Counter rotating propellers

Kevin Brooks wrote:
"Ken Duffey" wrote in message
...

Kevin Brooks wrote:
I believe they have had not one but two accidents ('95 and '01) tied to the
engines and props?

"10 February 1995.........Approximately at 17.30 local time, when
executing a manoeuvre not envisaged by the mission assignment, the An-70
collided with the An-72G that was flying ahead of it. The An-70 fell
into a wood near Velikiy Lis ....disintegrating utterly"

27 January 2001.......... at Omsk for cold-weather trials .... "Suddenly
the engine indication and crew alerting system (EICAS) indicated the
failureof starboard inboard engine; 20 or 30 seconds later the port
outboard engine cut as well..........

The accident investigation commission panel completed its work in March
2001......

.....stated that immediately after takeoff an overspeeding of the No 3
(starboard inboard) engines propfan occurred and the FADEC shut the
engine down. In so doing the second row of propfan blades failed to
feather due to a broken pipeline supplying oil to the blade pitch
control mechanism in the propfan hub .........The crew increased power
output of the other three engines, but at that moment the FADEC shut
down the No 1 (port outboard) engine....."

There is more - but from the above you can see that it has had two
crashed - one due to a mid-air collision with the chase plane, the
second due to a failure in the propfans - which has apparently been
fixed to the satisfaction of the Russians.

In neither case was the engine to blame.

The Ukrainian/Russian An-70 is a troubled program - but don't write it
off just yet!

Ken