there is a rule that for every 1,000 ft in elevation, the plane can glide for 10 mi?

Question

When airline pilots travel over water, they
say to each other "we have now reached our
point of no return."

But mathematically, if a commercial jet
flies 45,000 ft, it should be able to glide for
450 miles......or is it 45 miles?

how does one fly safely to Hawaii--2600 miles out?

Answer 1

That would be a 52,800 ft glide with a 1,000 foot loss of altitude or a glide ratio of 52.8 to 1 if you are using statute miles instead of nautical miles

Your 45 mile glide would be more realistic for an airliner.

Some examples
A Cessna 150 has a 7:1
Sailplanes as high as 60:1
Fabric hang gliders average about 12:1
Paraglider 9:1
Airliners about 17:1
The space shuttle about 1:1

The point of no return would depend on wind speed and direction; the heading the aircraft would have to take; and the nearest runway the aircraft could safely land

Answer 2

Airliners typically glide very well, though not that well. A handy rule-of-thumb is 12:1. For every 1 foot of altitude lost, the airliner can glide forward about 12 feet.

Aircraft that operate over the ocean are required to be certified under a program called ETOPS (Extended Trans-oceanic Operations) where the engines must have a proven track record of reliability, the aircraft will not be operated more than a certain distance from shore, and additional survival equipment is carried on board.

A point-of-no-return is simply a point where if one engine fails, it is shorter in point of time, to continue to the other side than to return back to base. It varies depending on wind and altitude of course.

If a commercial jet is at 45,000 feet and happens to have a dual, simultaneous, engine failure (EXTREMELY unlikely) they could probably glide about 540,000 feet. Thats about 102.27 miles. They glide fast so it wouldnt take long to cover that distance, but they would be able to glide it for a while. However, having 2 turbine engines fail at the same time is so extremely rare I can't imagine it happening. the only case in recent history is the A-300 where the pilots accidentally pumped all their fuel overboard and flamed both engines out. They then had to make a glide onto an airstrip ion the middle of the Atlantic. Airbus has since re-written their emergency checklists so pilots don't do this any more.

This is actually the story the guy above my post is referring to. the pilots were complete morons and pumped their fuel into the ocean. They never stopped to think about WHY they were burning so much more fuel than predicted, but they were able to glide onto a runway and nobody was injured.

Answer 3

So you know that it CAN glide but I think your question is still open. Yes, a jetliner can glide but with a complete loss of power, it becomes very difficult towards the end. If you have no electronic backup to support the actual necessities to guide the plane, you're in trouble. You can reduce speed by taking the nose up or add speed by nose-diving. You can lower the undercarriage to slow down. You can do several things but with no power at all, nothing AT ALL, it's difficult to set the flaps, to deploy slats, to move the elevators, to do anything. The lower you get, the less you can control it because at one point, the weight of the plane will make it fall out of the sky if the speed is too low. That was the problem of the poor crew who tried the ditching on the Comoros. They ran out of fuel, hence out of power. The aircraft was not manageable anymore once it was so low. They could have avoided the banking which caused the left wing touching the surface of the sea, had they had any power left. But without power, there was nothing they could do. So to your question: a jetliner can glide but it's extremely difficult to make it parading in and do a point landing.

Answer 4

Typical glide ratio of a commercial airplane is about 16 or 17 to 1. So, for every 1000 feet of altitude it can glide about 3 miles. From cruise altitude that gives a glide range of roughly 100 miles (with no allowance for airport area maneuver.

Point of no return doesn't refer to engine out glide. It is the point at which, in case of emergency, it is better to either divert to an alternate or continue to the destination rather than returning to the origin airport.

Answer 5

no not 2600 !!! thats way to much you get about 3 miles of glide per 1 mile of alltitude.....no pilots dont say here we are no point of return because the aircraft will still operate on one engine. The chance of both engines or 4 on a 747 is the the chance that a deer will come flying through your front window dressed in a santas suit and give you fruit cake ..... your safe

Answer 6

The glide ratio for each aircraft is different, and differs for the weight at the time of engine loss. For example, a King Air will glide approx. 2NM per thousand feet at it's best glide speed. This may be 2.2NM light or 1.8NM if heavy. Other aircraft have much different performance envelopes. A heavy, swept wing transport may get 1NM per thousand feet.

A point of no return is the point at which, if you go farther, you don't have enough fuel to go back. This doesn't happen much now, as flight plans are plotted on a great circle route in most cases with diversion airports carefully analyzed for suitability and weather conditions.

As far as a flight to the islands, the weather at the destination, and an alternate must meet FAA guidelines and fuel must be loaded such that if one field goes down, you can get to another. When I flew into Iceland in the service, our minimum "on top" fuel was such that, if we couldn't get into Keflavick, we had enough gas to get to Scotland and shoot multiple approaches to land.

Answer 7

There is no such "rule" and the 3 to one rule of thumb mentioned in another answer is NOT a power-off glide ratio. The "point of no return" refers essentially to the fact that there is not enough fuel to return to the departure point or to some specified en-route diversionary point. It is not related to glide ratio. And please stop referring to airliners as if they are the only jets in the sky. I have flown private jets at 45,000 feet, but there weren't any airliners up there. They're usually lower. Indeed, most if not all have ceilings well below 45,000.

Answer 8

The following story will enlighten you.

A Canadian airline en route from Toronto to Portugal (I think) completely lost/ran out of fuel about 60 miles from the Azores (again I think). Miraculously, they had asked to be diverted 60 miles to the south of their filed route. They were granted permission and this was probably what saved them.

They glided in for a very hard landing. It was an emergency landing that made aviation history. I believe it was the second officer's first trip with the airline.

If you google this, you will find it fascinating reading.

Answer 9

To the best of my knowledge, "point of no return" refers to fuel consumption. Also, every aircraft type has its own glide ratio. For instance, a Lear Jet drops like a rock. No way will it glide for ten miles from an altitude of one thousand feet.

Answer 10

The "Point of No Return" is that point in the flight when you don't have enough fuel to make it back to the place where you started. It has nothing to do with glide angles or aircraft emergencies.