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Medium large transport flight director on programmed departure at lax, flight director commanded a left turn which captain flying started but realized his error and came back to departure heading.
| Attributes | |
| ACN | 118724 |
| Time | |
| Date | 198908 |
| Day | Thu |
| Local Time Of Day | 0601 To 1200 |
| Place | |
| Locale Reference | atc facility : lax |
| State Reference | CA |
| Altitude | msl bound lower : 1000 msl bound upper : 1000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | tower : lax |
| Operator | common carrier : air carrier |
| Make Model Name | Medium Large Transport, Low Wing, 2 Turbojet Eng |
| Navigation In Use | Other Other |
| Flight Phase | climbout : intermediate altitude climbout : initial |
| Route In Use | departure sid : sid |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp |
| Experience | flight time last 90 days : 200 flight time total : 15000 |
| ASRS Report | 118724 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : atp |
| Events | |
| Anomaly | aircraft equipment problem : less severe non adherence : published procedure non adherence : clearance other spatial deviation |
| Independent Detector | other controllera other flight crewa |
| Resolutory Action | flight crew : overcame equipment problem |
| Consequence | Other |
| Supplementary | |
| Primary Problem | Flight Crew Human Performance |
| Air Traffic Incident | Pilot Deviation |
Narrative:
This aircraft is equipped with a highly accurate inertial navigation system with most routes and many departure and arrival procedures stored in the data base. There is nothing wrong with the hardware but the software is another matter. Many SID's and profile dscnts are not stored exactly as published (close, but no cigar). This occurrence is but one tiny example. The flipr SID off 25R specified runway heading to the shoreline (or abeam lax VOR) then left to a 220 degree heading. The runway heading to the shoreline is to avoid overflying parts of el segundo adjacent to the airport. The navigation system commanded an early turn to 220 degree, I rolled into a left bank then realized the error (which the first officer and tower caught simultaneously) then rolled back to runway heading. No far violation that I know of since heading never varied more than 5 or 6 degree, but I can't help worrying how many pilots have been led down the primrose path by the same type of errors. Callback conversation with reporter revealed the following: the automatic programs require a great deal of close monitoring. Company has a system of advising of needed corrections that are incorporated into the next updated program. Each time a program is updated (there are almost always some minor changes in procedures) one must be wary of changes over what one has become accustomed to in the way of departure routes, crossing altitudes, etc.
Original NASA ASRS Text
Title: MLG FLT DIRECTOR ON PROGRAMMED DEP AT LAX, FLT DIRECTOR COMMANDED A LEFT TURN WHICH CAPT FLYING STARTED BUT REALIZED HIS ERROR AND CAME BACK TO DEP HEADING.
Narrative: THIS ACFT IS EQUIPPED WITH A HIGHLY ACCURATE INERTIAL NAVIGATION SYSTEM WITH MOST ROUTES AND MANY DEP AND ARR PROCS STORED IN THE DATA BASE. THERE IS NOTHING WRONG WITH THE HARDWARE BUT THE SOFTWARE IS ANOTHER MATTER. MANY SID'S AND PROFILE DSCNTS ARE NOT STORED EXACTLY AS PUBLISHED (CLOSE, BUT NO CIGAR). THIS OCCURRENCE IS BUT ONE TINY EXAMPLE. THE FLIPR SID OFF 25R SPECIFIED RWY HDG TO THE SHORELINE (OR ABEAM LAX VOR) THEN LEFT TO A 220 DEG HDG. THE RWY HDG TO THE SHORELINE IS TO AVOID OVERFLYING PARTS OF EL SEGUNDO ADJACENT TO THE ARPT. THE NAVIGATION SYSTEM COMMANDED AN EARLY TURN TO 220 DEG, I ROLLED INTO A LEFT BANK THEN REALIZED THE ERROR (WHICH THE F/O AND TWR CAUGHT SIMULTANEOUSLY) THEN ROLLED BACK TO RWY HDG. NO FAR VIOLATION THAT I KNOW OF SINCE HDG NEVER VARIED MORE THAN 5 OR 6 DEG, BUT I CAN'T HELP WORRYING HOW MANY PLTS HAVE BEEN LED DOWN THE PRIMROSE PATH BY THE SAME TYPE OF ERRORS. CALLBACK CONVERSATION WITH REPORTER REVEALED THE FOLLOWING: THE AUTO PROGRAMS REQUIRE A GREAT DEAL OF CLOSE MONITORING. COMPANY HAS A SYSTEM OF ADVISING OF NEEDED CORRECTIONS THAT ARE INCORPORATED INTO THE NEXT UPDATED PROGRAM. EACH TIME A PROGRAM IS UPDATED (THERE ARE ALMOST ALWAYS SOME MINOR CHANGES IN PROCS) ONE MUST BE WARY OF CHANGES OVER WHAT ONE HAS BECOME ACCUSTOMED TO IN THE WAY OF DEP ROUTES, XING ALTS, ETC.
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.