Severe engine roughness on initial climb. Return and land.

Attributes
ACN	170702
Time
Date	199102
Day	Sun
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : lal
State Reference	FL
Altitude	msl bound lower : 2900 msl bound upper : 2900
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : lal
Operator	general aviation : personal
Make Model Name	Small Aircraft, Low Wing, 1 Eng, Fixed Gear
Flight Phase	climbout : intermediate altitude
Flight Plan	None
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : instrument pilot : private
Experience	flight time last 90 days : 45 flight time total : 640 flight time type : 550
ASRS Report	170702
Person 2
Affiliation	government : faa
Function	controller : local
Qualification	controller : non radar
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	other flight crewa
Resolutory Action	flight crew : declared emergency other
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

We were departing from lal. The aircraft developed a sudden, severe vibration and an approximately 50% power loss. Altitude could not be maintained, however the descent rate was approximately 300 FPM. The problem appeared at 2900' MSL. We advised lal tower and requested a straight-in landing to runway 23. 7700 was entered in the transponder. The landing was made on 23 with marginal difficulty. Once on the ground the problem could not be duplicated. After 3 hours of testing and consultation with an a&P tech, the aircraft was flown over lal west/O a problem. I then flew it back to orl where a careful review revealed that a tappet bore housing broke, causing major internal damage.

Original NASA ASRS Text

Title: SEVERE ENGINE ROUGHNESS ON INITIAL CLIMB. RETURN AND LAND.

Narrative: WE WERE DEPARTING FROM LAL. THE ACFT DEVELOPED A SUDDEN, SEVERE VIBRATION AND AN APPROX 50% PWR LOSS. ALT COULD NOT BE MAINTAINED, HOWEVER THE DSNT RATE WAS APPROX 300 FPM. THE PROB APPEARED AT 2900' MSL. WE ADVISED LAL TWR AND REQUESTED A STRAIGHT-IN LNDG TO RWY 23. 7700 WAS ENTERED IN THE XPONDER. THE LNDG WAS MADE ON 23 WITH MARGINAL DIFFICULTY. ONCE ON THE GND THE PROB COULD NOT BE DUPLICATED. AFTER 3 HRS OF TESTING AND CONSULTATION WITH AN A&P TECH, THE ACFT WAS FLOWN OVER LAL W/O A PROB. I THEN FLEW IT BACK TO ORL WHERE A CAREFUL REVIEW REVEALED THAT A TAPPET BORE HOUSING BROKE, CAUSING MAJOR INTERNAL DAMAGE.

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.