DC9. Similar call signs result in aircraft taking the wrong clearance.

Attributes
ACN	460499
Time
Date	200001
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : zmp.artcc
State Reference	MN
Altitude	msl bound lower : 28000 msl bound upper : 31000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : zmp.artcc
Operator	common carrier : air carrier
Make Model Name	DC-9 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	cruise : enroute altitude change
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : zmp.artcc
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	cruise : enroute altitude change
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 240 flight time total : 29170 flight time type : 14100
ASRS Report	460499
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument pilot : multi engine
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : published procedure non adherence : far
Independent Detector	other flight crewa other flight crewb
Resolutory Action	controller : issued new clearance
Supplementary
Problem Areas	FAA ATC Human Performance Flight Crew Human Performance
Primary Problem	ATC Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Cruise at FL280. Center had 2 aircraft with close flight abcd and flight abc. We were cleared to FL310 and read back clearance to climb to FL310. At 29500 ft center said flight abc climb to FL310. I think center just cleared us again to FL310. We said 'roger, climbing to FL310' and with another flight with close flight abcd, all aircraft should make sure of flight number and flight following when 2 flts are close in flight numbers abcd and abc. No conflict.

Original NASA ASRS Text

Title: DC9. SIMILAR CALL SIGNS RESULT IN ACFT TAKING THE WRONG CLRNC.

Narrative: CRUISE AT FL280. CTR HAD 2 ACFT WITH CLOSE FLT ABCD AND FLT ABC. WE WERE CLRED TO FL310 AND READ BACK CLRNC TO CLB TO FL310. AT 29500 FT CTR SAID FLT ABC CLB TO FL310. I THINK CTR JUST CLRED US AGAIN TO FL310. WE SAID 'ROGER, CLBING TO FL310' AND WITH ANOTHER FLT WITH CLOSE FLT ABCD, ALL ACFT SHOULD MAKE SURE OF FLT NUMBER AND FLT FOLLOWING WHEN 2 FLTS ARE CLOSE IN FLT NUMBERS ABCD AND ABC. NO CONFLICT.

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.