Narrative:

After takeoff from jan en route to bed, and attempting to retract the flaps, discovered that the flaps would not retract past the 10 degree position. After following the checklist and proper procedures to correct the problem we determined that it was an asymmetry problem with the flaps and that the system had worked properly in stopping the flaps at the point of asymmetry. We continued the flight at FL190 and at a speed of no more than 250 KIAS, per the limitations of the afm for flaps extended at 10 degrees. Because of the low altitude flight, we had a higher fuel burn. We chose to land at an alternate airport (miv) along, and as far as we could legally and safely fly, our intended route. At a safe distance and altitude from miv, we tried one more time to operate the flaps, at which time they functioned normally in both directions. After making a normal landing without incident we taxied into the ramp and repeatedly cycled the flaps in their full range of motion numerous times to validate their proper function. Knowing from experience and from being taught during training, that this problem was and is a known occurrence of the gulfstream aircraft, though very rare, it is a 'quirk' that is consistent with its history. In addition, after functionally testing the flap system, my first officer and I both agreed that the problem no longer existed and therefore, did not warrant further action or a discrepancy report, as there no longer was a problem to report. Even if our calculations were incorrect, there never would have been a safety issue, as the worst possible scenario would be that after we would take off, the flaps would remain in the takeoff position of 20 degrees. The G1159 is easily capable of flying on 1 engine in that confign and all aircraft data is predicated on that confign. I explained to our far part 135 dispatch the above, and was released and dispatched for the continuation of our flight to our original destination of bed. After this whole event, we questioned if we were within proper procedure to have continued the flight, even though everything appeared as if we did everything that was in the best interest of safety, regulations and operational compliance. We feel that this report is warranted, because there is really nothing written or instructed that we should have done otherwise and this particular situation happens quite frequently in every and different aspects of aviation, just as someone would cycle their landing gear to achieve a down and locked indication then continue on their agenda without ever thinking about pursuing the matter further.

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Original NASA ASRS Text

Title: FLT CREW OF G159 ENCOUNTERS AN ASYMMETRICAL FLAP CONDITION ON TKOF FROM JAN. CONTINUE TO ALTERNATE FIELD AND LAND. DISCOVER FLAPS SEEM TO WORK OK AND DECIDE TO TAKE OFF AND CONTINUE TO ORIGINAL DEST.

Narrative: AFTER TKOF FROM JAN ENRTE TO BED, AND ATTEMPTING TO RETRACT THE FLAPS, DISCOVERED THAT THE FLAPS WOULD NOT RETRACT PAST THE 10 DEG POS. AFTER FOLLOWING THE CHKLIST AND PROPER PROCS TO CORRECT THE PROB WE DETERMINED THAT IT WAS AN ASYMMETRY PROB WITH THE FLAPS AND THAT THE SYS HAD WORKED PROPERLY IN STOPPING THE FLAPS AT THE POINT OF ASYMMETRY. WE CONTINUED THE FLT AT FL190 AND AT A SPD OF NO MORE THAN 250 KIAS, PER THE LIMITATIONS OF THE AFM FOR FLAPS EXTENDED AT 10 DEGS. BECAUSE OF THE LOW ALT FLT, WE HAD A HIGHER FUEL BURN. WE CHOSE TO LAND AT AN ALTERNATE ARPT (MIV) ALONG, AND AS FAR AS WE COULD LEGALLY AND SAFELY FLY, OUR INTENDED RTE. AT A SAFE DISTANCE AND ALT FROM MIV, WE TRIED ONE MORE TIME TO OPERATE THE FLAPS, AT WHICH TIME THEY FUNCTIONED NORMALLY IN BOTH DIRECTIONS. AFTER MAKING A NORMAL LNDG WITHOUT INCIDENT WE TAXIED INTO THE RAMP AND REPEATEDLY CYCLED THE FLAPS IN THEIR FULL RANGE OF MOTION NUMEROUS TIMES TO VALIDATE THEIR PROPER FUNCTION. KNOWING FROM EXPERIENCE AND FROM BEING TAUGHT DURING TRAINING, THAT THIS PROB WAS AND IS A KNOWN OCCURRENCE OF THE GULFSTREAM ACFT, THOUGH VERY RARE, IT IS A 'QUIRK' THAT IS CONSISTENT WITH ITS HISTORY. IN ADDITION, AFTER FUNCTIONALLY TESTING THE FLAP SYS, MY FO AND I BOTH AGREED THAT THE PROB NO LONGER EXISTED AND THEREFORE, DID NOT WARRANT FURTHER ACTION OR A DISCREPANCY RPT, AS THERE NO LONGER WAS A PROB TO RPT. EVEN IF OUR CALCULATIONS WERE INCORRECT, THERE NEVER WOULD HAVE BEEN A SAFETY ISSUE, AS THE WORST POSSIBLE SCENARIO WOULD BE THAT AFTER WE WOULD TAKE OFF, THE FLAPS WOULD REMAIN IN THE TKOF POS OF 20 DEGS. THE G1159 IS EASILY CAPABLE OF FLYING ON 1 ENG IN THAT CONFIGN AND ALL ACFT DATA IS PREDICATED ON THAT CONFIGN. I EXPLAINED TO OUR FAR PART 135 DISPATCH THE ABOVE, AND WAS RELEASED AND DISPATCHED FOR THE CONTINUATION OF OUR FLT TO OUR ORIGINAL DEST OF BED. AFTER THIS WHOLE EVENT, WE QUESTIONED IF WE WERE WITHIN PROPER PROC TO HAVE CONTINUED THE FLT, EVEN THOUGH EVERYTHING APPEARED AS IF WE DID EVERYTHING THAT WAS IN THE BEST INTEREST OF SAFETY, REGS AND OPERATIONAL COMPLIANCE. WE FEEL THAT THIS RPT IS WARRANTED, BECAUSE THERE IS REALLY NOTHING WRITTEN OR INSTRUCTED THAT WE SHOULD HAVE DONE OTHERWISE AND THIS PARTICULAR SIT HAPPENS QUITE FREQUENTLY IN EVERY AND DIFFERENT ASPECTS OF AVIATION, JUST AS SOMEONE WOULD CYCLE THEIR LNDG GEAR TO ACHIEVE A DOWN AND LOCKED INDICATION THEN CONTINUE ON THEIR AGENDA WITHOUT EVER THINKING ABOUT PURSUING THE MATTER FURTHER.

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.