Altitude deviation aircraft autplt equipment problem.

Attributes
ACN	111062
Time
Date	198905
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : ard
State Reference	PA
Altitude	msl bound lower : 5000 msl bound upper : 5000
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : phl
Operator	general aviation : personal
Make Model Name	Small Aircraft, Low Wing, 2 Eng, Retractable Gear
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : private pilot : instrument
Experience	flight time last 90 days : 44 flight time total : 6000 flight time type : 4000
ASRS Report	111062
Person 2
Affiliation	government : faa
Function	controller : departure
Qualification	controller : radar
Events
Anomaly	aircraft equipment problem : less severe altitude deviation : excursion from assigned altitude inflight encounter : weather non adherence : clearance other anomaly
Independent Detector	other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course none taken : unable
Consequence	Other
Supplementary
Primary Problem	Ambiguous
Air Traffic Incident	other

Narrative:

I was approaching yardley VOR, ard, level 5000'. Just as I was about 2 mi from the VOR, at cruise speed of 155 KTS, went into a strong cell, heavy rain, turbulence, the autoplt went into hysterics, pitching me into a 45 degree bank (being an older type with knobs to turn to disconnect, the pitch first and then the heading). As I struggled to override and disconnect the autoplt, level the aircraft, phl departure stated, 'new york says they can't take you, hold at ard.' the up and downdrafts went on the order of 500 FPM, and it is possible I exceeded the 300' allowed margin by perhaps 100 or 200'. I was too busy to accurately notice! Got things straightened out, and went into the holding pattern, more or less, with the 1 min advance notice! Made 1 circuit, and was cleared to continue to sbj. Tried the autoplt again. It again tried to roll the aircraft over. Left it off, and finally ran out of the rain cell, and made the approach by finally cancelling IFR, and was able to go VFR. The autoplt will be looked at in about 3 weeks, the first available time the repair service can look at it. This will make the third time it will be repaired for the same effect. The last repair lasted about 3 months. Interesting couple of mins!

Original NASA ASRS Text

Title: ALT DEVIATION ACFT AUTPLT EQUIPMENT PROBLEM.

Narrative: I WAS APCHING YARDLEY VOR, ARD, LEVEL 5000'. JUST AS I WAS ABOUT 2 MI FROM THE VOR, AT CRUISE SPD OF 155 KTS, WENT INTO A STRONG CELL, HEAVY RAIN, TURB, THE AUTOPLT WENT INTO HYSTERICS, PITCHING ME INTO A 45 DEG BANK (BEING AN OLDER TYPE WITH KNOBS TO TURN TO DISCONNECT, THE PITCH FIRST AND THEN THE HDG). AS I STRUGGLED TO OVERRIDE AND DISCONNECT THE AUTOPLT, LEVEL THE ACFT, PHL DEP STATED, 'NEW YORK SAYS THEY CAN'T TAKE YOU, HOLD AT ARD.' THE UP AND DOWNDRAFTS WENT ON THE ORDER OF 500 FPM, AND IT IS POSSIBLE I EXCEEDED THE 300' ALLOWED MARGIN BY PERHAPS 100 OR 200'. I WAS TOO BUSY TO ACCURATELY NOTICE! GOT THINGS STRAIGHTENED OUT, AND WENT INTO THE HOLDING PATTERN, MORE OR LESS, WITH THE 1 MIN ADVANCE NOTICE! MADE 1 CIRCUIT, AND WAS CLRED TO CONTINUE TO SBJ. TRIED THE AUTOPLT AGAIN. IT AGAIN TRIED TO ROLL THE ACFT OVER. LEFT IT OFF, AND FINALLY RAN OUT OF THE RAIN CELL, AND MADE THE APCH BY FINALLY CANCELLING IFR, AND WAS ABLE TO GO VFR. THE AUTOPLT WILL BE LOOKED AT IN ABOUT 3 WKS, THE FIRST AVAILABLE TIME THE REPAIR SVC CAN LOOK AT IT. THIS WILL MAKE THE THIRD TIME IT WILL BE REPAIRED FOR THE SAME EFFECT. THE LAST REPAIR LASTED ABOUT 3 MONTHS. INTERESTING COUPLE OF MINS!

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.