Young airline pilot with his bride of a couple of days into the mountain. Not a lot to learn other than you cannot defy physics…..again!
No explanation for why he got so low to the rising ground.
I flew a rented Pa28-161 in that area, and took off from Gunnison 7,600’ before flying near (but NOT landing at) Telluride. It just needed care to avoid boxing in. My memory is of wide valleys being available.
I think there was an explanation: his climb rate was poor (< 300 ft/min), and his climb gradient didn’t exceed the gradient of the rising terrain. Additionally he was flying well below best climb speed – one thing the maker of this video didn’t point out was the ADS-B groundspeed doesn’t need to be just corrected for windspeed (to come up with an idea of TAS) but then must be converted to IAS, which at that density altitude and the speed ranges he was flying at means you need to knock off another 10 knots to get IAS. This meant he was pretty far removed from best rate and best angle of climb, and very close to stall speed well before the point he actually stalled.
The video does point out the instinct to keep pulling back when terrain looks big and close, which was probably why he got that slow and why he was that slow for so long.
alioth wrote:
The video does point out the instinct to keep pulling back when terrain looks big and close
We all did it, one way or another, finding that you are pulling too much than what you should when you lose horizon references near big terrain and human factor kicks in, the main question is what you do about that?
The flaps position is really puzzling, unless he was planning a forced landing, or just the usual pilot reaction of trying weird things under stress…
If you are flying toward raising terrain make sure the valley is wide (or gets wider), if you are flying tight valley make sure the terrain ahead goes down, as at some point when you get caught you either need to climb or turn back or as last resort climb while turning
It seems he entered at the wrong low height, but also he was flying toward rising terrain & tight valley, plus that valley tilted 90deg to the right while he was also initiating his right turn back? that would be about 270deg right turn then 90deg left turn to roll back…
Of course securing the right height while space is available such that no climb is needed would be the “right thing to do” at +10kft
Ibra wrote:
the main question is what you do about that?
Crosscheck with your instruments.
When in rising terrain, it’s very easy to have too high of a pitch attitude if you don’t confirm it with the airspeed indicator and attitude indicator (if you have one – and this Bonanza, I’m willing to bet, had a perfectly functional AI). Especially if you’re a flatlander, and this is likely a scenario that the pilot was unfamiliar with in his airline flying or day to day GA flying, and I can entirely understand why he was probably flying well below Vy and Vx – and it wasn’t intentional. I’ve experienced this illusion first hand and it’s a very strong illusion of false horizon, and only by cross checking your instruments can you know what’s really going on – which may be difficult when you’re surrounded by granite you’re trying not to hit.
It is probably similar to this crash.
In both cases, the failure of the pilot was to not be at the required altitude before entering the pass or canyon.
One can usually tell whether one will be high enough from whether one can see terrain / mountain peaks a long way behind the immediate-obstacle terrain. That method also deals with any false horizon issues. One can see this after 38:50 in this video
Peter wrote:
whether one can see terrain / mountain peaks a long way behind the immediate-obstacle terrain.
One follow-up trick on this: if the terrain/peak behind the immediate obstacle is getting bigger/appearing more and more when approaching, then you are higher than the immediate obstacle. If the terrain/peak is disappearing behind the immediate obstacle, your are lower than the obstacle.
This is easy to remember and can be useful, eg. if the terrain is disappearing behind an obstacle, change course (whatever that might mean in your situation, turn, climb…).
Peter wrote:
One can usually tell whether one will be high enough from whether one can see terrain / mountain peaks a long way behind the immediate-obstacle terrain.
Indeed and also magically works when facing the biggest peak 
Peter wrote:
That method also deals with any false horizon issues. One can see this after 38:50 in this video
In theory, you have a decent AI backup for pitch & bank as given by your attitude vs the 0C snow line on those mountain and combining your OAT & Altimeter readings, the ground will be slightly hot than the air on that southerly sun 
At Ibra, the flaps position is not unusual.
When I learned mountain/canyon flying (in the mountains of British Columbia) and for float flying (where you do lots of 180 degree turns above lakes and rivers), it was not unusual to put out one notch of flaps. This allows you to fly slower, and thus have a tighter radius of turn. Alternatively, staying at the same speed, it gives you more of a buffer from a stall when turning. Of course, this is offset by the increased drag and might have consequences, but I think this will depend on the drag/lift curves for each aircraft individually. Depending on the pilot’s background this might have been on their mind.
The first thing my mountain flying instructor did for me was an accelerated stall with a wing drop to the outside in a sharp turn (left turn, with a right wing drop). It was a rude reminder of the abstract idea, ’don’t stall in a turn’, to holy sh!t you are going to eat dirt if you do that at low level for real. Although we had done this during my normal PPL training, it was always pretty tame, e.g. a typical 30 degree bank climbing turn (to stall) for the practical test standards. During my PPL training, I had never done a stall at a 45 degree bank (or more). An eye opener for sure.
My PPL instructor, whom I thought had excellent aircraft handling skills (but was young), later died in a canyon stall spin similar to this incident. I had just been mountain flying with a grizzled experienced bush/aerobatic pilot, and couldn’t help thinking that my deceased instructor would have likely benefited from the training…
Coming to terms with tight turns at low altitudes was one of the biggest learning curves for me in float flying…. I will admit it is very uncomfortable to pick the floats up off the water, eek out some acceleration and then bank for maximum rate of turn because the trees or mountains are coming up quick! I ended up with speed gates, similar to aerobatics. No banks beyond 30 degrees until faster than xxx knots…
Canuck wrote:
When I learned mountain/canyon flying (in the mountains of British Columbia) and for float flying (where you do lots of 180 degree turns above lakes and rivers), it was not unusual to put out one notch of flaps. This allows you to fly slower, and thus have a tighter radius of turn. Alternatively, staying at the same speed, it gives you more of a buffer from a stall when turning. Of course, this is offset by the increased drag and might have consequences, but I think this will depend on the drag/lift curves for each aircraft individually. Depending on the pilot’s background this might have been on their mind.
Yes thanks for the clarifications, in theory, yes I would have thought the same, in some types at sea level you get best angle at Vx with takeoff flaps and then best climb rate with clean flaps at Vy, but with heigh density altitude things will start to converge halfway in between Vx = Vy and everything goes clean flaps
In practice, it’s clear at least on the types I flew above 10kft that flaps or slow speeds are definitely NO GO for any sort of climb performance in high density altitude but yes I do agree some flaps & slow speeds do make sense for tight turns (preferably unloaded+coordinated), or generally any “ground ref manoeuvres”, but I don’t think I would have flown valleys so tight where the radius at 45deg turn between clean flaps and takeoff flaps makes a huge of difference (in my usual type, R0 = (VS0*1.2)^2/11= 550ft with 65kts clean stall and R1 = (VS1*1.2)^2/11 = 450ft with 59kts flap stall, the latter would be even illegal vis-a-vis the 500ft lateral/vertical low flying rules )
