Similar call signs during departure cause confusion with clearance.

Attributes
ACN	545530
Time
Date	200204
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : hpn.airport
State Reference	NY
Altitude	msl bound lower : 7000 msl bound upper : 7500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : n90.tracon
Operator	common carrier : air taxi
Make Model Name	Citation Excel
Operating Under FAR Part	Part 135
Navigation In Use	other other vortac
Flight Plan	IFR
Aircraft 2
Controlling Facilities	tracon : n90.tracon
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 91
Flight Plan	IFR
Person 1
Affiliation	company : air taxi
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 100 flight time total : 4800 flight time type : 700
ASRS Report	545530
Person 2
Affiliation	company : air taxi
Function	flight crew : first officer
Events
Anomaly	altitude deviation : overshoot non adherence : published procedure other anomaly other other spatial deviation
Independent Detector	other flight crewa
Resolutory Action	controller : issued new clearance flight crew : returned to original clearance
Consequence	faa : reviewed incident with flight crew
Supplementary
Problem Areas	Flight Crew Human Performance ATC Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

During departure from hpn on the westchester 1 departure procedure, we were assigned to continue our climb to 7000 ft. Before reaching 7000 ft we were instructed to continue climb to 11000 ft and proceed direct to the cmk VOR. These instructions were understood by myself and the copilot. The copilot asked for clarification of the routing since cmk was not part of our cleared routing. Following this transmission, other departing traffic with similar call numbers asked if those instructions were for them. When hearing their transmission we reduced our rate of climb suspecting a problem. The controller had us level off at 8000 ft as we were passing 7500 ft in the climb and advised the other aircraft to proceed to the cmk VOR. The problem resulted from similar sounding call numbers from the same company aircraft. This created the confusion between the 2 aircraft and the controller.

Original NASA ASRS Text

Title: SIMILAR CALL SIGNS DURING DEP CAUSE CONFUSION WITH CLRNC.

Narrative: DURING DEP FROM HPN ON THE WESTCHESTER 1 DEP PROC, WE WERE ASSIGNED TO CONTINUE OUR CLB TO 7000 FT. BEFORE REACHING 7000 FT WE WERE INSTRUCTED TO CONTINUE CLB TO 11000 FT AND PROCEED DIRECT TO THE CMK VOR. THESE INSTRUCTIONS WERE UNDERSTOOD BY MYSELF AND THE COPLT. THE COPLT ASKED FOR CLARIFICATION OF THE ROUTING SINCE CMK WAS NOT PART OF OUR CLRED ROUTING. FOLLOWING THIS XMISSION, OTHER DEPARTING TFC WITH SIMILAR CALL NUMBERS ASKED IF THOSE INSTRUCTIONS WERE FOR THEM. WHEN HEARING THEIR XMISSION WE REDUCED OUR RATE OF CLB SUSPECTING A PROB. THE CTLR HAD US LEVEL OFF AT 8000 FT AS WE WERE PASSING 7500 FT IN THE CLB AND ADVISED THE OTHER ACFT TO PROCEED TO THE CMK VOR. THE PROB RESULTED FROM SIMILAR SOUNDING CALL NUMBERS FROM THE SAME COMPANY ACFT. THIS CREATED THE CONFUSION BTWN THE 2 ACFT AND THE CTLR.

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.