Crash caught on video from inside the plane

OK

Ever been in a mountain wave? Some are smooth as silk and not that sudden, but are still classified as turbulence and/or up and downdrafts.

They were on a reasonable flat plateau, and if headed west towards McCall, were approaching a junction of two valleys each of which contained streams. Pure speculation as to what the wind/thermal patterns were at that location.

 

I'm sure you are right-- what could possibly go wrong with loading 4 guys into a Stinson and taking off from a 6,400' msl strip on a summer afternoon, and flying into rising terrain?

They couldn't merely have been overloaded for conditions... right?

 

Maybe you should re-read post #21 again. Pay attention to the last para.

 

jedi, I guess that someone else may have answered your question but I wanted to chime in. High temperatures expand the air and keep the engine and wing from breathing just like people at high altitudes. The engine can't intake enough air to produce power, more particles of air feed the combustion process with more oxygen and produce more energy when they get together with fuel and produce greater expansion when ignited, thus greater push on the pistons. More particles of air (increased density) produce more lift when flowing over the wing at a given velocity. So, with higher temperatures coupled with less dense air at high altitudes hit you with a double whammy. No power to go fast enough to produce lift in thin air means one thing...

 

As always, thanks for the great 'splainin' Bob



Jedi

 

Glad these guys will be okay but that long a roll would have had even me, a non-pilot, shltting bricks. Pilot was determined to fly.

 

Does a T-craft have brakes?

Maybe he just felt at fairly early on that he was 'committed' and couldn't abort.

Of course, stomping on brakes on a taildragger would not be the same result as a tricycle.

 

The airplane involved was a Stinson 108-3 and it did have brakes that could have been used early in the take off after chopping the throttle to slow down.

 

He could easily have stopped, almost any time he wanted. Personally, I would have stopped the first time it settled back onto the ground, but then I wouldn't have started the takeoff in the first place.

It reminds me of a (probably apochryphal) story about an old Alaska charter operator. He took off in his overloaded Cherokee 6, flew through the scud, crashed into some trees, and pulling his passengers out of the wreckage, proudly announced, "With any other pilot, you'd all be dead!"

Of course, the general consensus among the pilots who worked for him was that with any other pilot, they wouldn't have crashed in the first place...

 

I have to admit to an incident much like this one where I went into a situation that could have been a disaster. We had to fly a photographer to the Abbotsford Air show in the Champ clown plane. My partner left in the L-3 with half the luggage and equipment that the TV photographer brought with him, a load. I was left with a 220 pound guy in the back with a bag of movie junque and a 15 pound 16 millimeter movie camera. It was 90 deg. and we had a wooden prop on the Champ and a full load of fuel. Just to add a bit of cushion, I taxied past the end of the strip into the runout area for take off. Getting the Champ off the ground took most of the Bellevue Washington Airport runway that wasn't too long, as I remember. Climb out was was not what anyone would want with a shopping center ahead and rising terrain beyond. It was obvious that there was gravel on top of the Albertsons grocery store roof and many power wires surrounded it. There was a shallow valley in front of the hill ahead, all of which was covered with trees. We followed the valley to the right and followed the down sloping terrain ,with trees 40 feet below, to Lake Washington. Maximum airspeed at 100% power was 50 mph and the stick was like a wet noodle and produced a pronounced complaint from the Champ if I even pulled back a tiny bit. Passed the shoreline onto Lake Washington with enough altitude to keep from hitting anything and gained a bit of speed as we headed north and things felt a lot better over the cool waters of the lake. Gradually got to 200 feet at the north end of the lake and headed for Arlington where we landed to meet another plane to which we off loaded some more weight . Approach to the runway indicated that we shouldn't retard power too much as we were already coming down at a good rate. I have no idea what the approach speed was but it was above normal and the tires agreed with a long loud chirp. The last leg to Canada was much better because the photographer was transferred to the other airplane and all we had was clothes and a sectional. The TV guy mentioned that he didn't realize that one could see so much on the ground from a little airplane. I had to agree. It was a dumb thing to do and I'm ashamed to admit it but it was a situation where everything and everybody was locked into a time restraint to be at Abottsford to do the show and there were too many other people locked into the plan to abort. Luck was with us and in my favor was being near sea level but I can see how it can happen so I cannot criticize this Stinson pilot too heavily for his mistake. However, the long take off run without too much happening in the lift department would have been a loud indication to quit.

 

I'm thinking the FAA will not look kindly upon continuing the t/o roll despite the airplane's obvious reluctance fly.

 

Even less on the overload situation, which should not be too difficult to reconstruct and add up.

 

+1

 

You've been one blessed (read: LUCKY!) fellow of the long years, Bob.

