Mailing List flyrotary@lancaironline.net Message #45698
From: John Slade <jslade@canardaviation.com>
Subject: Re: [FlyRotary] Re: forced landings
Date: Mon, 13 Apr 2009 19:11:16 -0400
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
>I don't have that one on my list.  Can you provide some more info?
Stock 2nd gen turbo was being deliberately pushed at 11000' and 42 map (5500 rpm) to see if it could handle the punishment.  It lasted about 45 mins. Bearings collapsed and impellor disintegrated (not sure which caused which) resulting in 1500 rpm drop. Aircraft was flown 35 miles at reduced power to a normal landing. Examination of the engine showed scores on the rear rotor and one stuck seal where the gap had been 'bent' closed. Bystanders reported oil smoke from exhaust. Oil was 2 quarts low on landing 15 mins after the event.  At that rate I would have been at zero oil in  45 mins.

>So, when will you be installing a turbo oil shutoff valve on your engine?  Sounds like cheap insurance to me.
I wasn't planning to. It seemed to me that the best solution was to remove the stock Mitsubishi unit and get a turbo that wont disintegrate. I have over 50 hours on the replacement turbonetics T04 with no problems.

>just because it is in flight does not make it newsworthy. 
I agree. It's not the actual PF that counts, it's the potential PF. Ed was very lucky to notice his woodruff key problem during run-up. If the oil pump had quit at rotation, he could have lost all power in the oh sh.t zone for a PF of 12. Similarly, if my turbo hose problem had occurred during max gross weight testing or during flights with the fixed pitch prop, I might not have been able to climb and complete the pattern. (Note - I DID have a bead on the pipe, but was using the thinner blue hose you can get on-line, and it had some oil on it. The thicker (3/16?) or good quality radiator hose is better, and it has to be dry. It's amazing how much pressure 44 map puts on a hose joint. What's really nasty is that often it won't blow during runup. It blows once the rpm comes up - typically just as you rotate.

>SO, a key factor of your table is some narrative of the 'incidents' impact on flight capabilities of the event.
Yes - or rather potential for impact.

John

Mark Steitle wrote:
John,
 
I don't have that one on my list.  Can you provide some more info?
 
So, when will you be installing a turbo oil shutoff valve on your engine?  Sounds like cheap insurance to me.
 
Mark

On Mon, Apr 13, 2009 at 8:34 AM, John Slade <jslade@canardaviation.com> wrote:
>interrupts the planned flight and results in a premature landing
Does anyone else find it amusing / ironic that blowing a turbo in flight, and ingesting enough debris to destroy a rotor doesn't necessarily constitute an "incident" because the engine kept running and the plane kept flying. :)
Actually, this one did "interrupt" the flight, or would have if I hadn't landed,  because I was loosing oil from the turbo housing. (I don't have Dave's oil shut off).


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