Test flight in an altitude deviation due to aircraft equipment problem malfunction.

Attributes
ACN	266336
Time
Date	199403
Day	Thu
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : san
State Reference	CA
Altitude	msl bound lower : 23800 msl bound upper : 25000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zla
Operator	general aviation : personal
Make Model Name	Experimental
Operating Under FAR Part	Part 91
Flight Phase	climbout : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : cfi pilot : atp
Experience	flight time last 90 days : 200 flight time total : 14000
ASRS Report	266336
Person 2
Affiliation	Other
Function	observation : observer observation : passenger
Qualification	other other : other
Events
Anomaly	aircraft equipment problem : critical altitude deviation : excursion from assigned altitude altitude deviation : undershoot non adherence : clearance other anomaly other
Independent Detector	other flight crewa
Resolutory Action	controller : issued new clearance flight crew : overcame equipment problem other
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	Pilot Deviation

Narrative:

We were climbing with a clearance to FL250. At 24500 ft propeller overspd occurred. We had to reduce power to keep from exceeding limitations. We told ZLA we were unable to maintain altitude and needed lower. They told us to maintain FL240. We told them we were unable and asked for a vector to descend. They did not respond. We were descending through 23800 ft when they cleared us lower.

Original NASA ASRS Text

Title: TEST FLT IN AN ALTDEV DUE TO ACFT EQUIP PROB MALFUNCTION.

Narrative: WE WERE CLBING WITH A CLRNC TO FL250. AT 24500 FT PROP OVERSPD OCCURRED. WE HAD TO REDUCE PWR TO KEEP FROM EXCEEDING LIMITATIONS. WE TOLD ZLA WE WERE UNABLE TO MAINTAIN ALT AND NEEDED LOWER. THEY TOLD US TO MAINTAIN FL240. WE TOLD THEM WE WERE UNABLE AND ASKED FOR A VECTOR TO DSND. THEY DID NOT RESPOND. WE WERE DSNDING THROUGH 23800 FT WHEN THEY CLRED US LOWER.

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.