B767 crew departing lax at the hold line were cleared for takeoff 60 seconds behind a B747.

Attributes
ACN	564790
Time
Date	200211
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : lax.airport
State Reference	CA
Altitude	agl single value : 0
Environment
Light	Daylight
Aircraft 1
Controlling Facilities	tower : lax.tower tower : okc.tower
Operator	common carrier : air carrier
Make Model Name	B767 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	ground : position and hold
Flight Plan	IFR
Aircraft 2
Controlling Facilities	tower : lax.tower
Operator	common carrier : air carrier
Make Model Name	B747-400
Operating Under FAR Part	Part 121
Navigation In Use	other other
Flight Phase	climbout : takeoff
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	564790
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial
ASRS Report	565082
Events
Anomaly	inflight encounter : wake turbulence non adherence : required legal separation
Independent Detector	other controllera other flight crewa other flight crewb
Resolutory Action	controller : issued new clearance flight crew : took precautionary avoidance action
Supplementary
Problem Areas	ATC Human Performance Flight Crew Human Performance
Primary Problem	Ambiguous

Narrative:

We were cleared for takeoff behind a B747/400 by lax tower with only 60 second separation. I refused clearance until proper separation. Supplemental information from acn 565082: I realize there is no time criteria if they have the distance for takeoff separation, but my TCASII showed the B747 less than 3 mi from me and with only 1 min timing. How far could a B747 be.

Original NASA ASRS Text

Title: B767 CREW DEPARTING LAX AT THE HOLD LINE WERE CLRED FOR TKOF 60 SECONDS BEHIND A B747.

Narrative: WE WERE CLRED FOR TKOF BEHIND A B747/400 BY LAX TWR WITH ONLY 60 SECOND SEPARATION. I REFUSED CLRNC UNTIL PROPER SEPARATION. SUPPLEMENTAL INFO FROM ACN 565082: I REALIZE THERE IS NO TIME CRITERIA IF THEY HAVE THE DISTANCE FOR TKOF SEPARATION, BUT MY TCASII SHOWED THE B747 LESS THAN 3 MI FROM ME AND WITH ONLY 1 MIN TIMING. HOW FAR COULD A B747 BE.

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.