How to crash an airplane

[ahramin]

Over and over again I hear this silliness of "Stall it in" when discussing crashing an aircraft so I was gratified to see the guidance in the new AOPA Survive publication.

http://www.aopa.org/-/media/Files/AOPA/ ... s/sa31.pdf

To reduce injuries, it is best to spread your deceleration over a longer distance. Hitting at a low angle and dissipating energy over as much distance as possible will minimize the G load of the crash. For example, an aircraft traveling at 60 knots that comes to a stop over 3 m (9.8 ft) generates about 18Gs of deceleration. If that same energy was spread over 9 m (29.5 ft) it would reduce deceleration to 5Gs. While stalling the plane may sound like a good way to attain the slowest possible speed, it also results in more downward forces that are far more dangerous. The human body can tolerate about 45Gs of forward deceleration, 20Gs side-to-side. But it can only tolerate about 15Gs of downward deceleration, or force, which commonly results in spinal injuries.

Simple fact is if you stall it in, you're guaranteeing you are going to stop in the shortest possible distance, at the worst angle.

[flyinthebug]

This is way to personal for me to really respond but I will say...

Stalling my DHC2 in saved my life. I survived a Transport Canada stamped "un survivable" crash by doing what *I* thought was best for my situation. TC told me that stalling it in is likely what saved my life. I take GREAT offence when you refer to the idea of stalling it in as "silliness". I made a decision, in the blink of an eye that was either going to kill me for sure, or was going to maybe give me a shot at living. I got busted up pretty well, but 6 1/2 years later I am still in the industry and still enjoy going to work. If I had crashed by the book, I wouldn't be here typing to you.

Silliness? Have you ever stared the Grim Reaper in the face? Hes a big scary guy, and you do what you feel you have to to survive. I somehow don't find my decision silly in any sense of the word.

And your a mod to boot.

[pdw]

Wait a minute ! Yes, I was also under the impression in your situation your survival hinged on the stalling ... into the trees (= slower) ....

However, apparently lots of stalling accidents are from a bit too high up ... a 50mph contact at 75-degree angle for example ... if no trees involved .. or (lets see) does that nose-down speed increase to/above the stallspeed again once the nose drops / given the chance ?

Remembering from training students don't see visually/outside how fast each practise stall will lose alitude right after stalling ... since no outside reference at tyhe higher altitude in the training area ... just the altimeter. The forward speed changes from straight ahead .. to very steep down .. in such a hurry.

Have the bending trees passing under the wings supported some of the initial 'falling' to some extent on the way in as it stalls from 50 60 feet up right through them at an initial shallow angle ? How many trees have we seen are taken out on some of these photos of treed crashes .. snapped off at various heights in the carnage trail left behind ..

[hangar3]

^ I definitely think you took this more personally than you should have.

What he (and the report) are saying, is that if you decelerate over a longer distance, then the lower the G forces. And the lower the G forces, the less damage your body has, and your chances of survival increase. It's scientifically proven, with numbers, and makes sense if you think about it, I don't see how you can disagree with that.
What this means (and should be obvious really), is give yourself as much distance in any direction to slow down if in a crash.

Stalling might have worked for you because you did what you had to do at the right time (I have no idea what the situation was).
And your stalling can work, but if it causes more than 15Gs vertically say bye bye to your spine. Those are the numbers.
Stalling too high above the ground WOULD be silly.

[Redneck_pilot86]

flyinthebug, I'm very curious as to the scenario you were in where stalling it in was the better option. I'd appreciate it if you would either tell me here or via pm if you'd rather.

[Rookie50]

I think the term "stalling it in" needs to be put in context by the OP --ie from what height -- if I eg stalled my bug smasher onto rough ground from only a foot or 2 over that ground, vertical forces wouldn't have time to build --- I'd like to hear more from fly if he's willing more detail -- obviously its a subject many of us have considered (and I have when in N Ontario and pushing "nearest" gives you an 80nm figure)

[timel]

On a "smooth hard surface", kiss it on the ground vs bang it at the smallest speed possible do actually make sens to me.

Over water, with a non retractable gear, would you reach at the lowest speed or the lowest rate of descent?

Just avoid water as much as possible if you have the option.

[CpnCrunch]

IIRC, flyinthebug gave a detailed explanation of his crash on this forum. Perhaps someone can post a link to it. I have to commend flyinthebug for having the courage to give a detailed description of his crash.

