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An as350b2 returned to the base due to an engine bleed valve failing to close. Found a loose B nut on the bleed valve airline.
| Attributes | |
| ACN | 694733 |
| Time | |
| Date | 200604 |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | airport : zzz.airport |
| State Reference | US |
| Environment | |
| Light | Daylight |
| Aircraft 1 | |
| Operator | common carrier : air taxi |
| Make Model Name | AS 350 Astar/Ecureuil |
| Operating Under FAR Part | Part 135 |
| Person 1 | |
| Affiliation | company : air taxi |
| Function | instruction : instructor |
| Qualification | technician : airframe technician : inspection authority technician : powerplant |
| Experience | maintenance lead technician : 21 |
| ASRS Report | 694733 |
| Person 2 | |
| Affiliation | company : air taxi |
| Function | instruction : trainee maintenance : technician |
| Events | |
| Anomaly | aircraft equipment problem : critical maintenance problem : improper maintenance maintenance problem : improper documentation non adherence : far non adherence : published procedure other anomaly other |
| Independent Detector | aircraft equipment other aircraft equipment : temp t4 high other flight crewa |
| Resolutory Action | other |
| Consequence | other |
| Factors | |
| Maintenance | contributing factor : schedule pressure performance deficiency : testing performance deficiency : scheduled maintenance performance deficiency : repair performance deficiency : inspection performance deficiency : non compliance with legal requirements |
| Supplementary | |
| Problem Areas | Aircraft Environmental Factor Maintenance Human Performance |
| Primary Problem | Maintenance Human Performance |
Narrative:
While training and supervising a new hire on changing a tail rotor gear box; I was also checking the bleed valve orifice for cleanliness/clogging of the 1.9 MM orifice. The new hire and I finished the tail rotor installation and installed the vibration analyzing equipment. The new hire stated he made the logbook entry for ground check approval. We started the helicopter; visually checked the bleed valve orifice area for leaks and balanced the tail rotor. On apr/sun/06 while responding to an EMS mission; the pilot noticed the bleed valve didn't close and the T4 temperature was high. He returned to base and found an airliner 'B' nut loose. 1) inadequate staffing levels and constantly being on call. 2) the inspector saws the engine work being performed but didn't assure proper signoff or after-work check. 3) doing multiple tasks at the same time. 4) not checking the new hire's signoff because it has always been correct and complete.
Original NASA ASRS Text
Title: AN AS350B2 RETURNED TO THE BASE DUE TO AN ENG BLEED VALVE FAILING TO CLOSE. FOUND A LOOSE B NUT ON THE BLEED VALVE AIRLINE.
Narrative: WHILE TRAINING AND SUPERVISING A NEW HIRE ON CHANGING A TAIL ROTOR GEAR BOX; I WAS ALSO CHKING THE BLEED VALVE ORIFICE FOR CLEANLINESS/CLOGGING OF THE 1.9 MM ORIFICE. THE NEW HIRE AND I FINISHED THE TAIL ROTOR INSTALLATION AND INSTALLED THE VIBRATION ANALYZING EQUIP. THE NEW HIRE STATED HE MADE THE LOGBOOK ENTRY FOR GND CHK APPROVAL. WE STARTED THE HELI; VISUALLY CHKED THE BLEED VALVE ORIFICE AREA FOR LEAKS AND BALANCED THE TAIL ROTOR. ON APR/SUN/06 WHILE RESPONDING TO AN EMS MISSION; THE PLT NOTICED THE BLEED VALVE DIDN'T CLOSE AND THE T4 TEMP WAS HIGH. HE RETURNED TO BASE AND FOUND AN AIRLINER 'B' NUT LOOSE. 1) INADEQUATE STAFFING LEVELS AND CONSTANTLY BEING ON CALL. 2) THE INSPECTOR SAWS THE ENG WORK BEING PERFORMED BUT DIDN'T ASSURE PROPER SIGNOFF OR AFTER-WORK CHK. 3) DOING MULTIPLE TASKS AT THE SAME TIME. 4) NOT CHKING THE NEW HIRE'S SIGNOFF BECAUSE IT HAS ALWAYS BEEN CORRECT AND COMPLETE.
Data retrieved from NASA's ASRS site as of January 2009 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.