 |
37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
Operational error less than standard separation when an LR24 descends through the altitude of an air carrier DC9. Flight crew of the LR24 miscopied the descent altitude although they questioned the altitude and reporter did not hear the call.
| Attributes | |
| ACN | 382242 |
| Time | |
| Date | 199710 |
| Day | Sat |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | atc facility : fdy |
| State Reference | OH |
| Altitude | msl bound lower : 21000 msl bound upper : 21000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | artcc : zob |
| Operator | common carrier : air carrier |
| Make Model Name | DC-9 Undifferentiated or Other Model |
| Operating Under FAR Part | Part 121 |
| Flight Phase | climbout : intermediate altitude cruise other |
| Flight Plan | IFR |
| Aircraft 2 | |
| Operator | common carrier : air carrier |
| Make Model Name | Learjet 24 |
| Operating Under FAR Part | Part 135 |
| Flight Phase | descent other |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | government : faa |
| Function | controller : radar |
| Qualification | controller : radar |
| Experience | controller radar : 10 |
| ASRS Report | 382242 |
| Person 2 | |
| Affiliation | government : faa |
| Function | other personnel other |
| Qualification | controller : radar |
| Events | |
| Anomaly | conflict : airborne less severe non adherence : published procedure non adherence : required legal separation other anomaly other |
| Independent Detector | atc equipment other atc equipment : unspecified |
| Resolutory Action | none taken : detected after the fact |
| Consequence | faa : investigated |
| Miss Distance | horizontal : 6000 vertical : 0 |
| Supplementary | |
| Primary Problem | ATC Human Performance |
| Air Traffic Incident | Operational Error |
Narrative:
A DC9 was climbed to FL210, an LR24 was cleared to FL220 but review of tape indicates the LR24 read back FL200 causing them to descend through DC9 altitude. Traffic was read to both pilots and the LR24 questioned his altitude assignment, but another controller cut in with coordination (impertinent) and I couldn't hear the aircraft question his altitude assignment. Resolution to prevent another occurrence: controllers should not be able to interrupt pilot-controller communications.
Original NASA ASRS Text
Title: OPERROR LTSS WHEN AN LR24 DSNDS THROUGH THE ALT OF AN ACR DC9. FLC OF THE LR24 MISCOPIED THE DSCNT ALT ALTHOUGH THEY QUESTIONED THE ALT AND RPTR DID NOT HEAR THE CALL.
Narrative: A DC9 WAS CLBED TO FL210, AN LR24 WAS CLRED TO FL220 BUT REVIEW OF TAPE INDICATES THE LR24 READ BACK FL200 CAUSING THEM TO DSND THROUGH DC9 ALT. TFC WAS READ TO BOTH PLTS AND THE LR24 QUESTIONED HIS ALT ASSIGNMENT, BUT ANOTHER CTLR CUT IN WITH COORD (IMPERTINENT) AND I COULDN'T HEAR THE ACFT QUESTION HIS ALT ASSIGNMENT. RESOLUTION TO PREVENT ANOTHER OCCURRENCE: CTLRS SHOULD NOT BE ABLE TO INTERRUPT PLT-CTLR COMS.
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.