IFR C182 inbound to sgd varies from assigned altitude.

Attributes
ACN	574768
Time
Date	200302
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	navaid : sgd.vortac
State Reference	CA
Altitude	msl single value : 7000
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	military facility : suu.milfac
Operator	general aviation : personal
Make Model Name	Skylane 182/RG Turbo Skylane/RG
Operating Under FAR Part	Part 91
Navigation In Use	other vortac
Flight Phase	cruise : level
Route In Use	enroute : direct
Flight Plan	IFR
Person 1
Affiliation	other
Qualification	pilot : commercial pilot : instrument pilot : multi engine pilot : cfi
Experience	flight time last 90 days : 20 flight time total : 390 flight time type : 1
ASRS Report	574768
Person 2
Affiliation	other
Function	oversight : pic
Qualification	other other : cfii
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance non adherence : far other spatial deviation
Independent Detector	other flight crewa
Resolutory Action	controller : issued new clearance flight crew : returned to intended or assigned course flight crew : became reoriented flight crew : returned to assigned altitude
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Myself and a cfii were on an IFR flight plan from stockton, ca, to napa, ca. The cfii was the PF. We were cleared direct to the sgd VOR and were flying direct as cleared. ATC asked if we were flying direct and we said we were. ATC said sgd was slightly to our left and we adjusted our VOR indicators accordingly. While adjusting the vors, the PF inadvertently descended below our assigned altitude -- about 400 ft. I announced the error and the PF immediately returned to our assigned altitude. ATC did not query the deviation. Clearly, our CRM could have been better. The PF should concentrate on flying the plane, while the PNF should make the VOR adjustments.

Original NASA ASRS Text

Title: IFR C182 INBOUND TO SGD VARIES FROM ASSIGNED ALT.

Narrative: MYSELF AND A CFII WERE ON AN IFR FLT PLAN FROM STOCKTON, CA, TO NAPA, CA. THE CFII WAS THE PF. WE WERE CLRED DIRECT TO THE SGD VOR AND WERE FLYING DIRECT AS CLRED. ATC ASKED IF WE WERE FLYING DIRECT AND WE SAID WE WERE. ATC SAID SGD WAS SLIGHTLY TO OUR L AND WE ADJUSTED OUR VOR INDICATORS ACCORDINGLY. WHILE ADJUSTING THE VORS, THE PF INADVERTENTLY DSNDED BELOW OUR ASSIGNED ALT -- ABOUT 400 FT. I ANNOUNCED THE ERROR AND THE PF IMMEDIATELY RETURNED TO OUR ASSIGNED ALT. ATC DID NOT QUERY THE DEV. CLRLY, OUR CRM COULD HAVE BEEN BETTER. THE PF SHOULD CONCENTRATE ON FLYING THE PLANE, WHILE THE PNF SHOULD MAKE THE VOR ADJUSTMENTS.

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.