 |
37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
B767 flight crew questions egll controller when issued takeoff clearance 1 mi behind departing B747. Flight crew delays takeoff until approximately separation exists.
| Attributes | |
| ACN | 440560 |
| Time | |
| Date | 199906 |
| Day | Sun |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | airport : egll.airport |
| State Reference | FO |
| Altitude | agl single value : 0 |
| Aircraft 1 | |
| Controlling Facilities | tower : egll.tower |
| Operator | common carrier : air carrier |
| Make Model Name | B767-200 |
| Operating Under FAR Part | Part 121 |
| Flight Phase | ground : position and hold |
| Flight Plan | IFR |
| Aircraft 2 | |
| Controlling Facilities | tower : egll.tower |
| Operator | common carrier : air carrier |
| Make Model Name | B747 Undifferentiated or Other Model |
| Operating Under FAR Part | Part 121 |
| Flight Phase | climbout : takeoff |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp |
| ASRS Report | 440650 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : multi engine pilot : instrument pilot : commercial |
| Events | |
| Anomaly | non adherence : clearance non adherence : published procedure other anomaly other |
| Independent Detector | other flight crewa |
| Resolutory Action | controller : issued advisory flight crew : took precautionary avoidance action |
| Miss Distance | horizontal : 6000 |
| Supplementary | |
| Problem Areas | ATC Human Performance |
| Primary Problem | ATC Human Performance |
Narrative:
Already in position and hold, we (aircraft X) were cleared for takeoff behind a B747 (aircraft Y) that had just broken ground ahead. Part 1 refers to a 2 min or 4 or 5 mi separation for wake turbulence separation. We questioned our clearance and the tower insisted 1 mi separation was enough. Rather than get into a dispute over the air waves we elected to delay takeoff until we considered it safe. Unable to find wake separation notes on the united kingdom in part 2 at this time. We considered asking for 4 mi prior to taking the runway but felt assured lhr operated under a similar separation to the united states system.
Original NASA ASRS Text
Title: B767 FLC QUESTIONS EGLL CTLR WHEN ISSUED TKOF CLRNC 1 MI BEHIND DEPARTING B747. FLC DELAYS TKOF UNTIL APPROX SEPARATION EXISTS.
Narrative: ALREADY IN POS AND HOLD, WE (ACFT X) WERE CLRED FOR TKOF BEHIND A B747 (ACFT Y) THAT HAD JUST BROKEN GND AHEAD. PART 1 REFERS TO A 2 MIN OR 4 OR 5 MI SEPARATION FOR WAKE TURB SEPARATION. WE QUESTIONED OUR CLRNC AND THE TWR INSISTED 1 MI SEPARATION WAS ENOUGH. RATHER THAN GET INTO A DISPUTE OVER THE AIR WAVES WE ELECTED TO DELAY TKOF UNTIL WE CONSIDERED IT SAFE. UNABLE TO FIND WAKE SEPARATION NOTES ON THE UNITED KINGDOM IN PART 2 AT THIS TIME. WE CONSIDERED ASKING FOR 4 MI PRIOR TO TAKING THE RWY BUT FELT ASSURED LHR OPERATED UNDER A SIMILAR SEPARATION TO THE UNITED STATES SYS.
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.