Emergency declared due to engine problems.

Attributes
ACN	98914
Time
Date	198811
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : iad
State Reference	DC
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zdc
Operator	general aviation : personal
Make Model Name	Small Aircraft
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : instrument pilot : commercial
Experience	flight time last 90 days : 45 flight time total : 750 flight time type : 35
ASRS Report	98914
Person 2
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Events
Anomaly	aircraft equipment problem : critical altitude deviation : excursion from assigned altitude
Independent Detector	other flight crewa
Resolutory Action	flight crew : declared emergency flight crew : overcame equipment problem
Consequence	Other
Supplementary
Primary Problem	Aircraft

Narrative:

At level flight, I reduced RPM and began to lose mp pressure which caused immediate loss of altitude and airspeed. I went through emergency checklist and squawked 7700 after losing altitude and unable to arrest descent I declared an emergency. After completing checklist I increased RPM to original setting of 2500 RPM and mp, etc stabilized. Center was very helpful and I then cancelled the emergency. Upon landing a loose clamp and hose was discovered and repaired on the turbocharger. The airplane was then test flown and the problem was corrected. This had been undetectable during runup and during climb. One of my concerns (outside of the obvious problem) was that I lost 500' before I was able to notify the center. I believe I squawked 7700 after around a 300-400' loss in altitude. I was concerned about an altitude deviation violation, but acted as quickly as possible to notify them west/O sacrificing my control of the aircraft. Callback conversation with reporter revealed the following: reporter states had some problem on trip stl to dca. Mechanics worked on aircraft and thought problem was waste gate sticking. Lubricated and seemed ok. On return trip when leveling at cruise difficulties occurred. Reporter felt declaring emergency was best when unable to hold altitude assigned. Wanted to be sure ATC knew where he was. He feels he received superb cooperation. The loose clamp was allowing turbocharger to develop only 1/2 of power it should.

Original NASA ASRS Text

Title: EMERGENCY DECLARED DUE TO ENGINE PROBLEMS.

Narrative: AT LEVEL FLT, I REDUCED RPM AND BEGAN TO LOSE MP PRESSURE WHICH CAUSED IMMEDIATE LOSS OF ALT AND AIRSPD. I WENT THROUGH EMER CHKLIST AND SQUAWKED 7700 AFTER LOSING ALT AND UNABLE TO ARREST DSCNT I DECLARED AN EMER. AFTER COMPLETING CHKLIST I INCREASED RPM TO ORIGINAL SETTING OF 2500 RPM AND MP, ETC STABILIZED. CENTER WAS VERY HELPFUL AND I THEN CANCELLED THE EMER. UPON LNDG A LOOSE CLAMP AND HOSE WAS DISCOVERED AND REPAIRED ON THE TURBOCHARGER. THE AIRPLANE WAS THEN TEST FLOWN AND THE PROB WAS CORRECTED. THIS HAD BEEN UNDETECTABLE DURING RUNUP AND DURING CLB. ONE OF MY CONCERNS (OUTSIDE OF THE OBVIOUS PROB) WAS THAT I LOST 500' BEFORE I WAS ABLE TO NOTIFY THE CENTER. I BELIEVE I SQUAWKED 7700 AFTER AROUND A 300-400' LOSS IN ALT. I WAS CONCERNED ABOUT AN ALT DEVIATION VIOLATION, BUT ACTED AS QUICKLY AS POSSIBLE TO NOTIFY THEM W/O SACRIFICING MY CONTROL OF THE ACFT. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING: RPTR STATES HAD SOME PROB ON TRIP STL TO DCA. MECHS WORKED ON ACFT AND THOUGHT PROB WAS WASTE GATE STICKING. LUBRICATED AND SEEMED OK. ON RETURN TRIP WHEN LEVELING AT CRUISE DIFFICULTIES OCCURRED. RPTR FELT DECLARING EMER WAS BEST WHEN UNABLE TO HOLD ALT ASSIGNED. WANTED TO BE SURE ATC KNEW WHERE HE WAS. HE FEELS HE RECEIVED SUPERB COOPERATION. THE LOOSE CLAMP WAS ALLOWING TURBOCHARGER TO DEVELOP ONLY 1/2 OF PWR IT SHOULD.

Data retrieved from NASA's ASRS site as of August 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.