Nose gear retracts on takeoff roll. Propeller damage.

Attributes
ACN	191367
Time
Date	199110
Day	Sat
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : pym
State Reference	MA
Altitude	agl bound lower : 0 agl bound upper : 2000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	general aviation : personal
Make Model Name	Small Aircraft, High Wing, 1 Eng, Retractable Gear
Flight Phase	climbout : takeoff
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : atp pilot : cfi
Experience	flight time last 90 days : 30 flight time total : 25000 flight time type : 200
ASRS Report	191367
Person 2
Affiliation	Other
Function	flight crew : single pilot observation : passenger
Qualification	pilot : private
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	other other : unspecified cockpit
Resolutory Action	none taken : detected after the fact
Consequence	other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

On takeoff I applied normal back pressure to lighten nose wheel. At approximately 45 KIAS the nose dropped, pitched down. It felt like a nose strut bottomed or a nose tire blowout. After recycling the gear twice, it operated normal. There was absolutely no vibration and all flight controls were normal. I figured it was a nose strut or tire problem and elected to continue to morristown, nj, (mmu) home base. I landed and taxied normally. Upon shutdown I observed propeller blades were nicked about 1/2 inch. I feel the landing gear lever moved from down to up without anyone touching it, possibly from being on the edge of the detent. I would appreciate an airworthiness directive on small aircraft with a more positive gear down locking mechanism to prevent additional like occurrences. If you have any similar cases on file I would sincerely appreciate information on same. Callback conversation with reporter revealed the following information: reporter states he is quite positive that gear handle was not securely in detent. He was demonstrating to pilot passenger how gear worked as they were turning base to final. Allowed pilot passenger to operate the handle. 3 green came on but apparently not securely down and locked. Reporter also stated that aircraft had had complete nose strut failure 2 days prior and he believed this might be a recurrence.

Original NASA ASRS Text

Title: NOSE GEAR RETRACTS ON TKOF ROLL. PROP DAMAGE.

Narrative: ON TKOF I APPLIED NORMAL BACK PRESSURE TO LIGHTEN NOSE WHEEL. AT APPROX 45 KIAS THE NOSE DROPPED, PITCHED DOWN. IT FELT LIKE A NOSE STRUT BOTTOMED OR A NOSE TIRE BLOWOUT. AFTER RECYCLING THE GEAR TWICE, IT OPERATED NORMAL. THERE WAS ABSOLUTELY NO VIBRATION AND ALL FLT CTLS WERE NORMAL. I FIGURED IT WAS A NOSE STRUT OR TIRE PROBLEM AND ELECTED TO CONTINUE TO MORRISTOWN, NJ, (MMU) HOME BASE. I LANDED AND TAXIED NORMALLY. UPON SHUTDOWN I OBSERVED PROP BLADES WERE NICKED ABOUT 1/2 INCH. I FEEL THE LNDG GEAR LEVER MOVED FROM DOWN TO UP WITHOUT ANYONE TOUCHING IT, POSSIBLY FROM BEING ON THE EDGE OF THE DETENT. I WOULD APPRECIATE AN AIRWORTHINESS DIRECTIVE ON SMA WITH A MORE POSITIVE GEAR DOWN LOCKING MECHANISM TO PREVENT ADDITIONAL LIKE OCCURRENCES. IF YOU HAVE ANY SIMILAR CASES ON FILE I WOULD SINCERELY APPRECIATE INFO ON SAME. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATES HE IS QUITE POSITIVE THAT GEAR HANDLE WAS NOT SECURELY IN DETENT. HE WAS DEMONSTRATING TO PLT PAX HOW GEAR WORKED AS THEY WERE TURNING BASE TO FINAL. ALLOWED PLT PAX TO OPERATE THE HANDLE. 3 GREEN CAME ON BUT APPARENTLY NOT SECURELY DOWN AND LOCKED. RPTR ALSO STATED THAT ACFT HAD HAD COMPLETE NOSE STRUT FAILURE 2 DAYS PRIOR AND HE BELIEVED THIS MIGHT BE 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.