Communications breakdown between flight crew and ATC resulted in operational error.

Attributes
ACN	291446
Time
Date	199412
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : emi
State Reference	MD
Altitude	msl bound lower : 9000 msl bound upper : 16000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : bwi
Operator	common carrier : air carrier
Make Model Name	DC-9 30
Operating Under FAR Part	Part 121
Flight Phase	climbout : intermediate altitude
Route In Use	departure other
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	other : unknown
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : flight engineer pilot : atp
Experience	flight time last 90 days : 190 flight time total : 8400 flight time type : 2400
ASRS Report	291446
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 200 flight time total : 13000
ASRS Report	291908
Events
Anomaly	conflict : airborne less severe non adherence : required legal separation
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	controller : issued new clearance flight crew : took evasive action other
Consequence	Other
Miss Distance	horizontal : 1500 vertical : 500
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

We were climbing to 9000 ft on a 330 degree heading. Passing 8700 ft we noticed traffic on TCASII at 9000 ft, 10 mi out at 12 O'clock headed our direction. We also acquired him visually. I leveled the aircraft at 9000 ft expecting a higher clearance. The captain was about to ask for higher when ATC told us to expedite our climb through 9000 ft. At the same time TCASII gave a TA and then an RA (climb). As I was complying with the RA, the captain asked what higher altitude we were cleared to. ATC replied 16000 ft. The captain read it back and said we had not been given the clearance earlier. ATC's reply was that he had. There was no squeal like a blocked transmission before this. The higher altitude clearance was forgotten by ATC until it was too late. The closest we came to the other aircraft was 500 ft vertically and 1/4 mi laterally. TCASII is worth its weight in gold. Supplemental information from acn 291908: it seemed like ATC thought he'd given us a higher altitude than 9000 ft when he said expedite through it but we never heard it or read it back.

Original NASA ASRS Text

Title: COMS BREAKDOWN BTWN FLC AND ATC RESULTED IN OPERROR.

Narrative: WE WERE CLBING TO 9000 FT ON A 330 DEG HDG. PASSING 8700 FT WE NOTICED TFC ON TCASII AT 9000 FT, 10 MI OUT AT 12 O'CLOCK HEADED OUR DIRECTION. WE ALSO ACQUIRED HIM VISUALLY. I LEVELED THE ACFT AT 9000 FT EXPECTING A HIGHER CLRNC. THE CAPT WAS ABOUT TO ASK FOR HIGHER WHEN ATC TOLD US TO EXPEDITE OUR CLB THROUGH 9000 FT. AT THE SAME TIME TCASII GAVE A TA AND THEN AN RA (CLB). AS I WAS COMPLYING WITH THE RA, THE CAPT ASKED WHAT HIGHER ALT WE WERE CLRED TO. ATC REPLIED 16000 FT. THE CAPT READ IT BACK AND SAID WE HAD NOT BEEN GIVEN THE CLRNC EARLIER. ATC'S REPLY WAS THAT HE HAD. THERE WAS NO SQUEAL LIKE A BLOCKED XMISSION BEFORE THIS. THE HIGHER ALT CLRNC WAS FORGOTTEN BY ATC UNTIL IT WAS TOO LATE. THE CLOSEST WE CAME TO THE OTHER ACFT WAS 500 FT VERTLY AND 1/4 MI LATERALLY. TCASII IS WORTH ITS WT IN GOLD. SUPPLEMENTAL INFO FROM ACN 291908: IT SEEMED LIKE ATC THOUGHT HE'D GIVEN US A HIGHER ALT THAN 9000 FT WHEN HE SAID EXPEDITE THROUGH IT BUT WE NEVER HEARD IT OR READ IT BACK.

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.