All 6 people on the Air Nootka beaver crash survived the initial impact into the trees at cruise speed, but two of them died in the post-crash fire. So clearly the beaver is a pretty sturdy plane. Possibly the lesson to be learnt is that you should turn the master off as soon as possible to help prevent a fire. (flyinthebug didn't have that problem, for obvious reasons

Anyway, I don't think anyone is blaming flyinthebug for being an idiot. He took what he thought was the best course of action in the heat of the moment, and it worked out ok. If I hadn't read articles like this from AOPA, I would probably have done precisely the same as flyinthebug, as it seems logical. (I haven't had any accidents yet to test the theory).

[pdw]

Hottest topic ever ... with a rate-of-response of one every 5 minutes . (let's be respectful of fly-in-the-bug's very serious accident experience)

[AirFrame]

I know someone else who is possibly here today due to stalling it in. In the case i'm familiar with, it was a stall into treetops, I daresay perfectly timed as the aircraft remained upright and settled (reasonably) gently to the ground in a mostly flat attitude.

As others have said, nobody with more authority than flyinthebug, every situation is different. Unless you've been there, I submit that you probably shouldn't be throwing opinion around as fact...

[flyinthebug]

I say let the thread carry on. I do understand what you are saying hanger3...I just found it ignorant to call it silliness when in my case it was my only option if I had any chance. In different circumstances, different airplane, different accident, maybe I wouldn't choose to stall it in...but in mine, it made the most sense.

Here is a link to the thread about my crash. A lot of details/pics in there Redneck_pilot86 or anyone else who is interested. The video has been removed though just so you know.

http://www.avcanada.ca/forums2/viewtopi ... 18&t=89238

Fly safe all.
FTB

[timel]

One of my first student lost his engine power 2-3 years ago with his c150, in an attempt to reach some trail he did stall it right over the forest. Him and his passenger did not get a scratch.

[Rookie50]

Thanks fly for sharing that link. What a tramatic experience. I'm really sorry for your injuries. Does make a good case for the 4 point belts. (I have them). I never saw the video. Did you stall into trees?

All the best to you.

[Rowdy]

Slowest forward speed into the trees.. that means you'll be at or close to a stall as you hit. Seems to be whats saved many from 'unsurvivable' accidents.

I am curious to know what they studied and referenced for that finding. Was it accidents that were stall related?

I have burst fractures and broken vertebrae myself…

[flyinthebug]

Thanks fly for sharing that link. What a tramatic experience. I'm really sorry for your injuries. Does make a good case for the 4 point belts. (I have them). I never saw the video. Did you stall into trees?

All the best to you.

Thanks and yes into spring hardwoods, with scattered pines. Came to rest at the treeline in a small bog. I agree on the 6 point belts!

Rowdy...Those stats were shared with me by the 2 inspectors from YQT that came to see me in ICU at T Bay Hospital. I do not know the origin of the statistics, but likely could find them with some effort on google. All I know is what they told me.

I hope you are continuing to heal up my friend!!

photofly...I saw your comment before it was deleted. PM me and call me that name again and then we`ll get together and discuss it. For real internet tough guy!

Fly safe all.

[J31]

A Beaver on floats or any float plane for that matter, has a lot of structure to absorb vertical forces, more so than a airplane on wheels.

[Rowdy]

flyinthebug I was talking about the one that started this thread that ahramin had posted. Many 'studies' end up with a bias, or by their nature or improper research, end up with totally erroneous information being portrayed as fact.

Sounds like I may need the hardware removed.

A floatplane presents an array of other issues in a crash though J31.

[stef]

I guess at some point as you go barreling through the trees at your shallow angle, you'll get slow enough to have the vertical forces regardless. If you're going into trees, the slowest controllable speed seems to make the most sense to me.

[ahramin]

Flyinthebug was there ever a TSB report on your accident? I couldn't find one. In any case, would you be willing to share with us what made this crash impossible to survive and why stalling it in saved you?

[pelmet]

Personally, I wouldn't recommend being fully stalled for a planned impact. Once the aircraft stalls, you have lost control and depending on type, things could become much worse. But being close to the stall will allow a controlled impact at minimum speed. However, the fully stalled guy may have things work out for him while the guy in control but near the stall may not. There are so many variables.

[old_man]

How to crash a helicopter. It's an interesting read. There is some relevance to the fixed wing world.

[flyinthebug]

Flyinthebug was there ever a TSB report on your accident? I couldn't find one. In any case, would you be willing to share with us what made this crash impossible to survive and why stalling it in saved you?

I don't have the CADORs handy but it wouldn't take much to search it. It was an occurrence 5...meaning no further investigation was required. I recall some people (including widow at the time) lost their minds over that fact...I was less than impressed myself.

