37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
Attributes | |
ACN | 389510 |
Time | |
Date | 199712 |
Day | Sun |
Local Time Of Day | 0601 To 1200 |
Place | |
Locale Reference | atc facility : sfo airport : oak |
State Reference | CA |
Altitude | msl bound lower : 2700 msl bound upper : 2700 |
Environment | |
Flight Conditions | VMC |
Light | Night |
Aircraft 1 | |
Controlling Facilities | tracon : oak |
Operator | common carrier : air carrier |
Make Model Name | B747-100 |
Operating Under FAR Part | Part 121 |
Navigation In Use | Other |
Flight Phase | descent : approach landing other |
Route In Use | approach : visual |
Flight Plan | IFR |
Person 1 | |
Affiliation | company : air carrier |
Function | flight crew : second officer |
Qualification | pilot : flight engineer pilot : instrument pilot : commercial pilot : atp pilot : cfi |
Experience | flight time last 90 days : 150 flight time total : 21000 flight time type : 2400 |
ASRS Report | 389510 |
Person 2 | |
Affiliation | company : air carrier |
Function | flight crew : captain oversight : pic |
Qualification | pilot : instrument pilot : flight engineer pilot : atp pilot : cfi pilot : commercial |
Experience | flight time last 90 days : 245 flight time total : 15000 flight time type : 245 |
ASRS Report | 389498 |
Events | |
Anomaly | other anomaly other other spatial deviation |
Independent Detector | aircraft equipment other aircraft equipment : unspecified other flight crewa |
Resolutory Action | flight crew : returned to intended course or assigned course |
Consequence | Other |
Supplementary | |
Primary Problem | Flight Crew Human Performance |
Air Traffic Incident | Pilot Deviation |
Narrative:
Flight hnl-sfo B747-100. WX reported clear, high winds 340 degrees/36 KTS gusting to 40 KTS, outside recommended B747 crosswind limits for runway 28. Sfo ATIS was reporting visual approachs runway 1R. Local time was predawn, black night with no moon light. The approach was straight in for runway 1R over the ridge line west of sfo. Minimum safe sector altitude is 3100 ft MSL. Highest terrain on approach path is the top of the ridge line 5 NM from the end of runway 1R at 1944 ft MSL, only 1156 ft below the minimum sector altitude. No visual clues of the ridge line are available, only a black hole. There is no visual approach slope indicator (VASI) on runway 1R. The descent from 3100 ft was started at an estimated 3 degree gradient. At 2700 ft the 'GPWS' warning system sounded with 'too low terrain, too low terrain.' the captain executed an immediate pull up and the warning stopped. He then re-established a descent profile and we made an uneventful approach and landing. I believe a study of the geometry of this approach, started at 3100 ft inside 5 NM will require an unacceptable high descent rate and will set off the GPWS. My recommendation would be to prohibit the use of straight in visual approachs to runway 1R. If, due to high winds, runway 1R is a necessity, then an approach to runway 28 with a circle to runway 1R could be made with the strong caution to the high terrain south of the approach end of the runway.
Original NASA ASRS Text
Title: FLC OF B747-100 ON STRAIGHT IN DSCNT TO SFO RWY 1 HAS GPWS ACTIVATE. PULL UP ACCOMPLISHED AND RETURN TO APCH ACCOMPLISHED.
Narrative: FLT HNL-SFO B747-100. WX RPTED CLR, HIGH WINDS 340 DEGS/36 KTS GUSTING TO 40 KTS, OUTSIDE RECOMMENDED B747 XWIND LIMITS FOR RWY 28. SFO ATIS WAS RPTING VISUAL APCHS RWY 1R. LCL TIME WAS PREDAWN, BLACK NIGHT WITH NO MOON LIGHT. THE APCH WAS STRAIGHT IN FOR RWY 1R OVER THE RIDGE LINE W OF SFO. MINIMUM SAFE SECTOR ALT IS 3100 FT MSL. HIGHEST TERRAIN ON APCH PATH IS THE TOP OF THE RIDGE LINE 5 NM FROM THE END OF RWY 1R AT 1944 FT MSL, ONLY 1156 FT BELOW THE MINIMUM SECTOR ALT. NO VISUAL CLUES OF THE RIDGE LINE ARE AVAILABLE, ONLY A BLACK HOLE. THERE IS NO VISUAL APCH SLOPE INDICATOR (VASI) ON RWY 1R. THE DSCNT FROM 3100 FT WAS STARTED AT AN ESTIMATED 3 DEG GRADIENT. AT 2700 FT THE 'GPWS' WARNING SYS SOUNDED WITH 'TOO LOW TERRAIN, TOO LOW TERRAIN.' THE CAPT EXECUTED AN IMMEDIATE PULL UP AND THE WARNING STOPPED. HE THEN RE-ESTABLISHED A DSCNT PROFILE AND WE MADE AN UNEVENTFUL APCH AND LNDG. I BELIEVE A STUDY OF THE GEOMETRY OF THIS APCH, STARTED AT 3100 FT INSIDE 5 NM WILL REQUIRE AN UNACCEPTABLE HIGH DSCNT RATE AND WILL SET OFF THE GPWS. MY RECOMMENDATION WOULD BE TO PROHIBIT THE USE OF STRAIGHT IN VISUAL APCHS TO RWY 1R. IF, DUE TO HIGH WINDS, RWY 1R IS A NECESSITY, THEN AN APCH TO RWY 28 WITH A CIRCLE TO RWY 1R COULD BE MADE WITH THE STRONG CAUTION TO THE HIGH TERRAIN S OF THE APCH END OF THE RWY.
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.