A pilot reports he heard a pop; felt a jolt forward of the firewall; smelled something burning and n...

Attributes
ACN	1103108
Time
Date	201307
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.TRACON
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Yankee AA1
Operating Under FAR Part	Part 91
Flight Phase	Cruise
Route In Use	Direct Vectors
Flight Plan	IFR
Component
Aircraft Component	Cowling
Person 1
Function	Pilot Flying Single Pilot
Qualification	Flight Crew Commercial Flight Crew Multiengine Flight Crew Sea Flight Crew Instrument
Experience	Flight Crew Last 90 Days 50 Flight Crew Total 840 Flight Crew Type 480
Events
Anomaly	Aircraft Equipment Problem Critical Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor

Narrative:

Heard a pop and felt a jolt forward of the firewall. Engaged electric fuel pump; suspected fuel flow fluctuation. Five minutes later; fuel pump turned off; engine instruments normal. Five minutes after that I smelled something burning and noticed an oil colored streak had appeared on the cowling moving aft. I initiated the engine fire in flight checklist and landed the aircraft on a us highway; northbound. The fiberglass nose cowling attach points failed and the cowling slid forward and came into contact with the propeller and the rear of the flywheel. The propeller and flywheel melted and wore through the fiberglass; causing the smell and the streak running up the cowling turned out to be fiberglass dust. I called my local mechanic that does all the work on my airplane to come down and we secured the cowling for the flight back to the home base of ZZZ. I do not see how this could have been avoided. The cowling felt secure when I checked it during preflight. I do believe I took the correct action by putting the airplane on the ground while I still had control over the situation.

Original NASA ASRS Text

Title: A pilot reports he heard a pop; felt a jolt forward of the firewall; smelled something burning and noticed an oil colored streak had appeared on the cowling moving aft while flying his Grumman AA-1 aircraft. Suspecting an engine fire; he landed on a Highway. The fiberglass nose cowling had slid forward; contacting propeller and aft side of the flywheel.

Narrative: Heard a pop and felt a jolt forward of the firewall. Engaged electric fuel pump; suspected fuel flow fluctuation. Five minutes later; fuel pump turned off; engine instruments normal. Five minutes after that I smelled something burning and noticed an oil colored streak had appeared on the cowling moving aft. I initiated the Engine Fire in Flight Checklist and landed the aircraft on a US Highway; northbound. The fiberglass nose cowling attach points failed and the cowling slid forward and came into contact with the propeller and the rear of the flywheel. The propeller and flywheel melted and wore through the fiberglass; causing the smell and the streak running up the cowling turned out to be fiberglass dust. I called my local Mechanic that does all the work on my airplane to come down and we secured the cowling for the flight back to the home base of ZZZ. I do not see how this could have been avoided. The cowling felt secure when I checked it during preflight. I do believe I took the correct action by putting the airplane on the ground while I still had control over the situation.

Data retrieved from NASA's ASRS site as of July 2013 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.