Mailing List flyrotary@lancaironline.net Message #16726
From: Bobby J. Hughes <bhughes@qnsi.net>
Subject: RE: [FlyRotary] Re: Bad day at the airport
Date: Tue, 8 Feb 2005 09:31:43 -0600
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Paul,
 
Glad you and your plane are ok.
 
It is my perception that the mixture knob may not control mixture trim by default. As you know I am going with a Microtech at least for the initial tuning of the engine on a test stand. Like the computer interface. Microtech indicated that they would have to configure my new controller for the knob to control mixture trim. As we have discussed offline their tech support guys told me twice that the knob would only work for boost control. The last email from then said it could be configured for mixture trim. Did Adkins provide any instructions for setup? It may not of had any effect on this problem but then again it might have.
 
Bobby Hughes


From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Paul
Sent: Monday, February 07, 2005 9:15 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Bad day at the airport

 
----- Original Message -----
From: John Slade
Sent: Monday, February 07, 2005 8:25 PM
Subject: [FlyRotary] Re: Bad day at the airport

I don't care to have this much fun again anytime soon.  I'm torn between a carburetor and a Cessna.  Paul Conner
Excellent job, Paul. The worst nightmare scenario, and you just "taxied back to the hangar". :)
 
So..... what caused it?
John
 
Hi, John....not exactly sure....most likely it was my attempts at programming the WOT mixture levels.  I just purchased the external mixture knob from Dave Atkins, but it only changes the mixture by plus and minus 10 percent, (so you don't have to go into the programming mode to make minor mixture adjustments). I tried that, but I suspect the mixture ratios were too far off for the external mixture knob to compensate for. Obviously, not enough time to start programming on the handheld ECU programmer during the flare.  Sh** happened very fast.   
      One thing I keep wondering about, however....Initially, I ran it up with the bigger prop and tried to get more rpm's.  Just wouldn't happen with a prop made for 200 horsepower, and a Turbo engine without a turbo that was probably capable of 140 horsepower.  I tried for quite some time, and the water temps finally hit 230 degrees, so I shut her down, and exchanged props.  It only took 10 minutes to change the prop, and when I turned on the ingintion to check temps, the water temp was still 210.  I started the engine. and while taxiing to the runway, the temps came down to 200. That's what the water temp was when I locked the brakes and checked my static rpm with the smaller prop. Temps of course started climbing, so I released the brakes to get some airflow to cool the radiator.  I have always been able to cool the engine in the climb, so I wanted to get airborne as soon as possible.  I assume the water temps were probably around 210 to 220 by the time I rotated.  I have never taken off with temps this high. I'm thinking it might be possible that the higher temps inside the cowling caused a vapor lock, or boiled the fuel out of the intake, or I ingested one of the many birds nests that the birds just constructed inside my cowling last night, or it was just the boogey-man.  Unfortunately, I was unable to get to 110 knots in the attempted climb, so I'm pretty sure I got no cooling assistance from incoming air. For some reason, I failed to watch all the gages while trying to avoid the windsock, so I didn't note just how high the water temp got.  I DO know that after I restarted the engine to get out of the mud, it had sufficient power to pull me out and back onto the taxiway, and back to the hangar.  I haven't run it since.  I may fire it up tomorrow and just take it up for one trip around the pattern (only kidding, Rusty). I may fire it up just to see if it runs OK and to see if there is any obvious problem. 
      We did an oil change, but I don't remember putting any oil back in after draining it...think that would make any difference?  (kidding).   Will keep you posted.  Paul, not flying now, Conner


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