REG NASA-LLIS-0117-1992 Lessons Learned - Helicopter Hydraulic Line Chafing.pdf

1、Lessons Learned Entry: 0117Lesson Info:a71 Lesson Number: 0117a71 Lesson Date: 1992-07-29a71 Submitting Organization: KSCa71 Submitted by: Lisa L. MusgraveSubject: Helicopter Hydraulic Line Chafing Description of Driving Event: Immediately after becoming airborne at the SLF, the pilot of a KSC NASA

2、helicopter noticed a failure in the No.1 hydraulic system (which supports helicopter flight controls). The loss of this system is an emergency. An inspection was conducted on the hydraulic system which revealed the line was approx. 0.5 inches shorter than required for optimal operation. Due to the c

3、urvature of the line passing through the spacer block, the line was not seated flush in its hole. The spacer block, with rotor vibration, caused the hydraulic line to experience strand separation, resulting in a puncture.Lesson(s) Learned: Vibration during helicopter rotor operation may cause shorte

4、ned hydraulic lines to become rub-fatigued/chafed at the spacer block contact points.Recommendation(s): Periodically inspect flight control lines and spacer blocks for chafing and replace as necessary, ensuring that proper size lines are used.Evidence of Recurrence Control Effectiveness: N/AProvided

5、 by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Documents Related to Lesson: N/AMission Directorate(s): a71 Exploration Systemsa71 Aeronautics ResearchAdditional Key Phrase(s): a71 AircraftAdditional Info: Approval Info: a71 Approval Date: 1994-06-02a71 Approval Name: James G. Klinea71 Approval Organization: KSC/HEIa71 Approval Phone Number: 407-867-7614Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-