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AC5 M safety?

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Nicholas L

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Jan 19, 2014, 2:34:05 PM1/19/14
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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

herbk...@gmail.com

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Jan 19, 2014, 4:19:47 PM1/19/14
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If I understand you correctly, the propeller is stowed inside the fuel tank?

Brad

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Jan 19, 2014, 5:30:52 PM1/19/14
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yes, that is true..............the designers felt storing the prop inside the fuel tank promoted better mixing of the 2-stroke mixture.

Brad

Waveguru

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Jan 19, 2014, 7:36:22 PM1/19/14
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Gives a whole new meaning to propping your head up.

Boggs

Nicholas L

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Jan 19, 2014, 7:40:41 PM1/19/14
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The prop stows just behind the pilots head, the fuel tank sits below the prop.

http://soarcny.blogspot.com/2008/05/dons-new-ac-5m-russia-may-13.html


gotovkotzepkoi

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Jan 19, 2014, 11:50:07 PM1/19/14
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Safe, quality? Ask yourself, do you know of any Russian products at all
that sell outside of Russia? No? That's because there aren't any. They
don't make anything worth buying.




--
gotovkotzepkoi

krasw

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Jan 20, 2014, 6:43:00 AM1/20/14
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AK47?

JJ Sinclair

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Jan 20, 2014, 9:33:35 AM1/20/14
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I would be more concerned with the what the prop might do when it comes off the engine...............tragic accident not long ago, where the ship was seen in a hard left turn at about 500', then the pilot tried to bailout, but was too low. Prop was found stick in the left wing!
JJ

Soartech

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Jan 20, 2014, 1:09:59 PM1/20/14
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Oh, I think Syria would disagree with you.

Dan Marotta

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Jan 20, 2014, 1:22:43 PM1/20/14
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Stolichnaya...


"Soartech" <pyroar...@gmail.com> wrote in message
news:35a860cb-da3c-4f46...@googlegroups.com...

Frank Whiteley

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Jan 20, 2014, 2:19:18 PM1/20/14
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groups.yahoo.com and join ac4

There is as much or more discussion among ac5m owners as anything else. There have been some prop shaft failures, but there is some discussion of a replacement part.

The ac5m listed on barnstormers.com is not listed in the group, but others there may be able to comment.

Frank W

Eric Greenwell

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Jan 20, 2014, 6:52:54 PM1/20/14
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Propellers have come off DG400 and PIK 20, so it's not specific to the
AC-5M. Who was pilot in the AC-5M accident you mentioned?

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

JJ Sinclair

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Jan 20, 2014, 9:11:59 PM1/20/14
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The fatal AC-5M accident I referred to happened on 19 May, 2012 at Kingston, NV. Preliminary accident report stated the prop was found imbedded in a wing, however the final report contains no such statement. The engine was displaced from its normal position and I suppose the prop may have been sticking into the left wing, but the finding was that no malfunctions were found in the airframe. Guess that's why preliminary reports are just that. The final report makes no attempt to explain what appears to be an uncontrollable turn or why the pilot attempted to bailout of a properly operating aircraft at very low altitude.
JJ

kru...@sbcglobal.net

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Jan 20, 2014, 10:08:56 PM1/20/14
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I don't think anyone can argue about the AK-47 - Throw it in the mud, drive over it with a jeep, chamber a round and it still throws lots of lead downrange. But one of the reasons it works so well is exactly because it is built with loose tolerance machining and metal stamping.

Brad

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Jan 21, 2014, 12:27:22 AM1/21/14
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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

Frank Whiteley

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Jan 21, 2014, 12:33:24 AM1/21/14
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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

GC

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Jan 21, 2014, 6:15:02 AM1/21/14
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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

Frank Whiteley

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Jan 21, 2014, 9:11:59 AM1/21/14
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Yeah I knew I'd flubbed that upon posting;^)

FW

Kevin Neave

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Jan 21, 2014, 12:55:01 PM1/21/14
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AC5M broke up during flight testing for BGA CofA in the UK.

Pilot parachuted safely

AC5M didn't get BGA CofA

KN

Luke Szczepaniak

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Jan 21, 2014, 1:36:28 PM1/21/14
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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

dchi...@gmail.com

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Jan 23, 2014, 8:09:10 PM1/23/14
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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.

Chris Davison

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Jan 24, 2014, 7:28:03 AM1/24/14
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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

JJ Sinclair

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Jan 24, 2014, 12:32:23 PM1/24/14
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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

chuc...@gmail.com

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Jan 24, 2014, 12:39:24 PM1/24/14
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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

Ramy

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Jan 26, 2014, 9:10:04 PM1/26/14
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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
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