Mistaking a vector for a clearance to climb to FL330, flight crew left their assigned altitude of 27...

Attributes
ACN	235710
Time
Date	199303
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : crg
State Reference	FL
Altitude	msl bound lower : 27000 msl bound upper : 28300
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zjx
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	climbout : intermediate altitude cruise other cruise other
Route In Use	enroute : on vectors enroute airway : j53
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : cfi
Experience	flight time last 90 days : 25 flight time total : 14500 flight time type : 4000
ASRS Report	235710
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance non adherence : required legal separation other spatial deviation
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance other
Consequence	Other
Miss Distance	horizontal : 16500 vertical : 700
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Level at FL270. We were looking for FL330 or FL370 as our final cruising altitude. The frequency was very congested. We then received what we both thought to be a clearance to climb to FL330. I responded with a quick '330 (airline and flight number).' the first officer dialed FL330 into the altitude window. I confirmed to him the FL330 setting and he began to climb. At FL283 the jax controller asked us to say what our altitude was. I responded that we were out of FL283 for FL330. The controller then replied, 'descend to FL280 and turn left heading 330.' the first officer immediately descended to FL280 and I turned the aircraft to a 330 degree heading. When I turned the aircraft, I saw another aircraft ahead of us -- later we learned that it was the aircraft that we lost separation with -- going the same direction. It was level at FL290 and we had gotten to within about 2 1/2 - 3 mi of his tail. The controller then told us that his original clearance was to 'turn left to heading 330 vectors for climb.' we had both heard the clearance as a climb to FL330.

Original NASA ASRS Text

Title: MISTAKING A VECTOR FOR A CLRNC TO CLB TO FL330, FLC LEFT THEIR ASSIGNED ALT OF 27000 FT.

Narrative: LEVEL AT FL270. WE WERE LOOKING FOR FL330 OR FL370 AS OUR FINAL CRUISING ALT. THE FREQ WAS VERY CONGESTED. WE THEN RECEIVED WHAT WE BOTH THOUGHT TO BE A CLRNC TO CLB TO FL330. I RESPONDED WITH A QUICK '330 (AIRLINE AND FLT NUMBER).' THE FO DIALED FL330 INTO THE ALT WINDOW. I CONFIRMED TO HIM THE FL330 SETTING AND HE BEGAN TO CLB. AT FL283 THE JAX CTLR ASKED US TO SAY WHAT OUR ALT WAS. I RESPONDED THAT WE WERE OUT OF FL283 FOR FL330. THE CTLR THEN REPLIED, 'DSND TO FL280 AND TURN L HDG 330.' THE FO IMMEDIATELY DSNDED TO FL280 AND I TURNED THE ACFT TO A 330 DEG HDG. WHEN I TURNED THE ACFT, I SAW ANOTHER ACFT AHEAD OF US -- LATER WE LEARNED THAT IT WAS THE ACFT THAT WE LOST SEPARATION WITH -- GOING THE SAME DIRECTION. IT WAS LEVEL AT FL290 AND WE HAD GOTTEN TO WITHIN ABOUT 2 1/2 - 3 MI OF HIS TAIL. THE CTLR THEN TOLD US THAT HIS ORIGINAL CLRNC WAS TO 'TURN L TO HDG 330 VECTORS FOR CLB.' WE HAD BOTH HEARD THE CLRNC AS A CLB TO FL330.

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.

Mistaking a vector for a clearance to climb to FL330, flight crew left their assigned altitude of 27000 ft.