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Picture this scenario:

A drop-plane drops off a group of skydivers. One of them pulls his chute and it fails, he pulls his reserve and nothing happens. The skydiver radios the plane to tell the pilot of his predicament. The jumper maximizes drag by spreading his arms and legs wide, the pilot pitches down 40 degrees and redlines the ASI to get parallel to the skydiver, who then flies safely back into the plane.

Is this possible?

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    $\begingroup$ It's been done (although as a stunt, not as an emergency recovery): youtube.com/watch?v=YL9sNrOlK-I $\endgroup$
    – Kenn Sebesta
    Jul 20 at 11:47
  • $\begingroup$ @KennSebesta Great link! The reverse thrust of the Pilatus Porter made this possible. I doubt a regular drop plane could do this. $\endgroup$
    – Peter Kämpf
    Jul 20 at 18:11
  • $\begingroup$ There was an Imax movie called "Flyers" that featured exactly this maneuver. It's been many years ago, don't know if you will have much luck googling it. And of course I can't speak to how closely what was shown on the screen matched to the actual reality of what was going on in real life during the filming -- i.e. whether the stunt was actually performed in real life, or not-- $\endgroup$
    – quiet flyer
    Jul 20 at 19:45
  • $\begingroup$ Re "It's been done (although as a stunt, not as an emergency recovery):" -- considering that this was done in the context of wingsuit flying off of terrain, not an actual skydive from a plane-- that seems extremely dumb. Can you say " compounding the risks as much as possible"? $\endgroup$
    – quiet flyer
    Jul 20 at 19:51
  • $\begingroup$ @quietflyer There's a nice valley at 1:44 in the video, if the entry was unsuccessful, I would assume they'd perform a landing there. Further, as normal for wingsuits, the flyers have parachutes, so a safe landing can be made over many types of terrain in minimal space. Flying an unpowered glider over the same terrain would seem to be a greater hazard. $\endgroup$
    – user71659
    Jul 23 at 4:15

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If the plane was highly modified, was in a dive when the jumpers exited, and everyone had a pretty good idea of what they were doing, maybe...

Red Bull sort of attempted this with their plane swap stunt which ended badly for one of the planes. Keep in mind these planes were equipped with dive brakes to make this stunt possible and were able to dive un-assisted with custom auto pilots (although in your case there is presumably a pilot flying it down). Its also worth mentioning this may have license implications.

Catching up to the sky diver in a maneuverable, stable, way is going to be a tall order if your in an unmodified plane.

Again, Red Bull proved you can indeed base jump into a plane which is also a similar situation and perhaps if the sky divers were wearing a similar suit they could pull it off.

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  • $\begingroup$ I see no fundamental reason why the plane needs to be "highly modified" or "in a dive". If it has a door big enough to get out of, then its big enough to get back in to. Having enough time/space/power/speed-brakes to be able to match speed is the most critical (and unlikely) bit. $\endgroup$
    – MikeB
    Jul 21 at 9:00
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As a choreographed stunt, it would be very difficult and dangerous, but might be possible. The drop plane would need to be in a nearly-vertical dive, since a skydiver in free fall is falling nearly vertically, at a rate of about 10000 feet per minute. Most planes can't dive like this- either they are moving too much horizontally (which will kill the skydivers) or they are essentially falling at their terminal velocity (which is, for most planes, much faster than the skydivers and also Vne).

As a practical matter, it's definitely impossible, and it would be incredibly reckless for a pilot to try. Skydivers don't usually pull their chutes immediately after exit and drop planes don't usually dive at Vne just in case one of the chutes fails. In other words, the skydiver is probably closer to the ground than to the plane by the time they discover their chute isn't working.

Even if the diver immediately radioed the plane and the plane immediately started a max-performance dive at Vne before deploying their magic dive brakes that let it match speed with a skydiver, there simply isn't time for the drop plane to intercept the diver and then recover while the altimeter is still reading a positive number.

To put some numbers on it, suppose a PC-6 drops a diver off at 10000 feet. Less than a minute later, the diver tries to pop their chute at 3000 feet, while the PC-6 is passing through 9000 feet. With around a 10000 fpm descent rate, the diver has a little under 20 seconds to be saved. The PC-6 would have to have an average descent rate of 30000 fpm just to hit the ground at the same time as the diver. As 30000 fpm is around twice Vne for a PC-6, that is unlikely to end well.

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  • $\begingroup$ After all skydivers are divers not airborne soldiers, and they open the chute at the end of the drop, not the beginning. The moment of truth is simply too low to do anything about it. $\endgroup$
    – user3528438
    Jul 21 at 2:10
  • $\begingroup$ Mike Patey did a stunt where people in wingsuits grabbed the wings of his plane. That was hard enough requiring significant reverse thrust to achive the required flight path and speed. Someone with nothing at all to arrest their fall would presumablly be even harder. $\endgroup$
    – Peter Green
    Jul 21 at 20:44
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A plane can dive at a vertical speed (~150 MPH) which exceeds the terminal velocity of a human with a dead parachute (~100 MPH). This means that in principle, a plane can catch up with a falling parachutist. However, whether or not the plane can save the falling parachutist depends on whether or not it is possible to keep him or her away from the propeller!

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The gravity force and air drag force reaches equilibrium and the falling speed stabilizes at about 200 km/h at this point. It is too fast to be survivable. It takes only about 12 seconds to reach this speed.

Hitting a horizontally flying aircraft with the same vertical velocity should not make any difference from hitting the ground.

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    $\begingroup$ As noted by Kenn Sebesta, this has actually been done as a stunt (James Bond iirc) so no, it clearly isn't impossible! $\endgroup$
    – MikeB
    Jul 20 at 14:25
  • $\begingroup$ Still do not understand how they did. I would leave the answer for now because Youtube video without comments is not the best ever source. If the vertical speed is zero, hitting the plane is the same as hitting the ground. If the vertical speed is close to 200 km/h, what kind of aircraft should it be to have horizontal speed low enough not to kill a human due that component of velocity. $\endgroup$
    – h22
    Jul 20 at 16:13
  • $\begingroup$ Use a PC-6 with reversible prop. Otherwise, the speed in a dive will quickly become too high for this to work out. $\endgroup$
    – Peter Kämpf
    Jul 20 at 18:17

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