When the Terrain climbs faster than the plane

[TripleZ]

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.

I will +1 this. Years back I dove with a Dive Master to 176ft on air to find my "limit" for nitrogen narcosis. I felt fine all the way to 170', then stopped at 176' when I started laughing at the squeak my regulator made when I moved the mouthpiece. Did a math problem......... 2+2 = 22 at that depth.

I haven't been through high altitude low O2 training, but would guess the onset is the same. Slow and unnoticed....... unless you're constantly checking yourself for effects. Getting narc'd out was a great way of learning my limits, which is why the altitude training has some appeal.

 

[Henning]

I will +1 this. Years back I dove with a Dive Master to 176ft on air to find my "limit" for nitrogen narcosis. I felt fine all the way to 170', then stopped at 176' when I started laughing at the squeak my regulator made when I moved the mouthpiece. Did a math problem......... 2+2 = 22 at that depth.

I haven't been through high altitude low O2 training, but would guess the onset is the same. Slow and unnoticed....... unless you're constantly checking yourself for effects. Getting narc'd out was a great way of learning my limits, which is why the altitude training has some appeal.

Problem is that the altutude chamber can lull you into a false sense of security. They take you up really high pretty fast to the point where you are really messed up like your instructor did with you going down to 176. The effects are full force there. Here's one for you to try. Next time, do a math problem at the surface, a simple double digit by double didgit multiplication. Time how long it takes to solve. Now dive to 130 and see how long it takes. Take your 20 minute dive on the wreck, come back to the ascent line, repeat the problem again. Come up to 50', hand there and pull out your slate and do it again. At 130' you likely "felt" just fine and full competent. I've done the trimix swap at 130' before and there is a noticeable difference.

 

[TripleZ]

^^^ Yup.... I should have added a bit more detail. The narcosis was pretty noticeable at 150', although manageable. And at 120', barely noticeable.

He had me doing a finger exercise. Touch thumb to each finger on alternating hands. At 176', I couldn't do it. At 150', I could, but was SLOW and would sometimes miss the alternate hand or do it at the same time. 120', I was slower than the surface, but got it. It was a fairly quick dive, treated as a decompression, but we didn't spend any time at depth.

I would imagine, as you said, the time factor has a HUGE effect. What I got out of that dive was.... "yup, 130' is a good dive limit for me"


How do the mixed gas altitude training sessions work, where they reduce the oxygen instead of reducing air pressure? Do they bring you up slower to get that time effect?

 

[Fearless Tower]

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.

Possible, but the 'official' stuff that I have read on it says he was on a job to document the beetle problem. If you watch the whole video, you will hear him talking about the beetle areas.

 

[denverpilot]

I'm not so sure that people that are living at altitude have full mental acuity.

Hey! I resemble that remark!

 

[denverpilot]

Possible, but the 'official' stuff that I have read on it says he was on a job to document the beetle problem. If you watch the whole video, you will hear him talking about the beetle areas.

Yeah, what I had heard was that he was prepping for the new contract he'd gotten to video the beetle kill areas and checking out the video camera.

I guess it doesn't matter either way... he killed himself and someone else, which is definitely not the goal of a successful mountain flight... sigh... sad.

 

[Henning]

How do the mixed gas altitude training sessions work, where they reduce the oxygen instead of reducing air pressure? Do they bring you up slower to get that time effect?

I'm not understanding what you're trying to get at with that question... I have no knowledge of mixed gas "altitude training". The only mixed gas training I have is for hyperbaric situations. The only "altitude training" I did was pressure based breathing air and recovering on O2. You can induce hypoxia by breathing a 12%O2 bottom mix while still on the surface though. On deep dives using 14%O2 bottom mix and below, we start our descent on deco gas and switch between 50 & 90'.

 

[Henning]

Hey! I resemble that remark!

Yeah, I know....

 

[TripleZ]

I'm not understanding what you're trying to get at with that question... I have no knowledge of mixed gas "altitude training". The only mixed gas training I have is for hyperbaric situations. The only "altitude training" I did was pressure based breathing air and recovering on O2. You can induce hypoxia by breathing a 12%O2 bottom mix while still on the surface though. On deep dives using 14%O2 bottom mix and below, we start our descent on deco gas and switch between 50 & 90'.

