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37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
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Fleet inconsistency and difficulty with audio selector lead to potential altitude deviation for air carrier-medium large transport.
| Attributes | |
| ACN | 137520 |
| Time | |
| Date | 199002 |
| Day | Wed |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | atc facility : pit |
| State Reference | PA |
| Altitude | msl bound lower : 29000 msl bound upper : 37000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | artcc : zob |
| Operator | common carrier : air carrier |
| Make Model Name | Medium Large Transport, Low Wing, 2 Turbojet Eng |
| Navigation In Use | Other |
| Flight Phase | climbout : intermediate altitude cruise other |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : instrument pilot : atp pilot : cfi pilot : flight engineer |
| Experience | flight time last 90 days : 180 flight time total : 13000 flight time type : 4000 |
| ASRS Report | 137520 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : commercial pilot : instrument |
| Events | |
| Anomaly | aircraft equipment problem : less severe other anomaly other |
| Independent Detector | other flight crewa |
| Resolutory Action | flight crew : returned to intended course or assigned course |
| Consequence | Other |
| Supplementary | |
| Primary Problem | Aircraft |
| Air Traffic Incident | other |
Narrative:
Aircraft cleared to 29000'. Clearance received to climb to 37000'. FMC and MCP reset and clearance read back. Passing 30500' ATC reclred aircraft to maintain 31000'. ATC was queried and response was no clearance was issued. Compounding problem was the audio panel selector box installed in aircraft. Because of sensitivity and poor design, use of anything other than overhead speakers, virtually impossible. My airline, air carrier a recently integrated into air carrier B, and fleet differences include the audio selector panel. Poor design include difficulty of varying vol, when used with high quality headsets/boom mics; limited and unsatisfactory night lighting; no vol control on PA and marker beacon position; and cumbersome transmit selector positions. Overhead speaker quality marginal and operative with headsets is highly desirable; virtually impossible with the installed slide-switch type audio selector panel.
Original NASA ASRS Text
Title: FLEET INCONSISTENCY AND DIFFICULTY WITH AUDIO SELECTOR LEAD TO POTENTIAL ALT DEVIATION FOR ACR-MLG.
Narrative: ACFT CLRED TO 29000'. CLRNC RECEIVED TO CLB TO 37000'. FMC AND MCP RESET AND CLRNC READ BACK. PASSING 30500' ATC RECLRED ACFT TO MAINTAIN 31000'. ATC WAS QUERIED AND RESPONSE WAS NO CLRNC WAS ISSUED. COMPOUNDING PROB WAS THE AUDIO PANEL SELECTOR BOX INSTALLED IN ACFT. BECAUSE OF SENSITIVITY AND POOR DESIGN, USE OF ANYTHING OTHER THAN OVERHEAD SPEAKERS, VIRTUALLY IMPOSSIBLE. MY AIRLINE, ACR A RECENTLY INTEGRATED INTO ACR B, AND FLEET DIFFERENCES INCLUDE THE AUDIO SELECTOR PANEL. POOR DESIGN INCLUDE DIFFICULTY OF VARYING VOL, WHEN USED WITH HIGH QUALITY HEADSETS/BOOM MICS; LIMITED AND UNSATISFACTORY NIGHT LIGHTING; NO VOL CONTROL ON PA AND MARKER BEACON POS; AND CUMBERSOME XMIT SELECTOR POSITIONS. OVERHEAD SPEAKER QUALITY MARGINAL AND OPERATIVE WITH HEADSETS IS HIGHLY DESIRABLE; VIRTUALLY IMPOSSIBLE WITH THE INSTALLED SLIDE-SWITCH TYPE AUDIO SELECTOR PANEL.
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.