37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
Attributes | |
ACN | 994429 |
Time | |
Date | 201202 |
Local Time Of Day | 0001-0600 |
Place | |
Locale Reference | SKED.ARTCC |
State Reference | FO |
Environment | |
Flight Conditions | VMC |
Aircraft 1 | |
Make Model Name | B777-200 |
Operating Under FAR Part | Part 121 |
Flight Phase | Cruise |
Flight Plan | IFR |
Person 1 | |
Function | First Officer Pilot Not Flying |
Qualification | Flight Crew Air Transport Pilot (ATP) |
Events | |
Anomaly | Other Unwanted situation |
Narrative:
I am concerned about the use of UQ108 due to high terrain between waypoints ilvir and gekar. There is a mountain peak (el cocuy) in colombia that is 5;428 meters or 17;841 ft high within 2 NM of the airway centerline (N0627.5 W07222.1). The B777 has an emergency descent profile for decompression that reads; 'when descending in vicinity of high terrain - level off at 17;000 ft for 10 minutes from the time the passenger oxygen was deployed.' my fear is that in the middle of the night under duress of a rapid decompression event; a crew would follow the emergency descent procedure and end up almost 1;000 ft below the terrain while on the airway. When I have been routed on UQ108 airway in the past I have discussed the issue with dispatch; the B777 fleet manager and navdata/terrain. All of these entities have told me they would look into the issue and get back to me. I am still waiting.there are other viable alternate airways in colombia to use such as UL417 located 40 NM west which does not pose as high a risk for terrain as UQ108. I am hoping that dispatch will block the use of UQ108 between ilvir and gekar.
Original NASA ASRS Text
Title: A B777 Captain reported that the use of UQ108 in Colombia is inconsistent with the aircraft's emergency descent procedure over high terrain in that there is a mountain peak; El Cucoy; that rises to an altitude some 871 FT higher than the procedure's temporary level off altitude of 17;000 FT.
Narrative: I am concerned about the use of UQ108 due to high terrain between waypoints ILVIR and GEKAR. There is a mountain peak (El Cocuy) in Colombia that is 5;428 meters or 17;841 FT high within 2 NM of the airway centerline (N0627.5 W07222.1). The B777 has an emergency descent profile for decompression that reads; 'When descending in vicinity of high terrain - level off at 17;000 FT for 10 minutes from the time the passenger oxygen was deployed.' My fear is that in the middle of the night under duress of a rapid decompression event; a crew would follow the emergency descent procedure and end up almost 1;000 FT below the terrain while on the airway. When I have been routed on UQ108 airway in the past I have discussed the issue with Dispatch; the B777 Fleet Manager and NavData/Terrain. All of these entities have told me they would look into the issue and get back to me. I am still waiting.There are other viable alternate airways in Colombia to use such as UL417 located 40 NM west which does not pose as high a risk for terrain as UQ108. I am hoping that Dispatch will block the use of UQ108 between ILVIR and GEKAR.
Data retrieved from NASA's ASRS site as of July 2013 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.