Posted for <n98pb@sbcglobal.net>:

First, I am writing this after reviewing all the information provided by the
 NTSB and the LML list.  The plane Dave was flying lifted off Somerset, PA,
 at treetop height it started emitting heavy black smoke and the engine
 sputtered and stopped producing power.
 
 
 Last week in Corona, CA I had an event that didn't strike me as relative
 until I reread those documents.  N98PB, IVP with 650 hours and just
 completing a 25 hour trip to East Coast Destinations.  During that trip I
 noticed that my normal Lean of Peak condition at 16.5 GPH was running rough
 until I increased it to about 17GPH where it settled down.  A LOP mag check
 was done at both fuel flow settings and at 16.5 it ran rough on both, at 17
 it was smooth on each of the mags.   I attributed this to a clogged injector
 and cleaned them upon returning home.  Temps during the trip all remained
 within the engines normal parameters.
 
 
 
 Now the issue:  I cleaned the injectors, pulled and cleaned the gascolator
 screen and blew out all the injector lines to the spider.   After this I did
 a full run-up and took to the air.  On the ground the run-up was uneventful.
 This changed once I left the ground.  Heavy black smoke and a very rough
 engine occurred just after lift off at about 100 feet or so.  I pulled the
 throttle back about 5 inches to just over 30, the engine smoothed out some
 and ground reports indicated that the smoking had ceased.  I realized the
 engine was going to continue running and turned back to the runway with a
 shallow 180.  I continued over the runway and again made a 180 for a normal
 landing into the wind.   Once on the ground the plane was de-cowled and
 inspected by a number of knowledgeable A/P types.   Again the injectors were
 inspected and cleaned, the valve covers removed to assure all rocker bosses
 and valves were acting normally through rotation and the gascolator removed
 and inspected.  All appeared normal.  I taxied the plane to the run-up area
 and did a high power run-up with all indications normal.  Two high speed
 taxi tests were done and everything appeared normal.  I lined up and took
 off again.  Same result ground run was perfect with the exception of
 slightly lower RPM (2650), rough engine once airborne, black exhaust, a
 check of the engine parameters indicated a full throttle fuel flow of 47.5
 gallons an hour(ff is set for 45.5 gph).  A pull back to 30 inches stopped
 the black exhaust and the engine ran much smoother.  An uneventful landing
 and another disassembly.  The fuel pump was sent to a shop for inspection
 and found to have a sticking aneroid and I am awaiting its return.  I also
 found several cracks in the right exhaust Tee which I don't think is related
 to the engine roughness and high fuel flow issue but is going to be a
 frequent inspection item as it could have been catastrophic.
 
 
 
 I don't know how of if this could relate to Dave's accident but it appeared
 so similar I wanted to put it out for thoughts and reference.  I won't have
 an positive answer to the issue until the parts are back and installed for a
 flight test but the pump is certainly outside of parameters.
 
 
 
 Comments and thoughts welcomed.
 
 
 
 Pat Brunner
 
 N98PB 650 hours IVP