A PA28 pilot descended 800 ft below assigned altitude because he was distraction by a vacuum warning...

Attributes
ACN	713698
Time
Date	200610
Local Time Of Day	1801 To 2400
Place
Locale Reference	intersection : shoos
State Reference	OH
Altitude	msl single value : 3000
Environment
Flight Conditions	IMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : day.tracon
Operator	general aviation : personal
Make Model Name	PA-28 Cherokee Arrow IV
Operating Under FAR Part	Part 91
Flight Phase	cruise : holding
Flight Plan	IFR
Person 1
Affiliation	other
Function	flight crew : single pilot oversight : pic
Qualification	pilot : instrument pilot : private
Experience	flight time last 90 days : 40 flight time total : 420 flight time type : 255
ASRS Report	713698
Person 2
Affiliation	government : faa
Function	controller : approach
Events
Anomaly	aircraft equipment problem : less severe altitude deviation : excursion from assigned altitude non adherence : clearance other anomaly other spatial deviation
Independent Detector	other controllera other flight crewb
Resolutory Action	flight crew : regained aircraft control flight crew : returned to intended or assigned course flight crew : returned to assigned altitude
Supplementary
Problem Areas	Aircraft Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance

Narrative:

After I was cleared for a hold at the shoos intersection to set up for the GPS 26 approach at axv after being cleared to hold 2 laps at 3000 ft MSL during the second lap of the hold I became distraction due to a low vacuum warning light. Before I knew it I was descending in a right 40 degree bank. I instantly leveled the wings and pulled back from 2200 ft to 3000 ft (an 800 ft descent). Dayton approach control advised me of my altitude and I advised them I had it under control and requested the GPS 26 from present position. I flew the approach with my back up electric attitude indicator and never got the light to come back on. Landed and had the system svced the next day. The a&P found the line to the warning transducer was split and replaced it. I believe my scan could have been better during the distraction. Additionally just this morning (oct/xa/06) I went out in VMC with a cfii and did 1.5 of partial panel and asked for some distrs to improve my skills at managing cockpit situations like this.

Original NASA ASRS Text

Title: A PA28 PLT DSNDED 800 FT BELOW ASSIGNED ALT BECAUSE HE WAS DISTR BY A VACUUM WARNING LIGHT.

Narrative: AFTER I WAS CLRED FOR A HOLD AT THE SHOOS INTXN TO SET UP FOR THE GPS 26 APCH AT AXV AFTER BEING CLRED TO HOLD 2 LAPS AT 3000 FT MSL DURING THE SECOND LAP OF THE HOLD I BECAME DISTR DUE TO A LOW VACUUM WARNING LIGHT. BEFORE I KNEW IT I WAS DSNDING IN A R 40 DEG BANK. I INSTANTLY LEVELED THE WINGS AND PULLED BACK FROM 2200 FT TO 3000 FT (AN 800 FT DSCNT). DAYTON APCH CTL ADVISED ME OF MY ALT AND I ADVISED THEM I HAD IT UNDER CTL AND REQUESTED THE GPS 26 FROM PRESENT POS. I FLEW THE APCH WITH MY BACK UP ELECTRIC ATTITUDE INDICATOR AND NEVER GOT THE LIGHT TO COME BACK ON. LANDED AND HAD THE SYS SVCED THE NEXT DAY. THE A&P FOUND THE LINE TO THE WARNING TRANSDUCER WAS SPLIT AND REPLACED IT. I BELIEVE MY SCAN COULD HAVE BEEN BETTER DURING THE DISTR. ADDITIONALLY JUST THIS MORNING (OCT/XA/06) I WENT OUT IN VMC WITH A CFII AND DID 1.5 OF PARTIAL PANEL AND ASKED FOR SOME DISTRS TO IMPROVE MY SKILLS AT MANAGING COCKPIT SITUATIONS LIKE THIS.

Data retrieved from NASA's ASRS site as of January 2009 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.

A PA28 pilot descended 800 ft below assigned altitude because he was distraction by a vacuum warning light.