B737 crew, in descent to bwi, undershot their assigned altitude, missing a crossing restr.

Attributes
ACN	546071
Time
Date	200205
Day	Thu
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : bwi.airport
State Reference	MD
Altitude	msl bound lower : 5000 msl bound upper : 9500
Environment
Flight Conditions	Mixed
Light	Dusk
Aircraft 1
Controlling Facilities	tracon : bwi.tracon
Operator	common carrier : air carrier
Make Model Name	B737-700
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	descent : approach
Route In Use	arrival : 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 : 1000 flight time type : 4000
ASRS Report	546071
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : multi engine pilot : instrument
Experience	flight time last 90 days : 182 flight time total : 2250 flight time type : 750
ASRS Report	546072
Events
Anomaly	altitude deviation : undershoot altitude deviation : crossing restriction not met inflight encounter : weather inflight encounter : turbulence inflight encounter other non adherence : clearance
Independent Detector	other controllera other flight crewa
Resolutory Action	controller : issued alert controller : issued new clearance none taken : unable
Consequence	faa : reviewed incident with flight crew other
Supplementary
Problem Areas	Flight Crew Human Performance Environmental Factor Weather
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

We had an altitude deviation approximately 25 NM north of bwi. We were given a clearance direct bwi out of 16000 ft and a descent to cross 20 mi north of bwi at 5000 ft followed. We missed the restr. About the time that the descent clearance was given, I (PNF) was getting ATIS, gate information and answering a call from the back. To add to the workload, we were monitoring numerous thunderstorms in the area. Numerous things contributed to the altitude deviation. Bwi ATIS is weak, so reception occurs close in where workloads are already heavy. Anytime 1 pilot has to leave the frequency, he or she has just taken themselves out of the loop. Add a 1 1/2 hour delay for WX and the list of factors increases. While the ultimate responsibility remains in the hands of the crew, there obviously were numerous things that affected cockpit performance during this mishap. Supplemental information from acn 546072: the captain (PNF) was called by the flight attendants and went off the ATC frequency to attend to the call. At this time, bwi approach cleared us to 'cross 20 NM north of bwi at and maintain 5000 ft.' about this time we started picking up some continuous light turbulence and the captain reported back up from being off. The captain reported that he would be 'off' to get us a gate. After setting up a 1000 FPM descent, I switched to the descent page on the CDU. This was my first indication that something was wrong. I immediately deployed the speed brakes to the flight detent and increased my rate of descent. I attempted to hold 280 KTS keeping in mind the new speed brake/airspeed limitation for the B737-700. I wasn't going to make the 5000 ft restr and needed to inform ATC. Before any calls could be made, bwi approach asked us if we were going to make the restr. The captain told approach we would be high or unable to make 5000 ft. We were approximately 25 NM off of bwi at 9500 ft and 250 KTS. Baltimore approach vectored us left for 180 degrees and then ultimately back on course. The remainder of the flight was uneventful.

Original NASA ASRS Text

Title: B737 CREW, IN DSCNT TO BWI, UNDERSHOT THEIR ASSIGNED ALT, MISSING A XING RESTR.

Narrative: WE HAD AN ALTDEV APPROX 25 NM N OF BWI. WE WERE GIVEN A CLRNC DIRECT BWI OUT OF 16000 FT AND A DSCNT TO CROSS 20 MI N OF BWI AT 5000 FT FOLLOWED. WE MISSED THE RESTR. ABOUT THE TIME THAT THE DSCNT CLRNC WAS GIVEN, I (PNF) WAS GETTING ATIS, GATE INFO AND ANSWERING A CALL FROM THE BACK. TO ADD TO THE WORKLOAD, WE WERE MONITORING NUMEROUS TSTMS IN THE AREA. NUMEROUS THINGS CONTRIBUTED TO THE ALTDEV. BWI ATIS IS WEAK, SO RECEPTION OCCURS CLOSE IN WHERE WORKLOADS ARE ALREADY HVY. ANYTIME 1 PLT HAS TO LEAVE THE FREQ, HE OR SHE HAS JUST TAKEN THEMSELVES OUT OF THE LOOP. ADD A 1 1/2 HR DELAY FOR WX AND THE LIST OF FACTORS INCREASES. WHILE THE ULTIMATE RESPONSIBILITY REMAINS IN THE HANDS OF THE CREW, THERE OBVIOUSLY WERE NUMEROUS THINGS THAT AFFECTED COCKPIT PERFORMANCE DURING THIS MISHAP. SUPPLEMENTAL INFO FROM ACN 546072: THE CAPT (PNF) WAS CALLED BY THE FLT ATTENDANTS AND WENT OFF THE ATC FREQ TO ATTEND TO THE CALL. AT THIS TIME, BWI APCH CLRED US TO 'CROSS 20 NM N OF BWI AT AND MAINTAIN 5000 FT.' ABOUT THIS TIME WE STARTED PICKING UP SOME CONTINUOUS LIGHT TURB AND THE CAPT RPTED BACK UP FROM BEING OFF. THE CAPT RPTED THAT HE WOULD BE 'OFF' TO GET US A GATE. AFTER SETTING UP A 1000 FPM DSCNT, I SWITCHED TO THE DSCNT PAGE ON THE CDU. THIS WAS MY FIRST INDICATION THAT SOMETHING WAS WRONG. I IMMEDIATELY DEPLOYED THE SPD BRAKES TO THE FLT DETENT AND INCREASED MY RATE OF DSCNT. I ATTEMPTED TO HOLD 280 KTS KEEPING IN MIND THE NEW SPD BRAKE/AIRSPD LIMITATION FOR THE B737-700. I WASN'T GOING TO MAKE THE 5000 FT RESTR AND NEEDED TO INFORM ATC. BEFORE ANY CALLS COULD BE MADE, BWI APCH ASKED US IF WE WERE GOING TO MAKE THE RESTR. THE CAPT TOLD APCH WE WOULD BE HIGH OR UNABLE TO MAKE 5000 FT. WE WERE APPROX 25 NM OFF OF BWI AT 9500 FT AND 250 KTS. BALTIMORE APCH VECTORED US L FOR 180 DEGS AND THEN ULTIMATELY BACK ON COURSE. THE REMAINDER OF THE FLT WAS UNEVENTFUL.

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.