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I understand this may be a dumb question to ask, but - in the opening sequence of Golden Eye - James Bond chases after a plane that has rolled off the side of a cliff in his motorcycle, and then somehow (movie magic) climbs into it and pilots it away.

I am not asking about the physics of the motorcycle stunt - except keeping it to the aircraft part:

Is this something that can happen in real life - that is, an elevated airfield so short, that the plane has to "fall" to obtain enough speed to gain lift?

Has something like this ever been attempted, even if simply as an exercise in flight dynamics?

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We're looking for long answers that provide some explanation and context. Don't just give a one-line answer; explain why your answer is right, ideally with citations. Answers that don't include explanations may be removed.

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Perhaps a more realistic scenario would be launching a plane from an airship. – tas Jan 24 at 9:27
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There are birds - fulmars and probably albatrosses - that cannot take off from flat ground. (Or flat water in the absence of wind and waves) They nest on high cliff ledges and this is their normal mode of takeoff. Imagine the chicks who have one chance to learn to fly! – Brian Drummond Jan 24 at 15:11
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@JonathanWalters I meant with a pilot in command and not superman-ing their way into the cockpit like everyone's favorite spy. – Burhan Khalid Jan 24 at 15:17
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Pilots, if I'm not mistaken hang-gliders do this every single time, right? It's more a matter of scale. For a hang-glider you need only a small amount of forward speed to achieve this, and then use the added speed of the fall to achieve flight. For a large aircraft, you'd need more "starter speed" to make it work, and not just messily tumble in to the cliff. That seems to be all there is to it. – Joe Blow Jan 24 at 16:12
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I've actually sort of done it. Stead airport (near Reno), hot day, overweight flying instructor (and me at ~190 lbs) in a tired Cessna 150. At the east end of the runway there's a sharp drop (not quite a cliff) down to a dry lake. So do takeoff run, and get airborne in ground effect, pass over the end of the runway, and look back to see that we're actually below it. – jamesqf Jan 24 at 19:23

11 Answers 11

Is it theoretically possible? Sure.
Is it realistic or probable? Absolutely not.


If there is not enough space for the airplane to accelerate to takeoff speed it will be effectively stalled when it reaches the end of the ground. That means that as soon as it runs out of ground it effectively becomes a ballistic projectile: it keeps moving forward, but it also starts to fall because of gravity. You can see this in the Goldeneye clip - the plane adopts a nose-down attitude shortly after it leaves the ground.

Eventually, given enough time, the airplane will reach a flyable airspeed (between gravity accelerating it down and its thrust propelling it forward). How far it needs to fall before that happens depends on a number of factors, but if the ground is sloping downward at an angle such that the aircraft's ballistic trajectory does not intersect the ground before it can reach flying speed you could theoretically make such a takeoff.
The obvious downside is that if things don't go perfectly in the attempt you will intersect the ground in uncontrolled flight ("crash").


In the Goldeneye scenario the aircraft is already in a fairly extreme dive when Bond manages to get aboard, so for our intrepid secret agent it's not so much a matter of getting the aircraft to a flying speed (it's probably there already) but rather of recovering from the dive before hitting the ground and without over-stressing the airframe and causing parts to break off.

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+1 for "you will intersect the ground in uncontrolled flight" – Au101 Jan 24 at 18:40
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"You will not go to space today" – Edward Falk Jan 24 at 23:24
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Isn't flying off a cliff and only gaining sufficient airspeed to remain in flight afterwards what fixed wing aviators on sky-jump style carriers do every time they take off? OTOH every part of what naval aviators do could be called insane I suppose. – Dan Neely Jan 25 at 1:15
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I think there can be a phase when wing isn't stalled already, yet still not generating enough lift to support all the weight. youtube.com/watch?v=cWOcRl2Q1T4&t=2m00s Depends on the plane, I guess, but seems like all hang gliders are designed for that. – Agent_L Jan 25 at 12:43
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@Agent_L Generating some lift but not enough to support all the weight is called "descending". – Oktalist Jan 25 at 18:45

I'm taking that you mean taking off (for the want of a better word) when the runway is unavailable- trade altitude for gaining speed and get back to controlled flight. This is certainly possible but not recommended as it puts too much premium on pilot skill and luck.

There are videos in the internet which shows exactly this being done, but whether anyone would want to try this is questionable. Atleast this shows that as long as the aircraft is kept clear of the ground below for a reasonable amount of time and the aircraft does not stall, the aircraft could be flown off the cliff.

Another way of looking at this is to consider the experiments carried out in 1930s with airships and 1950s with large bombers, which launced aircraft from an altitude.