Thanks for the great story



Jedi

 

4*200+6*20+40=960 (guesstimates on possible wt of people, fuel, baggage)

What is the useful load of a 108-3, and the service ceiling?

 

You are only estimating 20 gallons of fuel? I would have guessed he had it filled up all the way - I thought these could hold at least 35 callons...

 

There is no gas at Bruce Meadows, therefore he would not have had full tanks when they departed from there. 20 gal would provide over 2 hrs flying time, plenty to get back to McCall and still have plenty (>legal) reserve. He could have been overweight, but that would mean he was overweight when he took off to go there. The payload (usable weight) of a 108-3 is approx 960 lb (new airplane spec wt). Further from the video I doubt the average wt of those guys was 200lb, and they likely had little baggage for a short day hike so the 200 is conservative.

The service ceiling of a 108-3 is over 15000ft. DA on that day was around 10000. Service ceiling is determined by loading the plane up to gross wt and then seeing how high you can fly. Of course that is based on a new engine developing full power.

Length of takeoff run does not really matter, in and of itself, provided the runway is long enough.
http://www.aviationbull.com/2008/mar/01/long-takeoff-roll

 

So you are saying then that he probably was NOT overloaded?

If so - could there have been a power issue? <like maybe he did not lean it out correctly before attempting the takeoff?>

 

Per book, doubtful IMO. But an old motor will not give book performance, so in practical terms, maybe. The NTSB will run the motor, if able, and comment.

That was something I contemplated in my first post on this thread. I have a neighbor with a 108-2 that I asked to view the video to see if he could discern the mixture setting. Would seem odd given the experience of the pilot.

The one thing I am not discounting is the mention by (at least) two of the passengers that there was sinking air.

 

Resurrecting an old post from the dead...

This video is incredible and should be shown in ground schools around the world as a warning regarding the absolute need to understand performance data. Furthermore, assuming the data supported a GO decision, a pilot needs to understand how to measure actual performance during a takoff roll.

We could argue DA/load/performance vs "air pocket" all day and the answer is DA/laod/performance. How do we know? Just watch the flightpath throughout the entire video! With the exception of the point where the aircraft initially becomes airborne, while still over "runway" and for a few seconds after it gets airborne the second and final time [sic] over what appears to be grass that likely few other aircraft had ever continued to takoff on, the flight path (the spot in the field of view that has terrain NOT MOVING up or down in the visual field) varies from being a few hundred yards in front of the plane to right around where they hit the trees. This plane was never going to make it. Period.

Any pilots who fail to compute a Normal Acceleration Check Speed (or some other takeoff performance benchmark) and then confirm that they are meeting it, are setting themselves up for failure in situations such as this, when conditions are marginal at best. A NACS can be computed at any distance, the earlier the better for fast jets. In this case, where there are likely no runway distance markers, calculating takeoff roll for conditions and comparing to runway length would have been a good start. Brief yourself at runup: If not airborne by the end of used/rutted runway, something is wrong, so use ratty grass field to stop... Obviously I made that last part up, not being a stinson pilot, but the principle of a performance check point applies to any plane. Even the Shuttle had mach windows at set altitudes that would verify main motors and SRB performance during launch.

There are so many great comments here, but this is a great, great teaching video that should prompt all of us to work the devil out of the details when it comes to looking after the lives of our friends, family, and selves while flying.

You are all a great forum, keep up the great discussions!

Blue Skies...

Hannibal

 

It could be as simple as checking engine RPM to see if it is in a normal range.

 

While important, engine RPM tells you little about the aircraft is doing under current conditions...

The key is to calculate a "gate" that is extrinsic to what you can see just looking at ops limits on an instrument panel. In fighters we calculate a normal accel check speed and from that derive a min accel check speed that serves as a very early GO/NO GO decision "gate"...for example, at 1000' down the runway, minimum speed should be 87KIAS. If it's not, then something's wrong...speed brake is out, flaps are wrong, a brake's hung up, engine performance is wrong in spite of normal ops limits, etc. So you stop...figure out what's wrong. It's a true indicator of overall performance at that point in time, which is what really matters.

All the performance charts in the world could have told the mishap pilot in the video that he was good to go in those conditions, but guess what, lets say he left a baggage door open or is towing a 100 feet of tiedown chain behind him, or whatever...his plane isn't going to takeoff!

 

However, in his case I think that the performance charts did not tell him he was good to go, and he went anyway. Or, to be more accurate, never bothered to look.

 

Completely agree...

The point I'm trying to make is that we can argue chart data this, service ceiling that, air pocket whatever, but an airplane that takes a mile to get out of ground effect is not going to get anywhere.

Blue Skies...

Hannibal

 

With a fixed pitch prop engine RPM will tell you a lot about the power available under the current conditions.