Commuter descends below assigned.

Attributes
ACN	245538
Time
Date	199306
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : dpk
State Reference	NY
Altitude	msl bound lower : 13700 msl bound upper : 15000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zny artcc : zdc
Operator	common carrier : air carrier
Make Model Name	Medium Transport, High Wing, 2 Turboprop Eng
Flight Phase	descent other
Route In Use	arrival other enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 200 flight time total : 6700 flight time type : 200
ASRS Report	245538
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	aircraft equipment problem : less severe altitude deviation : overshoot non adherence : clearance
Independent Detector	other controllera other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course other
Consequence	faa : reviewed incident with flight crew
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

We were descending to cross deer park at 15000 ft, on the bouno 2 arrival in white plains, ny. The controller gave us a 060 degree heading for the descent and descent from 17000 ft to 15000 ft. I noticed right away the first officer didn't hit the altitude select button on the autoplt, but he was still rolling the wheel to increase his rate of descent to 1500 FPM. I thought he was going to hit the altitude select button. About the time he took his hand away, the airplane yawed to the left calling my attention to the engine instruments and the caution panel. By the time I realized the engine on the left side had gone from electronic fuel scheduling to manual fuel scheduling the controller had asked us our altitude. We reported 13700 ft for 15000 ft. This is when I realized we had busted our altitude. I told the first officer to climb back to 15000 ft while I took care of the fuel scheduling problem. About that time the controller asked why we were below our assigned altitude. I told him we just got a caution light and he accepted it as a TCASII RA. His assumption of a TCASII RA sounded like a good idea to assume on my part, which I feel was a bad idea now. From now on I'll ask my first officer's when, on the autoplt and changing altitude, to push the altitude select button first.

Original NASA ASRS Text

Title: COMMUTER DSNDS BELOW ASSIGNED.

Narrative: WE WERE DSNDING TO CROSS DEER PARK AT 15000 FT, ON THE BOUNO 2 ARR IN WHITE PLAINS, NY. THE CTLR GAVE US A 060 DEG HDG FOR THE DSCNT AND DSCNT FROM 17000 FT TO 15000 FT. I NOTICED RIGHT AWAY THE FO DIDN'T HIT THE ALT SELECT BUTTON ON THE AUTOPLT, BUT HE WAS STILL ROLLING THE WHEEL TO INCREASE HIS RATE OF DSCNT TO 1500 FPM. I THOUGHT HE WAS GOING TO HIT THE ALT SELECT BUTTON. ABOUT THE TIME HE TOOK HIS HAND AWAY, THE AIRPLANE YAWED TO THE L CALLING MY ATTN TO THE ENG INSTS AND THE CAUTION PANEL. BY THE TIME I REALIZED THE ENG ON THE L SIDE HAD GONE FROM ELECTRONIC FUEL SCHEDULING TO MANUAL FUEL SCHEDULING THE CTLR HAD ASKED US OUR ALT. WE RPTED 13700 FT FOR 15000 FT. THIS IS WHEN I REALIZED WE HAD BUSTED OUR ALT. I TOLD THE FO TO CLB BACK TO 15000 FT WHILE I TOOK CARE OF THE FUEL SCHEDULING PROB. ABOUT THAT TIME THE CTLR ASKED WHY WE WERE BELOW OUR ASSIGNED ALT. I TOLD HIM WE JUST GOT A CAUTION LIGHT AND HE ACCEPTED IT AS A TCASII RA. HIS ASSUMPTION OF A TCASII RA SOUNDED LIKE A GOOD IDEA TO ASSUME ON MY PART, WHICH I FEEL WAS A BAD IDEA NOW. FROM NOW ON I'LL ASK MY FO'S WHEN, ON THE AUTOPLT AND CHANGING ALT, TO PUSH THE ALT SELECT BUTTON FIRST.

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.