The McDonnel Douglass XF 85 Goblin was purpose built to be carried and launched from bombers; the launches were successful, the trouble was with the retrieval of the aircraft. The advent of the air-to-air refueling put and end to the experiments.

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Yes, an airplane can be launched by gravity acceleration, whether by a short takeoff run, or actual free fall. As other answers have indicated, there are many instances of this taking place from short runways or hillsides.

An obscure application of this ability is found in the curious history of the Curtiss Sparrowhawk, a "parasite fighter" that launched from US Navy airships. The aircraft was stored in the airship, which was a sort of flying aircraft carrier. To launch, the Sparrowhawk was lowered below the airship by the hook above the wings, the engine was powered up, and the aircraft was released to fall away and gain airspeed.

enter image description here [Source, public domain]

Video the USS Akron showing Sparrowhawk launch (launch sequence starts at 1:40)

Interestingly, the Sparrowhawk used the launch mechanism for retrieval into the airship. Read more about the Curtiss F9C Sparrowhawk, and the two airships that carried it, the USS Akron and the USS Macon on their Wikipedia pages.

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I wouldn't think this actually qualifies as a "takeoff on an elevated short field". Interesting, still. – Stéphane Gourichon Jan 25 at 6:42
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@StéphaneGourichon You are correct that the sparrowhawk example does not involve a field at all. The point of that example is to illustrate that a freefall is sufficient to accelerate an aircraft into flight. – Jonathan Walters Jan 25 at 14:41
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@StéphaneGourichon Technically, it is elevated and the field length is 0 feet, which seems very short. :) – reirab Jan 25 at 22:11
    
But the Sparrowhawk would already have the airspeed of the carrying aircraft, so it doesn't have to accelerate much more, does it? – Sumyrda Jan 27 at 6:45

It sure is possible, and sure has happened!

Check out this video. Looks like a whole lot of fun. As long as there is enough forward trajectory to clear the edge, and enough room before the ground, it can be done. I wouldn't like your chances of pulling it off in a larger aircraft however, and the piloting technique would need to be precise.

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You have to consider that this plane you showed takes off in probably something like... 100 ft? – Nelson Jan 24 at 14:22
    
@Nelson At 6:00 in that video, he seems to take off in even less than that! – David Richerby Jan 25 at 1:02
    
That plane is definitely an exception. It's a twin propeller designed so that it can even take off on only one engine. – Nelson Jan 25 at 1:35
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The fact that this is a taildragger may also be relevant. It means the pilot is already actively balancing the aircraft pitch during the takeoff run. He probably has to make a massive correction as it goes over the cliff, but at least he has some feedback. The plane in Goldeneye is also a taildragger, and a stuntman presumably did have to more or less fly the plane off a cliff in order to get the footage. – Level River St Jan 25 at 6:27
    
The propeller visible at the top of the video may suggest that it's a helicopter, but the link on the video shows a photo and it's indeed a plane: bushplanedesign.com – Stéphane Gourichon Jan 25 at 6:40

One of the greatest books on aviation ever written, Fate is the Hunter by Ernest K. Gann, has a story about departing Africa fully loaded with fuel off of a river in a seaplane, and they couldn't get airbore before the river turned into a waterfall. When they reached the waterfall, they lowered the nose until they reached flying airspeed, and flew away. It wasn't planned, but they made it anyway. So, yes, it is possible. And run, don't walk, to your favorite bookstore and buy this book. I read it every year.

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Now I'm remembering something about the wings being overloaded with fuel and pinching a cable so they couldn't rotate until they were airborne. Does any one have a better recollection? – rbp Jan 24 at 14:59
    
Ah, good story. While we are on the aviation books, nobody won't regret to read St Ex Wind, Sand and Stars and re-discover what has been the life of aviation pioneers. So humanist. – mins Jan 24 at 18:09

I'm surprised to see Courchevel Altiport being only mentioned in comments in this question. While this is not exactly a free fall, the middle part of the runway has a significant slope (18%), which contributes toward accelerating the planes taking off (as well as slowing down the landing planes).

enter image description here

One similarity with a free fall is that once the plane reaches the slope, the pilot cannot do RTO anymore, because of a short remaining distance and additional acceleration from the slope:

And that’s where we come to the ‘dilemma’ on this runway. Once the DASH 7 has started moving there, there’s no turning back: it just has to take off. Aborting a take-off on a runway this steep is absolutely unthinkable. We could no longer bring the aircraft to a standstill, and I don’t even want to think about the consequences of that…

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I think that it was contained to comments because it does not actually answer the question. – Federico Jan 25 at 12:08
    
Well, there's still gravity contributing towards accelerating the plane. – Dmitry Grigoryev Jan 25 at 12:18
    
Can a glider take off from there? If not, it's not really an answer to the Q. – yo' Jan 26 at 16:08

voretaq7's answer seems to explain quite well what's going on but I suggest taking a look at the 'bungee launching' of gliders/sailplanes. Effectively the aircraft is initially accelerated by an elastic band, and then gains airspeed by falling down from a hill, almost exactly as you ask. It is still is used at 2 places in the UK occasionally. The hill must be 'right' for it to work.

