BE58 has loss of manifold pressure at FL220.

Attributes
ACN	322019
Time
Date	199511
Day	Tue
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : clt
State Reference	NC
Altitude	msl bound lower : 22000 msl bound upper : 22000
Environment
Flight Conditions	VMC
Light	Dusk
Aircraft 1
Controlling Facilities	artcc : ztl
Operator	general aviation : personal
Make Model Name	Baron 58/58TC
Operating Under FAR Part	Part 91
Flight Phase	cruise other
Route In Use	enroute : direct
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : cfi pilot : commercial
Experience	flight time last 90 days : 300 flight time total : 2200 flight time type : 250
ASRS Report	322019
Person 2
Affiliation	Other
Function	observation : passenger
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	flight crew : overcame equipment problem other
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

Shortly after reaching FL220, I observed the manifold pressure at 20 inches below the 30 inches normal cruise. Most likely the waste gate closed and would not allow the aircraft to generate the normal 30 inches. Opening the cowl flaps and enrichening the mixture did not resolve the problem. I advised center I needed to go back to clt. No emergency was declared and priority was requested. As a descent was made the manifold pressure began to climb as in a normal aspirated engine. A normal approach and landing without further incident was made. No further report to ATC was submitted. Recommend pilots involved in such sits to monitor cylinder head temperature, oil pressure and temperature indications to avoid exceeding limits when such conditions occur. Any indication of failing engine should necessitate shutting down the engine to prevent damage to internal components, and proper feathering of the propeller. Callback conversation with reporter revealed the following information: reporter states the problem was a cracked cylinder. The turbo could not compress due to the crack and the manifold pressure could not be sustained. He mentioned the cylinder head temperature because the needle was fluctuating a great deal and was of concern to flight crew. They found out that the crack was at the point where the cylinder head temperature probe was located and the probe was alternately getting cold air and warm air causing this fluctuation. Cylinder has been repaired and the aircraft works like a charm.

Original NASA ASRS Text

Title: BE58 HAS LOSS OF MANIFOLD PRESSURE AT FL220.

Narrative: SHORTLY AFTER REACHING FL220, I OBSERVED THE MANIFOLD PRESSURE AT 20 INCHES BELOW THE 30 INCHES NORMAL CRUISE. MOST LIKELY THE WASTE GATE CLOSED AND WOULD NOT ALLOW THE ACFT TO GENERATE THE NORMAL 30 INCHES. OPENING THE COWL FLAPS AND ENRICHENING THE MIXTURE DID NOT RESOLVE THE PROB. I ADVISED CTR I NEEDED TO GO BACK TO CLT. NO EMER WAS DECLARED AND PRIORITY WAS REQUESTED. AS A DSCNT WAS MADE THE MANIFOLD PRESSURE BEGAN TO CLB AS IN A NORMAL ASPIRATED ENG. A NORMAL APCH AND LNDG WITHOUT FURTHER INCIDENT WAS MADE. NO FURTHER RPT TO ATC WAS SUBMITTED. RECOMMEND PLTS INVOLVED IN SUCH SITS TO MONITOR CYLINDER HEAD TEMP, OIL PRESSURE AND TEMP INDICATIONS TO AVOID EXCEEDING LIMITS WHEN SUCH CONDITIONS OCCUR. ANY INDICATION OF FAILING ENG SHOULD NECESSITATE SHUTTING DOWN THE ENG TO PREVENT DAMAGE TO INTERNAL COMPONENTS, AND PROPER FEATHERING OF THE PROP. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATES THE PROB WAS A CRACKED CYLINDER. THE TURBO COULD NOT COMPRESS DUE TO THE CRACK AND THE MANIFOLD PRESSURE COULD NOT BE SUSTAINED. HE MENTIONED THE CYLINDER HEAD TEMP BECAUSE THE NEEDLE WAS FLUCTUATING A GREAT DEAL AND WAS OF CONCERN TO FLC. THEY FOUND OUT THAT THE CRACK WAS AT THE POINT WHERE THE CYLINDER HEAD TEMP PROBE WAS LOCATED AND THE PROBE WAS ALTERNATELY GETTING COLD AIR AND WARM AIR CAUSING THIS FLUCTUATION. CYLINDER HAS BEEN REPAIRED AND THE ACFT WORKS LIKE A CHARM.

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.