|37000 Feet||Browse and search NASA's
Aviation Safety Reporting System
|Local Time Of Day||1201 To 1800|
|Locale Reference||airport : gck.airport|
|Altitude||agl single value : 0|
|Operator||general aviation : personal|
|Make Model Name||PA-28 Cherokee/Archer II/Dakota/Pillan/Warrior|
|Operating Under FAR Part||Part 91|
|Flight Phase||landing : roll|
|Function||flight crew : single pilot|
|Qualification||pilot : instrument|
pilot : commercial
pilot : cfi
|Experience||flight time last 90 days : 20|
flight time total : 1375
flight time type : 600
|Affiliation||government : faa|
|Function||controller : local|
|Anomaly||aircraft equipment problem : critical|
other anomaly other
|Independent Detector||aircraft equipment other aircraft equipment : engine/prop rpm|
other flight crewa
I had departed a twred airport and settled into a cruise climb with full throttle and recommended RPM in my cherokee 235. Once clear of the airport control zone, I attempted to contact FSS 2 or 3 times to activate my VFR flight plan but had no response (over the past 5 yrs this has become more and more common with either delayed or no response when attempting to contact FSS in the midwestern and western states). About 1 min or 2 after my last instrument scan, I heard a change of pitch in the engine, and discovered that the tachometer was indicating well above the redline. (I was surprised that the change in the sound of the engine wasn't more pronounced for a propeller overspd.) I reduced the throttle, finally stabilizing the RPM at about 2350. The propeller control had no effect, even when pulled full aft. My first thought was that the propeller control cable had broken, and my second thought was that the propeller governor may have failed. I began turning back toward the airport (at about 4000 ft MSL) while reducing the RPM, and after I had the RPM stabilized I notified the tower that I was returning due to a propeller overspd. 1 or 2 mins later the plane began heavily vibrating to the extent that I could not understand the tower when they responded to my call regarding the vibration. I determined that I couldn't make the airport, brought the throttle back to reduce vibration, began slowing the plane down to the best glide speed, and turned my attention to a field that I had earlier idented as a potential landing site. As I maneuvered toward the harvested wheat field I checked for other possible landing sites including roads, but it still appeared to be the best option. Once I had the field set up to my left with my airspeed/descent rate stabilized and determined that I could make the field, I cut the engine. I extended the downwind, turned base close in to the field, then turned final (a bit lower and steeper than ideal), added full flaps, began bleeding off airspeed, and lined up with the grain of the field. I held off touchdown for as long as I could with the nose up. The main wheels touched lightly as did the nosewheel when I could no longer hold the nose up. Within seconds, the nose pitched down and to the right quickly, although I only had a light tug on my shoulder harness as the plane came to a full stop with the nose down. I quickly exited the plane, checking for smoke, fire, or fuel leaks. There were none that I could see nor any oil either near or on the plane. The nosewheel assembly was collapsed underneath the cowling and the propeller blade on the right side was bent. An initial inspection subsequently found that the oil plug for the primary oil screen was missing and that the engine had about 8 quarts of oil still in it (there had been more than 10 1/2 quarts at preflight). The inspector speculated that oil was lost through the hole and then air was drawn through the opening, preventing the flow of oil to the propeller and cylinders. As I reviewed this event, it occurred to me that I had no training on propeller overspd except being verbally told to pull back the throttle to reduce RPM. As I looked through my training material, none of it even mentioned reducing power, nor that engine failure could be imminent. The piper arrow manual has amplified procedures, but the cessna complex model manuals that I have in my possession do not. I could not find information on propeller overspd in any of my high performance materials. It is not singled out as an emergency procedure in the practical test standards (except in the twin pts), yet an adjustable propeller is one of the requirements for asel commercial and CFI check ride. Significant emphasis is placed on landing gear emergencys, why not the propeller? Lessons learned: get a more modern aircraft manual with extended procedures (the original manual is very sparse). Mental checklist -- throttle back first, check oil pressure second, look immediately for a place for a precautionary landing if oil pressure is low, maintain altitude, and check to see if the propeller control has any effect. Walk the fields a few more times near my home airport for the best choices for emergency lndgs, and find a crusty old pilot to learn about grass and dirt lndgs.
Original NASA ASRS Text
Title: PIPER PA35 PLT MAKES AN OFF ARPT FORCED LNDG DUE LOSING CONSTANT SPD PROP CTL. THE ACFT SUSTAINED DAMAGE WHEN THE NOSEWHEEL ASSEMBLY COLLAPSED.
