Narrative:

We were cleared into position and hold on runway 1R in sfo, with a caution for a departing L1011 for wake turbulence. When the L1011 started his roll, we started the clock (SOP). 1 min later, tower advised 'clear for takeoff' with 'traffic on a 2 1/2 mi final for runway 28.' we responded we would need a delay for wake turbulence. Tower said 'how much do you need?' we responded 2 mins or 5 mi. At the time, we could see the L1011 below the clouds, and TCASII showed it a bit over 2 mi away. Tower claimed L1011 was more than 5 mi and that we would have to either take off or clear the runway. We accepted clearance to exit runway 1R and began moving toward taxiway M. The tower then told us to hold in position, and followed shortly with a takeoff clearance with adequate separation. The controller was obviously annoyed. It was obviously not 5 mi of separation for us. This controller was either mistaken, or he deliberately lied to expedite our takeoff. I hope the former was true, but this is not the first time we have seen this. This event was the most flagrant and obvious disregard for wake turbulence separation I have seen. I believe the dangers of flying into wake turbulence need to be re-emphasized to ATC personnel. An aircraft at a low speed, heavy, and close to the ground is especially vulnerable. Occurrences like this one seem to be happening more frequently.

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Original NASA ASRS Text

Title: LGT CREW ALLEGES TWR CTLR MANIPULATION OF WAKE TURB TOLERANCES TO EXPEDITE DEPS AND ARRS AT SFO.

Narrative: WE WERE CLRED INTO POS AND HOLD ON RWY 1R IN SFO, WITH A CAUTION FOR A DEPARTING L1011 FOR WAKE TURB. WHEN THE L1011 STARTED HIS ROLL, WE STARTED THE CLOCK (SOP). 1 MIN LATER, TWR ADVISED 'CLR FOR TKOF' WITH 'TFC ON A 2 1/2 MI FINAL FOR RWY 28.' WE RESPONDED WE WOULD NEED A DELAY FOR WAKE TURB. TWR SAID 'HOW MUCH DO YOU NEED?' WE RESPONDED 2 MINS OR 5 MI. AT THE TIME, WE COULD SEE THE L1011 BELOW THE CLOUDS, AND TCASII SHOWED IT A BIT OVER 2 MI AWAY. TWR CLAIMED L1011 WAS MORE THAN 5 MI AND THAT WE WOULD HAVE TO EITHER TAKE OFF OR CLR THE RWY. WE ACCEPTED CLRNC TO EXIT RWY 1R AND BEGAN MOVING TOWARD TXWY M. THE TWR THEN TOLD US TO HOLD IN POS, AND FOLLOWED SHORTLY WITH A TKOF CLRNC WITH ADEQUATE SEPARATION. THE CTLR WAS OBVIOUSLY ANNOYED. IT WAS OBVIOUSLY NOT 5 MI OF SEPARATION FOR US. THIS CTLR WAS EITHER MISTAKEN, OR HE DELIBERATELY LIED TO EXPEDITE OUR TKOF. I HOPE THE FORMER WAS TRUE, BUT THIS IS NOT THE FIRST TIME WE HAVE SEEN THIS. THIS EVENT WAS THE MOST FLAGRANT AND OBVIOUS DISREGARD FOR WAKE TURB SEPARATION I HAVE SEEN. I BELIEVE THE DANGERS OF FLYING INTO WAKE TURB NEED TO BE RE-EMPHASIZED TO ATC PERSONNEL. AN ACFT AT A LOW SPD, HVY, AND CLOSE TO THE GND IS ESPECIALLY VULNERABLE. OCCURRENCES LIKE THIS ONE SEEM TO BE HAPPENING MORE FREQUENTLY.

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.