As a Mod for this website you ask a ridiculous question when you ask ME what made my crash un survivable?...you would have to ask TC what criteria they use when deeming accidents as survivable or un survivable? I don't write accident reports nor do I know how they come to these conclusions...but I do know all other accidents are categorized or deemed un survivable or survivable so there must be a formula. I suppose they base it on factors such as impact speed, aircraft type, area of the crash, what caused the aircraft to lose lift etc etc. I honestly don't know, but a simple call to TC would clear that right up for you.

BTW, I agree with Rowdy and wonder where all your "many" studies are?...I read one study by AOPA and that's it. Have any other links to the other many studies you reviewed to come to the conclusion that stalling it in is silliness??

Rowdy just had some hardware removed a couple months ago...the surgery sucks of course but my arm feels much better now and in 12 weeks the bone completely heals and the screw holes all fill in with bone. Its pretty cool after you get it done...and I promise you will feel better! Its worth the effort my friend and may well relieve some of your pain.

Fly safe all.

[pdw]

No need to answer too many questions in a hurry flyinthebug ...

I'm not a lawyer .. but also there may be more info under SEARCH since it's been discussed before. From my own experience, it might improve over time .. ie to get to a point where responding to comments that are forthcoming about the decision making involved (when you have it from memory ... the REAL thing ... where your 'near demise' was involved), and you've rehearsed it over and overhow it really played out in real time; it eventually becomes more practical to relate.

The farmer where I overan during an 'overshoot decision' recently passed away, and I went to his funeral south of Vineland on "The Bench" where the family has farmed for years along the north slope of the Niagara Escarpment. A great mentor he was. Was invited to the big tent after and wow there was the big Murphy Moose, the floats parked beside. Venturing a little farther, by that time found myself halfway up the strip already towards the south end, and having looked up and see the windsock nowadays mounted way high on the 3 story century barn alongside (after the farmers similar mishap), soon came to the point about a 1/4 ways in from the south end where I'd first touched down after four trys downslope / northbound / clearing trees ... so many years ago. What did I find ? ... A low area where surface water collects although underdrained ... exactly where I'd firewalled full power after recognizing the strangely high touchdown speed after the 65kts (an occluded front passage .. so it was tailwind above the woodlot-obstacle on higher elevation). It was a soft area that day being just after a rain ... and the 172 was bogging down at 3/4 gross... but JUST for the 5-8 seconds of full power that "triggered" to reconsider ... and then just missed that point of no return on the 1800' (already both too slow and far-along for TODA) while going right past the 80deg (still 'north alluring') windsock ...

Point being, even though it's happened a while ago ... it also takes long to learn presenting one's own accident-details when engaging banter with Volks who have never had an accident of any kind big or small. When someone is genuinely asking for input for something aviation to do with your 'first hand experience' there is a good chance it can make a real difference to improving the safety aspects that 'those someone's questions' (who hasn't been where you've gone) are seeking. Even here ... my questioning if dense hardwoods might cushion a beaver fuselage from higher G-force down OR forward, ... won't query for the same accident characteristics how the stall-in might fare in a sparser Florida Savannah (ahramin's quoted article).

[pelmet]

Flyinthebug was there ever a TSB report on your accident? I couldn't find one. In any case, would you be willing to share with us what made this crash impossible to survive and why stalling it in saved you?

I don't have the CADORs handy but it wouldn't take much to search it. It was an occurrence 5...meaning no further investigation was required. I recall some people (including widow at the time) lost their minds over that fact...I was less than impressed myself.

There are a lot of accidents every year in Canada and a limited budget for investigations. For smaller aircraft, the TSB will decide whether there is anything to learn from investigating the accident and if not or not much, like most accidents, there will not be a full investigation.

In this case, there appears to have been a fuel flow problem according to the CADORS report. If it was a case of fuel exhaustion, there would not be much new to learn. If there was a mechanical problem which could affect any other pilot in similar circumstances, greater consideration might be given to a full investigation. Media attention may have an effect as well.

That being said, there have been some fairly large aircraft crashes that were not fully investigated and fairly minor ones that were investigated. Perhaps because different regional offices investigate, different standards, personalities and budgets could have an effect on the decision-making.

However, we do have the PIC on the board. Giving us details could prevent a future accident if so inclined.

[GyvAir]

but I do know all other accidents are categorized or deemed un survivable or survivable so there must be a formula.

At risk of sounding like I'm piling on, I haven't seen any real record of this. Sometimes in a clear case, they make a statement in the report that crash impact forces were not survivable, and sometimes they discuss the survivability aspects of an accident. Often the word isn't even mentioned in accident reports. But categorizing survivability? I haven't seen that anywhere. I stand to be corrected, of course.