Mdt cleared to climb through altitude of widebody transport with less than standard separation.

Attributes
ACN	84707
Time
Date	198803
Day	Thu
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : mmu
State Reference	NJ
Altitude	msl bound lower : 5200 msl bound upper : 5700
Environment
Flight Conditions	VMC
Light	Dawn
Aircraft 1
Controlling Facilities	tracon : n90
Operator	general aviation : corporate
Make Model Name	Medium Transport, Low Wing, 2 Turbojet Eng
Flight Phase	climbout : intermediate altitude
Route In Use	departure sid : sid
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Widebody, Low Wing, 3 Turbojet Eng
Navigation In Use	Other
Flight Phase	cruise other
Route In Use	departure sid : sid
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 120 flight time total : 6800 flight time type : 1525
ASRS Report	84707
Person 2
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	conflict : airborne less severe
Independent Detector	other flight crewa
Resolutory Action	none taken : detected after the fact
Consequence	Other
Miss Distance	horizontal : 6000 vertical : 700
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Departed runway 5 on the morristown 1 departure. We were cleared to maintain 2000'. Then, cleared to turn 090 degrees and climb to 5000'. Shortly thereafter we were cleared to turn right to 310 degree heading and climb to 10000'. While in the turn leaving 5200' I observed a widebody transport at 12 O'clock, less than 2 mi near my altitude. We climbed over the traffic. I asked the controller for the altitude of the 12 O'clock traffic. As we were passing over the traffic and passing 5700' the controller responded that the traffic was now at our 6 O'clock at 5000' and no longer a factor. Obviously someone had made some wrong assumptions. Either I should not have been cleared to 5000' from my initial 2000' altitude or the widebody transport should not have been cleared to 5000' when I was in a right climbing turn and had not yet departed 6000'. Another mdt with a very similar call sign had departed immediately before our departure. Perhaps the controller momentarily confused the 2 mdts. The other mdt was already at 10000' when this happened. It pays to listen closely to aircraft clrncs other than your own.

Original NASA ASRS Text

Title: MDT CLEARED TO CLIMB THROUGH ALT OF WDB WITH LESS THAN STANDARD SEPARATION.

Narrative: DEPARTED RWY 5 ON THE MORRISTOWN 1 DEP. WE WERE CLRED TO MAINTAIN 2000'. THEN, CLRED TO TURN 090 DEGS AND CLB TO 5000'. SHORTLY THEREAFTER WE WERE CLRED TO TURN RIGHT TO 310 DEG HDG AND CLB TO 10000'. WHILE IN THE TURN LEAVING 5200' I OBSERVED A WDB AT 12 O'CLOCK, LESS THAN 2 MI NEAR MY ALT. WE CLBED OVER THE TFC. I ASKED THE CTLR FOR THE ALT OF THE 12 O'CLOCK TFC. AS WE WERE PASSING OVER THE TFC AND PASSING 5700' THE CTLR RESPONDED THAT THE TFC WAS NOW AT OUR 6 O'CLOCK AT 5000' AND NO LONGER A FACTOR. OBVIOUSLY SOMEONE HAD MADE SOME WRONG ASSUMPTIONS. EITHER I SHOULD NOT HAVE BEEN CLRED TO 5000' FROM MY INITIAL 2000' ALT OR THE WDB SHOULD NOT HAVE BEEN CLRED TO 5000' WHEN I WAS IN A RIGHT CLBING TURN AND HAD NOT YET DEPARTED 6000'. ANOTHER MDT WITH A VERY SIMILAR CALL SIGN HAD DEPARTED IMMEDIATELY BEFORE OUR DEP. PERHAPS THE CTLR MOMENTARILY CONFUSED THE 2 MDTS. THE OTHER MDT WAS ALREADY AT 10000' WHEN THIS HAPPENED. IT PAYS TO LISTEN CLOSELY TO ACFT CLRNCS OTHER THAN YOUR OWN.

Data retrieved from NASA's ASRS site as of August 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.