A PA34 single pilot did not identify a vacuum system failure while in IMC, and was off heading by 180 degrees until breaking out of WX in D21's airspace.

Home

Browse by month

Random

Latest

About

Contact

Attributes
ACN	602916
Time
Date	200312
Day	Mon
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : d21.tracon
State Reference	MI
Altitude	agl single value : 1500
Environment
Flight Conditions	IMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : d21.tracon
Operator	general aviation : personal
Make Model Name	PA-34-200 Seneca I
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 : private
Experience	flight time last 90 days : 60 flight time total : 1900 flight time type : 900
ASRS Report	602916
Person 2
Affiliation	government : faa
Function	controller : departure
Events
Anomaly	aircraft equipment problem : critical inflight encounter : weather non adherence : clearance non adherence : far non adherence : published procedure other anomaly other spatial deviation
Independent Detector	other controllera other flight crewa
Resolutory Action	controller : issued new clearance controller : provided flight assist flight crew : became reoriented flight crew : exited adverse environment flight crew : returned to intended or assigned course
Consequence	other
Supplementary
Problem Areas	Aircraft Flight Crew Human Performance Weather
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Shortly after takeoff and entering IMC (1000 ft AGL), annunciator for 'loss of gyro' on left engine appeared. Noted the attitude indicator on pilot's and copilot's side did not agree. The difference was about 15 degrees. Also, the vacuum gauge did not show the required 4.8 MM hg -- was showing 4.5 MM hg to maintain gyros. The attitude indicator began to show bank left. I was not confident the gyros were accurate and attempted to keep wings level with the turn and bank instrument. We broke out of IMC at about 2700 ft. Our assigned heading had been 270 degrees. We were now heading approximately 90 degrees. We were advised by detroit to 'make left turn to 270 degrees.' we maintained VFR from then on and were fortunate to be able to land at grr in visual conditions and to have failed vacuum pump replaced. The attitude indicator worked reasonably well for the remainder of the flight. I don't think it failed, and with a proper scan, checking the HSI earlier, I think the deviation could have been avoided.

Original NASA ASRS Text

Title: A PA34 SINGLE PLT DID NOT IDENTIFY A VACUUM SYS FAILURE WHILE IN IMC, AND WAS OFF HDG BY 180 DEGS UNTIL BREAKING OUT OF WX IN D21'S AIRSPACE.

Narrative: SHORTLY AFTER TKOF AND ENTERING IMC (1000 FT AGL), ANNUNCIATOR FOR 'LOSS OF GYRO' ON L ENG APPEARED. NOTED THE ATTITUDE INDICATOR ON PLT'S AND COPLT'S SIDE DID NOT AGREE. THE DIFFERENCE WAS ABOUT 15 DEGS. ALSO, THE VACUUM GAUGE DID NOT SHOW THE REQUIRED 4.8 MM HG -- WAS SHOWING 4.5 MM HG TO MAINTAIN GYROS. THE ATTITUDE INDICATOR BEGAN TO SHOW BANK L. I WAS NOT CONFIDENT THE GYROS WERE ACCURATE AND ATTEMPTED TO KEEP WINGS LEVEL WITH THE TURN AND BANK INST. WE BROKE OUT OF IMC AT ABOUT 2700 FT. OUR ASSIGNED HDG HAD BEEN 270 DEGS. WE WERE NOW HDG APPROX 90 DEGS. WE WERE ADVISED BY DETROIT TO 'MAKE L TURN TO 270 DEGS.' WE MAINTAINED VFR FROM THEN ON AND WERE FORTUNATE TO BE ABLE TO LAND AT GRR IN VISUAL CONDITIONS AND TO HAVE FAILED VACUUM PUMP REPLACED. THE ATTITUDE INDICATOR WORKED REASONABLY WELL FOR THE REMAINDER OF THE FLT. I DON'T THINK IT FAILED, AND WITH A PROPER SCAN, CHKING THE HSI EARLIER, I THINK THE DEV COULD HAVE BEEN AVOIDED.

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.