When the Terrain climbs faster than the plane

bfergie10

bfergie10

Pre-Flight
Joined
Aug 29, 2010
Messages
64
Location
Salem, VA
Display Name
Display name:
B. Ferguson
I don't know if this video has made the rounds or not. Video quality is not good, it's from 1984. I'm not sure how you get yourself into this situation, but maybe there is a lesson to be learned here.

Fast forward to about 6:00 to see the end result. The two clues that I saw were at 3:40 and 4:20.

 
There's a natural desire to not want to believe that your plan's not working.
Add that to prior incidents of bad decision making working out.
 
Be interesting to see the track to determine exactly what the route was. Were they trying to go over Corona Pass or someplace else? What's a Cessna L-12 anyway?
 
Well that was haunting. Was the pilot just not looking out to the right as he was executing the turn?
Moreover, why wouldn't he just have leveled the wings, built speed, and climbed out straight?
Maybe it just is one of those things that can't be armchair quarterbacked... but it does seem like that turn never should have been started at that elevation.
 
Telemakhos said:
Well that was haunting. Was the pilot just not looking out to the right as he was executing the turn?
Moreover, why wouldn't he just have leveled the wings, built speed, and climbed out straight?
Maybe it just is one of those things that can't be armchair quarterbacked... but it does seem like that turn never should have been started at that elevation.
Click to expand...

NTSB says it was a 60 deg bank.
 
We've been discussing this for a few days over in the "Interesting view for a departure" thread.

It's an L-19E Bird Dog, the crash was 2x fatal, the videotape, aircraft, and bodies weren't found for three years, crash site near but not exactly right for Corona/Rollins Pass.

Sooooo many Mountain Flying technique problems with this one, mainly that he never left himself any "outs". And when he ran out of options he didn't recognize it or refused to believe it and tried to make the turn anyway. A straight ahead CFIT into the Aspen grove lower left of the frame before the turn, they both might have walked away.

Details in the other thread.
 
bartmc said:
NTSB says it was a 60 deg bank.
Click to expand...
That would explain the stall warning horn. I just can't believe he kept going into that turn.
Perhaps he forgot, because the trees were getting ominously bigger, that lift slides off the side of wings in a steep bank.
 
bfergie10 said:
I don't know if this video has made the rounds or not. Video quality is not good, it's from 1984. I'm not sure how you get yourself into this situation, but maybe there is a lesson to be learned here.

Fast forward to about 6:00 to see the end result. The two clues that I saw were at 3:40 and 4:20.

Click to expand...

This video was shown and discussed more than a few years ago at FAA Flight Saftey seminars. It's amazing that the video survived 3 years until discovered.
 
This is a oldie was posted many years ago but never a bad opportunity to learn a lesson. It is indeed a haunting video. I always wondered if they survived the crash and for how long.
 
I wonder what percent hypoxia played in this. That's what's dangerous about it, it's not a switch with a symptom, it just creeps up on you with a bad case of the stupids.
 
Henning said:
I wonder what percent hypoxia played in this. That's what's dangerous about it, it's not a switch with a symptom, it just creeps up on you with a bad case of the stupids.
Click to expand...
He sounded lucid when describing the pretty lake, which would suggest that he was merely distracted with the scenery.
Of course, that means nothing.
 
Telemakhos said:
He sounded lucid when describing the pretty lake, which would suggest that he was merely distracted with the scenery.
Of course, that means nothing.
Click to expand...

It can even mean the opposite which still means nothing. Unless you have the results of his Sats at the time, it's a guess at best.

Probably wouldn't be too tough to mod a yoke with a built in pulse oximeter that can warn you. He had to be at a pretty good altitude there.
 
Last edited:
Henning said:
It can even mean the opposite which still means nothing. Unless you have the results of his Sats at the time, it's a guess at best.
Click to expand...
I think you're right, but would add that there are plenty of pilots have attempted a climbing steep turn for whatever reason and crashed. When trees aren't a factor, those pilots often have a nasty stall/spin accident; when trees are a factor, as they were in this case, the plane can't out-climb the rising ground and hits it.
I'm just saying, hypoxia or not, this is a common class of accident. Climbing steep turns are something that most pilots never learn or practice.
 
Telemakhos said:
I think you're right, but would add that there are plenty of pilots have attempted a climbing steep turn for whatever reason and crashed. When trees aren't a factor, those pilots often have a nasty stall/spin accident; when trees are a factor, as they were in this case, the plane can't out-climb the rising ground and hits it.
I'm just saying, hypoxia or not, this is a common class of accident. Climbing steep turns are something that most pilots never learn or practice.
Click to expand...