I read a short article on altitude chamber training without the pressure chamber (because chambers are rare and seating is limited). It said hypoxia was caused by mixed gases............ Based on your response I'm assuming that means using a bottom mix of around 12%. Not really "mixed" but a specific concentration.

That pretty much answers my question.

With the right rig, the test proxy could swing O2 from 21 to 12% slowly to create hypoxia slowly to simulate flying.

 

[TripleZ]

Found the website.

http://altitudetraining.com/main/aviation/products

 

[denverpilot]

There was some company doing something like that as a demo of a new system they wanted to show off over at KAPA at Independence Aviation recently.

Mess with your O2 level while you were sitting at a desk in an FBO/Flight School.

They paired it up with a "High Altitude Flying" WINGS event.

I couldn't make it that weekend.

 

[N801BH]

Probably not 7-8K higher than the altitude. Terrain is 13-14k at the peaks so even there for the DA to be above the SC of 20k it would have to be HOT

My take on this sad event....

1 - Treeline here in NW Wyoming is right about 10,200 msl, anything above 10,000 the trees start looking pretty thin.. Those trees look very healthy so my guess is they went in around 8500-9000 msl, or maybe even lower. For the DA to be 13,000 it would have been pretty hot outside. Maybe down in Colorado the treeline is higher .

2 - A turn to the left instead of the right was no doubt the way to go... What was he thinking?

3 - As another poster noted.. I am AMAZED the video tape didn't degrade by it just being out in the branches , and that it actually was usuable. .

Still,,,, the tape is sobering to say the least.

 

[ChrisS]

My take on this sad event....

1 - Treeline here in NW Wyoming is right about 10,200 msl, anything above 10,000 the trees start looking pretty thin.. Those trees look very healthy so my guess is they went in around 8500-9000 msl, or maybe even lower. For the DA to be 13,000 it would have been pretty hot outside. Maybe down in Colorado the treeline is higher .

They went down in terrain of between 10,000ft and 10,400ft. (see my link above )

 

[denverpilot]

The tape was also covered in fuel - well until it evaporated and left behind whatever it leaves behind.

Three years out in the elements it did pretty well. Three winters in the snow, etc.

The bigger issue I heard was that it was tattered and torn from it's case.

A lot of splice tape later, fed into a new case, it was playable and immediately copied. Of course.

 

[Henning]

I read a short article on altitude chamber training without the pressure chamber (because chambers are rare and seating is limited). It said hypoxia was caused by mixed gases............ Based on your response I'm assuming that means using a bottom mix of around 12%. Not really "mixed" but a specific concentration.

That pretty much answers my question.

With the right rig, the test proxy could swing O2 from 21 to 12% slowly to create hypoxia slowly to simulate flying.

Yeah, you can do it with a standard gas blending panel hooked to a scuba regulator set and induce hypoxia, but there is a bit more to depressurizing the bodyin physical symptoms and discomforts so that they are familiar and "normal" when you experience them in an emergency.

There are actually a butt load of chambers out there, just not many with a vacuum pump hooked to them.

 

[Fearless Tower]

The tape was also covered in fuel - well until it evaporated and left behind whatever it leaves behind.

Three years out in the elements it did pretty well. Three winters in the snow, etc.

The bigger issue I heard was that it was tattered and torn from it's case.

A lot of splice tape later, fed into a new case, it was playable and immediately copied. Of course.

IIRC, they actually found the tape strewn out hanging from the trees.

 

[BellyUpFish]

IIRC, they actually found the tape strewn out hanging from the trees.

Wow..

 

[N801BH]

They went down in terrain of between 10,000ft and 10,400ft. (see my link above )

Hmmm..... That is a 400 thousand foot split.... was the crash site at 10,000 or 14,000 feet ?? Since he was flying about 100 feet above the trees determining the EXACT location of the debris will give the ACCURATE operating atitude he flew. Can you share with me elevation of the crash site sir...

Thanks in advance.

 

[ChrisS]

Hmmm..... That is a 4000 thousand foot split.... was the crash site at 10,000 or 14,000 feet ?? Since he was flying about 100 feet above the trees determining the EXACT location of the debris will give the ACCURATE operating atitude he flew. Can you share with me elevation of the crash site sir...

Thanks in advance.

Unless I'm missing something, that is a 400ft (four hundred feet) split. The link I provided above (Google Maps) shows the area of the crash and it has terrain elevation details on it, I'm just referring to those.

