Narrative:

A friend and I rented an aircraft and decided to fly a cross country flight. Part 1 would be flown by me to maui (VFR). Part 2 was flown by my friend under an IFR flight plan from maui to honolulu. During part 2 of the flight (IFR), center told us to descend from 6000 ft to 4000 ft. We turned on carburetor heat, reduced throttle, and began to descend. After hitting our assigned altitude, my friend (the PIC) tried to increase power with the throttle, but the throttle was stuck. Neither he nor I could make the throttle move. With the reduced power applied, we were descending at 500 FPM whether we wanted to or not. After declaring an emergency, we began looking for a place to land. At this point we also agreed to turn carburetor heat off, thinking this may be causing the problem. At about 2000 ft, we were able to move the throttle and make a controled landing at the molokai airport. After approximately 2 1/2 hours of waiting for a commercial flight out of molokai to honolulu, I began looking in my 1999 far/aim for any regulation that specifically prohibits flight after an emergency situation or mechanical problem. After searching the far/aim for about 20-30 mins, I concluded that nothing specifically prohibits flight after an emergency or mechanical problem (so I thought). After talking with my friend, we both concluded that we would visually inspect the engine again, run the aircraft up and conduct extensive ground runup checks with the throttle. After extensive ground runup checks moving the throttle back and forth, I called the owner of the aircraft and told him that my friend and I felt comfortable enough to one-time-fly the aircraft back provided we never reduced the throttle below 2300 RPM, and never used carburetor heat. He agreed. I again talked with my friend and decided I would fly the aircraft back as the PIC. We took off out of molokai airport, never reduced the throttle below 2300 RPM (until we were on short final into honolulu), never used carburetor heat, and returned the aircraft to honolulu without incident. A few days after the flight, I received a call from the FAA who informed me the flight was not authority/authorized. All of my flight time, except 50 hours, is with the military, so I was unfamiliar with the FAA's policies that make an aircraft 'not airworthy' once a mechanical problem was idented. I thought I was within my authority/authorized to determine whether the aircraft was airworthy for a one-time flight back to its home base. After extensive visual checks and ground runup checks, and with a plan of action that would return me safely home, I thought I was completely within my rights as the PIC to determine whether that aircraft was airworthy for that one-time flight. I did not know that a 'ferry authority/authorized' was required nor does the far/aim state clearly that requirement. I also know that no time was I informed of such a requirement. I think a more clearly worded far/aim would prevent a recurrence.

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Original NASA ASRS Text

Title: PLT OF A PIPER PA28-140 FLEW ACFT TO HOME BASE AFTER DIVERTING TO ANOTHER ARPT IN AN EMER DUE TO A STUCK ENG THROTTLE CTL WITHOUT A MECH'S RELEASE FOR SVC, OR A FERRY PERMIT.

Narrative: A FRIEND AND I RENTED AN ACFT AND DECIDED TO FLY A XCOUNTRY FLT. PART 1 WOULD BE FLOWN BY ME TO MAUI (VFR). PART 2 WAS FLOWN BY MY FRIEND UNDER AN IFR FLT PLAN FROM MAUI TO HONOLULU. DURING PART 2 OF THE FLT (IFR), CTR TOLD US TO DSND FROM 6000 FT TO 4000 FT. WE TURNED ON CARB HEAT, REDUCED THROTTLE, AND BEGAN TO DSND. AFTER HITTING OUR ASSIGNED ALT, MY FRIEND (THE PIC) TRIED TO INCREASE PWR WITH THE THROTTLE, BUT THE THROTTLE WAS STUCK. NEITHER HE NOR I COULD MAKE THE THROTTLE MOVE. WITH THE REDUCED PWR APPLIED, WE WERE DSNDING AT 500 FPM WHETHER WE WANTED TO OR NOT. AFTER DECLARING AN EMER, WE BEGAN LOOKING FOR A PLACE TO LAND. AT THIS POINT WE ALSO AGREED TO TURN CARB HEAT OFF, THINKING THIS MAY BE CAUSING THE PROB. AT ABOUT 2000 FT, WE WERE ABLE TO MOVE THE THROTTLE AND MAKE A CTLED LNDG AT THE MOLOKAI ARPT. AFTER APPROX 2 1/2 HRS OF WAITING FOR A COMMERCIAL FLT OUT OF MOLOKAI TO HONOLULU, I BEGAN LOOKING IN MY 1999 FAR/AIM FOR ANY REG THAT SPECIFICALLY PROHIBITS FLT AFTER AN EMER SIT OR MECHANICAL PROB. AFTER SEARCHING THE FAR/AIM FOR ABOUT 20-30 MINS, I CONCLUDED THAT NOTHING SPECIFICALLY PROHIBITS FLT AFTER AN EMER OR MECHANICAL PROB (SO I THOUGHT). AFTER TALKING WITH MY FRIEND, WE BOTH CONCLUDED THAT WE WOULD VISUALLY INSPECT THE ENG AGAIN, RUN THE ACFT UP AND CONDUCT EXTENSIVE GND RUNUP CHKS WITH THE THROTTLE. AFTER EXTENSIVE GND RUNUP CHKS MOVING THE THROTTLE BACK AND FORTH, I CALLED THE OWNER OF THE ACFT AND TOLD HIM THAT MY FRIEND AND I FELT COMFORTABLE ENOUGH TO ONE-TIME-FLY THE ACFT BACK PROVIDED WE NEVER REDUCED THE THROTTLE BELOW 2300 RPM, AND NEVER USED CARB HEAT. HE AGREED. I AGAIN TALKED WITH MY FRIEND AND DECIDED I WOULD FLY THE ACFT BACK AS THE PIC. WE TOOK OFF OUT OF MOLOKAI ARPT, NEVER REDUCED THE THROTTLE BELOW 2300 RPM (UNTIL WE WERE ON SHORT FINAL INTO HONOLULU), NEVER USED CARB HEAT, AND RETURNED THE ACFT TO HONOLULU WITHOUT INCIDENT. A FEW DAYS AFTER THE FLT, I RECEIVED A CALL FROM THE FAA WHO INFORMED ME THE FLT WAS NOT AUTH. ALL OF MY FLT TIME, EXCEPT 50 HRS, IS WITH THE MIL, SO I WAS UNFAMILIAR WITH THE FAA'S POLICIES THAT MAKE AN ACFT 'NOT AIRWORTHY' ONCE A MECHANICAL PROB WAS IDENTED. I THOUGHT I WAS WITHIN MY AUTH TO DETERMINE WHETHER THE ACFT WAS AIRWORTHY FOR A ONE-TIME FLT BACK TO ITS HOME BASE. AFTER EXTENSIVE VISUAL CHKS AND GND RUNUP CHKS, AND WITH A PLAN OF ACTION THAT WOULD RETURN ME SAFELY HOME, I THOUGHT I WAS COMPLETELY WITHIN MY RIGHTS AS THE PIC TO DETERMINE WHETHER THAT ACFT WAS AIRWORTHY FOR THAT ONE-TIME FLT. I DID NOT KNOW THAT A 'FERRY AUTH' WAS REQUIRED NOR DOES THE FAR/AIM STATE CLRLY THAT REQUIREMENT. I ALSO KNOW THAT NO TIME WAS I INFORMED OF SUCH A REQUIREMENT. I THINK A MORE CLRLY WORDED FAR/AIM WOULD PREVENT A RECURRENCE.

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.