True. Thing is, this situation happens a lot more in the high mountains than flat lands so it's not too easy to say what's attributable by what. The fact that he's looking down and commenting on the pretty lake while maintaining flight directly at a wall he very obviously won't clear for considerably longer than the average pilot to realize he was in trouble makes me suspect that hypoxia is one of the links in the accident chain. He did not realize he was not going to make it and warn his friend for a few seconds after he probably should have.

You would think that someone flying into that bowl who had a clear mind would circle up around the perimeter of the lake until they can manage to clear the ridge line. Your typical Bird Dog pilot isn't a newbie or idiot, and what you're watching is an "idiot" crossing that bowl right down the middle. The question that remains open is "why was he being an idiot?"
 
Not a left turn all the way around.

Briefings around here included some research that was done by reverse engineering the amount of control inputs by utilizing the timing of the stall horn and the movement of the frame.

Not an exact science, but he wouldn't have cleared the ridgeline after the left turn according to the folks who presented the video around here back then.

Not if he kept the bank angle shallow enough not to stall anyway. If steep, he would have lost too much altitude.

He was also trying to rudder it around the turn which didn't help.

He flew himself into a canyon with no way out and not even close to any kind of margin for a mistake.

Henning's comment was interesting. Never heard anyone bring that aspect up, but it's certainly possible it was a factor.

He needed to be 1000' AGL higher and flying downhill if he needed to video that area. Never up the center bottom of a canyon.

If he would have even just hugged the downwind side he'd have known it was time to turn out away from the trees when they got too close, 'cause he wouldn't have made it that far up the canyon. That would have been his "out". Center of a canyon, going uphill, is a common killer here.
 
I have 0 mtn. flying experience.... can someone point out on a Sectional map the vicinity of the accident?
 
Aircraft found on a slope near Tabernash. Center bottom of this clip. Rollins Pass to the right is one of the most popular light aircraft crossings in the Rockies, just west of KBJC northwest of Denver.

4b94241c-9120-be4c.jpg
 
EdFred said:
Left turn prevents everything.
Click to expand...

True, but most people tend to favor their dominant hand and it seems especially so under duress, which may explain (if he was right handed) why he made the right hand turn.

I read a study back in college about how people tend to navigate towards their dominant hand. Someone back in the early 1900's, I think did a study of museum goers and their tendency to navigate towards their dominant hand upon entering a round room with a left or right option.
 
The hand thing is interesting. He would have had a stick in the L-19 correct? Pull to the right? I'm trying to remember my one and only Bird Dog ride.

I tend toward left turns in the 182. Harder to clear to the right and my left hand is on the yoke, right hand is on the power cluster or in my lap after cruise altitude. Pulling down is easier with two fingers than pushing up.

I was hunting for my notes on this crash but can't find them.

I swear I remember the aircraft was found *north* of the ridgeline that's northeast of Tabernash. That's a lot more dangerous valley than the one directly over Tabernash and a whole lot narrower going to the East. No maneuvering room if you're low.

I know the lat-long is around here somewhere...
 
EdFred said:
Left turn prevents everything.
Click to expand...


I don't think so, but he would have gained a bit of turning ability due to prop effects. (If the top of your prop goes one direction, you'll turn tighter in the opposite. He went right because the terrain left is even taller. A primary mountain flying error he was making was flying in the middle of a high mountain valley. You always fly the "downwind" side of a valley. Two things, first you will likely find lift there to help you climb and second it allows you the tightest turn around with the least bank.
 
I've flown in there with my Tiger a few times to get to Granby from Front Range. That is really sad. Good lessons to be learned here, and if you do some mountain flying in CO, The CPO Mountain Flying course is a good start. The first time I went through there was with a CPO Mountain Flying instructor.
 
Looks to me he had a lot more room to the left. He's well above the floor and that's mostly left. As soon as he turns right, the trees are right there.
 
EdFred said:
Looks to me he had a lot more room to the left. He's well above the floor and that's mostly left. As soon as he turns right, the trees are right there.
Click to expand...

That's how I'm seeing it too. Plus there were some openings to the left to put a plane like an L-19 down, perhaps with no damage.
 
murphey said:
Be interesting to see the track to determine exactly what the route was. Were they trying to go over Corona Pass or someplace else?
Click to expand...
They were doing a Forest Service contract mission to document beetle infestation (that is why the camera was mounted). AFAIK, they were intentionally flying low.
 
Anthony said:
That's how I'm seeing it too. Plus there were some openings to the left to put a plane like an L-19 down, perhaps with no damage.
Click to expand...
If it is in the area I'm thinking, the terrain actually gets worse to the left. Lower terrain is to the right, but he waited way too long to start going right.