 

[N801BH]

Unless I'm missing something, that is a 400ft (four hundred feet) split. The link I provided above (Google Maps) shows the area of the crash and it has terrain elevation details on it, I'm just referring to those.

Yup,,, correct,, to early......

Can you give the link to the NTSB report

 

[ChrisS]

Yup,,, correct,, to early......

Can you give the link to the NTSB report

Factual
http://dms.ntsb.gov/aviation/AccidentReports/gxidcmnaoie430qdwrj5vmzm1/E09102011120000.pdf

Probable Cause
http://dms.ntsb.gov/aviation/AccidentReports/swa5n2b30pqkxn45uwlpqz451/P09102011120000.pdf

THE AIRPLANE DEPARTED GRANDBY 8/10/84 AND FAILED TO ARRIVE AT ITS DESTINATION. ON 8/23/87, IT WAS FOUND ON THE SLOPE OF A HIGH TREE-COVERED RIDGE. VIDEO TAPE RECOVERED FROM THE WRECKAGE PROVIDED A VISUAL AND AUDIO RECORD OF THE FLIGHT FROM TAKEOFF TO IMPACT. COMPARING THE RECORDING TO A TOPOGRAPHICAL MAP, THE FLIGHT WAS CLIMBING AND ITS ALTITUDE ABOVE THE GROUND WAS DECREASING WHEN IT CRASHED AT THE 10,200-FT LEVEL. DURING THE LAST FEW SECONDS OF THE TAPE, THE TERRAIN DOMINATED THE VIEW THROUGH THE COCKPIT WINDOW. THE PILOT MADE A 60-DEG BANK, AND THE STALL WARNING HORN COULD BE HEARD 3 TIMES DURING APRX 180 DEG OF TURN. THE AIRPLANE SUBSEQUENTLY STALLED, FLIPPED OVER, AND ENTERED THE TREES. THE DENSITY ALTITUDE WAS ABOUT 13,000 FT.​

 

[N801BH]

Perfect,,,,, thanks, 10,200 it is..... Seems the treeline is alot higher in Colorado then up here..... Must be a latitude thing..

Thanks again for the link.

 

[ChrisS]

I have my own personal theory based on nothing but a feeling that the guy knew what he was doing and where he was going. Maybe the ridge that he crashed into should have been to his left and he missed the slight turn to the south just before it which is a valley back down to Tabernash, maybe that explains the right turn. Can't ever prove it but just my own theory on the accident.

 

[thomascannon]

Anyone know what the winds were like out there? It's not uncommon for downdrafts that you just cannot climb out of to force someone into the terrain. Seems to happen in the Sierras somewhat regularly (in overloaded airplanes in particular). I only watched the crash once and it's so spooky that I don't want to watch it again, but I can't tell if he's losing altitude because of the turn, or a downdraft, or both. A 300fpm climb gradient fighting a 400fpm downdraft makes the right or left turn decision moot.

As if that video wasn't bad enough, the picture with this article (about a different crash) should give you some nightmares:

http://helenair.com/news/local/article_1fcf0639-3278-5daf-9cef-bc6098e18e47.html

 

[Fearless Tower]

Anyone know what the winds were like out there? It's not uncommon for downdrafts that you just cannot climb out of to force someone into the terrain. Seems to happen in the Sierras somewhat regularly (in overloaded airplanes in particular). I only watched the crash once and it's so spooky that I don't want to watch it again, but I can't tell if he's losing altitude because of the turn, or a downdraft, or both. A 300fpm climb gradient fighting a 400fpm downdraft makes the right or left turn decision moot.

As if that video wasn't bad enough, the picture with this article (about a different crash) should give you some nightmares:

http://helenair.com/news/local/article_1fcf0639-3278-5daf-9cef-bc6098e18e47.html

Anyone catch this quote in that linked article:

Imeson, who's been a pilot since 1966, said, "I don't plan to be in one (an accident) again"

 

[denverpilot]

I miss Sparky.

 

[Fearless Tower]

I miss Sparky.

Me too....it was just sad to see him go the way he did.

