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Pilot Says Too Many Jumpers Outside Led to King Air Spin

176 points by graderjs 5y ago

ngcc_hk 5y ago
One of the great thing of flying is not that there is no mistake or design issue. But there is a feedback loop that work.
isoprophlex 5y ago
Comments under the article are pretty insightful. It seems prudent to tell divers not to loiter around the door too long... > skydivers often aren’t well versed in aircraft operations (after all, they have a lot more takeoffs than landings!) Made me giggle
deleted 5y ago
[deleted]
aosaigh 5y ago
Amazing footage. I’m sure the video distorts perspective but it looks like they were very lucky the plane didn’t hit a skydiver after spinning. I know very little about aviation but this seems like a pretty foolish and avoidable incident. I would have thought there would be a procedure for how many people can leave or hang from the back of the plane as it would very obviously affect how it flies. I can’t imagine that sort of manoeuvre is good for the airframe?
- vedosity 5y ago
  At my local drop zone one of our pilots posted this video as a reminder of why we let the pilot know when we have large groups leaving the plane. Large groups outside like this can starve the elevator of airflow, and the sudden change in center of gravity is also a factor. This seems like a weakness of a king air as a jump plane. The pilot has to throttle down the left engine so jumpers aren’t thrown into the tail on exit by the prop wash. I’m happy with our single-engine super caravan with its wide door so not so many people have to be outside to do big groups like this.
- necovek 5y ago
  > ...it looks like they were very lucky the plane didn’t hit a skydiver after spinning. I always find it interesting how we underestimate the expanse of 3D space depending on the view: jumpers are exactly between the airplane and camera, which is not surprising since the cameraperson and jumpers came from the direction of the airplane, with the camera going out first. From another angle (eg satellite view from above or a sideways view), I am sure the distance between jumpers and the plane would be more obvious. Still risky (you wouldn't plan on passing that close), but not as much as it seems.
  - krisoft 5y ago
    Absolutely, you are right about the distance. But the thing is, I think risk is not measured in meters. The question more is what made sure that the airplane didn't re-contact the skydivers. When an airplane after the drop flies on straight and steady you know that they wont hit the skydivers because the skydivers have no propulsion and relatively lot of drag. The skydivers will lose horizontal speed quickly and gain vertical speed downwards even quicker. This basically guarantees that the separation between the squishy humans and the airplane will be maintained. With the spinning airplane staying close to the divers who knows. Maybe the pilot is an ACE and they kept a mental model of the parachutist's position relative to theirs at all times. Maybe what appears to us as uncontrolled tumbling is anything but. Or maybe it was just up to "luck".
    - cbhl 5y ago
      My mental model is that the biggest risk is the turning turboprop. The rest of the dynamics fall out from that: during the dive, the engine on the divers' side is already off, and once the stall happens, the pilot cuts off both engines (to avoid a spinning engine hitting anyone), dives to gain speed. Being inside the plane as a jumper during the recovery was probably the least pleasant -- normally one doesn't have a seatbelt in that scenario. I think at 0:54 one more person falls out the open jump door?
    - jaywalk 5y ago
      Aside from the fact that the skydivers weren't really that close to the plane during the recovery, it was pretty much just luck. In a situation like that training takes over, and the only thing you're really looking out for is the ground to keep your bearings straight.
- Syntonicles 5y ago
