B1.3 CRS, an unserviceable radio altimeter and an MEL deferral
A Part-145 organisation at a regional base maintains a single-engine turbine helicopter (Airbus H125, maximum mass 2,250 kg) for a commercial air-transport operator. The helicopter is in for its 100-hour inspection. A B1.3 licence holder employed by the organisation performs the airframe, engine and electrical inspection and finds the radio altimeter unserviceable. The operator's MEL permits dispatch with the radio altimeter inoperative for VFR day operations only, with a rectification interval of 10 days. The B1.3 holder does not hold a B2 licence, and the organisation has no B2 staff on shift until Monday, three days later. The operator wants the helicopter back tonight for a charter. The B1.3 holder proposes to sign a single CRS for the whole inspection, noting the radio altimeter as 'deferred per MEL'. The organisation's MOE says a CRS may be issued by authorised certifying staff for work they are competent to certify.
1. Can the B1.3 holder sign a single CRS covering the whole 100-hour inspection? Explain the certification privilege issue and the compliant alternatives.
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No. A B1.3 licence covers airframe, engine and electrical systems, but the radio altimeter is an avionics/radio system, which falls within B2 privileges. The B1.3 holder cannot certify that part of the inspection, and issuing one CRS 'for the whole inspection' would misrepresent the scope of his certification. The organisation has two compliant options: (a) wait for a B2 holder to certify the avionics work and coordinate the CRS under the MOE's split-certification procedure; or (b) if the MOE permits, issue separate CRSs - B1.3 for the mechanical/electrical work and B2 for the avionics. The MEL deferral is an operational decision and does not create certification privileges. The B1.3 holder should not sign until the avionics portion is properly certified.
2. Assuming the avionics work is properly certified by a B2 holder, may the helicopter be dispatched tonight with the radio altimeter deferred? What conditions apply?
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The MEL is the operator's approved document, not the Part-145's. Dispatch with the radio altimeter inoperative is possible only if the MEL entry applies to this aircraft configuration and operation (VFR day only), the 10-day rectification interval has not expired, the operator's dispatch procedure is followed, and the deferred defect is recorded and reflected in the release documentation. The Part-145 must have procedures for accepting and recording MEL deferrals. So the aircraft may go tonight only if the avionics work is certified by a B2 holder and the deferral is properly documented. The B1.3 holder's proposed single CRS is still wrong.
3. The radio altimeter is on backorder and the 10-day interval expires. The operator asks the Part-145 to 'extend the MEL by a week'. What is the correct response?
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There is no extension. The rectification interval in the MEL is a limit; the operator cannot extend it because a part is on backorder. When the 10 days expire, the aircraft is not airworthy for dispatch and must be grounded until the radio altimeter is repaired or the MEL itself is amended by the competent authority, which is unlikely for a simple backorder. A permit to fly is not a substitute for an MEL extension for commercial air transport. The CAMO should plan spares and the operator should consider an AOG repair or a temporary substitute. The Part-145 must not release the aircraft after the interval expires.