GA small aircraft in-flight engine roughness. Return land.

Attributes
ACN	150006
Time
Date	199006
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : olu
State Reference	NE
Altitude	msl bound lower : 9000 msl bound upper : 9000
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Operator	general aviation : personal
Make Model Name	Small Aircraft, Low Wing, 1 Eng, Fixed Gear
Flight Phase	climbout : intermediate altitude
Route In Use	enroute airway : v172
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : commercial pilot : instrument pilot : cfi
Experience	flight time last 90 days : 30 flight time total : 1500 flight time type : 350
ASRS Report	150006
Person 2
Affiliation	Other
Function	other personnel
Qualification	other other : other
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	other flight crewa
Resolutory Action	flight crew : declared emergency none taken : unable
Consequence	Other
Supplementary
Primary Problem	Airport

Narrative:

Engine roughness, variable egt on cylinder #1 followed by fuel smell in cockpit. Advised ZMP of problem and that we were returning to point of departure (columbus, nb). Requested assistance of fire department at airport. Fuel was shut off on short final, aircraft was evacuated with no injuries following uneventful landing. Subsequent examination of the aircraft by a local mechanic revealed that the fuel injection lines to all 6 cylinders had not been tightened following annual inspection approximately 3 weeks (12-14 light hours) prior to this incident. In addition the spark plug wires to 5 of 12 spark plugs were improperly tightened (loose). Initial reaction to indications of a problem was that 'this can't be really happening' delaying response to the problem for several mins. Any further delay may have resulted in an in-flight fire. This points out the need for prompt reaction to a developing problem.

Original NASA ASRS Text

Title: GA SMA INFLT ENGINE ROUGHNESS. RETURN LAND.

Narrative: ENG ROUGHNESS, VARIABLE EGT ON CYLINDER #1 FOLLOWED BY FUEL SMELL IN COCKPIT. ADVISED ZMP OF PROB AND THAT WE WERE RETURNING TO POINT OF DEP (COLUMBUS, NB). REQUESTED ASSISTANCE OF FIRE DEPT AT ARPT. FUEL WAS SHUT OFF ON SHORT FINAL, ACFT WAS EVACUATED WITH NO INJURIES FOLLOWING UNEVENTFUL LNDG. SUBSEQUENT EXAMINATION OF THE ACFT BY A LCL MECH REVEALED THAT THE FUEL INJECTION LINES TO ALL 6 CYLINDERS HAD NOT BEEN TIGHTENED FOLLOWING ANNUAL INSPECTION APPROX 3 WKS (12-14 LIGHT HRS) PRIOR TO THIS INCIDENT. IN ADDITION THE SPARK PLUG WIRES TO 5 OF 12 SPARK PLUGS WERE IMPROPERLY TIGHTENED (LOOSE). INITIAL REACTION TO INDICATIONS OF A PROB WAS THAT 'THIS CAN'T BE REALLY HAPPENING' DELAYING RESPONSE TO THE PROB FOR SEVERAL MINS. ANY FURTHER DELAY MAY HAVE RESULTED IN AN INFLT FIRE. THIS POINTS OUT THE NEED FOR PROMPT REACTION TO A DEVELOPING PROB.

Data retrieved from NASA's ASRS site as of July 2007 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.