RV-9
Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Flight Instructor
Flight Crew Last 90 Days 45; Flight Crew Total 6500; Flight Crew Type 1000
Aircraft Equipment Problem Critical; Inflight Event / Encounter Fuel Issue
Air Traffic Control Provided Assistance; Aircraft Equipment Problem Dissipated; General Declared Emergency
Aircraft
Ten minutes after departing [from a refueling stop] the engine RPM started to decay from 2;500 to 2;350. Adjusted mixture to rich and engine became rough and RPM fluctuated between 1;900 and 2;300 RPM. Found a likely landing spot on paved highway and set up glide and ran Engine Fail In-flight Checklist; changed tanks; boost pump on; mixture rich; throttle idle; at that point engine started to run better but not normally. I made initial contact with Center; on the flight following frequency I have used prior to starting approach to [the airport]. Controller answered. I informed him I was having engine trouble and declared an emergency. I told him I was planning on landing on the paved highway below. He initially asked for position and altitude; gave me a squawk and tried to locate us. Sometime later fuel and Souls On Board (SOB). He was unable to locate us and I gave him coordinates. During this time; I kept trying to get power from the engine; sometime during initial contact; after trying several combinations of throttle and mixture settings the engine started running normally. I suspected fuel contamination; and whatever was causing the problem passed through the system. After determining the engine was providing normal power; I informed the Controller; I was going to try to make an airstrip further [along my route. I was eventually able to climb up to 11;500 FT and continue to my destination; always with an airport in gliding range but no further problems occurred.]
The reporter states that he flew three hours to the fuel stop in question then ten minutes after takeoff the engine began to loose power. The engine analyzer indicated that the back two cylinders had no EGT with the others indicating normal. Once power returned to normal so did the EGT's and the flight was continued another three hours to destination at 11;500 FT with no problems. Fuel samples after landing indicated no contamination and two subsequent flights have been uneventful. This engine is equipped with a carburetor.
RV-9 pilot reports loosing power ten minutes after takeoff from a fuel stop. The engine continues to make power and a landing on a highway is delayed in hopes of landing at an airport. Before that can happen the engine begins to run normally again and the flight continues to destination.