Narrative: I HAD DEPARTED A TWRED ARPT AND SETTLED INTO A CRUISE CLB WITH FULL THROTTLE AND RECOMMENDED RPM IN MY CHEROKEE 235. ONCE CLR OF THE ARPT CTL ZONE, I ATTEMPTED TO CONTACT FSS 2 OR 3 TIMES TO ACTIVATE MY VFR FLT PLAN BUT HAD NO RESPONSE (OVER THE PAST 5 YRS THIS HAS BECOME MORE AND MORE COMMON WITH EITHER DELAYED OR NO RESPONSE WHEN ATTEMPTING TO CONTACT FSS IN THE MIDWESTERN AND WESTERN STATES). ABOUT 1 MIN OR 2 AFTER MY LAST INST SCAN, I HEARD A CHANGE OF PITCH IN THE ENG, AND DISCOVERED THAT THE TACHOMETER WAS INDICATING WELL ABOVE THE REDLINE. (I WAS SURPRISED THAT THE CHANGE IN THE SOUND OF THE ENG WASN'T MORE PRONOUNCED FOR A PROP OVERSPD.) I REDUCED THE THROTTLE, FINALLY STABILIZING THE RPM AT ABOUT 2350. THE PROP CTL HAD NO EFFECT, EVEN WHEN PULLED FULL AFT. MY FIRST THOUGHT WAS THAT THE PROP CTL CABLE HAD BROKEN, AND MY SECOND THOUGHT WAS THAT THE PROP GOVERNOR MAY HAVE FAILED. I BEGAN TURNING BACK TOWARD THE ARPT (AT ABOUT 4000 FT MSL) WHILE REDUCING THE RPM, AND AFTER I HAD THE RPM STABILIZED I NOTIFIED THE TWR THAT I WAS RETURNING DUE TO A PROP OVERSPD. 1 OR 2 MINS LATER THE PLANE BEGAN HEAVILY VIBRATING TO THE EXTENT THAT I COULD NOT UNDERSTAND THE TWR WHEN THEY RESPONDED TO MY CALL REGARDING THE VIBRATION. I DETERMINED THAT I COULDN'T MAKE THE ARPT, BROUGHT THE THROTTLE BACK TO REDUCE VIBRATION, BEGAN SLOWING THE PLANE DOWN TO THE BEST GLIDE SPD, AND TURNED MY ATTN TO A FIELD THAT I HAD EARLIER IDENTED AS A POTENTIAL LNDG SITE. AS I MANEUVERED TOWARD THE HARVESTED WHEAT FIELD I CHKED FOR OTHER POSSIBLE LNDG SITES INCLUDING ROADS, BUT IT STILL APPEARED TO BE THE BEST OPTION. ONCE I HAD THE FIELD SET UP TO MY L WITH MY AIRSPD/DSCNT RATE STABILIZED AND DETERMINED THAT I COULD MAKE THE FIELD, I CUT THE ENG. I EXTENDED THE DOWNWIND, TURNED BASE CLOSE IN TO THE FIELD, THEN TURNED FINAL (A BIT LOWER AND STEEPER THAN IDEAL), ADDED FULL FLAPS, BEGAN BLEEDING OFF AIRSPD, AND LINED UP WITH THE GRAIN OF THE FIELD. I HELD OFF TOUCHDOWN FOR AS LONG AS I COULD WITH THE NOSE UP. THE MAIN WHEELS TOUCHED LIGHTLY AS DID THE NOSEWHEEL WHEN I COULD NO LONGER HOLD THE NOSE UP. WITHIN SECONDS, THE NOSE PITCHED DOWN AND TO THE R QUICKLY, ALTHOUGH I ONLY HAD A LIGHT TUG ON MY SHOULDER HARNESS AS THE PLANE CAME TO A FULL STOP WITH THE NOSE DOWN. I QUICKLY EXITED THE PLANE, CHKING FOR SMOKE, FIRE, OR FUEL LEAKS. THERE WERE NONE THAT I COULD SEE NOR ANY OIL EITHER NEAR OR ON THE PLANE. THE NOSEWHEEL ASSEMBLY WAS COLLAPSED UNDERNEATH THE COWLING AND THE PROP BLADE ON THE R SIDE WAS BENT. AN INITIAL INSPECTION SUBSEQUENTLY FOUND THAT THE OIL PLUG FOR THE PRIMARY OIL SCREEN WAS MISSING AND THAT THE ENG HAD ABOUT 8 QUARTS OF OIL STILL IN IT (THERE HAD BEEN MORE THAN 10 1/2 QUARTS AT PREFLT). THE INSPECTOR SPECULATED THAT OIL WAS LOST THROUGH THE HOLE AND THEN AIR WAS DRAWN THROUGH THE OPENING, PREVENTING THE FLOW OF OIL TO THE PROP AND CYLINDERS. AS I REVIEWED THIS EVENT, IT OCCURRED TO ME THAT I HAD NO TRAINING ON PROP OVERSPD EXCEPT BEING VERBALLY TOLD TO PULL BACK THE THROTTLE TO REDUCE RPM. AS I LOOKED THROUGH MY TRAINING MATERIAL, NONE OF IT EVEN MENTIONED REDUCING PWR, NOR THAT ENG FAILURE COULD BE IMMINENT. THE PIPER ARROW MANUAL HAS AMPLIFIED PROCS, BUT THE CESSNA COMPLEX MODEL MANUALS THAT I HAVE IN MY POSSESSION DO NOT. I COULD NOT FIND INFO ON PROP OVERSPD IN ANY OF MY HIGH PERFORMANCE MATERIALS. IT IS NOT SINGLED OUT AS AN EMER PROC IN THE PRACTICAL TEST STANDARDS (EXCEPT IN THE TWIN PTS), YET AN ADJUSTABLE PROP IS ONE OF THE REQUIREMENTS FOR ASEL COMMERCIAL AND CFI CHK RIDE. SIGNIFICANT EMPHASIS IS PLACED ON LNDG GEAR EMERS, WHY NOT THE PROP? LESSONS LEARNED: GET A MORE MODERN ACFT MANUAL WITH EXTENDED PROCS (THE ORIGINAL MANUAL IS VERY SPARSE). MENTAL CHKLIST -- THROTTLE BACK FIRST, CHK OIL PRESSURE SECOND, LOOK IMMEDIATELY FOR A PLACE FOR A PRECAUTIONARY LNDG IF OIL PRESSURE IS LOW, MAINTAIN ALT, AND CHK TO SEE IF THE PROP CTL HAS ANY EFFECT. WALK THE FIELDS A FEW MORE TIMES NEAR MY HOME ARPT FOR THE BEST CHOICES FOR EMER LNDGS, AND FIND A CRUSTY OLD PLT TO LEARN ABOUT GRASS AND DIRT LNDGS.
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.