  A 9 person exit is not at all unusual. We used to do a 10-way angle track at sunset every day. Larger formations are both possible and routine. As long as the pilot is aware of and can anticipate the weight shifting there's generally no issue at all. You are right that there is a clear limit to the number of people allowed on the outside step set by the DZ. In the original video you can count the heads on climb-out and these jumpers are exceeding every guideline that I've been subject to. My formations adhere to five outside and one crouched, max - but do note that several bodies may follow the exit with as little delay as possible. We try to exit as a unit. I'm only a coach with ~500 jumps, by no means an authority. This model plane in particular is less forgiving and the airspeed is high on jump run. As skydivers we are cautioned about the exits and take extra care to maintain a forward CoG. I have experience with aerodynamic modelling and private pilot training but won't speculate other than to say that structural integrity is not an issue. It's more like capsizing a boat than overloading a trailer hitch.
catlikesshrimp 5y ago
That looks dangerous!
bentcorner 5y ago
Videographer & Pilot perspectives: https://www.facebook.com/story.php?story_fbid=815758609269982&id=800288897 https://www.facebook.com/story.php?story_fbid=81575860926998... Pilot perspective copied here: https://www.reddit.com/r/aviation/comments/qm1952/an_absolutely_astounding_video_of_a_jump_ship/ https://www.reddit.com/r/aviation/comments/qm1952/an_absolut...
- eigenhombre 5y ago
  From the second thread: "One of the jumpers [exited later]. She was tossed around inside the aircraft and ended up on the floor next to the door. During the final motions of the aircraft she bounced off the door frame and out the door." Yikes.
  - jaywalk 5y ago
    Scary as hell for sure, but at least she was wearing a parachute.
    - usefulcat 5y ago
      And a helmet, I would presume
      - jaywalk 5y ago
        The other jumpers were, so that's a pretty safe assumption.
  - JoeDaDude 5y ago
    If I was in the airplane getting tossed about like that, I would be scrambling like mad to get out! Just to embellish and clarify: During my first jump training, one of the things the instructor drilled into us was "You have a parachute. If something goes wrong and you need to save your life, use it!".
  - foogazi 5y ago
    You can see someone exit the plane just as it’s about to stabilize at around the 1:40 mark
graderjs 5y ago
“The aircraft behaved very well, and the recovery was surprisingly easy,” Xei wrote. Sounds like the pilot is talking about the simplest thing in the world. Video makes the pilot seem incredibly calm in the face of the plane moving in a crazy way. Edit: what would make the plane move that way?--it seems to recover after initial spin only to drop nose down, then start strafing (correct term?) left and right like it's in a half pipe before starting to spin again. It looks almost totally of control, to me it looks like it hit a wall of air. I have no idea. I'm amazed the pilot was so cool. Very impressive
- k8sToGo 5y ago
  Because this scenario is something you learn when getting a license.
  - dagurp 5y ago
    Regular stalls, sure. But I'm not sure that stalls that go into a spin are part of it.
    - FabHK 5y ago
      When I learned in the US, stall and spin avoidance and recovery was taught, but only stalls were actually practiced (because apparently too many accidents happened practicing spins). Not sure how the situation is in South Africa. https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_61-67C_Chg_2.pdf https://www.faa.gov/documentLibrary/media/Advisory_Circular/...
      - snovv_crash 5y ago
        My dad did his PPL in South Africa, and I know he practiced spins. Not sure if they were tested though.
    - speedbird 5y ago
      Spinning into cloud in a twin - absolute nightmare.
kelnos 5y ago
If you read the comments, two commenters (one claiming experience piloting quite a few different plane types as a skydiver pilot, as well as plenty of hours on King Air planes) suggest that the pilot here was doing it wrong, and that there's no need (and it's dangerous) to throttle back the engine on the side that the skydivers jump out of. Anyone here experienced enough to comment on this claim?
- nemetroid 5y ago
  I think the commenters are saying that both engines should have been throttled back.
  - speedbird 5y ago
    Yes, and accept that the aircraft will lose some height. Asymmetric thrust, flaps down, large group disrupting airflow over horizontal stabilizer and creating a substantial CofG shift to aft, what could go wrong ...
- jillesvangurp 5y ago
