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Air carrier large transport made a takeoff at gross weight in excess of allowable for wind conditions. Flight crew failed to make adequate gross weight correction for tailwind.
| Attributes | |
| ACN | 134419 |
| Time | |
| Date | 199001 |
| Day | Sun |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | airport : sna |
| 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 | Widebody, Low Wing, 2 Turbojet Eng |
| 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 |
| Experience | flight time last 90 days : 92 flight time total : 6924 flight time type : 396 |
| ASRS Report | 134419 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : atp |
| Events | |
| Anomaly | non adherence : far non adherence : published procedure |
| Independent Detector | other flight crewa |
| Resolutory Action | none taken : detected after the fact |
| Consequence | Other |
| Supplementary | |
| Primary Problem | Flight Crew Human Performance |
| Air Traffic Incident | Pilot Deviation |
Narrative:
We were flying a sleek late model twin jetliner with power to spare. Wind was 040/13. Ground control cleared us to runway 1L for takeoff. We weighed 209000#, which was 11000 pounds below the aircraft limit nd 15000 pounds below the runway limit for 0 wind. As we waited in line the wind shifted south. When cleared for takeoff after about 30 mins, we weighted 209000# and the wind was 180/8, 2 KTS below the maximum allowable tailwind. Our maximum power takeoff used all but about 1000' of runway, which surprised us both. I reviewed the departure plan and discovered that runway limited weight with 8 KTS of tailwind had been 207000#, based on a 2200# reduction for each knot of tailwind. We had been 1000 pounds too heavy on takeoff. The lesson for me is the 'power to spare' is a generalization and a dangerous mindset. Performance is relative to specific conditions, and there is no substitute for the required arithmetic, especially when actual conditions are not as planned.
Original NASA ASRS Text
Title: ACR LGT MADE A TKOF AT GROSS WEIGHT IN EXCESS OF ALLOWABLE FOR WIND CONDITIONS. FLT CREW FAILED TO MAKE ADEQUATE GROSS WEIGHT CORRECTION FOR TAILWIND.
Narrative: WE WERE FLYING A SLEEK LATE MODEL TWIN JETLINER WITH PWR TO SPARE. WIND WAS 040/13. GND CTL CLRED US TO RWY 1L FOR TKOF. WE WEIGHED 209000#, WHICH WAS 11000 LBS BELOW THE ACFT LIMIT ND 15000 LBS BELOW THE RWY LIMIT FOR 0 WIND. AS WE WAITED IN LINE THE WIND SHIFTED S. WHEN CLRED FOR TKOF AFTER ABOUT 30 MINS, WE WEIGHTED 209000# AND THE WIND WAS 180/8, 2 KTS BELOW THE MAX ALLOWABLE TAILWIND. OUR MAX PWR TKOF USED ALL BUT ABOUT 1000' OF RWY, WHICH SURPRISED US BOTH. I REVIEWED THE DEP PLAN AND DISCOVERED THAT RWY LIMITED WT WITH 8 KTS OF TAILWIND HAD BEEN 207000#, BASED ON A 2200# REDUCTION FOR EACH KNOT OF TAILWIND. WE HAD BEEN 1000 LBS TOO HEAVY ON TKOF. THE LESSON FOR ME IS THE 'PWR TO SPARE' IS A GENERALIZATION AND A DANGEROUS MINDSET. PERFORMANCE IS RELATIVE TO SPECIFIC CONDITIONS, AND THERE IS NO SUBSTITUTE FOR THE REQUIRED ARITHMETIC, ESPECIALLY WHEN ACTUAL CONDITIONS ARE NOT AS PLANNED.
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.