As we discussed in the other thread, the airplane was well below the L-19 service ceiling. I think this was more a case of not thinking ahead and getting himself in a corner.
 
denverpilot said:
I swear I remember the aircraft was found *north* of the ridgeline that's northeast of Tabernash. That's a lot more dangerous valley than the one directly over Tabernash and a whole lot narrower going to the East. No maneuvering room if you're low.

I know the lat-long is around here somewhere...
Click to expand...

Have a look at my post above. :rolleyes:
 
denverpilot said:
The hand thing is interesting. He would have had a stick in the L-19 correct? Pull to the right? I'm trying to remember my one and only Bird Dog ride.

I tend toward left turns in the 182. Harder to clear to the right and my left hand is on the yoke, right hand is on the power cluster or in my lap after cruise altitude. Pulling down is easier with two fingers than pushing up.

I was hunting for my notes on this crash but can't find them.

I swear I remember the aircraft was found *north* of the ridgeline that's northeast of Tabernash. That's a lot more dangerous valley than the one directly over Tabernash and a whole lot narrower going to the East. No maneuvering room if you're low.

I know the lat-long is around here somewhere...
Click to expand...

It's a weird phenomenon, but apparently it happens. Whether it caused him to go right, beats me.
 
BellyUpFish said:
It's a weird phenomenon, but apparently it happens. Whether it caused him to go right, beats me.
Click to expand...

I was talking to a cop who had just had a guy get away during a foot chase that went through some woods. After they had given up they found out that the guy was left handed, they lost him when they came to a creek, he said their training taught them that an adrenaline fueled person on the run would most likely turn right if only left the option of left and right.... The left handed guy went left.
 
The other thing I would have done differently is perform a series of slow, circling climbs until I can see rising terrain before committing to crossing a ridgeline or pass. A ridgeline should be approached at a 45 degree angle to to make a turnback easier if things go South. He sort of was but it looked like he turned the wrong direction.
 
Fearless Tower said:
If it is in the area I'm thinking, the terrain actually gets worse to the left. Lower terrain is to the right, but he waited way too long to start going right.

As we discussed in the other thread, the airplane was well below the L-19 service ceiling. I think this was more a case of not thinking ahead and getting himself in a corner.
Click to expand...
What was the DA?
 
DA was 13k according to NTSB. Tail number was N4584A.
 
GeorgeC said:
DA was 13k according to NTSB. Tail number was N4584A.
Click to expand...

That is enough to slow your thinking down.... It's not a lot, you don't really even notice it mostly, but if he had recognized how f-ed he was even 5 seconds earlier he would have had the space to swing wide and around in an easy circle. It's a lot like diving deep on air. You don't realize how messed up on nitrogen narcosis you just were until you take a couple hits of tri-mix (reduced nitrogen partial pressure with helium) straighten you right up. Some guys get so narced on wall dives they just drop off into the abyss.
 
Yeah, and thanks ChrisS for posting the lat/long. I was in "trust but verify" mode. That's where I remember the accident being charted from briefings years ago, too. North of the ridge line north of Tabernash, and basically straight out and up the valley from Lake Granby.

That is some serious terrain up there on that side of that ridge.

I believe you're going to have a hard time finding this in the reports because they family withheld it, but I don't believe he was filming for the USFS that day. I believe he had a family member on board, and it was just a "fun flight". I've been hunting to see if the name of the other person on board is mentioned anywhere, and it seems "scrubbed". I seem to recall the passenger was a minor, perhaps his grandson.

A very very sad accident.

Someone asked if they survived it. The ground team folks I've talked to said no, back then. Airplane crumpled into a very small physical space. The quintessential "straight in between the trees" that barely breaks a tree branch or two on the way down, was how the crash site was described to me, many years ago.

I believe the initial "find" on this one was by a hiker. I know it was three years later. I forget who actually ran across the thing. I recall someone saying that the person didn't recognize it as an aircraft at first.
 
The turn required in a situation like that is a 45* bank swing down wind for 45* or as far as terrain will let you followed by an immediate bank reversal to 45* bank toward the wind until you're on your reciprocal or on a clear path out. You also apply flaps to help you slow down and tighten the turn. If it gets really tight and you have accepted that you're about to die, you can go full power and dive at the ground and get as much energy as you can and hope to God that there is enough air density to allow you to generate a ballistic path where you can unload the wing and force the turn through.

In order to do any of that or even realize you need to though, you need mental acuity and that is why O2 is so important in the mountains. I hear the "But I live at altitude and I'm acclimated" and I agree that makes a difference...to a point. I'm not so sure that people that are living at altitude have full mental acuity. They have way more than you need for general life so no one ever really notices. But mountain flying is not "general life", it requires full mental acuity, and for that it needs sufficient oxygen.
 
You must log in or register to reply here.
Back
Top