Acknowledged clearance to FL240. Controller claimed only cleared to FL280.

Attributes
ACN	90628
Time
Date	198807
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : den
State Reference	CO
Altitude	msl bound lower : 27000 msl bound upper : 33000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zdv
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	descent other
Route In Use	enroute airway : zdv
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : cfi pilot : atp
Experience	flight time last 90 days : 240 flight time total : 15000 flight time type : 260
ASRS Report	90628
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	other anomaly other
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance other
Consequence	Other
Supplementary
Primary Problem	Ambiguous
Air Traffic Incident	Pilot Deviation

Narrative:

We were given holding instructions to hold at smity intersection as published. Both the copilot and I thought the controller said to hold at FL240 and read the clearance back as FL240. As we approached the smity fix we heard the controller clear another aircraft, already in the hold, to FL240, so we asked for clarification and were told that our cleared altitude was FL280. We told the controller we had understood FL240 and had read back FL240. As we were already below FL280 the controller vectored us away from the area with no further incident. It pays to stay alert and listen for possible conflicts. I guess we will never know who was in error, us or the controller.

Original NASA ASRS Text

Title: ACKNOWLEDGED CLRNC TO FL240. CTLR CLAIMED ONLY CLEARED TO FL280.

Narrative: WE WERE GIVEN HOLDING INSTRUCTIONS TO HOLD AT SMITY INTXN AS PUBLISHED. BOTH THE COPLT AND I THOUGHT THE CTLR SAID TO HOLD AT FL240 AND READ THE CLRNC BACK AS FL240. AS WE APCHED THE SMITY FIX WE HEARD THE CTLR CLR ANOTHER ACFT, ALREADY IN THE HOLD, TO FL240, SO WE ASKED FOR CLARIFICATION AND WERE TOLD THAT OUR CLRED ALT WAS FL280. WE TOLD THE CTLR WE HAD UNDERSTOOD FL240 AND HAD READ BACK FL240. AS WE WERE ALREADY BELOW FL280 THE CTLR VECTORED US AWAY FROM THE AREA WITH NO FURTHER INCIDENT. IT PAYS TO STAY ALERT AND LISTEN FOR POSSIBLE CONFLICTS. I GUESS WE WILL NEVER KNOW WHO WAS IN ERROR, US OR THE CTLR.

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.