Mailing List flyrotary@lancaironline.net Message #54288
From: Mark Steitle <msteitle@gmail.com>
Subject: Re: [FlyRotary] Re: Forced Landing.
Date: Sun, 20 Mar 2011 20:37:57 -0500
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Bill, 

The DNA (Dynamic Noise Attenuation) muffler is the only one I've used that has not self-destructed in a matter of hours, except for the tangential muffler which was too restrictive and caused other problems and gave poor performance.  (I should have listened to Lynn.)  The DNA is not as quiet as other mufflers, but it has worked for about 100 hours so far with no sign of fatigue.  Also, it has no packing to blow/burn out.  ANR headsets are a given.

Mark  



On Sun, Mar 20, 2011 at 4:10 PM, Bill Bradburry <bbradburry@bellsouth.net> wrote:

Bobby,

That is an excellent job of both flying and troubleshooting to discover the cause of the problem.  I am wondering why you have a muffler if you have a turbo?

 

My Hushpower is welded in and up inside the cowl.  I would not be able to see inside if or remove or replace it with the current setup.  This incident has really made me start to think about the muffler..  Thanks for the great report!

 

Bill B

 


From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Bobby J. Hughes
Sent: Sunday, March 20, 2011 4:02 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Forced Landing.

 

Since it’s been so quiet lately.

 

I had a complete loss of engine power yesterday during climb out from Tyler TX (KTYR). I had executed a Vx climb to see you hot I could get the oil with the supplemental oil cool I recently added. The engine was running but stopped making any power. I switch fuel tanks, adjusted the mixture both directions, toggled the primary injector switch for cold start and check my breakers. I did everything but switch to the B controller. All the troubleshooting took place in about 10 seconds or less. At that time my AOA starting telling me “angle, angle, push, push” . Glad I had the AOA as I’m not sure my attention was focused on the right priorities. I told the tower I had an engine failure and was landing. 35. Very happy this happened at an airport with three long runways with different headings. I pointed the nose down and made a right turn to the runway. The landing was downwind with 15 knot wind. I was too fast and used all 3500ft I had left. I coasted onto a taxiway with the engine idling very rough. I couldn’t make enough power to taxi. The FBO was there within two minutes and towed me back to their hanger. At this point I figured I had lost an apex seals. I pulled the prop through but had good compression. I pulled the cowl and everything was in place. Up until now I had remained very calm but that changed when I realized there was no smoking gun. I checked my injector power connections at the switches but everything seem good. The EC2 coil test worked but the injector test did not. I attempted an engine start and it ran normally. “What the h***” I later realized I had not activated the cold start switch for the injector test. Injectors tested fine. I was at a complete loss as what to look at next. I thought about a CAS intermediate failure but nothing I could come up with fit the problem. After another five minute full power run to 38”MP on both controllers I rolled the plane back into the FBO’s hanger and took a break. So here I am 200 miles from home after a forced landing and the plane is making full power as usual. Now the nerves set in full force. It downed on me to check the muffler for blockage. From what I could see with a flashlight the cone in my HushpowerII was out of place. I dropped the muffler from the belly and about a ½” cup of material came out. It was small pieces of mess from the cone. About 1/3 of the entrance side cone was still intact but the rest was gone. The internal steel support that forms the cone was still intact but movable with a large screw driver. I knocked as much out as I could and reinstalled the muffler. I was unable to knock out any of the mesh that was still in place. I decided to conduct a flight test over the airport for ten minutes. If all was good then I would head for home and climb to 8500 for the trip back. The headwind at 8500 would add 20 minutes to the flight unless I ran the engine above 30” MP. I didn’t think it was a good time to stress the muffler any more than necessary. I took off and climbed to 3000 ft on the B controller and circled for several laps. I switched controllers, fuel, injector cold start, coils and everything was normal. So I nervously departed for the 200 mile trip. I picked up flight following and had the autopilot/ flight director take me home. I spent the entire flight with the nearest airport active on my Advanced EFIS moving map. It draws a line, gives a distance and runway lengths. I also check airport information on my ipad and Foreflight. The flight was uneventful but was the most stressful I have ever experienced.

 

I’m guessing the muffler internals came loose and slid rearward trapping all the small come material that was dislodged. I was somewhere between Vx and Vy at a very high angle of attack when the problem occurred. The muffler is parallel l with the bottom of the fuselage so I believe any small dislodged material would remain inside the muffler. The plan now is to go through the entire electrical system and check every connection associated with the EC2 and fuel delivery. I will also be looking for a different muffle and putting the plane back into flight testing until I can regain my confidence with the install. I am also very thankful none of my family was onboard. My teenage daughter had decided she didn’t want to spend the remainder of spring break with me visiting my sister.

 

Bobby Hughes

(shaken not stirred)---- check your mufflers!!!!


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