Has the fuel pump been inspected, especially the aneroid bellows?  I have had a similar issue on takeoff, high fuel flow with a very rich mixture to the point that people on the ground radioed that I was pouring black smoke.  I reduced the throttle as I had excess power and it smoothed the very rough running engine so I felt confident it would continue running.  I was afraid to do much more and left it alone until I got back to terra firma.  After this exercise, the ignition was completely gone through, the fuel setup was redone and all appeared perfect on run up, including a high speed taxi.  I took off again and it occurred once more.  I local mechanic suggested the fuel pump and aneroid valve.  I sent the pump in for inspection and rebuild if necessary.  The aneroid was found to be sticking, it was rebuilt and the problem has been gone for about 100 hours.  I believe this could very well be the problem, especially if the fuel set up was off to begin with.  The symptoms are exactly what I experienced.  Placing the fuel pump on would increase the problem. 

 

The engine on each takeoff was indicating a perfect running engine until I reached about 100 AGL.  This is when the engine is able to wind up and the fuel flow is at the maximum.  It did not do it on run up or high speed taxi.  Hope this is of some help.

 

Pat Brunner

LVP

 

-----Original Message-----
From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Rick Argente
Sent: Tuesday, June 05, 2007 6:15 AM
To: lml@lancaironline.net
Subject: [LML] Hickman's Accident: NTSB Probable Cause Report

 

The NTSB's probable cause report is now out on Dave Hickman's accident:

        http://www.ntsb.gov/ntsb/brief.asp?ev_id=20060522X00601&key=1

        http://www.ntsb.gov/ntsb/GenPDF.asp?id=NYC06LA112&rpt=fi

The National Transportation Safety Board determines the probable cause(s) of this accident as follows:

The pilot's failure to maintain sufficient airspeed after takeoff to preclude a stall, which resulted in a loss of control and an inadvertent stall. Factors associated with the accident are the inadvertent stall, the loss of engine power due to the pilot's inadvertent activation of the high pressure auxiliary fuel pump, and the pilot's failure to abort the takeoff after receiving abnormal engine and fuel flow warnings on the primary flight display.

IMHO, I find it difficult to believe that accidentally activating the auxiliary fuel pump will cause the fuel flow to increase approximately 10 gallons/hour (see detailed report) and cause the engine to fail.  I read the report a few times and cannot find any testing of the engine fuel pump.  Only the electric/auxiliary fuel pump was tested based on the report. 

Has any IV drivers here ever accidentally switched the aux fuel pump on while in flight?  What happened? 

-Rick