Altitude crossing restriction not met. Altitude deviation.

Attributes
ACN	223901
Time
Date	199210
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : mrb
State Reference	WV
Altitude	msl bound lower : 15000 msl bound upper : 15350
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	descent other
Route In Use	enroute airway : iad
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	cruise other
Flight Plan	VFR
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 : 15000 flight time type : 5000
ASRS Report	223901
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : flight engineer pilot : instrument pilot : cfi pilot : atp
Experience	flight time last 90 days : 200 flight time total : 7000 flight time type : 1000
ASRS Report	224724
Events
Anomaly	altitude deviation : crossing restriction not met altitude deviation : undershoot non adherence : clearance other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other controllera
Resolutory Action	flight crew : took evasive action
Consequence	Other
Miss Distance	horizontal : 21000 vertical : 500
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	Pilot Deviation

Narrative:

We were inbound to bwi on the westminster 2 arrival. We were cleared to cross mumsy intersection (mrb 284 degree/14) at 15000 ft. Dulles approach called VFR traffic at approximately 10 O'clock near mumsy at 14500 ft. Our aircraft was descending at approximately 2000- 3000 FPM. At approximately 18 DME, we were near 15000 ft (about 15200 ft) and leveling. At approximately 17 DME, TCASII sounded an RA and commanded a climb. A slight climb was started, then the traffic was sighted visually. Traffic appeared to be at 14500 ft and no closer than 3-4 mi. Visual contact was reported to the controller. During the TCASII RA and the attempt to sight the traffic, mumsy intersection may have been crossed at an altitude slightly high (no greater than 300-400 ft). A level 15000 ft was obtained after the traffic cleared. Our rate of descent and the traffic's VFR altitude probably caused the TCASII to give a climb RA. We had no visual contact at the initial RA, and we started a climb. After we saw the traffic. It was clear that there was no conflict. No other traffic was in our area.

Original NASA ASRS Text

Title: ALT XING RESTRICTION NOT MET. ALTDEV.

Narrative: WE WERE INBOUND TO BWI ON THE WESTMINSTER 2 ARR. WE WERE CLRED TO CROSS MUMSY INTXN (MRB 284 DEG/14) AT 15000 FT. DULLES APCH CALLED VFR TFC AT APPROX 10 O'CLOCK NEAR MUMSY AT 14500 FT. OUR ACFT WAS DSNDING AT APPROX 2000- 3000 FPM. AT APPROX 18 DME, WE WERE NEAR 15000 FT (ABOUT 15200 FT) AND LEVELING. AT APPROX 17 DME, TCASII SOUNDED AN RA AND COMMANDED A CLB. A SLIGHT CLB WAS STARTED, THEN THE TFC WAS SIGHTED VISUALLY. TFC APPEARED TO BE AT 14500 FT AND NO CLOSER THAN 3-4 MI. VISUAL CONTACT WAS RPTED TO THE CTLR. DURING THE TCASII RA AND THE ATTEMPT TO SIGHT THE TFC, MUMSY INTXN MAY HAVE BEEN CROSSED AT AN ALT SLIGHTLY HIGH (NO GREATER THAN 300-400 FT). A LEVEL 15000 FT WAS OBTAINED AFTER THE TFC CLRED. OUR RATE OF DSCNT AND THE TFC'S VFR ALT PROBABLY CAUSED THE TCASII TO GIVE A CLB RA. WE HAD NO VISUAL CONTACT AT THE INITIAL RA, AND WE STARTED A CLB. AFTER WE SAW THE TFC. IT WAS CLR THAT THERE WAS NO CONFLICT. NO OTHER TFC WAS IN OUR AREA.

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.