AC5 M safety?

On Monday, January 20, 2014 10:27:22 PM UTC-7, Brad wrote:
just for the record:



I built a kit version of the Russia AC4-C and found it to be a very delightful sailplane to fly and never has any doubts as to it's structural integrity.



The aircraft employed many clever design features and while a lightweight machine, seemed very capable for what it was designed to do.



Brad



N199RK

The Collegiate Soaring Association has a Russia AC-4c based with the Penn
State Soaring Club. Many long flights have been accomplished in it. I have personally rigged it one-handed.

Frank Whiteley

On 21/01/2014 16:33, Frank Whiteley wrote:

The Collegiate Soaring Association has a Russia AC-4c based with the Penn
State Soaring Club. Many long flights have been accomplished in it. I have personally rigged it one-handed.

Frank Whiteley

Would that be one-handed or single-handed?

GC

On Tuesday, January 21, 2014 4:15:02 AM UTC-7, GC wrote:
On 21/01/2014 16:33, Frank Whiteley wrote:



The Collegiate Soaring Association has a Russia AC-4c based with the Penn

State Soaring Club. Many long flights have been accomplished in it. I have personally rigged it one-handed.



Frank Whiteley



Would that be one-handed or single-handed?



GC

Yeah I knew I'd flubbed that upon posting;^)

FW

AC5M broke up during flight testing for BGA CofA in the UK.

Pilot parachuted safely

AC5M didn't get BGA CofA

KN

At 19:34 19 January 2014, Nicholas L wrote:
Does anyone have any thoughts regarding the safety of the Russia AC5M
self
launcher?

The propeller is inches from the pilots head with the engine in the
stowed
position. How much of a hazard would this be in a hard landing or crash?

How safe is the cockpit? I dont much like the location of the fuel tank
The
2.5 gallon fuel tank is directly behind the pilots head.

I haven't found much data on the AC5M so any info would be appreciated.

Nick

On 01/21/2014 12:55 PM, Kevin Neave wrote:
AC5M broke up during flight testing for BGA CofA in the UK.

Interesting, is there a write up of the event? "broke up" is rather
broad...

Cheers,
Luke Szczepaniak

There's a known safety issue with AC5s, an aluminium propeller shaft should be replaced with a steel one. This have been discussed time and time again in the AC4 group. The replacement part can be ordered at the engine manufacturer. It takes a few minutes call to order a new shaft and an hour to replace it. If anyone is still flying with the aluminium propeller shaft, this is a stupid risk and one is just looking for trouble.

The BGA test pilot chose (rightly) to parachute out of the still flying
AC4 turbo (not self launching) after hearing a noise following the
'Vne' part of the test flight. Subsequently it was found to be an
airbrake issue that made the noise for which an AD was released
and additionally the VNE was lowered to 87 knots (if I remember
correctly). There was some discussion at the time that the ASI
might have been reading incorrectly due to the change of position
of the pitot for the turbo version? For what it's worth I am a huge
fan of the AC4 as a light weight soaring glider, not sure I would
personally be happy with one with a vibration creating engine
however, but many people have been very happy.

Chris


At 18:36 21 January 2014, Luke Szczepaniak wrote:
On 01/21/2014 12:55 PM, Kevin Neave wrote:
AC5M broke up during flight testing for BGA CofA in the UK.

Interesting, is there a write up of the event? "broke up" is rather
broad...

Cheers,
Luke Szczepaniak

I agree with Chris Davison regarding the AC4. Our club owned one for about 9 years and I flew it for about 100 hours. It is wonderful little glider and I loved flying it, but it is rather delicate and does not do well in a club atmosphere. Ours got banged up in off field landings and a couple of ground loops. Understanding the construction and light weight, like Chris Davison, I'd be worried about motor induced vibration too. However, it still a great little glider and I believe there are over 40 flying in the US.

Chuck Zabinski

Well, lets see. Two bailouts (1 successful), prop has a tendency to come off. Guess the original poster (Nick) has sufficient information to make an informed decision about the AC5M!
JJ

So if the aluminum shaft needs to be replaced with steel to prevent propellor separation, shouldn't there be an AD for it and non complying gliders should be grounded, especially since apparently it already killed at least one pilot?
I am curious if the NTSB report even mentioned if it was aluminum or steel shaft. Based on the quality of NTSB reports I have seen I wouldn't be surprised if the investigator wasn't even aware of this issue.

Ramy