EC135
Joined: May 2003
Posts: 921
Likes: 30
From: Europe
traicar,
These are different failure modes addressed in different ways. My suggestion would be that they continue to be so.
A tail rotor failure before a safety speed has been reached in a CAT A helicopter, in any type of departure, will (likely) result in a poor outcome.
A CAT A helicopter relies upon certification standards for avoidance of single-point-of-failure component accidents; yes the tail rotor and its drive system are weak points - that is why there are proposals to monitor their health.
These emergencies should be addressed as independent events. The probability of an engine failure is (about) 1:100,000 flight hours. The tail rotor should have a failure rate better than that. The evidence that I have seen appears to show that tail-rotor failures are a more common event on non-CAT A helicopters.
Jim
These are different failure modes addressed in different ways. My suggestion would be that they continue to be so.
A tail rotor failure before a safety speed has been reached in a CAT A helicopter, in any type of departure, will (likely) result in a poor outcome.
A CAT A helicopter relies upon certification standards for avoidance of single-point-of-failure component accidents; yes the tail rotor and its drive system are weak points - that is why there are proposals to monitor their health.
These emergencies should be addressed as independent events. The probability of an engine failure is (about) 1:100,000 flight hours. The tail rotor should have a failure rate better than that. The evidence that I have seen appears to show that tail-rotor failures are a more common event on non-CAT A helicopters.
Jim
Joined: Sep 2000
Posts: 1,605
Likes: 6
From: UK
There was that Japanese 135 which had a tail-rotor-driveshaft/control failure IIRC.
The important bit I remember was that it was a 135 which had no Autopilot fitted and the bit in the tail which gets replaced with another bit which allows the Autopilot to control the Fenestron had failed. So as long as you have the Autopilot fitted to the aircraft that particular failure shouldn't happen.
Does that make sense?
The important bit I remember was that it was a 135 which had no Autopilot fitted and the bit in the tail which gets replaced with another bit which allows the Autopilot to control the Fenestron had failed. So as long as you have the Autopilot fitted to the aircraft that particular failure shouldn't happen.
Does that make sense?
Joined: Feb 2006
Posts: 1,067
Likes: 40
From: On the big blue planet
And there was another one, which lost the T/R driveshaft somewhere near Manching airfield. It was a ECD testpilot, who encountered this experience in the early days of the 135 ( Problems with T/R driveshaft bearings ).
The japanese H/C had a broken fenestron pitch link due to a blocked bearing (?), after that, EC changed the design.
I know of at least two complete enginefailures ...
skadi
The japanese H/C had a broken fenestron pitch link due to a blocked bearing (?), after that, EC changed the design.
I know of at least two complete enginefailures ...
skadi
Joined: Feb 2006
Posts: 1,067
Likes: 40
From: On the big blue planet
One was a engine-fuelpump driveshaft failure and the otherone also a mechanical failure in the engine gearbox, but I do not remember exactly what it was. Both engines stopped working, but no problem, cause the otherone did
skadi
skadi
Joined: Feb 2006
Posts: 1,067
Likes: 40
From: On the big blue planet
So it wasn't both engines on the same aircraft decided to stop working at the same time.....
skadi
Joined: Feb 2006
Posts: 1,067
Likes: 40
From: On the big blue planet
It was PT-6 or Turbomeca Arriel?
and powerful.I do not remember very well, but i think, the fuelpump issue was on a T1 and the other one was a P2 ( PW 206 ).
skadi
Joined: Feb 2006
Posts: 1,067
Likes: 40
From: On the big blue planet
Joined: Nov 2006
Posts: 1,951
Likes: 90
From: After all, what’s more important than proving to someone on the internet that they’re wrong? - Manson
Looks like a T2+ or e.
With the IBF fitted there is no longer any engine air going in the front of the cowling. The oil cooler exhaust is ducted up to the top rear of the upper cowling (gear cover) so it is not ingested into the engine from the normal outlet via the IBF. When the IBF is in bypass there is probably enough air available from the area of the mast and swashplate opening.
They may all end up looking like this in the future?
With the IBF fitted there is no longer any engine air going in the front of the cowling. The oil cooler exhaust is ducted up to the top rear of the upper cowling (gear cover) so it is not ingested into the engine from the normal outlet via the IBF. When the IBF is in bypass there is probably enough air available from the area of the mast and swashplate opening.
They may all end up looking like this in the future?
Joined: Sep 2000
Posts: 1,605
Likes: 6
From: UK
What I would like to know is how those particular flights finish after having lost an engine...I mean did the pilot scare himself or did he just take this bit of info in and land back on?
Isn't that where the aircraft will show it's mettle as in how it deals with problems? Or am I being naive......
Isn't that where the aircraft will show it's mettle as in how it deals with problems? Or am I being naive......
Joined: Feb 2006
Posts: 1,067
Likes: 40
From: On the big blue planet
What I would like to know is how those particular flights finish after having lost an engine...I mean did the pilot scare himself or did he just take this bit of info in and land back on?
skadi