Crash filmed from cockpit
Ah well there's a whole separate debate brewing there.
I've been asked several times as an instructor to help recalibrate low hour PPLs who keep trying to interfere with another PPL's flying, to the point it's becoming dangerous to have them as a passenger. On the other hand, it is entirely right and valid that a passenger (and don't forget that if you are a passenger, that's what you are, however experienced and qualified) should point out if anything is endangering a flight. The balance is extremely difficult to get right, and this sort of CRM is not routinely taught to PPLs.
G
I've been asked several times as an instructor to help recalibrate low hour PPLs who keep trying to interfere with another PPL's flying, to the point it's becoming dangerous to have them as a passenger. On the other hand, it is entirely right and valid that a passenger (and don't forget that if you are a passenger, that's what you are, however experienced and qualified) should point out if anything is endangering a flight. The balance is extremely difficult to get right, and this sort of CRM is not routinely taught to PPLs.
G
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and not one of you have even considered windshear, downdraft, improper air speed indication
so many things could have contributed to this crash.
how many people saw the interview on CBS in which the pilot stated: it was an airpocket (cringe).?
so many things could have contributed to this crash.
how many people saw the interview on CBS in which the pilot stated: it was an airpocket (cringe).?
Windshear under a near cloudless sky?
Improper air speed indication? He's got visual attitude and a VSI to use.
Downdraft from where?
Sounds like the pilot is even more in need of recalibration than I thought if he's stupid enough to go defending his poor flying like that.
The sheer length of that take-off run is more than enough clue that he should not have continued with the flight. The near-zero climb gradient for a sustained period only re-inforced that.
G
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Is it just my vivid imagination or does the aircraft actually become airborne at 0:50secs but then touch down again twelve seconds later?
Another issue is the sort of "risk creep" you get having completed a manoeuvre several times without understanding how near to the edge you were if any environmental factors changed for the worse.
If you get used to staggering across the airfield boundary at 20ft, it becomes a sort of benchmark. An extra degree of temperature, less favourable wind, higher weight, dirty prop... The percentage reduction in performance to turn the takeoff into an accident is very small, especially in this case where they had 1,500m (5,000') of strip to get airborne in a piston single. Throw in any vertical airmass movement, even as little as 100-200fpm and you're sunk.
I remember seeing the aftermath of a series of identical training circuits by a low-performance aircraft. They were consistently clearing the boundary hedge by 30ft or so from an 8-900m takeoff run, according to witnesses. On the last takeoff, the wind had shifted imperceptibly, plus an almost invisible fine drizzle had started to fall - the combined effects of slightly damp grass, a tiny bit of moisture on the wing and a knot of tailwind meant they clipped the hedge then crashed and burned. Lucky to survive.
I'm pretty sure it does then runs along for quite a while before staggering into the air again. I think most of us would have taken that as an ideal time to quit flying and go have a drink somewhere!
If you get used to staggering across the airfield boundary at 20ft, it becomes a sort of benchmark. An extra degree of temperature, less favourable wind, higher weight, dirty prop... The percentage reduction in performance to turn the takeoff into an accident is very small, especially in this case where they had 1,500m (5,000') of strip to get airborne in a piston single. Throw in any vertical airmass movement, even as little as 100-200fpm and you're sunk.
I remember seeing the aftermath of a series of identical training circuits by a low-performance aircraft. They were consistently clearing the boundary hedge by 30ft or so from an 8-900m takeoff run, according to witnesses. On the last takeoff, the wind had shifted imperceptibly, plus an almost invisible fine drizzle had started to fall - the combined effects of slightly damp grass, a tiny bit of moisture on the wing and a knot of tailwind meant they clipped the hedge then crashed and burned. Lucky to survive.
Is it just my vivid imagination or does the aircraft actually become airborne at 0:50secs but then touch down again twelve seconds later?
Last edited by FullWings; 10th Aug 2012 at 10:44.
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genghis the engineer
perhaps you have heard of KTVL or KRNO? You see, I have spent most of my life flying the mountains of California and Nevada, USA.
On a day with with 100 miles visibility, and one tiny cloud in the air at KRNO, I had to use max power to maintain the glideslope. (1986, Metroliner III). And some A&&&&^$^& in a 737 ahead of me had the same problem only he didn't make a PIREP untill after I MADE MY PIREP.
Oh, and teaching mountain checkouts as a CFIIMEI, and seeing how people used thermals to climb and then ending up out of the thermal and not being able to climb?
No, the mountains can be unforgiving. Temperature, density altitude, performance are all part of the equation. But unless your plane has the performance of an F15, you better be ready for anything.
Now, I think the guy was pretty close to max gross and the density altitude was very high, and maybe the old franklin wasn't producing all its power well due to aging valve seals...but mountain flying in the summertime is tough.
Actually we just had a commanche crash at Truckee tahoe airport with a density altitude of 9000'. The pilot thought there might have been engine problems so he rejected takeoff , let off two passengers and went back to try again. Crashed into a hangar and died.
perhaps you have heard of KTVL or KRNO? You see, I have spent most of my life flying the mountains of California and Nevada, USA.
On a day with with 100 miles visibility, and one tiny cloud in the air at KRNO, I had to use max power to maintain the glideslope. (1986, Metroliner III). And some A&&&&^$^& in a 737 ahead of me had the same problem only he didn't make a PIREP untill after I MADE MY PIREP.
