Narrative:

I am a CFI and was giving commercial instruction to a student. This student is very familiar with this aircraft with over 250 hours in it. We did a complete preflight including sumping all fuel drains and directly inspecting the fuel quantity which was approximately half tank; which is about 3 hours fuel in this aircraft. I personally checked the fuel samples for water and found no water or other contaminants. After a complete preflight and pretkof briefing; I instructed the student to perform a soft field takeoff. She made a perfect soft field takeoff; and as she was just starting to push the nose down to gain airspeed after simulating 'all obstacles cleared' at about 60 ft; she said 'something is wrong' at the same moment I felt a large loss of power. It felt to me as if she had retarded the throttle and that is where I looked first. She continued to push the nose down to go to best glide speed. As soon as I looked at the throttle I saw that all 3 power controls were full forward and realized that we really had a serious emergency. I glanced outside to look for an immediate landing spot and saw that we probably had enough runway left in front of us as a result of the soft field takeoff. She was already pulling the throttle to idle as I grabbed the throttle right over her hand and pulled it all the way back. The plane was still configured with gear and flaps in the takeoff position. I also grabbed the control yoke with my r-hand and rolled the plane back to the centerline since we had drifted a bit right; and then slipped the plane down. As I was doing this with my right hand; I stabbed the push to talk switch on the left side of the control wheel with my l-hand and said 'mayday; mayday; mayday XXXX landing.' this is a very busy airport and I wanted to make sure the tower understood we had an emergency and would clear other traffic. Within 15 seconds of the power loss; I made a pretty smooth landing and had about 2000 ft remaining if I had really needed it. I was pretty amazed at how well it had gone; as was my student. Tower asked if we needed any assistance; and I didn't know; so that is what I said; but I did seem to have enough power to taxi off the runway and the engine now appeared to be running fine. We verified that there was no fire; smoke or other obvious problem; and the engine was running ok; so we got a taxi clearance to the run-up area to see if we could find any problem doing full power run-ups. We found no problem; so taxied back to the hangar and parked the aircraft there. A quick examination revealed no obvious problems. I am also an a&P mechanic; but will have another a&P do a full examination and sign a maintenance release before further flight. In retrospect; I probably should have allowed my student; who is almost as familiar with this aircraft as I am; handle the full emergency and landing with me supervising. She was handling well until I took the aircraft from her. However; it was happening too fast for there to be any chance of success if there was the slightest miscoms so I just took the aircraft and put it on the ground quickly. The tower did a perfect job; by not saying or doing anything to distract us until we were safely on the ground. Callback conversation with reporter revealed the following information: reporter stated that he and another a&P mechanic thoroughly inspected the engine over a period of days. The components disassembled and examined were: intake; exhaust; and fuel tank; fuel filters; and lines. They found nothing. This aircraft just had an annual with no problems found. Additionally; fuel had been run through the tank because the aircraft had been flown regularly and refueled. The only assumption the reporter can make is that there was slug of water somewhere in the system that was pulled through at that particular high power setting during takeoff.

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Original NASA ASRS Text

Title: A C177 LOST PWR DURING TKOF WITH ENOUGH RWY REMAINING TO DECLARE AN EMER AND LAND ON THE DEP RWY.

