General Aviation folk, I need your help again ~

In My Humble Opinion
1

I hope you clever people can help me reconstruct the chain of events. I’ll try to be succinct, but I’m a little stressed…

Short version is that some truly good guys found my husband sitting by his plane with a great gash in his skull, blood on the ground in front of the plane, and the plane not running but with the magnetos on. The plane is a 1956 Piper Tri-Pacer. The assumption is that he took a single prop blow to the head, but I don’t know enough about planes or engines to understand how it happened, and for some reason I feel I need to know.

My husband is a very cautious person and has worked on mechanical stuff all his life, cars and motorcycles though, the plane is a newish thing though he’s read everything about them for years and years. I just can’t wrap my own brain around this. What did he do/not do?
Longer version:

A guy (who I talked to last night & who told me all this) and his buddy were driving around the outside ring road to do some work on a derelict building nearby that they’re saving. They were driving slowly, and saw my husband sitting on the bench in his hangar, and the buddy said “he doesn’t look right” so they stopped and went back. When they got to him, Dave was sitting on the bench with a 5 gal bucket between his feet, wiping the blood off his head with a rag and rinsing it in the bucket - over and over. And there was a giant pool of blood in front of the plane, spatters here and there, and a handprint on his car. They saw the blood and had 911 on the phone in an instant.

They said the magnetos were on in the plane and so yes, he did indeed take a prop strike to his head. Probably knocked him senseless for a bit given the size of the blood patch, and then he came to and sort of realized he needed to do something but couldn’t figure out how. When the guys talked to him he did remember his name and mine, but couldn’t remember my number or the code for his phone.

There is no way I can express how grateful I am to these guys who went back to look instead of driving on and laughing about the weird dude. Neither one knew him from Adam…

This happened on Friday afternoon. He spent 4 hrs in surgery to remove a plum sized blood clot from his brain and to piece together the bits of his skull. He’s now got a 9" incision that appears to be healing nicely, and a skull put together with plates and titanium mesh. He’s off the ventilator and responding to commands, knows his name and who I am, and is pretty mobile - he helped get himself onto the CT scan table. He’s having trouble with words, though we’re not sure yet if that’s the outraged brain, the after effects of serious meds, or the sore throat from the tube. Probably a combination of all.

I don’t know what if anything he remembers, and frankly I’m not sure I want to make him remember it, once he’s talking again.

Keep a fellow flight fanatic in your thoughts, ok?

Thanks guys.

2

Wow.

If he did take a prop strike to the head and he’s doing that well he is a very, very, very lucky man.

It’s also possible he fell as he was moving from the cockpit to the prop to start the plane and hit the prop on the way down - even a stopped prop can cause significant injury.

I hope he has an uneventful and complete recovery. Best wishes. Don’t forget to take care of yourself during all this.

3

Agree with Broomstick; amazing story and I hope he makes a full recovery.

As for what may have happened, do you know what he was doing with the plane at the time? If I remember my flying days correctly, it was considered good practice to shut the engine off by pulling the mixture control to full lean and starving it of fuel. If you just turned off the ignition (as you would with a car or motorcycle) there might be some fuel vapor remaining in the cylinders. Before the next flight you’ll do a walk-around inspection of the plane. When you’re near the propeller you don’t want the chance that that leftover fuel vapor could ignite and turn the prop.

I’m not sure that explains everything, though. This is not a plane that requires hand starting, is it?

4

I knew a of a guy who had taken his family flying. He had pulled the mixture to cut off, and exited the plane when the prop stopped spinning. He was in the process of bending over to chalking the front wheel when the engine popped, and made a partial arc with the prop. The prop hit him in the head with enough force to kill him. Lesson taught was that you always approach the prop from the side. Never through the arc of the prop regardless of the situation.

Was he parking/securing the plane?

BTW. Tri-Pacers are an awesome plane. I love fabric planes.

5

Thanks guys.

I don’t really know what he was doing, I don’t think he’d been up though. He may have been preparing to go? The damage done is definitely a strike though and not a fall, unless he was climbing in the rafters and fell. Much too deep a slice, through the skull itself.

