Grumman-AA5 pilot reported engine roughness in cruise flight that may have been related to fuel syst...

Attributes
ACN	1437982
Time
Date	201704
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	Cheetah Tiger Traveler AA5 Series
Operating Under FAR Part	Part 91
Flight Phase	Cruise
Route In Use	Vectors
Flight Plan	IFR
Component
Aircraft Component	Fuel System
Person 1
Function	Pilot Flying Single Pilot
Qualification	Flight Crew Instrument Flight Crew Flight Instructor Flight Crew Air Transport Pilot (ATP) Flight Crew Multiengine
Experience	Flight Crew Last 90 Days 100 Flight Crew Total 12000 Flight Crew Type 250
Events
Anomaly	Aircraft Equipment Problem Less Severe Inflight Event / Encounter Fuel Issue

Narrative:

After completing maintenance [at a nearby airport]; we departed IFR for the return to home base. An oil change; brake check; and the replacement of an aircraft [exhaust] stack had been performed. The aircraft departed with full tanks on the right side tank. After approximately 90 minutes of operation -departure and cruise at 4000'- the left tank was selected to balance the fuel and the next hour of flight was flown on that side of the fuel system. (Note: the grumman AA5A does not cross-feed. The aircraft carries 51 gallons of usable fuel.) selecting the right side tank again; and approximately 30 minutes from the destination; we were vectored toward [destination]. Shortly after the vectors began; low fuel pressure was noted; followed shortly thereafter by diminishing power; followed by surges. Suspecting a fault related to the recent maintenance; we immediately turned toward the nearest airport in the interest of safety. Nearing [divert airport]; we performed an emergency check on the system; part of which involved selecting the left (fuller) tank. Power was immediately restored. Additional checks were completed and the emergency was cancelled with a return to 4000' assigned altitude. The flight was completed safely.on arrival we investigated the right-hand tank fuel vent and found it clear and also a small amount of fuel still remaining in the right tank as well. The left tank still contained 15 gallons of fuel.

Original NASA ASRS Text

Title: Grumman-AA5 pilot reported engine roughness in cruise flight that may have been related to fuel system management.

Narrative: After completing maintenance [at a nearby airport]; we departed IFR for the return to home base. An oil change; brake check; and the replacement of an aircraft [exhaust] stack had been performed. The aircraft departed with full tanks on the right side tank. After approximately 90 minutes of operation -departure and cruise at 4000'- the left tank was selected to balance the fuel and the next hour of flight was flown on that side of the fuel system. (Note: the Grumman AA5A does not cross-feed. The aircraft carries 51 gallons of usable fuel.) Selecting the right side tank again; and approximately 30 minutes from the destination; we were vectored toward [destination]. Shortly after the vectors began; low fuel pressure was noted; followed shortly thereafter by diminishing power; followed by surges. Suspecting a fault related to the recent maintenance; we immediately turned toward the nearest airport in the interest of safety. Nearing [divert airport]; we performed an emergency check on the system; part of which involved selecting the left (fuller) tank. Power was immediately restored. Additional checks were completed and the emergency was cancelled with a return to 4000' assigned altitude. The flight was completed safely.On arrival we investigated the right-hand tank fuel vent and found it clear and also a small amount of fuel still remaining in the right tank as well. The left tank still contained 15 gallons of fuel.

Data retrieved from NASA's ASRS site 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.