  Not a pilot, but my interpretation is that the pilot probably tried to slow down to make the jump easier. That got him closer to the stall speed. Having one engine with less thrust is something twin engine pilots train a lot for (engine out scenario) but also something that puts you closer to stall speeds. The rudder is the primary way to control airplane direction when you are close to stall speeds because you lose aileron controls around that time (they don't do much when you stall). It's also what you use during engine out and what can trigger a spin during a stall. Now having the center of gravity change would be dangerous under those circumstances. Stall recovery is also something pilots train for as that is highly dangerous during takeoffs and landings. A landing is basically a controlled stall. Spin recovery is less commonly trained for because it basically means you messed up the stall recovery, which should not happen. Sounds like the pilot did the correct thing (eliminate async trust and nose down). So, not a good incident but it happened at an altitude where there was plenty of time to recover.
  - 5y ago
Cthulhu_ 5y ago
Reminds me of the one clip where one plane of jumpers actually crashes into the other.
- throw0101a 5y ago
  Wisconsin in 2013: * https://www.youtube.com/watch?v=ZvXdFrlHv3s https://www.youtube.com/watch?v=ZvXdFrlHv3s
07835169998 5y ago
سبيد
audiometry 5y ago
https://youtu.be/8D6-fJdGTac https://youtu.be/8D6-fJdGTac This commercial pilot gives a very thorough explanation of the problem and includes a report from the pilot of the flight.
- geocrasher 5y ago
  Came here to post that. It's a good analysis.
  - BuildTheRobots 5y ago
    Mr Browne / Blancolerio has some fantastic flight information and covers most USA based crashes and subsequent FAA investigations in great detail. Highly recommended if you're even vaguely interested in flying.
- jprupp 5y ago
  My goal as a pilot is never to attract Juan Browne's attention. :P
spicybright 5y ago
I can't imagine how difficult 3d space would be to navigate when spinning like this. I already have trouble mastering driving a car, and that's removing like half the dimensions a pilot has to deal with.
- colechristensen 5y ago
  When you’re spinning like this you don’t have control, it just happens to you. The dangerous part of being in a spin like this isn’t being able to regain control, if you push up the throttle it just happens. The dangerous part is damaging the airframe in the process (too much force “too many g’s) will rip the wings off or do permanent damage that requires the plane to be scrapped.
khazhoux 5y ago
I recently learned that this is an issue that bomber pilots / airplanes must deal with, when they deploy their payloads. Here is a video of a test pilot giving a talk at MIT on the F-22 and its advanced flying capabilities which --as he puts it-- makes flying an F-22 actually easier than a Cessna. https://www.youtube.com/watch?v=n068fel-W9I https://www.youtube.com/watch?v=n068fel-W9I Apologies in advance for you losing an hour -- the talk is that good!
- egberts1 5y ago
  that was the best one hour in quite some; time well spent.
bradgranath 5y ago
That rate of rotation on the roll is so fast. I'm surprised the wings weren't overstressed
RNCTX 5y ago
"The thing they don't want you to know..." (/clickbait_headline) Nary a King Air has counter-rotating props. As such, they all have a critical engine. Beechcraft as a company is sort of like the black-box storage providers of the 2000s pre-cloud IT world. They're not doing anything better than anyone else, with the exception of marketing... The terms you wanna google here if you're curious and not familiar are "P-factor" and "adverse yaw." There are lots of better airplanes to toss parachute jumpers out of than a King Air for this reason. For that matter, there are a lot better airplanes for the owner of this airplane in question to take his family to Aspen or Grand Cayman in, for the exact same reason. If the aforementioned early 2000s IT storage salesman responds to a question of how you recover from disk failure with "don't have a disk failure," you would probably walk away not not buy his black box, right? Yet people buy King Airs because they bought a Baron before it, and bought the Baron because it was just a Bonanza with two props. "What's going on with all these King Air crashes?" [1] 1. https://www.bjtonline.com/business-jet-news/whats-going-with-all-these-king-air-crashes https://www.bjtonline.com/business-jet-news/whats-going-with...

