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Pilot of a piper PA41 turboprop overshot cruise altitude due in part to a failed altitude alerter system and the expectation of being cleared to a higher altitude.
| Attributes | |
| ACN | 365280 |
| Time | |
| Date | 199704 |
| Day | Fri |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | atc facility : mtj |
| State Reference | CO |
| Altitude | msl bound lower : 23000 msl bound upper : 23700 |
| Environment | |
| Flight Conditions | IMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | artcc : zdv |
| Operator | common carrier : air taxi |
| Make Model Name | PA-31T-1 Cheyenne I |
| Operating Under FAR Part | Part 135 |
| Flight Phase | climbout : intermediate altitude |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air taxi |
| Function | flight crew : single pilot |
| Qualification | pilot : atp |
| Experience | flight time last 90 days : 50 flight time total : 15000 flight time type : 500 |
| ASRS Report | 365280 |
| Person 2 | |
| Affiliation | government : faa |
| Function | controller : radar |
| Qualification | controller : radar |
| Events | |
| Anomaly | altitude deviation : overshoot non adherence : clearance |
| Independent Detector | other controllera |
| Resolutory Action | flight crew : returned to intended course or assigned course other |
| Consequence | Other |
| Supplementary | |
| Primary Problem | Flight Crew Human Performance |
| Air Traffic Incident | Pilot Deviation |
Narrative:
During climb to assigned FL230, with autoplt engaged in altitude preselect mode, pilot engaged in discussion with ATC (ZDV) whether FL250 would be required due icing. ATC advised FL250 available if necessary. Altitude alerter/preselect unit failed to annunciate or capture. Aircraft climbed to FL237 before controller alerted crew. Contributing factors: 1) failed altitude alerter/preselector. 2) crew's habitual dependence on altitude alert preselect system (single pilot turboprop). 3) prior discussion of FL250 caused confusion 'saw altimeter go over FL230 but didn't get altitude alert, so unconsciously assumed we were cleared to FL250.'
Original NASA ASRS Text
Title: PLT OF A PIPER PA41 TURBOPROP OVERSHOT CRUISE ALT DUE IN PART TO A FAILED ALT ALERTER SYS AND THE EXPECTATION OF BEING CLRED TO A HIGHER ALT.
Narrative: DURING CLB TO ASSIGNED FL230, WITH AUTOPLT ENGAGED IN ALT PRESELECT MODE, PLT ENGAGED IN DISCUSSION WITH ATC (ZDV) WHETHER FL250 WOULD BE REQUIRED DUE ICING. ATC ADVISED FL250 AVAILABLE IF NECESSARY. ALT ALERTER/PRESELECT UNIT FAILED TO ANNUNCIATE OR CAPTURE. ACFT CLBED TO FL237 BEFORE CTLR ALERTED CREW. CONTRIBUTING FACTORS: 1) FAILED ALT ALERTER/PRESELECTOR. 2) CREW'S HABITUAL DEPENDENCE ON ALT ALERT PRESELECT SYS (SINGLE PLT TURBOPROP). 3) PRIOR DISCUSSION OF FL250 CAUSED CONFUSION 'SAW ALTIMETER GO OVER FL230 BUT DIDN'T GET ALT ALERT, SO UNCONSCIOUSLY ASSUMED WE WERE CLRED TO FL250.'
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.