<< >> NASA ASRS Report 395140, February 1998

Flight crew of a B737 overshot crossing altitude during a STAR arrival descent due to misinterp of an amended ATC clearance. The flight crew set up their altitude alert window with the second of the 2 lower crossing altitudes.

Attributes
ACN	395140
Time
Date	199802
Day	Thu
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : mrb
State Reference	WV
Altitude	msl bound lower : 13000 msl bound upper : 15000
Environment
Flight Conditions	Mixed
Light	Night
Aircraft 1
Controlling Facilities	artcc : zdc
Operator	common carrier : air carrier
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	Other
Flight Phase	descent other
Route In Use	arrival other arrival star : star enroute airway : zdc
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 50 flight time total : 10000 flight time type : 5000
ASRS Report	395140
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	altitude deviation : overshoot altitude deviation : crossing restriction not met non adherence : clearance
Independent Detector	other controllera
Resolutory Action	none taken : detected after the fact
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

ATC issued a clearance to cross mrb at 15000 ft and cross ruane at 11000 ft, 250 KTS. I should have set 15000 ft in the altitude alert window and then reset it to 11000 ft after passing mrb. I set 11000 ft in the window and ended up crossing mrb at 13000 ft in a descent. We simply put the wrong altitude in the window, however, in our minds both my first officer and I thought it was a discretionary descent to mrb. The EMI 3 arrival to bwi depicts crossing mumsy at 15000 ft which is the normal clearance into bwi. When we were given something different especially at night with very few other aircraft around we interpreted the clearance as a shortcut which led to complacency.

Related reports:

• Flight crew of an embraer 120 overshot assigned altitude dur...
• A330 airbus flight crew overshot intermediate arrival fix du...

	Enter your search terms Submit search form
	Web www.37000feet.com

Original NASA ASRS Text

Title: FLC OF A B737 OVERSHOT XING ALT DURING A STAR ARR DSCNT DUE TO MISINTERP OF AN AMENDED ATC CLRNC. THE FLC SET UP THEIR ALT ALERT WINDOW WITH THE SECOND OF THE 2 LOWER XING ALTS.

Narrative: ATC ISSUED A CLRNC TO CROSS MRB AT 15000 FT AND CROSS RUANE AT 11000 FT, 250 KTS. I SHOULD HAVE SET 15000 FT IN THE ALT ALERT WINDOW AND THEN RESET IT TO 11000 FT AFTER PASSING MRB. I SET 11000 FT IN THE WINDOW AND ENDED UP XING MRB AT 13000 FT IN A DSCNT. WE SIMPLY PUT THE WRONG ALT IN THE WINDOW, HOWEVER, IN OUR MINDS BOTH MY FO AND I THOUGHT IT WAS A DISCRETIONARY DSCNT TO MRB. THE EMI 3 ARR TO BWI DEPICTS XING MUMSY AT 15000 FT WHICH IS THE NORMAL CLRNC INTO BWI. WHEN WE WERE GIVEN SOMETHING DIFFERENT ESPECIALLY AT NIGHT WITH VERY FEW OTHER ACFT AROUND WE INTERPED THE CLRNC AS A SHORTCUT WHICH LED TO COMPLACENCY.

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.