So yes, this does actually happen in real life, but not with 'normal' (powered) aircraft.

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To add, at Camphill airfield and a site in Kent in the UK. – D. Clayton Jan 24 at 18:58

Short answer: yes, but...

There are already a number of good answers and examples that, while unprobable (in the sense of "requiring a specific combination of factors") and dangerous in most of the cases, it is definitely really possible (since it happened).

Adding an historical example

At the beginning of commercial aviation, unreliable planes carried paper mail (a.k.a. post, letters) in daredevil conditions. In between 1927 and 1929, Jean Mermoz was trying to open a route across the Andes. He and his mechanic stranded at high altitude after an incident, rode into a precipice to gain enough speed to fly again. This has been widely documented for decades.

See for example:

Jean Mermoz (1901 - 1936) - SP's Aviation

He rode an updraft that carried the plane through a high mountain pass, but then a downdraft slammed the aircraft onto a plateau at 12,000 feet. Though the small machine suffered only mild damage and was still airworthy, there wasn’t enough take-off run available on the plateau. Mermoz cleared a rough path to the edge of the precipice and they removed whatever they could from the aircraft. They strapped themselves in and Mermoz just rolled off the mountain hoping to gain enough flying speed before hitting the ground. They succeeded; otherwise it would have been certain death.

Famous Aviators | 10 famous aviators

Mermoz next tackled shortening the Argentina-to-Chile route; pilots had to make a thousand-mile detour to get around the Andes. With mechanic Alexandre Collenot, Mermoz set out in a Latécoère 25 monoplane and found an updraft that carried them through a mountain pass, but a downdraft smashed the aircraft onto a plateau at 12,000 feet. After determining that they could not hike out, Mermoz cleared a crude path to the edge of the precipice and removed from the aircraft anything that wasn’t bolted down. He and Collenot strapped themselves in, and Mermoz got the airplane rolling down the path.

In effect, they dove off the mountain, and Mermoz pointed the nose straight down, hoping to gain flying speed. Again, luck was with him.

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Some British aircraft carriers have ski-jumps at the end of their flight decks. These allow aircraft that are rolling forward already (but too slow to sustain flight) to convert some of their forward velocity into vertical speed, in effect "lobbing" them into the air.

Obviously if their engines were not providing thrust, they would soon get wet, but it would take longer to hit the water than if they had just rolled off a flat deck. This gives the aircraft extra time to accelerate to the speed required to sustain flight, and allows a shorter flight deck (so smaller ship, which means cheaper)

Depending on your frame of reference, you could say that the aircraft "fall" of the end of the ski jump. They certainly have a negative vertical acceleration for a small amount of time, until the airspeed is high enough for the wings to totally counter gravity.

https://en.wikipedia.org/wiki/Flight_deck#Ski-jump_ramp

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IIRC the ski-jump followed on from some WWII operations in which dropping off the end of a flat deck was sued -- whether this was by design or in emergency I don't know. – Chris H Jan 25 at 13:54
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@ChrisH, If I was told to simply accelerate until I ran out of deck, then hope for the best, I would probably sue, too! :) – FreeMan Jan 25 at 16:28

The book Hitler's Raid to Save Mussolini by Greg Annussek (page 6, second to last paragraph) discusses the rescue of Mussolini; they used a 200 meter runup then off a cliff in a Storch.

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To be fair, I've seen a Storch in person accelerate from inside a hangar in and be in the air by the time it was out of the hangar doors. It's more of a kite than an airplane. – HCBPshenanigans Jan 26 at 1:36

I see no reason why it should not be possible if you have enough speed to clear the cliff and keep the nose pointed into the relative wind. In this 0 g maneuver the wings will not stall as long as no lift is being generated. If there is sufficient clearance to gain enough speed to reach a flyable speed and pull up before hitting the ground, it should be ok (not considering practicality).

Make a good paper airplane and drop it forward-end facing down, it will fly without a problem (if you made the plane properly)

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protected by voretaq7 Jan 25 at 18:02

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