 |
|
Sortieren nach:
Datum - neue zuerst |
Datum - alte zuerst |
Bewertung
|
|
|
Hallo, hab grad den Report zur Navajo gefunden , poste ihn hier mal:
Piper PA-31-325 C/R Navajo, G-BMGH (07 June 1993)
Piper PA-31-325 C/R Navajo, G-BMGH 4 nm south east of King's Lynn, Norfolk on 7 June 1993
Aircraft Incident Report 6/94
Synopsis
The aircraft was operating on a scheduled passenger flight from Birmingham to Norwich, with a pilot and seven passengers on board when, as the flight passed south of King's Lynn, there was a loud 'bang' and the aircraft immediately rolled to the right and entered a tight spiral dive, or spin. The loud bang was caused by a blade, that had detached from the right propeller, penetrating the aircraft's nose baggage bay and exiting through the upper left fuselage structure. This blade then struck and removed the front of the left propeller assembly. The rigbht engine tore away from the wing, precipitating the loss of control, and tghe left engine stopped. The commander managed to regain control of the aircraft and successfully carried out a forced landing in a field of cereal crop. All eight occupants evacuated the aircraft with no serious injury.
The investigation identified the following causal factors:
i) Separation of the right engine, as a result of massive out-of-balance forces following fatigue failure of the right propeller hub and associated release of one blade, caused an immediate and critical loss of control which was only recovered and a successful forced landing accomplished by the exceptionally skilful handling of this commander.
ii) The grease nipple holes in such Hartzell HC-()3Y()-() type propeller hubs had not been masked prior to the shot peening process at manufacture and had therefore suffered deformation of the associated threads, which weakened their fatigue resistance.
iii) No detailed stress calculations from direct strain gauge testing had been undertaken, or had been required, on this propeller hub type at the time of its design and certification.
iv) Fatigue cracking that emanated from deformed grease nipple threads and which broke through to the outside surface of the propeller hub may not have been visible at the last maintenance inspection prior to the in-flight failure of the right propeller hub.
v) Despite the occurrence of fatigue cracking from grease nipple holes on such propeller hubs in service which had caused the manufacturer to redesign this type of hub in 1983, some 10 years prior to this accident, and to issue three related Service Bulletins in the period between October 1989 and September 1992 with the introduction of an optional eddy current inspection, in addition to visual inspection, the FAA had only issued one Airworthiness Directive (No. 89-22-05) requiring compliance with the initial SB 165. This had merely required periodic visual inspections and the FAA had not issued revised ADs to include eddy current inspections (as per SB 165A of 27 August 1992) or to emphasise the manufacturer's strong recommendation (SB 165B of 11 September 1992) for the replacement of such hubs with the improved post - 1983 type of hub.
vi) During the last visual inspection to FAA Airworthiness Directive (AD) No. 89-22-05, no cracking was observed on the propeller hub; the grease nipples had been removed from the hub to facilitate inspection. Such removal was not a requirement of this AD (which did not, however, warn against such removal) and may have tended to 'close up' any crack()s) present, reducing the chances of such visual detection.
vii) The original hub design was certificated in the knowledge that the vibration stresses on the left-hand rotating propeller of this type were generally higher than those on the right-hand rotating propeller, but were deemed acceptable.
viii) Operators and pilots of affected aircraft had not been made aware that the sudden initiation of unexplained vibration or grease leakage could indicate a potentially dangerous defect on such propeller hum assemblies although related Service Bulletins had warned aircraft engineers of such symptoms subsequent to 27 August 1992.
Four safety recommendations were made during the course of this investigation.
For further information contact the AAIB:
Air Accidents Investigation Branch
Berkshire Copse Road
Aldershot###-MYBR-###Hampshire
GU11 2HH
Tel: 01252 510300
Fax: 01252 376999
E-mail: enquiries@aaib.gov.uk
###-MYBR-###
Mit freundlichen Fliegergrüßen
Florian Guthardt
|
|
|
|
|
Jetzt habe ich auch endlich den Link zum King-Air Crash gefunden!http:
http://www.bfu-web.de/berichte/99_4x019dub.pdf###-MYBR-###
MFG
Florian Guthardt
|
|
|
|
|
Ich weiß von einer King (ohne Druckkabine) die flog immer Frankfurt-England und oder Beligien, nachts, eine ist vor ein paar Jahren nachts abgestürzt, weil erst das eine und später das andere Triebwerk ausfiel. Beide Piloten fanden den Tod. Ich bin mir aber nicht mehr ganz sicher, aber soweit ich weiß, wollten die mit dem einem verbleibende Triebwerk noch weiter fliegen, als notwendig. Dabei ist das laufende Triebwerk(aufgrund hoher Belastung ?) auch noch ausgefallen. War glaub ich "Night Express" in FFM, kann mich da aber auch täuschen. Also wie ihr seht, es gibt den doppelten Ausfall. Aber ich fliege seit einem Malibu Absturz aufgrund Triebwerkstotalausfall nur noch 2-Mot, fühle mich deutlich sicherer. Das Vertrauen in die Techmik ist seit dem stark gesunken. Ich hatte insgesamt 2 x Malibu Motorprobleme, davon einmal Absturz, einmal Triebaussetzer bei eine Cheyenne III, dann bei C414 linker Motor Riß im Zylinder, Motor hatte darauf hin nur wenig Leistung. Das alles in der Zeitspanne von 1993-1999 und ca 1000 Flugstunden.
|
|
|
|
|
|
3 Beiträge Seite 1 von 1
|
|
|
|
|
|
|
|
|
|
