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37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
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Air carrier widebody transport gets safety alert on gap departure at sfo.
| Attributes | |
| ACN | 109085 |
| Time | |
| Date | 198904 |
| Day | Sat |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | airport : sfo |
| State Reference | CA |
| Altitude | msl bound lower : 1200 msl bound upper : 2200 |
| Environment | |
| Flight Conditions | Mixed |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | tracon : oak |
| Operator | common carrier : air carrier |
| Make Model Name | Widebody, Low Wing, 4 Turbojet Eng |
| Navigation In Use | Other |
| Flight Phase | climbout : initial climbout : intermediate altitude |
| 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 : flight engineer pilot : atp pilot : cfi |
| Experience | flight time last 90 days : 210 flight time total : 25000 flight time type : 1000 |
| ASRS Report | 109085 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Events | |
| Anomaly | other anomaly other other spatial deviation |
| Independent Detector | atc equipment other atc equipment : unspecified other controllera |
| Resolutory Action | flight crew : exited adverse environment other |
| Consequence | Other |
| Supplementary | |
| Primary Problem | Flight Crew Human Performance |
| Air Traffic Incident | Pilot Deviation other |
Narrative:
Aircraft was within 300# of maximum gross for takeoff (734000#). Followed SOP for takeoff profile. Started flap retraction at 1000' MSL and at about 1200' MSL departure control said they had a low altitude alert on us. As we continued maximum climb at our next flap retraction scheduled (about 2200' MSL) they called again saying they had another altitude alert on us. At that point we abandoned our SOP and pulled back on the yoke climbing at below maneuvering speed till we broke out on top approximately 2700' MSL. In cases like this, when terrain clearance becomes critical, I shall abandon SOP and set up the best flap confign giving the maximum roc to at least 3000' AGL. Currently our climb profiles end at 3000' AGL. I do not know if ATC filed a report. I hope not, but feel an impending low altitude should be reported to the crew in sufficient time to take corrective action. Callback conversation with reporter revealed the following: reporter states that aircraft was very heavy and climb performance on the low side with reference to rising terrain. The day was hot and the winds non existent. This could be the prime reason for a low altitude alert as the aircraft was tracking out on the 281 degree right of the sfo VOR as called for and was on course. The climb rate was positive during the start of initial flap retraction and may have slipped to a 0 rate or a negative rate momentarily during final flap retraction and setting of climb power.
Original NASA ASRS Text
Title: ACR WDB GETS SAFETY ALERT ON GAP DEP AT SFO.
Narrative: ACFT WAS WITHIN 300# OF MAX GROSS FOR TKOF (734000#). FOLLOWED SOP FOR TKOF PROFILE. STARTED FLAP RETRACTION AT 1000' MSL AND AT ABOUT 1200' MSL DEP CTL SAID THEY HAD A LOW ALT ALERT ON US. AS WE CONTINUED MAX CLB AT OUR NEXT FLAP RETRACTION SCHEDULED (ABOUT 2200' MSL) THEY CALLED AGAIN SAYING THEY HAD ANOTHER ALT ALERT ON US. AT THAT POINT WE ABANDONED OUR SOP AND PULLED BACK ON THE YOKE CLBING AT BELOW MANEUVERING SPD TILL WE BROKE OUT ON TOP APPROX 2700' MSL. IN CASES LIKE THIS, WHEN TERRAIN CLRNC BECOMES CRITICAL, I SHALL ABANDON SOP AND SET UP THE BEST FLAP CONFIGN GIVING THE MAX ROC TO AT LEAST 3000' AGL. CURRENTLY OUR CLB PROFILES END AT 3000' AGL. I DO NOT KNOW IF ATC FILED A RPT. I HOPE NOT, BUT FEEL AN IMPENDING LOW ALT SHOULD BE RPTED TO THE CREW IN SUFFICIENT TIME TO TAKE CORRECTIVE ACTION. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING: RPTR STATES THAT ACFT WAS VERY HVY AND CLB PERFORMANCE ON THE LOW SIDE WITH REF TO RISING TERRAIN. THE DAY WAS HOT AND THE WINDS NON EXISTENT. THIS COULD BE THE PRIME REASON FOR A LOW ALT ALERT AS THE ACFT WAS TRACKING OUT ON THE 281 DEG R OF THE SFO VOR AS CALLED FOR AND WAS ON COURSE. THE CLB RATE WAS POSITIVE DURING THE START OF INITIAL FLAP RETRACTION AND MAY HAVE SLIPPED TO A 0 RATE OR A NEGATIVE RATE MOMENTARILY DURING FINAL FLAP RETRACTION AND SETTING OF CLB PWR.
Data retrieved from NASA's ASRS site as of August 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.