This is an excerpt from a report made to the Aviation Safety Reporting System. The narrative is written by the pilot, rather than FAA or NTSB officials. To maintain anonymity, many details, such as aircraft model or airport, are often scrubbed from the reports.
I was picking up my PA-28 from the annual inspection.
I was three miles east of ZZZ2 and directly overhead of the raceway. I swapped fuel tanks and I could smell a distinct smell of oil/rubber burning. I immediately swapped the fuel tanks back and requested priority handling with ZZZ3 Approach. I was already talking to them for flight following.
At that point I requested vectors to ZZZ2, gave fuel quantity and souls on board. At that point the smell continued, however there was no sign of smoke or fire.
I decided to get the fire extinguish ready and available if a fire broke out. By the time I retrieved the fire extinguisher I was already passed the ZZZ2 airport and could visibly see helicopter traffic over the runway.
At this point the burning smell was gone and there was still no sign of smoke or fire.
I requested to proceed to ZZZ3, Approach asked if I would like to proceed to ZZZ.
At that point I determined the smell was gone and I was maintaining altitude and airspeed, so I proceeded to ZZZ.
Once Approach handed me to ZZZ I told them I did not have the burning smell and would switch fuel tanks 1-2 miles from the runway. I swapped fuel tanks and had no smell. I then landed without incident.
Once I landed I visually inspected the engine and cockpit and there was no sign of fire damage or short circuit.
During the flight I did have all available vents open and I believe this smell was from the ground.
Primary Problem: Aircraft
ACN: 1900439
Flying near a raceway, where burnouts are performed before each and every race to improve traction, would be a likely place to pick up burning rubber odor. Glad it wasn’t the plane.
The same thing happened to me years ago. The PA28 I was flying had just come out of annual. Turns out it was Varsol “cooking” off the engine after an engine cleaning. Scary, but not necessarily dangerous.
Not to suggest this was causal, but good annual inspections often include a wash down of the engine and engine compartment. This will leave elements of washdown material in heat muffs, shields, and trays to be evaporated once the engine reaches operating temperatures.