Corporate jet flight crew descends below prescribed altitude on localizer DME approach.

Attributes
ACN	315380
Time
Date	199509
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : mry
State Reference	CA
Altitude	msl bound lower : 3800 msl bound upper : 4200
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : mry
Operator	general aviation : corporate
Make Model Name	Gulfstream IV
Operating Under FAR Part	Part 91
Navigation In Use	Other Other
Flight Phase	descent : approach descent other
Route In Use	enroute : direct
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : cfi
Experience	flight time last 90 days : 90 flight time total : 15000 flight time type : 1000
ASRS Report	315380
Person 2
Affiliation	Other
Function	flight crew : first officer
Qualification	pilot : instrument pilot : atp pilot : commercial
Events
Anomaly	altitude deviation : overshoot non adherence : far non adherence : published procedure
Independent Detector	atc equipment other atc equipment : unspecified other controllera
Resolutory Action	flight crew : became reoriented other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Descent and approach to runway 28L at mry airport. Set up for localizer DME approach to runway 28L and cleared for visual approach. Crew was involved in troubleshooting, diagnosing, investigating, an asymmetric thrust control problem. Mry tower called and advised us to check our altitude due to low altitude alert warning they were receiving and simultaneously our GPWS sounded an alert. We stopped our descent and checked our altitude to be 3800 ft which was approximately 400 ft below the published crossing altitude (at rodne waypoint) for the area of the approach we were on to runway 28L. We got back on the published altitude/vertical profile and landed runway 27L. This occurrence points out that flcs must not neglect their primary duty to 'fly the aircraft' regardless of anything else going on with the aircraft they must continue to 'fly the aircraft.'

Original NASA ASRS Text

Title: CORPORATE JET FLC DSNDS BELOW PRESCRIBED ALT ON LOC DME APCH.

Narrative: DSCNT AND APCH TO RWY 28L AT MRY ARPT. SET UP FOR LOC DME APCH TO RWY 28L AND CLRED FOR VISUAL APCH. CREW WAS INVOLVED IN TROUBLESHOOTING, DIAGNOSING, INVESTIGATING, AN ASYMMETRIC THRUST CTL PROB. MRY TWR CALLED AND ADVISED US TO CHK OUR ALT DUE TO LOW ALT ALERT WARNING THEY WERE RECEIVING AND SIMULTANEOUSLY OUR GPWS SOUNDED AN ALERT. WE STOPPED OUR DSCNT AND CHKED OUR ALT TO BE 3800 FT WHICH WAS APPROX 400 FT BELOW THE PUBLISHED XING ALT (AT RODNE WAYPOINT) FOR THE AREA OF THE APCH WE WERE ON TO RWY 28L. WE GOT BACK ON THE PUBLISHED ALT/VERT PROFILE AND LANDED RWY 27L. THIS OCCURRENCE POINTS OUT THAT FLCS MUST NOT NEGLECT THEIR PRIMARY DUTY TO 'FLY THE ACFT' REGARDLESS OF ANYTHING ELSE GOING ON WITH THE ACFT THEY MUST CONTINUE TO 'FLY THE ACFT.'

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.