AD/BEECH 65/64 - Wing Structural Fatigue Limitation

COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY

SCHEDULE OF AIRWORTHINESS DIRECTIVES

Beechcraft 65 and 70 (Queen Air) Series Aeroplanes

AD/BEECH 65/64 Wing Structural Fatigue Limitation 12/88

Applicability: All models listed in the Retirement Schedule below. For models not listed, the Authority must be contacted as a fatigue evaluation has not yet been carried out.

Requirement: Retire from service the centre section and outer wing main spar lower caps, including the centre section to outer wing attachment fittings.

RETIREMENT SCHEDULE

Note 1: This Retirement Schedule is based on certain assumptions regarding average cruise weight, and also assumes one flight per hour. Should the average take-off weight, assessed over the life of the aircraft, be greater than the values shown in the Retirement Schedule, the Authority must be advised as it will be necessary to re- assess the life limitation. Similarly, the Authority must be advised if the average time per flight stage (lift-off to touchdown) is shorter than the value shown.

Note 2: Some aircraft have been fitted with engines of a different type to the original, including IO-720 installation to US FAA STC SA444SW. Whilst the engine installation itself would not normally affect the wing life limitation, for some models there is a concomitant MTOW increase and thus NOTE 1 may be applicable.

Note 3: For aircraft which, because of an unusual operational role, have had individual life assessments approved by the Authority prior to 1 December 1988, those assessments still stand.

COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY

SCHEDULE OF AIRWORTHINESS DIRECTIVES

Note 4: On the basis of the currently available fatigue substantiation for the aircraft, only one spar cap replacement is permitted. Any proposal for a further extension in life incorporating a second spar change must be supported by a substantiation covering all the remaining primary structure including empennage, control surface hinge arms etc. This substantiation must incorporate a safe life assessment, or a sufficiently rigorous revised inspection schedule to ensure that any fatigue cracking which could occur in service will be detected before the aircraft is endangered. A third spar change will not be permitted.

Effective: Forthwith.

Background: The Queen Air fatigue lives were previously promulgated by AD/BEECH 65/19, 20 and 21. They were reviewed in the course of assessing a re-engining modification which is applicable to all models. This review showed some inconsistencies in the lives, having regard to the fact that a range of models have structurally similar wings and should thus have the same life for a given configuration/weight etc. The inconsistencies have been resolved and all retirement lives now relate to a common basis of either short span or long span wing. Differences between models are accounted for purely because of weight/configuration.

Lives for some models have been extended slightly, but it has been necessary to reduce the 65-A80 life by 500 hours. A separate life has also been listed for the 65- A80-8800 which may appear to be a life reduction, but which is in fact consistent with the 65-A80 life taken in conjunction with the increased weight, in accordance with NOTE 1. For aircraft of this model which are nearing the life limitation as at 1 December 1988, consideration will be given to approval of concession applications for some restoration of life to reduce the economic penalty. However, safety will not be compromised.

Because of the availability of modifications which may increase the MTOW for some models and hence lead to a life reduction, it has become necessary to list lives for the 65, 65-80 and A65 (short span) models which were previously not published because they were so long.