Narrative: I AM A CFI AND WAS GIVING COMMERCIAL INSTRUCTION TO A STUDENT. THIS STUDENT IS VERY FAMILIAR WITH THIS ACFT WITH OVER 250 HRS IN IT. WE DID A COMPLETE PREFLT INCLUDING SUMPING ALL FUEL DRAINS AND DIRECTLY INSPECTING THE FUEL QUANTITY WHICH WAS APPROX HALF TANK; WHICH IS ABOUT 3 HRS FUEL IN THIS ACFT. I PERSONALLY CHKED THE FUEL SAMPLES FOR WATER AND FOUND NO WATER OR OTHER CONTAMINANTS. AFTER A COMPLETE PREFLT AND PRETKOF BRIEFING; I INSTRUCTED THE STUDENT TO PERFORM A SOFT FIELD TKOF. SHE MADE A PERFECT SOFT FIELD TKOF; AND AS SHE WAS JUST STARTING TO PUSH THE NOSE DOWN TO GAIN AIRSPD AFTER SIMULATING 'ALL OBSTACLES CLRED' AT ABOUT 60 FT; SHE SAID 'SOMETHING IS WRONG' AT THE SAME MOMENT I FELT A LARGE LOSS OF PWR. IT FELT TO ME AS IF SHE HAD RETARDED THE THROTTLE AND THAT IS WHERE I LOOKED FIRST. SHE CONTINUED TO PUSH THE NOSE DOWN TO GO TO BEST GLIDE SPD. AS SOON AS I LOOKED AT THE THROTTLE I SAW THAT ALL 3 PWR CTLS WERE FULL FORWARD AND REALIZED THAT WE REALLY HAD A SERIOUS EMER. I GLANCED OUTSIDE TO LOOK FOR AN IMMEDIATE LNDG SPOT AND SAW THAT WE PROBABLY HAD ENOUGH RWY LEFT IN FRONT OF US AS A RESULT OF THE SOFT FIELD TKOF. SHE WAS ALREADY PULLING THE THROTTLE TO IDLE AS I GRABBED THE THROTTLE RIGHT OVER HER HAND AND PULLED IT ALL THE WAY BACK. THE PLANE WAS STILL CONFIGURED WITH GEAR AND FLAPS IN THE TKOF POS. I ALSO GRABBED THE CTL YOKE WITH MY R-HAND AND ROLLED THE PLANE BACK TO THE CTRLINE SINCE WE HAD DRIFTED A BIT R; AND THEN SLIPPED THE PLANE DOWN. AS I WAS DOING THIS WITH MY R HAND; I STABBED THE PUSH TO TALK SWITCH ON THE L SIDE OF THE CTL WHEEL WITH MY L-HAND AND SAID 'MAYDAY; MAYDAY; MAYDAY XXXX LNDG.' THIS IS A VERY BUSY ARPT AND I WANTED TO MAKE SURE THE TWR UNDERSTOOD WE HAD AN EMER AND WOULD CLR OTHER TFC. WITHIN 15 SECONDS OF THE PWR LOSS; I MADE A PRETTY SMOOTH LNDG AND HAD ABOUT 2000 FT REMAINING IF I HAD REALLY NEEDED IT. I WAS PRETTY AMAZED AT HOW WELL IT HAD GONE; AS WAS MY STUDENT. TWR ASKED IF WE NEEDED ANY ASSISTANCE; AND I DIDN'T KNOW; SO THAT IS WHAT I SAID; BUT I DID SEEM TO HAVE ENOUGH PWR TO TAXI OFF THE RWY AND THE ENG NOW APPEARED TO BE RUNNING FINE. WE VERIFIED THAT THERE WAS NO FIRE; SMOKE OR OTHER OBVIOUS PROB; AND THE ENG WAS RUNNING OK; SO WE GOT A TAXI CLRNC TO THE RUN-UP AREA TO SEE IF WE COULD FIND ANY PROB DOING FULL PWR RUN-UPS. WE FOUND NO PROB; SO TAXIED BACK TO THE HANGAR AND PARKED THE ACFT THERE. A QUICK EXAM REVEALED NO OBVIOUS PROBS. I AM ALSO AN A&P MECH; BUT WILL HAVE ANOTHER A&P DO A FULL EXAM AND SIGN A MAINT RELEASE BEFORE FURTHER FLT. IN RETROSPECT; I PROBABLY SHOULD HAVE ALLOWED MY STUDENT; WHO IS ALMOST AS FAMILIAR WITH THIS ACFT AS I AM; HANDLE THE FULL EMER AND LNDG WITH ME SUPERVISING. SHE WAS HANDLING WELL UNTIL I TOOK THE ACFT FROM HER. HOWEVER; IT WAS HAPPENING TOO FAST FOR THERE TO BE ANY CHANCE OF SUCCESS IF THERE WAS THE SLIGHTEST MISCOMS SO I JUST TOOK THE ACFT AND PUT IT ON THE GND QUICKLY. THE TWR DID A PERFECT JOB; BY NOT SAYING OR DOING ANYTHING TO DISTRACT US UNTIL WE WERE SAFELY ON THE GND. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATED THAT HE AND ANOTHER A&P MECH THOROUGHLY INSPECTED THE ENG OVER A PERIOD OF DAYS. THE COMPONENTS DISASSEMBLED AND EXAMINED WERE: INTAKE; EXHAUST; AND FUEL TANK; FUEL FILTERS; AND LINES. THEY FOUND NOTHING. THIS ACFT JUST HAD AN ANNUAL WITH NO PROBS FOUND. ADDITIONALLY; FUEL HAD BEEN RUN THROUGH THE TANK BECAUSE THE ACFT HAD BEEN FLOWN REGULARLY AND REFUELED. THE ONLY ASSUMPTION THE RPTR CAN MAKE IS THAT THERE WAS SLUG OF WATER SOMEWHERE IN THE SYS THAT WAS PULLED THROUGH AT THAT PARTICULAR HIGH PWR SETTING DURING TKOF.

Data retrieved from NASA's ASRS site as of January 2009 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.