A DC9 crew misinterped clearance, proceeded direct, before ARTCC intended.

Attributes
ACN	497822
Time
Date	200101
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	navaid : mrb.vortac
State Reference	WV
Altitude	msl bound lower : 31000 msl bound upper : 31300
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zny.artcc
Operator	common carrier : air carrier
Make Model Name	DC-9 30
Operating Under FAR Part	Part 121
Flight Phase	climbout : vacating altitude
Route In Use	enroute : direct enroute airway : j6.airway
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : zny.artcc
Operator	common carrier : air carrier
Operating Under FAR Part	Part 121
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	controller military : 3 controller non radar : 2 controller radar : 14 flight time last 90 days : 200 flight time total : 13000 flight time type : 10000
ASRS Report	497822
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : cfi pilot : flight engineer
Experience	flight time last 90 days : 200 flight time total : 13300 flight time type : 8000
ASRS Report	497821
Events
Anomaly	non adherence : published procedure other anomaly other other spatial deviation
Independent Detector	other flight crewa other flight crewb
Resolutory Action	controller : issued new clearance
Miss Distance	horizontal : 5000 vertical : 300
Supplementary
Problem Areas	Aircraft ATC Human Performance Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Flight XXX departed phl for bna on 01/01/thur. Our departure from phl and climb up to FL290 was without incident. At FL290, we were in contact with ZNY. We were flying wbound on J110 and were about to intercept J6 on our flight plan route when ZNY assigned us a heading of 260 degrees and to climb to FL350 at 300 KIAS or greater. We did request a mach speed for the climb. We were to climb to FL330 and then resume normal speed, to proceed direct to martinsburg, join J6 and resume our own navigation. We turned to martinsburg NAVAID and out of FL310 noticed on our TCASII an aircraft off our left wing about 5 NM and 300 ft below us as we continued our climb. No TA or RA appeared on the TCASII. We immediately turned right in a 30 degree angle bank to a heading of 240 degrees, at which time ATC asked us what our heading was and told us to turn further right to a heading of 280 degrees. We continued on our assigned hg, continuing our climb to FL350. We did not hear xmissions from the other aircraft at FL310. The remainder of the flight to bna was without incident. I believe what caused the situation of 'loss of separation' between aircraft was the controller's intention in the issued clearance and our interpretation of the clearance, a multiple clearance. Without a doubt, we should have clarified the given clearance, verifying with the controller our understanding of the said clearance.

Original NASA ASRS Text

Title: A DC9 CREW MISINTERPED CLRNC, PROCEEDED DIRECT, BEFORE ARTCC INTENDED.

Narrative: FLT XXX DEPARTED PHL FOR BNA ON 01/01/THUR. OUR DEP FROM PHL AND CLB UP TO FL290 WAS WITHOUT INCIDENT. AT FL290, WE WERE IN CONTACT WITH ZNY. WE WERE FLYING WBOUND ON J110 AND WERE ABOUT TO INTERCEPT J6 ON OUR FLT PLAN RTE WHEN ZNY ASSIGNED US A HDG OF 260 DEGS AND TO CLB TO FL350 AT 300 KIAS OR GREATER. WE DID REQUEST A MACH SPD FOR THE CLB. WE WERE TO CLB TO FL330 AND THEN RESUME NORMAL SPD, TO PROCEED DIRECT TO MARTINSBURG, JOIN J6 AND RESUME OUR OWN NAV. WE TURNED TO MARTINSBURG NAVAID AND OUT OF FL310 NOTICED ON OUR TCASII AN ACFT OFF OUR L WING ABOUT 5 NM AND 300 FT BELOW US AS WE CONTINUED OUR CLB. NO TA OR RA APPEARED ON THE TCASII. WE IMMEDIATELY TURNED R IN A 30 DEG ANGLE BANK TO A HDG OF 240 DEGS, AT WHICH TIME ATC ASKED US WHAT OUR HDG WAS AND TOLD US TO TURN FURTHER R TO A HDG OF 280 DEGS. WE CONTINUED ON OUR ASSIGNED HG, CONTINUING OUR CLB TO FL350. WE DID NOT HEAR XMISSIONS FROM THE OTHER ACFT AT FL310. THE REMAINDER OF THE FLT TO BNA WAS WITHOUT INCIDENT. I BELIEVE WHAT CAUSED THE SIT OF 'LOSS OF SEPARATION' BTWN ACFT WAS THE CTLR'S INTENTION IN THE ISSUED CLRNC AND OUR INTERP OF THE CLRNC, A MULTIPLE CLRNC. WITHOUT A DOUBT, WE SHOULD HAVE CLARIFIED THE GIVEN CLRNC, VERIFYING WITH THE CTLR OUR UNDERSTANDING OF THE SAID CLRNC.

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.