176 points by graderjs 5y ago

One of the great thing of flying is not that there is no mistake or design issue. But there is a feedback loop that work.

isoprophlex 5y ago

Comments under the article are pretty insightful. It seems prudent to tell divers not to loiter around the door too long... > skydivers often aren’t well versed in aircraft operations (after all, they have a lot more takeoffs than landings!) Made me giggle

deleted 5y ago

[deleted]

aosaigh 5y ago

Amazing footage. I’m sure the video distorts perspective but it looks like they were very lucky the plane didn’t hit a skydiver after spinning. I know very little about aviation but this seems like a pretty foolish and avoidable incident. I would have thought there would be a procedure for how many people can leave or hang from the back of the plane as it would very obviously affect how it flies. I can’t imagine that sort of manoeuvre is good for the airframe?

vedosity 5y ago
At my local drop zone one of our pilots posted this video as a reminder of why we let the pilot know when we have large groups leaving the plane. Large groups outside like this can starve the elevator of airflow, and the sudden change in center of gravity is also a factor. This seems like a weakness of a king air as a jump plane. The pilot has to throttle down the left engine so jumpers aren’t thrown into the tail on exit by the prop wash. I’m happy with our single-engine super caravan with its wide door so not so many people have to be outside to do big groups like this.
necovek 5y ago
> ...it looks like they were very lucky the plane didn’t hit a skydiver after spinning. I always find it interesting how we underestimate the expanse of 3D space depending on the view: jumpers are exactly between the airplane and camera, which is not surprising since the cameraperson and jumpers came from the direction of the airplane, with the camera going out first. From another angle (eg satellite view from above or a sideways view), I am sure the distance between jumpers and the plane would be more obvious. Still risky (you wouldn't plan on passing that close), but not as much as it seems.
- krisoft 5y ago
  Absolutely, you are right about the distance. But the thing is, I think risk is not measured in meters. The question more is what made sure that the airplane didn't re-contact the skydivers. When an airplane after the drop flies on straight and steady you know that they wont hit the skydivers because the skydivers have no propulsion and relatively lot of drag. The skydivers will lose horizontal speed quickly and gain vertical speed downwards even quicker. This basically guarantees that the separation between the squishy humans and the airplane will be maintained. With the spinning airplane staying close to the divers who knows. Maybe the pilot is an ACE and they kept a mental model of the parachutist's position relative to theirs at all times. Maybe what appears to us as uncontrolled tumbling is anything but. Or maybe it was just up to "luck".
  - cbhl 5y ago
    My mental model is that the biggest risk is the turning turboprop. The rest of the dynamics fall out from that: during the dive, the engine on the divers' side is already off, and once the stall happens, the pilot cuts off both engines (to avoid a spinning engine hitting anyone), dives to gain speed. Being inside the plane as a jumper during the recovery was probably the least pleasant -- normally one doesn't have a seatbelt in that scenario. I think at 0:54 one more person falls out the open jump door?
  - jaywalk 5y ago
    Aside from the fact that the skydivers weren't really that close to the plane during the recovery, it was pretty much just luck. In a situation like that training takes over, and the only thing you're really looking out for is the ground to keep your bearings straight.
Syntonicles 5y ago
A 9 person exit is not at all unusual. We used to do a 10-way angle track at sunset every day. Larger formations are both possible and routine. As long as the pilot is aware of and can anticipate the weight shifting there's generally no issue at all. You are right that there is a clear limit to the number of people allowed on the outside step set by the DZ. In the original video you can count the heads on climb-out and these jumpers are exceeding every guideline that I've been subject to. My formations adhere to five outside and one crouched, max - but do note that several bodies may follow the exit with as little delay as possible. We try to exit as a unit. I'm only a coach with ~500 jumps, by no means an authority. This model plane in particular is less forgiving and the airspeed is high on jump run. As skydivers we are cautioned about the exits and take extra care to maintain a forward CoG. I have experience with aerodynamic modelling and private pilot training but won't speculate other than to say that structural integrity is not an issue. It's more like capsizing a boat than overloading a trailer hitch.

catlikesshrimp 5y ago

That looks dangerous!

bentcorner 5y ago

Videographer & Pilot perspectives: https://www.facebook.com/story.php?story_fbid=815758609269982&id=800288897 https://www.facebook.com/story.php?story_fbid=81575860926998... Pilot perspective copied here: https://www.reddit.com/r/aviation/comments/qm1952/an_absolutely_astounding_video_of_a_jump_ship/ https://www.reddit.com/r/aviation/comments/qm1952/an_absolut...

eigenhombre 5y ago
From the second thread: "One of the jumpers [exited later]. She was tossed around inside the aircraft and ended up on the floor next to the door. During the final motions of the aircraft she bounced off the door frame and out the door." Yikes.
- jaywalk 5y ago
  Scary as hell for sure, but at least she was wearing a parachute.
  - usefulcat 5y ago
    And a helmet, I would presume
    - jaywalk 5y ago
      The other jumpers were, so that's a pretty safe assumption.
- JoeDaDude 5y ago
  If I was in the airplane getting tossed about like that, I would be scrambling like mad to get out! Just to embellish and clarify: During my first jump training, one of the things the instructor drilled into us was "You have a parachute. If something goes wrong and you need to save your life, use it!".
- foogazi 5y ago
  You can see someone exit the plane just as it’s about to stabilize at around the 1:40 mark

graderjs 5y ago

“The aircraft behaved very well, and the recovery was surprisingly easy,” Xei wrote. Sounds like the pilot is talking about the simplest thing in the world. Video makes the pilot seem incredibly calm in the face of the plane moving in a crazy way. Edit: what would make the plane move that way?--it seems to recover after initial spin only to drop nose down, then start strafing (correct term?) left and right like it's in a half pipe before starting to spin again. It looks almost totally of control, to me it looks like it hit a wall of air. I have no idea. I'm amazed the pilot was so cool. Very impressive

k8sToGo 5y ago
Because this scenario is something you learn when getting a license.
- dagurp 5y ago
  Regular stalls, sure. But I'm not sure that stalls that go into a spin are part of it.
  - FabHK 5y ago
    When I learned in the US, stall and spin avoidance and recovery was taught, but only stalls were actually practiced (because apparently too many accidents happened practicing spins). Not sure how the situation is in South Africa. https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_61-67C_Chg_2.pdf https://www.faa.gov/documentLibrary/media/Advisory_Circular/...
    - snovv_crash 5y ago
      My dad did his PPL in South Africa, and I know he practiced spins. Not sure if they were tested though.
  - speedbird 5y ago
    Spinning into cloud in a twin - absolute nightmare.

