<< >> NASA ASRS Report 381300, September 1997

MD80 captain asks for a delay in takeoff behind a departing B747-400. He said he didn't have the required separation of 5 mi or 2 mins. Controller argued with him and the delay in takeoff provided the necessary 5 mi.

Attributes
ACN	381300
Time
Date	199709
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : lax
State Reference	CA
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	MD-80 Super 80
Operating Under FAR Part	Part 121
Navigation In Use	Other
Flight Phase	ground : holding
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	B747-400
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	climbout : initial climbout : takeoff
Route In Use	departure other departure sid : sid
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	381300
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	inflight encounter other non adherence : clearance non adherence : far non adherence : published procedure non adherence : required legal separation
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	other
Consequence	Other
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Pilot Deviation Operational Deviation
Situations
ATC Facility	procedure or policy : unspecified

Narrative:

Location: on runway 25R lax. Lax tower cleared us for takeoff following a B747-400 with only 3 mi separation. I asked for 30 seconds more time. He stated that 'you should have asked for more time prior to taking the runway.' we stated that we do not have the wake turbulence separation needed. The controller said that we had the separation and that it was '8 mi' when in fact it was approximately 3 mi visually and with TCASII by the time we questioned this, we had in fact the required separation. This particular B747-400 was very heavy and utilized almost all of the runway in its departure roll. He attempted to clear us for takeoff without the required 5 mi separation or 2 min separation.

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Original NASA ASRS Text

Title: MD80 CAPT ASKS FOR A DELAY IN TKOF BEHIND A DEPARTING B747-400. HE SAID HE DIDN'T HAVE THE REQUIRED SEPARATION OF 5 MI OR 2 MINS. CTLR ARGUED WITH HIM AND THE DELAY IN TKOF PROVIDED THE NECESSARY 5 MI.

Narrative: LOCATION: ON RWY 25R LAX. LAX TWR CLRED US FOR TKOF FOLLOWING A B747-400 WITH ONLY 3 MI SEPARATION. I ASKED FOR 30 SECONDS MORE TIME. HE STATED THAT 'YOU SHOULD HAVE ASKED FOR MORE TIME PRIOR TO TAKING THE RWY.' WE STATED THAT WE DO NOT HAVE THE WAKE TURB SEPARATION NEEDED. THE CTLR SAID THAT WE HAD THE SEPARATION AND THAT IT WAS '8 MI' WHEN IN FACT IT WAS APPROX 3 MI VISUALLY AND WITH TCASII BY THE TIME WE QUESTIONED THIS, WE HAD IN FACT THE REQUIRED SEPARATION. THIS PARTICULAR B747-400 WAS VERY HVY AND UTILIZED ALMOST ALL OF THE RWY IN ITS DEP ROLL. HE ATTEMPTED TO CLR US FOR TKOF WITHOUT THE REQUIRED 5 MI SEPARATION OR 2 MIN SEPARATION.

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.