 |
37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
B737 captain reports missing a descent crossing restriction with the first officer flying due to a new cruise altitude being programed into the FMC.
| Attributes | |
| ACN | 1245500 |
| Time | |
| Date | 201503 |
| Local Time Of Day | 1201-1800 |
| Place | |
| Locale Reference | ZID.ARTCC |
| State Reference | IN |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Make Model Name | B737-700 |
| Operating Under FAR Part | Part 121 |
| Flight Phase | Descent |
| Flight Plan | IFR |
| Component | |
| Aircraft Component | FMS/FMC |
| Person 1 | |
| Function | Captain |
| Qualification | Flight Crew Air Transport Pilot (ATP) |
| Experience | Flight Crew Last 90 Days 157 |
| Events | |
| Anomaly | Deviation - Altitude Crossing Restriction Not Met Deviation - Altitude Undershoot Deviation - Procedural Published Material / Policy Deviation - Procedural Clearance |
Narrative:
In cruise at FL400; we were instructed to cross 125 NM south of okk at FL300. The restriction was put in the FMC and MCP in accordance with SOP. Due to choppy ride at FL400; we started descent early in V/south. The FMC showed top of descent over 90 NM away and we had no magenta vertical path indicator when I noticed the crossing point approaching. I voiced my concern to the first officer (first officer) who immediately increased descent rate. When it was clear that we would be high at the restriction; I notified ATC who; of course; said 'no problem.' we ended up about 1500 feet high. Both first officer and I were confused about why the top of descent point showed so far away and why we had no magenta vertical path indicator.later we were given a further crossing restriction and I was unable to execute the altitude in the FMC. I checked the cruise altitude and found that the first officer had changed the cruise altitude to fl 310 during the descent without my knowledge. The top of descent and vertical guidance were missing because we hadn't yet reached our 'new' cruising altitude.SOP works when both pilots follow it. In my monitoring and intervening; we caught the error; but a little too late.
Original NASA ASRS Text
Title: B737 Captain reports missing a descent crossing restriction with the First Officer flying due to a new cruise altitude being programed into the FMC.
Narrative: In cruise at FL400; we were instructed to cross 125 NM south of OKK at FL300. The restriction was put in the FMC and MCP in accordance with SOP. Due to choppy ride at FL400; we started descent early in V/S. The FMC showed Top of Descent over 90 NM away and we had no magenta vertical path indicator when I noticed the crossing point approaching. I voiced my concern to the First Officer (FO) who immediately increased descent rate. When it was clear that we would be high at the restriction; I notified ATC who; of course; said 'no problem.' We ended up about 1500 feet high. Both FO and I were confused about why the Top of Descent point showed so far away and why we had no magenta vertical path indicator.Later we were given a further crossing restriction and I was unable to execute the altitude in the FMC. I checked the cruise altitude and found that the FO had changed the cruise altitude to FL 310 during the descent without my knowledge. The Top of Descent and vertical guidance were missing because we hadn't yet reached our 'new' cruising altitude.SOP works when both Pilots follow it. In my monitoring and intervening; we caught the error; but a little too late.
Data retrieved from NASA's ASRS site 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.