Air carrier X refused takeoff clearance behind B757 because of wake turbulence separation.

Attributes
ACN	290283
Time
Date	199412
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : den
State Reference	CO
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : cno
Operator	common carrier : air carrier
Make Model Name	MD-80 Super 80
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	climbout : takeoff ground : holding
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	B757 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	climbout : takeoff climbout : initial
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	290283
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	conflict : airborne less severe conflict : ground less severe other anomaly other
Independent Detector	other flight crewa
Resolutory Action	controller : issued new clearance
Consequence	faa : reviewed incident with flight crew
Miss Distance	horizontal : 24000 vertical : 0
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	other

Narrative:

During taxi-out at denver, air carrier X was behind a B-757 aircraft, and was told to proceed to runway 25L. The WX at the time was clear, with calm winds. When the 757 released brakes we were simultaneously cleared into position to hold. We started our stop-clock when the 757 began to roll, and were in position when we were told to take off. However, only 1 min 5 seconds had elapsed behind the 757 so we asked for another min. The response from the controller was that our clearance was canceled and that we should clear the runway to be placed back in line. When we emphasized that we only were asking for separation behind the 757, he told us again to clear and then gave clearance to another aircraft to take the runway. We were airborne 5 or 6 mins later. When I arrived at dfw I called the denver tower and spoke with the supervisor although she was not sympathetic, stating that the tower only needs 4 mi separation behind a 757. I argued that 1 min was not enough time to ensure separation but she continued to defend her controllers and his actions. Before hanging up she said she would talk to him about being more diplomatic on the radio but that she felt he was right in allowing only the 1 min separation. I advised her that I would file this report.

Original NASA ASRS Text

Title: ACR X REFUSED TKOF CLRNC BEHIND B757 BECAUSE OF WAKE TURB SEPARATION.

Narrative: DURING TAXI-OUT AT DENVER, ACR X WAS BEHIND A B-757 ACFT, AND WAS TOLD TO PROCEED TO RWY 25L. THE WX AT THE TIME WAS CLR, WITH CALM WINDS. WHEN THE 757 RELEASED BRAKES WE WERE SIMULTANEOUSLY CLRED INTO POS TO HOLD. WE STARTED OUR STOP-CLOCK WHEN THE 757 BEGAN TO ROLL, AND WERE IN POS WHEN WE WERE TOLD TO TAKE OFF. HOWEVER, ONLY 1 MIN 5 SECONDS HAD ELAPSED BEHIND THE 757 SO WE ASKED FOR ANOTHER MIN. THE RESPONSE FROM THE CTLR WAS THAT OUR CLRNC WAS CANCELED AND THAT WE SHOULD CLR THE RWY TO BE PLACED BACK IN LINE. WHEN WE EMPHASIZED THAT WE ONLY WERE ASKING FOR SEPARATION BEHIND THE 757, HE TOLD US AGAIN TO CLR AND THEN GAVE CLRNC TO ANOTHER ACFT TO TAKE THE RWY. WE WERE AIRBORNE 5 OR 6 MINS LATER. WHEN I ARRIVED AT DFW I CALLED THE DENVER TWR AND SPOKE WITH THE SUPVR ALTHOUGH SHE WAS NOT SYMPATHETIC, STATING THAT THE TWR ONLY NEEDS 4 MI SEPARATION BEHIND A 757. I ARGUED THAT 1 MIN WAS NOT ENOUGH TIME TO ENSURE SEPARATION BUT SHE CONTINUED TO DEFEND HER CTLRS AND HIS ACTIONS. BEFORE HANGING UP SHE SAID SHE WOULD TALK TO HIM ABOUT BEING MORE DIPLOMATIC ON THE RADIO BUT THAT SHE FELT HE WAS RIGHT IN ALLOWING ONLY THE 1 MIN SEPARATION. I ADVISED HER THAT I WOULD FILE THIS RPT.

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.