Thought cleared to maintain 270 KTS at FL330. Clearance to maintain 250 KTS at FL270.

Attributes
ACN	94695
Time
Date	198809
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : bna
State Reference	TN
Altitude	msl bound lower : 27000 msl bound upper : 27500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zme
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other
Flight Phase	climbout : intermediate altitude
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : flight engineer pilot : cfi pilot : atp
Experience	flight time last 90 days : 100 flight time total : 10500 flight time type : 1000
ASRS Report	94695
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	altitude deviation : overshoot other anomaly other anomaly other
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance other
Consequence	Other
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

We were assigned to climb to 33000' and hold 250 KTS in the climb due to same direction traffic ATC was trying to get ahead of us. We advised ATC that due to our weight we could not hold 250 KTS at 33000'. We said we must increase speed. ATC said maintain 270 KTS. We read back to maintain 270 KTS. ATC did not question our readback. What ATC wanted was maintain 250 KTS and 27000'. At 27800' ATC questioned our altitude and told us to maintain 28000' and 250 KTS. I feel this problem was due to ATC failure to be specific in his clearance and listen to our readback.

Original NASA ASRS Text

Title: THOUGHT CLEARED TO MAINTAIN 270 KTS AT FL330. CLRNC TO MAINTAIN 250 KTS AT FL270.

Narrative: WE WERE ASSIGNED TO CLB TO 33000' AND HOLD 250 KTS IN THE CLB DUE TO SAME DIRECTION TFC ATC WAS TRYING TO GET AHEAD OF US. WE ADVISED ATC THAT DUE TO OUR WT WE COULD NOT HOLD 250 KTS AT 33000'. WE SAID WE MUST INCREASE SPD. ATC SAID MAINTAIN 270 KTS. WE READ BACK TO MAINTAIN 270 KTS. ATC DID NOT QUESTION OUR READBACK. WHAT ATC WANTED WAS MAINTAIN 250 KTS AND 27000'. AT 27800' ATC QUESTIONED OUR ALT AND TOLD US TO MAINTAIN 28000' AND 250 KTS. I FEEL THIS PROB WAS DUE TO ATC FAILURE TO BE SPECIFIC IN HIS CLRNC AND LISTEN TO OUR READBACK.

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.