His plane has an ignition which he usually uses, but it can also be prop started.

6

As others have said, the ignition & starting system on light airplanes is similar to how cars did it in the 1920s & 1930s.

The advantage is simplicity. The disadvantage is the possibility of the engine starting, or farting violently once, if the last shutdown or the current pre-flight prep was/is done wrongly. And unlike a car, it’s common (in fact it’s good practice) to manipulate the engine a bit in the course of pre-flight prep.

It’s pretty clear your husband triggered such a fart. Which swung the prop like a dull axe at his head, then quit.

There’s a bunch of ways to screw the shutdown/pre-flight procedure up, and even doing everything wrong is no guarantee of triggering a dangerous fart, much less being injured by it. But woe betide the unlucky soul who does so.

You and he are very fortunate. Here’s hoping he makes a complete recovery.

Ask away if you want more detail.

7

I will be praying for your husband to have a quick & full recovery. I will also be praying for you to be strong though out this experience.

As to what happened, It is probable that he was trying to “hand prop” the engine. Was the Tri-Pacer out of the hanger enough that the prop wash would not be a problem? If so, that is your answer. If not, I have no idea as to why the mags would be on.

I am glad that these fellows were there & that they noticed your husband’s predicament. Life is good.

Hang in there, I am pulling for both of you, 48.

8

The magneto switch in a plane is the exact OPPOSITE of every other ‘electrical switch’ you know.

The switch turns “OFF” by CLOSING - it is a ground wire which is supposed to ground the mags.

If that wire loses contact with the “ground”, the switch position is meaningless - it is “hot” 7/24.

Add to that - the engines are 1930’s technology - they will “kick” all by themselves.

The rule drummed into the student’s head in Ground School is “Never put anything in the arc of the prop you don’t want destroyed”.

If the engine stops at just the “right” point on its compression cycle, it can kick.

Best wishes and deepest sorrow.

9

Hang tough & best wishes for a full recovery.

10

It’s customary when putting a plane away to move the props so they are straight up. This prevents walking into the tips when pulling the chocks and inspecting the engine on the next outing. As you’re aware, the front nose wheel is close to the prop with this plane. Most of the Tri-Pacers have a Lycoming O-320 with a carburetor. One of the magnetos on that plane has what is called an impulse coupling. It literally has what looks like a clock spring in it that will tighten through part of the rotation of the engine and then release to create the optimally timed spark for starting. If you pull the prop through a rotation you’ll hear it click when this happens.

In essence, he likely hand propped the plane unintentionally. Since the engine was already leaned out there was little fuel left to run the engine but apparently enough to pop it through one or two revolutions.

Hope things go well for him.

11

Just as an FYI, this scenario plays out ALL THE TIME in aviation. At some point every single pilot will make this mistake. I’m pretty religious about taking the key out immediately upon coming to a full stop and putting them on the glare shield. But crap happens.

Last year I was putting a plane away with a friend of mine. I watched him move the prop up and to my horror the key was still engaged and turned to both mags. the sound of the coupling snapping over was like an electrical shock to my system. Very happy nothing happened.

12

My best wishes to your husband as well saje.

As Magiver said, you can be sure that whatever he did, plenty (most?) of us have done something similar or at least set ourselves up for something similar but by pure chance we’ve got away with it. It’s one of those things where the series of mistakes/inactions required is completely outweighed by the consequences.

He is human, we are an imperfect species and make mistakes. To eliminate errors in humans is an impossible task. The best we can do is try to spot the error before it has a chance to turn into something serious, even then it is an uphill battle. What did he do? We can’t know. The likely scenarios have been covered by the previous posters. What we do know is that if it was caused by an error in judgement or procedures, it was a very human error and his only failing was being a person.

13

On the subject of swinging props and unintended consequences:

My second commercial flying job was thanks to the sacking of my predecessor. As I said above, we all make mistakes, and sometimes they bite us, but a run of errors and an inability to learn from them is less forgivable. The following was just one of this bloke’s transgressions.

