Propeller spinner breaks off small aircraft while at cruise.

Attributes
ACN	184818
Time
Date	199107
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : apa
State Reference	CO
Altitude	msl bound lower : 8000 msl bound upper : 8000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : den
Operator	general aviation : personal
Make Model Name	Small Aircraft, Low Wing, 1 Eng, Retractable Gear
Flight Phase	cruise other descent : approach
Person 1
Affiliation	Other
Function	instruction : trainee
Qualification	pilot : private
Experience	flight time last 90 days : 27 flight time total : 420 flight time type : 56
ASRS Report	184818
Person 2
Affiliation	Other
Function	instruction : instructor
Qualification	pilot : cfi pilot : commercial
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	other flight crewa
Resolutory Action	other
Consequence	other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

My instrument instructor and I, flying my small aircraft from 48V VFR to apa under the control of denver approach control. We were going to do some instrument approachs into apa. While in level flight around 8000 ft, 22 in mp, 2450 RPM, I looked down briefly to look at the chart when I heard a 'thump' and briefly saw something hit the windscreen on the left side. I thought we had experienced a bird strike. We immediately checked at instruments and found that everything was normal. We did 2 approachs without incident and landed after the second approach. Upon landing, I might have pulled too much power and the engine quit, we pulled off to the taxiway, I wasn't able to restart the engine. My instructor, got out, attached the tow bar and discovered that the spinner had been damaged and 2 nicks were on one of the propellers. We towed the plane to a tie-down spot and left it there. In retrospect, I believe we should have landed after the first approach. In my preflight, I did notice the small crack in the spinner but had been told by my mechanic that it was not a problem. I am not sure if it failed because of the crack or if we could have hit a bird.

Original NASA ASRS Text

Title: PROP SPINNER BREAKS OFF SMA WHILE AT CRUISE.

Narrative: MY INST INSTRUCTOR AND I, FLYING MY SMA FROM 48V VFR TO APA UNDER THE CTL OF DENVER APCH CTL. WE WERE GOING TO DO SOME INST APCHS INTO APA. WHILE IN LEVEL FLT AROUND 8000 FT, 22 IN MP, 2450 RPM, I LOOKED DOWN BRIEFLY TO LOOK AT THE CHART WHEN I HEARD A 'THUMP' AND BRIEFLY SAW SOMETHING HIT THE WINDSCREEN ON THE L SIDE. I THOUGHT WE HAD EXPERIENCED A BIRD STRIKE. WE IMMEDIATELY CHKED AT INSTS AND FOUND THAT EVERYTHING WAS NORMAL. WE DID 2 APCHS WITHOUT INCIDENT AND LANDED AFTER THE SECOND APCH. UPON LNDG, I MIGHT HAVE PULLED TOO MUCH PWR AND THE ENG QUIT, WE PULLED OFF TO THE TAXIWAY, I WASN'T ABLE TO RESTART THE ENG. MY INSTRUCTOR, GOT OUT, ATTACHED THE TOW BAR AND DISCOVERED THAT THE SPINNER HAD BEEN DAMAGED AND 2 NICKS WERE ON ONE OF THE PROPS. WE TOWED THE PLANE TO A TIE-DOWN SPOT AND L IT THERE. IN RETROSPECT, I BELIEVE WE SHOULD HAVE LANDED AFTER THE FIRST APCH. IN MY PREFLT, I DID NOTICE THE SMALL CRACK IN THE SPINNER BUT HAD BEEN TOLD BY MY MECH THAT IT WAS NOT A PROBLEM. I AM NOT SURE IF IT FAILED BECAUSE OF THE CRACK OR IF WE COULD HAVE HIT A BIRD.

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.