Oh, and teaching mountain checkouts as a CFIIMEI, and seeing how people used thermals to climb and then ending up out of the thermal and not being able to climb?
No, the mountains can be unforgiving. Temperature, density altitude, performance are all part of the equation. But unless your plane has the performance of an F15, you better be ready for anything.
Now, I think the guy was pretty close to max gross and the density altitude was very high, and maybe the old franklin wasn't producing all its power well due to aging valve seals...but mountain flying in the summertime is tough.
Actually we just had a commanche crash at Truckee tahoe airport with a density altitude of 9000'. The pilot thought there might have been engine problems so he rejected takeoff , let off two passengers and went back to try again. Crashed into a hangar and died.
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FullWings - thank you, that was just what I was thinking, it was a great big hint which was ignored but should have been taken very seriously.
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Gertrude - that's the reason why I will never fly again with that person and will remain on the ground should I ever have to face the same situation.
Genghis - spot on and I have always said CRM applies for all types of aircraft. CRM is the issue at hand here; not lame excuses by a "pilot" unable to accept the truth.
Genghis - spot on and I have always said CRM applies for all types of aircraft. CRM is the issue at hand here; not lame excuses by a "pilot" unable to accept the truth.
To add to what Sevenstrokeroll said about flying in mountainous areas, once convection really gets going, you can get some impressive sinking air without any storms or even clouds. It wouldn't be at all unusual to find an area going down at 1,000fpm plus that might take some time to get out of.
I've flown a fair bit in Nevada and at times the ground appears to be porous if you're in the wrong place! The mountains in Idaho probably behave in much the same manner. The middle of the afternoon is not the ideal time to go aviating in a marginally-performing aircraft...
I've flown a fair bit in Nevada and at times the ground appears to be porous if you're in the wrong place! The mountains in Idaho probably behave in much the same manner. The middle of the afternoon is not the ideal time to go aviating in a marginally-performing aircraft...
7SR, I hear what you say, and your mountain experience is certainly greater than mine and to be fair KGCN in summer is probably the highest density altitude I've flown from. I do at last count have 115hrs in Stinson 108s so have a reasonable understanding of the type.
But really it's a generic point - continuation of an incredibly marginal performance take-off, onto a near zero RoC and continuing that over trees where there were absolutely no options.
G
But really it's a generic point - continuation of an incredibly marginal performance take-off, onto a near zero RoC and continuing that over trees where there were absolutely no options.
G
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Interesting point Matt.
That's around the stall most likely given a near zero climb angle.
So the pilot *may* have been nibbling the stall for climb angle, rather than flying about the best climb speed which is relatively high (80mph) on the Stinson. (Checking pilots out on type, I find that most have a distinct tendency to climb too slow - 70mph seems more natural to many but with a flapless take-off and around MTOW stall would be just under that , giving poor stall margins and poor climb rates both. It's also something that pilots can tend to do if they are getting nervous about hitting something in front of them (and that seems a near certainty in this case).
G
That's around the stall most likely given a near zero climb angle.
So the pilot *may* have been nibbling the stall for climb angle, rather than flying about the best climb speed which is relatively high (80mph) on the Stinson. (Checking pilots out on type, I find that most have a distinct tendency to climb too slow - 70mph seems more natural to many but with a flapless take-off and around MTOW stall would be just under that , giving poor stall margins and poor climb rates both. It's also something that pilots can tend to do if they are getting nervous about hitting something in front of them (and that seems a near certainty in this case).
G
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continuation of an incredibly marginal performance take-off, onto a near zero RoC and continuing that over trees where there were absolutely no options.
An aircraft which has very marginal performance is not going to suddenly get better unless something changes. Perhaps, a distant possibility is that you started your takeoff on downward moving air, and you're going to fly out of it. But that slim chance is not enough to continue on the hope. Anything else which causes degraded performance (engine controls not set right, too much flaps out etc.) should be fixed after the takeoff is aborted, not during.
I spend a lot of time doing performance climb testing, which involves single engine climbs in twins, and partial power climbs in both types. Once the aircraft is established in a climb, however marginal, it's not going to get better unless something changes. If the pilot is in the correct configuration, wit power set right, and at the correct speed, there's not much for him to change....
As I struggle for 3 minutes in my test climbs to record a climb of 50 feet, I'm reminded about the criticality of doing that off the runway. Leaving ground effect is going to worsen the climb capability. Any turn is going to worsen the climb capability. I wonder which the accident pilot thought was going to change for the good as he pressed on....
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When to stop the takeoff? Do the performance calculation per the POH, find out the takeoff distance - define a distance reference point by the runway in your takeoff briefing. If not airborne by that point, stop. Performance is very unlikely to improve even if you ever get airborne...
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Do the performance calculation per the POH
Last month I did a flight test program on the prototype aircraft which was made in 1967, and type certified to FAR Part 23, and it has no performance information at all in the POH.
Hats off to those pilots who familiarize themselves with performance data before they fly, but the Stinson pilot likely had none whatsoever. However, that is no excuse for very poor decision making!
I agree with DAR; also even if an aeroplane of that vintage has performance data (the Stinson actually has published data - TODR is 1400ft for the 108-2 that I know well) it's for a new aeroplane back then, and anybody with any sense will add at-least 50% to that, and then still regard it with a pinch of salt.
G
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Big news - made the BBC: BBC News - Passengers capture Idaho plane crash on film