kelnos 5y ago

If you read the comments, two commenters (one claiming experience piloting quite a few different plane types as a skydiver pilot, as well as plenty of hours on King Air planes) suggest that the pilot here was doing it wrong, and that there's no need (and it's dangerous) to throttle back the engine on the side that the skydivers jump out of. Anyone here experienced enough to comment on this claim?

nemetroid 5y ago
I think the commenters are saying that both engines should have been throttled back.
- speedbird 5y ago
  Yes, and accept that the aircraft will lose some height. Asymmetric thrust, flaps down, large group disrupting airflow over horizontal stabilizer and creating a substantial CofG shift to aft, what could go wrong ...
jillesvangurp 5y ago
Not a pilot, but my interpretation is that the pilot probably tried to slow down to make the jump easier. That got him closer to the stall speed. Having one engine with less thrust is something twin engine pilots train a lot for (engine out scenario) but also something that puts you closer to stall speeds. The rudder is the primary way to control airplane direction when you are close to stall speeds because you lose aileron controls around that time (they don't do much when you stall). It's also what you use during engine out and what can trigger a spin during a stall. Now having the center of gravity change would be dangerous under those circumstances. Stall recovery is also something pilots train for as that is highly dangerous during takeoffs and landings. A landing is basically a controlled stall. Spin recovery is less commonly trained for because it basically means you messed up the stall recovery, which should not happen. Sounds like the pilot did the correct thing (eliminate async trust and nose down). So, not a good incident but it happened at an altitude where there was plenty of time to recover.
- 5y ago

Cthulhu_ 5y ago

Reminds me of the one clip where one plane of jumpers actually crashes into the other.

throw0101a 5y ago
Wisconsin in 2013: * https://www.youtube.com/watch?v=ZvXdFrlHv3s https://www.youtube.com/watch?v=ZvXdFrlHv3s

07835169998 5y ago

سبيد

audiometry 5y ago

https://youtu.be/8D6-fJdGTac https://youtu.be/8D6-fJdGTac This commercial pilot gives a very thorough explanation of the problem and includes a report from the pilot of the flight.

geocrasher 5y ago
Came here to post that. It's a good analysis.
- BuildTheRobots 5y ago
  Mr Browne / Blancolerio has some fantastic flight information and covers most USA based crashes and subsequent FAA investigations in great detail. Highly recommended if you're even vaguely interested in flying.
jprupp 5y ago
My goal as a pilot is never to attract Juan Browne's attention. :P

spicybright 5y ago

I can't imagine how difficult 3d space would be to navigate when spinning like this. I already have trouble mastering driving a car, and that's removing like half the dimensions a pilot has to deal with.

colechristensen 5y ago
When you’re spinning like this you don’t have control, it just happens to you. The dangerous part of being in a spin like this isn’t being able to regain control, if you push up the throttle it just happens. The dangerous part is damaging the airframe in the process (too much force “too many g’s) will rip the wings off or do permanent damage that requires the plane to be scrapped.

khazhoux 5y ago

I recently learned that this is an issue that bomber pilots / airplanes must deal with, when they deploy their payloads. Here is a video of a test pilot giving a talk at MIT on the F-22 and its advanced flying capabilities which --as he puts it-- makes flying an F-22 actually easier than a Cessna. https://www.youtube.com/watch?v=n068fel-W9I https://www.youtube.com/watch?v=n068fel-W9I Apologies in advance for you losing an hour -- the talk is that good!

egberts1 5y ago
that was the best one hour in quite some; time well spent.

bradgranath 5y ago

That rate of rotation on the roll is so fast. I'm surprised the wings weren't overstressed

RNCTX 5y ago

"The thing they don't want you to know..." (/clickbait_headline) Nary a King Air has counter-rotating props. As such, they all have a critical engine. Beechcraft as a company is sort of like the black-box storage providers of the 2000s pre-cloud IT world. They're not doing anything better than anyone else, with the exception of marketing... The terms you wanna google here if you're curious and not familiar are "P-factor" and "adverse yaw." There are lots of better airplanes to toss parachute jumpers out of than a King Air for this reason. For that matter, there are a lot better airplanes for the owner of this airplane in question to take his family to Aspen or Grand Cayman in, for the exact same reason. If the aforementioned early 2000s IT storage salesman responds to a question of how you recover from disk failure with "don't have a disk failure," you would probably walk away not not buy his black box, right? Yet people buy King Airs because they bought a Baron before it, and bought the Baron because it was just a Bonanza with two props. "What's going on with all these King Air crashes?" [1] 1. https://www.bjtonline.com/business-jet-news/whats-going-with-all-these-king-air-crashes https://www.bjtonline.com/business-jet-news/whats-going-with...