|37000 Feet||Browse and search NASA's
Aviation Safety Reporting System
|Local Time Of Day||0601 To 1200|
|Locale Reference||atc facility : den|
|Altitude||msl bound lower : 6500|
msl bound upper : 7500
|Controlling Facilities||tower : aus|
|Make Model Name||Small Aircraft, High Wing, 1 Eng, Fixed Gear|
|Flight Phase||cruise other|
|Function||flight crew : single pilot|
|Qualification||pilot : atp|
|Experience||flight time last 90 days : 150|
flight time total : 9500
flight time type : 7500
|Anomaly||other anomaly other|
|Independent Detector||other other : unspecified|
|Resolutory Action||aircraft : equipment problem dissipated|
|Primary Problem||Flight Crew Human Performance|
|Air Traffic Incident||other|
I was breaking in a new engine on one of our small aircraft's in eastern co. I was over a sparsely populated area. When looking down towards the ground I saw what appeared to be a human body laying on the edge of a gravel/dirt county road. Thinking this might be an incident of a recent car-pedestrian hit and run accident, I descended for a closer observation. When going down the engine was rough sounding and then it sputtered and I lost power causing me to go lower than anticipated or necessary for the observation. I immediately checked fuel selector and enrichened the gas/air mixture and the engine responded with power and ran smoothly. I regained my altitude and made a proper observation and identify. My problem was that I leaned out the gas/air mixture at my cruise altitude to being leaner than expected. When pulling the mixture control to the aft position as I have on that airplane in the past, and listening for engine roughness and then pushing forward the control, it was quite lean. Because I was thinking about a human body laying on a road and getting emergency medical aid to it, I failed to enrichen my mixture during the descent and my engine was starving for the proper gas/air ratio mixture. New engine break in flts should be just that and no other duties should be involved. It is a time to become familiar with the new engine because there may be different adjustments, ie, carburetor settings, from what the pilot is used to on past performance. Callback conversation with reporter revealed the following: reporter felt he should have kept concentration on task of checking new engine. As state trooper however, observations of the unusual are normal procedure too. What reporter observed was a blanket roll.
Original NASA ASRS Text
Title: MOMENTARY REDUCTION OF ENGINE POWER.
Narrative: I WAS BREAKING IN A NEW ENG ON ONE OF OUR SMA'S IN EASTERN CO. I WAS OVER A SPARSELY POPULATED AREA. WHEN LOOKING DOWN TOWARDS THE GND I SAW WHAT APPEARED TO BE A HUMAN BODY LAYING ON THE EDGE OF A GRAVEL/DIRT COUNTY ROAD. THINKING THIS MIGHT BE AN INCIDENT OF A RECENT CAR-PEDESTRIAN HIT AND RUN ACCIDENT, I DSNDED FOR A CLOSER OBSERVATION. WHEN GOING DOWN THE ENG WAS ROUGH SOUNDING AND THEN IT SPUTTERED AND I LOST PWR CAUSING ME TO GO LOWER THAN ANTICIPATED OR NECESSARY FOR THE OBSERVATION. I IMMEDIATELY CHKED FUEL SELECTOR AND ENRICHENED THE GAS/AIR MIXTURE AND THE ENG RESPONDED WITH PWR AND RAN SMOOTHLY. I REGAINED MY ALT AND MADE A PROPER OBSERVATION AND IDENT. MY PROB WAS THAT I LEANED OUT THE GAS/AIR MIXTURE AT MY CRUISE ALT TO BEING LEANER THAN EXPECTED. WHEN PULLING THE MIXTURE CONTROL TO THE AFT POS AS I HAVE ON THAT AIRPLANE IN THE PAST, AND LISTENING FOR ENG ROUGHNESS AND THEN PUSHING FORWARD THE CONTROL, IT WAS QUITE LEAN. BECAUSE I WAS THINKING ABOUT A HUMAN BODY LAYING ON A ROAD AND GETTING EMER MEDICAL AID TO IT, I FAILED TO ENRICHEN MY MIXTURE DURING THE DSCNT AND MY ENG WAS STARVING FOR THE PROPER GAS/AIR RATIO MIXTURE. NEW ENG BREAK IN FLTS SHOULD BE JUST THAT AND NO OTHER DUTIES SHOULD BE INVOLVED. IT IS A TIME TO BECOME FAMILIAR WITH THE NEW ENG BECAUSE THERE MAY BE DIFFERENT ADJUSTMENTS, IE, CARB SETTINGS, FROM WHAT THE PLT IS USED TO ON PAST PERFORMANCE. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING: RPTR FELT HE SHOULD HAVE KEPT CONCENTRATION ON TASK OF CHKING NEW ENG. AS STATE TROOPER HOWEVER, OBSERVATIONS OF THE UNUSUAL ARE NORMAL PROC TOO. WHAT RPTR OBSERVED WAS A BLANKET ROLL.
Data retrieved from NASA's ASRS site as of August 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.