This guy, lets call him “Maverick”, was flying Tiger Moth joyrides for a living. At the start of each day, part of his job was to get the Tiger out of the hanger, start it up and taxi it around to an area by the airport boundary where it could be easily seen by passing cars.

A few important points about this Tiger Moth (it was the one in the above link by the way). It doesn’t have brakes, there is no starter, and it has a hand-hold at each end of the lower wing. To start this particular Tiger Moth (all the owners had different theories on how to start one) you needed to open the throttle, ignition off, prime the engine with a little priming nipple under the cowling, and pull the prop through four compressions. Then making sure the wheels are chocked, the throttle is closed then cracked open a little, the ignition is switched on, and you walk around to the front and swing the prop.

Our friend Maverick got this starting sequence a little wrong and found himself swinging the prop with the aircraft chocked, the ignition on, and the throttle wide open. Not surprisingly the little biplane roared into life and revved up to full power, jumped over the chocks and proceeded to accelerate away from the poor chap who had leaped out of the way just in the nick of time. He had the presence of mind to grab something and that something happened to be the hand-hold at the end of lower wing.

So picture this. The aeroplane is motoring along at full power, eager to take-off, while Maverick is at the centre of the catastrophe, hanging on for dear life to the wing tip while the aeroplane swings around him like one of those control line model airplanes. If he lets go he loses $100,000 worth of someone else’s property, so all he can do is hang on until help arrives.

I don’t know exactly how he was extricated from the situation, all I know is that the Tiger lived to fight another day and by the time I got there, Maverick had been sent on his way.

14

Magiver, that sounds very plausible, thank you.

And **Richard ** - Holy shit! That must’ve taken several years off everyone’s lives. Wow.

It’s funny, when he was working towards getting this plane I was so unhappy about it, and mostly worried about crashes. I would never tell him NO you aren’t allowed to do this, but if you read my 1st thread I was pretty worried. But now that he’s had the plane, and gotten severely injured by it, the foremost thought in my mind is that I want him to be able to fly it again. I’m glad he’s alive of course, and even gladder that he seems to be making good progress even at this early stage, but he’s going to be so sad if he can never fly again. And I’ll be sad for him, because it is his pride and joy.

Well, time will tell.

15

Good luck to you both. He may or may not remember it, but tell him a lot of pilots are pulling for him. And each has said “there but for the grace of …”.

16

Please saje, keep us updated on his recovery.

If he doesn’t have one of these, you might get him one as a get well present. I don’t know if this was the problem, but I strongly suspect it might have been prevented if he had one.

17

I will and thanks.

And yes he does have one.

Stopped by the hangar today to pick up his car and anything else he’d left there and talked to his hangar neighbor. The plane wasn’t pulled out at all I guess, it was right where it is now which is in its usual spot inside. I saw a stepstool just to the front and side of it with various tools and bits and pieces in the tray, which tells me he wasn’t flying but just fiddling. God knows why he had it on… well, it doesn’t really matter now I guess.

He’s still in ICU, and while his words are clearer he’s not really lucid yet. His clear-ish moments are clearer, and I guess he told one of the docs that he got hit by a prop and that he knew he himself was a doc, so some things are coming back a bit. But its going to be a long long time til he’s in the air again, if ever.

18

This is also how folks shoot themselves while cleaning guns. (ignoring that being a common euphemism for gun suicides).

Once you start taking something apart, even a little bit, it naturally changes categories in your mind from “a working machine” to “a pile of disassembled inanimate parts.” Even if you’ve only removed a couple of minor screws.

Which sets up the next mental error which is doing something with the “pile of parts” (like look down the gun’s barrel) that you’d never do with “a fully functional gun”.

He probably needed to rotate the prop to continue whatever maintenance task he was on. But by then it wasn’t an “engine ready to start” in his mind which would trigger all the usual habits and alarm bells. Instead it was “the pile of parts I’m working on.”

We’ve all been there at least once. Some get lucky the first time, some get unlucky the first time.

19

Perhaps that is because when he recovers sufficiently to fly again it will mark a return to normal for you?

Unfortunately, I don’t have much help for you but my thoughts and best wishes are with you both.

20

Everything has already been said. Hoping for a full and rapid recovery.