Skymaster down Colorado

Thoughts on cause? Is "Left-hand Canyon" the kind of terrain where mountain flying is a factor?
 
It is high and hot so high density altitude. So yeah, mountain flying knowledge could be useful. Don’t know anything about this accident though.
 
Looking at a map of the crash area, it is a canyon with rising terrain, but not a particularly big or high one. Floor about halfway up is at 7800' and ridgeline to the south is at about 8600' with some lower saddles and passes. Mouth of the canyon is at 6000'. Boulder is at about 5500'.
 
Hats off to you high terrain folks. Flying today with a DA of 2500’ and felt like I was dragging an anchor on the tail. No experience with the real mountain stuff, but would get some training before attempting. Always sorry to hear this.
 
By pure coincidence I had a look at their website, bluebirdaviation.co (now offline) just few days ago. They seemed professional and were offering training in their skymaster. It is hard to believe that they did not consider the risks of high DA, since they were offering tours in the same area practically every day. There must be something more to this crash that we don't know yet.
 
This is local to me and there's been some minimal non-aviation press coverage: https://coloradosun.com/2022/07/19/sightseeing-flight-crash-boulder-county/
Definitely a high density altitude area day and significant rising terrain. However, seems like they had done this lots of times before?
I second the above suggestion from Sifossifoco - must be something else, too.
Very very sad for the people, their families, and, unfortunately, another piece of bad press for GA.
 
Sifossifoco said:
By pure coincidence I had a look at their website, bluebirdaviation.co (now offline) just few days ago. They seemed professional and were offering training in their skymaster. It is hard to believe that they did not consider the risks of high DA, since they were offering tours in the same area practically every day. There must be something more to this crash that we don't know yet.
Click to expand...
You can always go back to archive.org...

http://web.archive.org/web/20220331025114/https://www.bluebirdaviation.co/

And yes, it does look like they weren't just a a fly-by-night outfit. Odd.
 
Flying toward rising terrain the loss of an engine, particularly the rear one, would have put them in a bind. While not familiar with the area, I looked at the area of the crash on googol earth, but I can't tell if there would have been room to turn around ... or not. The only photo I've seen of the crash site is the one in the Colorado Sun article linked in G-Man's post above; consequently, it's tough to tell if it looked like a CFIT or something else. Does anyone know what of sort of AGL the tour operator would have maintained in the area?

R.I.P.
 
Capngrog said:
Flying toward rising terrain the loss of an engine, particularly the rear one, would have put them in a bind. While not familiar with the area, I looked at the area of the crash on googol earth, but I can't tell if there would have been room to turn around ... or not. The only photo I've seen of the crash site is the one in the Colorado Sun article linked in G-Man's post above; consequently, it's tough to tell if it looked like a CFIT or something else. Does anyone know what of sort of AGL the tour operator would have maintained in the area?

R.I.P.
Click to expand...
So I take it the rear engine provides more thrust than the front. How much?
 
I don't recall having read/been told what the thrust differential was/is, but I've known a couple of O-2 FACS who told me about the differential, and I've also read it somewhere. It does seem counter-intuitive to me that the rear engine would be the more efficient, because one would think that the turbulence created by the fuselage, scoops, etc. would decrease the efficiency of the rear propeller. I just did a quick search of the ol' "Interweb", but was not able to find anything on the Skymaster critical engine question. I'll have to look into this further, but not right now. I guess I could discount my information as "popular myth" except for the quality of the guys who gave me the story to begin with.
 
Here's an excerpt from an August, 2015 on line AVweb article

"What’s surprising is the difference between the front and rear engines. Climb on the front engine only is about 50 FPM less than on the rear, but not necessarily for all versions of the Skymaster. Reader Robert Prader told us his research reveals that later models have better front-engine performance. “It is true that front and rear engine single-engine climb rates are significantly different for all pre-1973 Skymaster models; however, the front and rear single-engine climb rates are not significantly different for the pressurized models and the 1978 and later turbo models,” he said. “If you consult the POH for any pressurized model, you will find that a single-engine climb rate of 375 FPM is listed for a standard day at sea level at gross weight, with no mention of which engine is out. If you consult the POH for the 1980 non-pressurized turbo model, you will find it specifies a climb rate of 335 FPM for the same conditions, again with no mention of which engine is out.”

A November, 1982 magazine article reproduced some performance figures from the Pilots' Operating Handbook as follows:
  • 1964 Cessna 336 single engine rate of climb - front only, 355 fpm, rear only 422 fpm;
  • 1964 Cessna 336 single engine service ceiling - front only, 8,200 ft, rear only, 9,500 ft;
  • 1965 Cessna 337 single engine rate of climb - front only, 360 fpm, rear only 450 fpm;
  • 1965 Cessna 337 single engine service ceiling - front only, 8,200 ft, rear only, 10,200 ft;
  • 1970 Cessna T337E (turbocharged) single engine rate of climb - front only, 295 fpm; rear only, 375 fpm;
  • 1970 Cessna T337E single engine service ceiling - front only, 14,400 ft., rear only, 17,200 ft;
  • 1973 Cessna T337G (turbocharged & pressurized) single engine rate of climb - front only, 375 fpm, rear only, 375 fpm;
  • 1973 Cessna T337G single engine service ceiling - front only, 18,700 ft; rear only, 18,700 ft.
For the 1960s era 337s, it seems that performance on the rear engine only was around 25% better than the performance on the front engine only. It is my understanding that the later model Cessna 337s had roughly the same single engine performance regardless of whether it was the front only or the rear only. It's my guess that the Cessna O-2As as flown in Vietnam were similar in performance to the 1965 Cessna 337.
 
I've read that the Rutan Voyager and Defiant (both push/pull twins) were not much better than gliders if the rear engine fails and you dont/cant feather or stop the rear from windmilling. The thrust of the front engine goes directly into the drag of the spinning rear prop. I'd assume the 337 would suffer this as well.
 
I'm unaware of any twin that can stay in the air with the failed engine unfeathered and windmilling. Unless really, really lightly loaded, even a 4 engine (recip) transport category aircraft is unable to maintain altitude with a windmilling failed engine. I'm not so sure about the turbine-powered aircraft, such as the Electra.
 
Back to the subject of this thread ...

The names of the crash victims have been released on Kathryn's Report Some of the Flightaware experts are citing pre-accident climb rates that would indicate an engine out several minutes before the crash.
 
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