 |
37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
Air carrier medium large transport altitude deviation overshot during descent. ZNY said FL290 flight crew heard and had confirmed FL250.
| Attributes | |
| ACN | 160868 |
| Time | |
| Date | 199010 |
| Day | Mon |
| Local Time Of Day | 0601 To 1200 |
| Place | |
| Locale Reference | atc facility : bwz |
| State Reference | NJ |
| Altitude | msl bound lower : 25000 msl bound upper : 29000 |
| Environment | |
| Flight Conditions | Mixed |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | artcc : zny |
| Operator | common carrier : air carrier |
| Make Model Name | Medium Large Transport, Low Wing, 2 Turbojet Eng |
| Flight Phase | cruise other descent other |
| Route In Use | enroute airway : zny |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp |
| Experience | flight time last 90 days : 150 flight time total : 14000 flight time type : 325 |
| ASRS Report | 160868 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : instrument pilot : commercial |
| Events | |
| Anomaly | altitude deviation : overshoot |
| Independent Detector | other controllera |
| Resolutory Action | controller : issued new clearance |
| Consequence | Other |
| Supplementary | |
| Primary Problem | ATC Human Performance |
| Air Traffic Incident | Pilot Deviation other other |
Narrative:
Ny center cleared air carrier flight to FL250. Since was unusual to be cleared to that altitude so far away from destination, I asked for confirmation on the altitude. Both pilot agreed that controller said affirmative FL250. I reported air carrier identification leaving FL310 for FL250. Going through FL285 controller said 'level at FL290.' we immediately reversed and started climbing to FL290. Controller said 'level off at FL280.' there was some static on controllers transmitter (reported by me and other aircraft). Controller had 3 chances to correct miscom and did not do so. When clearance was read back, when asked for confirmation, when I reported out of 310 for 250. Closer adherence to phonetic pronunciation especially when 5's or 9's are concerned would save confusion. Nine can sound much like five on a poor quality transmitter. Both the first officer and I heard FL250 not once but twice. Had the controller said two-niner zero I don't think we would have had any doubts.
Original NASA ASRS Text
Title: ACR MLG ALT DEVIATION OVERSHOT DURING DESCENT. ZNY SAID FL290 FLT CREW HEARD AND HAD CONFIRMED FL250.
Narrative: NY CTR CLRED ACR FLT TO FL250. SINCE WAS UNUSUAL TO BE CLRED TO THAT ALT SO FAR AWAY FROM DEST, I ASKED FOR CONFIRMATION ON THE ALT. BOTH PLT AGREED THAT CTLR SAID AFFIRMATIVE FL250. I RPTED ACR ID LEAVING FL310 FOR FL250. GOING THROUGH FL285 CTLR SAID 'LEVEL AT FL290.' WE IMMEDIATELY REVERSED AND STARTED CLBING TO FL290. CTLR SAID 'LEVEL OFF AT FL280.' THERE WAS SOME STATIC ON CTLRS XMITTER (RPTED BY ME AND OTHER ACFT). CTLR HAD 3 CHANCES TO CORRECT MISCOM AND DID NOT DO SO. WHEN CLRNC WAS READ BACK, WHEN ASKED FOR CONFIRMATION, WHEN I RPTED OUT OF 310 FOR 250. CLOSER ADHERENCE TO PHONETIC PRONUNCIATION ESPECIALLY WHEN 5'S OR 9'S ARE CONCERNED WOULD SAVE CONFUSION. NINE CAN SOUND MUCH LIKE FIVE ON A POOR QUALITY XMITTER. BOTH THE F/O AND I HEARD FL250 NOT ONCE BUT TWICE. HAD THE CTLR SAID TWO-NINER ZERO I DON'T THINK WE WOULD HAVE HAD ANY DOUBTS.
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.