ZBBYLW From Canada, joined Nov 2006, 1922 posts, RR: 7 Reply 1, posted (5 years 11 months 2 weeks 2 days ago) and read 4406 times:
While a DHC-8 "COULD" probably land here when you factor in things such as engine out situations then the aircraft may not be legally allowed to land there. I am sure a DH8 could do it, but legally I am not sure... Also they take off down hill so they get extra speed going down... I am not sure performance charts of high performance aircraft integrate the runway gradient into any calculations.
once again, no it is not a true STOL aircraft. The definition of STOL (NATO) is:
Short Take-Off and Landing (décollage et atterrissage courts) is the ability of an aircraft to clear a 15 m (50 ft) obstacle within 450 m (1,500 ft) of commencing take-off or, in landing, to stop within 450 m (1,500 ft) after passing over a 15 m (50 ft) obstacle.
The slightly less obscure FAA-proposed version:
STOL Takeoff distance of: 700' for aircraft under 500lbs MTOW, 1,200' for aircraft 5,001-15,000lbs MTOW, 1,800' for aircraft 15,001lbs MTOW or more.
The FAA version was never adopted, but it was the basis for the STOL aircraft designs of the 60s and 70s.
OyKIE From Norway, joined Jan 2006, 2575 posts, RR: 4 Reply 9, posted (5 years 11 months 2 weeks 1 day 6 hours ago) and read 3269 times:
Quoting 8B775ZQ (Reply 4): If the DHC8 is not a STOL, then what is it really?
When the Dash-8 was being developed, airlines was not that interested in STOL capability. The airlines wanted cheaper turboprop, and the Dash-7 was an expensive plane. The Dash-8 is cheaper both to build and in operation. STOL capability was abandoned since most airplanes in this segment has no use fo it.
Dream no small dream; it lacks magic. Dream large, then go make that dream real - Donald Douglas
Legacy135 From Switzerland, joined May 2005, 1052 posts, RR: 29 Reply 12, posted (5 years 11 months 2 weeks 1 day 5 hours ago) and read 2533 times:
Don't waist to much time about what a STOL aircraft is and what not. The fact is, the Dash 7 can be considered "safe enough" to meet commercial OPS requirement in Courchevel, while the Dash 8 can't. Let me explain why:
Any commercial operation needs to meet the required take off performance. This includes:
- All engine go
- Accelerate Stop (Accelerate to decision speed, loose an engine and come to a stop on the remaining part of the runway)
- Accelerate Go (Accelerate to decision speed, loose and engine and continue your take off safely)
Any take off has to be aborted, if "VMC G" (Minimum Control Speed Ground) is not met. Otherwise it will leave the runway and crash. It for sure can't be rotated either, before Minimum Control Air is reached, otherwise you lift off and crash right away. Here we come to the big problem for any Multi Engine Take Off in Courchevel. Due to the slope, the Take Off can't be aborted, once initiated. So, Accelerate Stop you can forget for any aircraft taking off in Courchevel. This for the very simple reason, once the aircraft comes in the slope, there will be no way to bring it to a stop. It has to lift off or will crash at the end of the runway.
All engine go would probably be met also for the Dash 8. As the Dash 7 was successfully operated in Courchevel for years, I think we do not need to debate if it meets or not
Accelerate Go on the Dash 7 isn't a big issue, as the aircraft will lift off in Courchevel anyhow on the 3 remaining engines (more details at the end). The Dash 8 on the other hand has the big problem, that between a certain speed and Minimum Control Speed Ground, it ends up uncontrollable but the take off could not be aborted either.
The Dash 7 had a Minimum Control Speed Ground Issue in Couchevel as well. The thing was, that loosing one of the outboard engines below a certain speed would not allow to keep the aircraft straight. So Tyrolean developed a procedure which was finally accepted by the authorities and allowed them to fly safely for years in and out of Courchevel.
Their procedure was to bring both inboard engines to take off power, but the outboard ones only to a reduced setting, allowing them still to keep straight if one of them was lost. At Minimum Control Speed Ground, the assisting pilot had then to advance the two outboard throttles as well to take off power. So in fact, they started their take off roll in Courchevel with a partially reduced power setting, which was brought up during the roll.
Tyrolean demonstrate here that even unconventional procedures can give a safe and successful operation, if it is adapted seriously and the crews well trained for.
Legacy135 From Switzerland, joined May 2005, 1052 posts, RR: 29 Reply 13, posted (5 years 11 months 2 weeks 1 day 5 hours ago) and read 2452 times:
Quoting Thepilot (Reply 11): do any DHC-6 twin otters go into Courchevel? Also, I wonder, would it theoretically be possible for a DHC-7 to land in Lukla? Just curious...
About 6 to 7 years ago they tried to create an airline, if I remember right it was "Alp Azure" or so. They flew a Twin Otter in and out of Courchevel, but not very long....... for the same issue I described already above: Minimum Control Speed Ground.
They had a ferry flight to GVA and during the take off the crew wanted to do an exercise, simulating an engine failure. They successfully demonstrated that their calculation presented to the authority about control-ability of the aircraft on one engine was wrong: They plane departed in the snow and one wing was broken off.
Flying in Courchevel is fun, but their is also a risk. On approach there comes the point where no Go Around is possible anymore, on departure no abortion is possible either. So in either case it has to work on the first attempt. Probably the best and only workhorse to fly there commercially is a Dash 7 as it eliminates basically any need to abort a take off.