 

[TangoWhiskey]

There used to be a really informative page about this tragic accident on the Alexis Park Inn website... it's not there anymore, but the Way Back Machine found this archived copy:

http://web.archive.org/web/20100726093447/http://www.alexisparkinn.com/l-19_crash_documents.htm

 

[Jeanie]

I've been seriously considering going to McCall ID next summer to take a mountain canyon flying seminar - I've been watching youtube vids of landing approaches to some of those strips and now considering the downdraft thing - which I have experienced here in my neighborhood maybe I'll rethink this.....

I guess Sparky's final flight ended due to a downdraft right? As I recall.

 

[denverpilot]

Nobody really knows. He was over near his original crash site and judging by the weather in the area that day, lower than necessary.

The folks in McCall aren't known for flying in conditions where winds are high into those canyons. They're pretty well regarded instructors, and likely teach folks not to go when conditions are like that.

I'd have no qualms learning from them about their local airports and conditions. The biggest skill I hear you need to have nailed before attempting some of those strips, is landing exactly on your target at your desired airspeed. They work with students on that. Knowing the exact power settings for the aircraft, and consistently hitting the spot on-speed, at airports where it's not as critical, working the way toward the more difficult backcountry strips. Learning the conventions for each strip for announcements, how to approach and depart, etc.

 

[Jeanie]

Well, I've been thinking of flying Rosy (the SD) up there from here E38, about 1200 NM and then using their Super Cub for the actual back country flying.

 

[denverpilot]

That'd be a hoot.

 

[TangoWhiskey]

A little forensic work with Google Earth... I've accurately placed the final track of his flight using distinctive views from the video. You can use the attached KML file to follow along in Google Earth; if you don't have Google Earth, I've marked the locations on this Google Map. I've named the push pins to match times in the original video frame, snippets are shown below, along with a final view looking from the ridge of Mt. Neva, which is the peak he was headed towards, back along his route of flight towards the mountain.

I still can't figure out why he was headed into that bowl at Mt. Neva; his route was to KDEN. I know they were running video looking for evidence of beetle infestation, so maybe it was a little side foray?

10,200' does indeed look to be the correct altitude, by the way... to get the perspectives right, I had to hug the terrain pretty close. They were definitely down low...

@ 4:32

@ 4:47

@ 5:09

@ 5:31

@ 5:50

@ 6:09

@ 6:20, just before he started the turn to the right...

Looking back along his track:

 

[Jay Honeck]

Very nice work.

 

[TangoWhiskey]

Oh, and now I know why he turned to the right... he wasn't trying to turn around... he was planning on crossing that little ridge at tree top level like he had all the other ridges... and continue south down this valley:

 

[Fearless Tower]

Oh, and now I know why he turned to the right... he wasn't trying to turn around... he was planning on crossing that little ridge at tree top level like he had all the other ridges... and continue south down this valley:

That is kind of what I was thinking....that is pretty much the direction he wanted to go, by staying low just above the trees, he waited way too long before starting the turn which led to him overbanking and losing what little performance the airplane had at that DA.

 

[Henning]

I've been seriously considering going to McCall ID next summer to take a mountain canyon flying seminar - I've been watching youtube vids of landing approaches to some of those strips and now considering the downdraft thing - which I have experienced here in my neighborhood maybe I'll rethink this.....

I guess Sparky's final flight ended due to a downdraft right? As I recall.

Sadly it can really never be more than speculation, but the conditions conducive to were available.... If one day it can be definitively determined it was a downdraft, I would be more surprised that they actually managed to prove it..

 

[Skylane81E]

Yeah, we will never really know what killed Sparky, happy to have learned from him while he was still with us.

 

[Skylane81E]

My take on this sad event....

1 - Treeline here in NW Wyoming is right about 10,200 msl, anything above 10,000 the trees start looking pretty thin.. Those trees look very healthy so my guess is they went in around 8500-9000 msl, or maybe even lower. For the DA to be 13,000 it would have been pretty hot outside. Maybe down in Colorado the treeline is higher .

2 - A turn to the left instead of the right was no doubt the way to go... What was he thinking?

3 - As another poster noted.. I am AMAZED the video tape didn't degrade by it just being out in the branches , and that it actually was usuable. .

Still,,,, the tape is sobering to say the least.

I was going for worst case but yeah

 

[Skylane81E]

Anyone catch this quote in that linked article:

Imeson, who's been a pilot since 1966, said, "I don't plan to be in one (an accident) again"

No one plans on it