loses it's engines you can rest fairly easy as there's probably a suitable airport within a 100 mile radius of nearly every point along the route of flight. Landing it without engines does take some skill but most senior pilots could do this without too much difficulty at all.

Although the air density at altitude is low, this won't impact the aircraft's ability to glide. It does come into play trying to restart the engines using a technique known as an air start. That uses the air rushing through the engine to spin it up to sufficient speed for a normal start. At altitide there won't be enough air but as altitude declines it is very possible to restart the engines, assuming that all other systems are operational and there is enough fuel on board. If the engines flamed out due to fuel mis-management, an air start is a virtual certainty once a tank with fuel is selected and altitude drops below about 20,000 feet or so.

I experienced this exact situation back in 1983 on a military charter DC8 enroute to Tokyo, Japan. At about 100 miles from Tokyo, just before we started our initial decent, all 4 engines quit due to fuel mismanagement. While the cabin staff prepared everyone for the worst, the cockpit crew trimmed us up for max glide and went about trying to restart the engines. They assured us repeatedly that they could restart the engines but even if they couldn't we had enough altitude to make it to Tokyo safely. After about 20 minutes (which seemed like 5 hours!) they actually did get a successful engine start and we landed uneventfully. We wound up spending the night in Tokyo as they inspected the aircraft (and probably replaced the cockpit crew) and continued on to Korea the following day. At least one atheist on board got religion that day.

Additionally, there are aircraft that don't have any engines at all. For pretty obvious reasons they're called gliders. A typical glider has a glide ratio of around 40:1. They're towed up to about 5,000 feet or so by a tow aircraft and released. By riding the thermals, a skilled glider pilot can fly quite a bit higher, the record currrenty is 49,009 feet! Steve Fosset will attempt to smash that record in a few days in New Zealand with an attempt at 62,000 feet.

Answer 2

1. It would gradually descend as long as the pilot kept sufficient air speed to keep it from stalling (the point at which there isn't enough air moving across the wing to keep it flying) 2. The rate of decent depends on the aircraft, altitude, weight, and speed. I'm not sure of specific decent rates for different aircraft, but say it was 15:1. That would mean the aircraft would move 15 feet forward for every 1 foot it dropped. 3. You wouldn't have the sensation of falling. After the initial drop from level flight into a decent, it would be at such a shallow angle it would once again feel like level flight. 4. Most larger aircraft are equipped with an APU, or Auxiliary Power Unit. However, the APU is essentially a small jet engine, which, to my understanding, is fed from the mail fuel reserves, meaning a dry tank would render it inoperable. There are certain aircraft, such as certain Airbus models, I believe, that have an emergency APU, which is, in essence, a small windmill that can be extended from underneath the fuselage and generates a very small amount of power which can be used for cockpit lights and hydraulic controls. This, obviously, can only work while the aircraft is in motion, and would not be able to supply enough power for the pressurization system. The pressure would slowly return to the atmospheric pressure at altitude. The pilots would need to descend to a certain altitude in a certain amount of time before the entire cabin depressurized. The oxygen masks are set to deploy after the cabin pressure falls below a certain PSI, so depending on how quickly the pilots descended, it is possible oxygen would be deployed. 5. If I didn't answer it thoroughly enough in 4, cabin pressure is maintained by an air compressor which is either powered by the main engines or the APU, and pressurizes the cabin to around 8,000ft on most commercial flights above 10,000ft. Without power from the engines or APU, the generator cannot run and will consequently lose pressure. 6. Turbulence is a pocket of disturbed air. It can be caused by numerous things such as jet wash from another aircraft or atmospheric pressure changes.

Answer 3

Yes,even if the engines shut off at a high altitudes,airplanes can fly but without control over it as the gravitational control is over when the airplanes are out of orbit.

Answer 4

Yes it can. Because the air is the most important energy that makes the plane fly. At high altitudes, the air could still make the plane move without using the engine! So therefore, the air could still make the plane move! Let's say you fly in a rocket ship. It glides into the air even though it doesn't have the engine on. But planes can't do this at 90,000 feet since it is too high and has a small volume of air.

Answer 5

The engines of the airplane provide thrust, which lifts the craft and propels it forward, as air rushes under its wings. If the engines are off, the planes can glide, but it will constantly be losing altitude. Eventually in order to clime, or maintain altitude, the plane needs power from its engines.

Answer 6

No , The Density of Air At High Altitudes is very low, so its difficult to get a lift for the airplane without an engine.

Answer 7

to piggy back on a story above:

there were plenty of times where SR-71s (that real fast aircraft) would have engine shutdowns at 80 thousand feet..call the control tower at Beale AFB..tell them they had an engine out over Oklahoma...and glide in to Beale.

The U-2s would sometimes have engine shutdowns..and have to glide out of enemy held air space. but they were designed to do that, as they have a high lift wing much like a gliders.

so the answer is yes. there is also a large semi powered glider in the works that will glide most of the time at high altitudes also.

Answer 8

Yes. All planes can glide pretty well because that is the principle behind flight. But the weight of the aircraft is a big factor in gliding. And moreover the 747's of today couldnt make it without the gauges and everything they have on them. They are fed continous data. It's like babysitting...

Answer 9

They become gliders. Some aircraft deploy a ram air turbine to generate some electrical and hydraulic power for controls. But they lose altitude as they glide.

Answer 10

Yes, aircraft are designed that way---so that they can glide during an emergency or during a routine practice (new pilots do it as practice).

But the glide slope will be very steep due to increased {drag & gravity} & {zero thrust hence reduced Lift}...except in a glider (airplane without engines).