The Slat at the End of the Runway
Nordic Airframe Services holds a Part-145 approval at its main base for A320 and B737NG base maintenance, and for line maintenance at three airports named in its capability matrix. The MOE contains a procedure for mobile/remote support, restricted to approved types and to locations listed in that matrix. The customer's airport is 900 km from base. On Sunday a B737NG operated by a company Nordic has never worked for suffers a bird strike there: the No. 3 leading-edge slat is dented and the No. 1 engine has several bent fan blades and inlet FOD. The operator's CAMO asks Nordic to recover the aircraft. Nordic has a B1.1/B737NG certifying engineer available, a mobile tooling set, and can move two mechanics plus equipment in six hours. The airport has a heated hangar for hire and good lighting.
1. Work through what Nordic must establish before it accepts the recovery job.
Read the worked answer
Approval scope first, then resources, then data.
- Scope: the B737NG is on the approval, and the work is line-type recovery, not base maintenance. But the location is not in the capability matrix, so the MOE remote-support procedure must actually permit work away from the listed stations - if it does not, the MOE must be amended and accepted before the job, not after.
- Facilities and equipment: 145.A.25 obliges the organisation to have suitable facilities, tooling and material wherever it works. The hired hangar, lighting, ground equipment, calibrated torque tooling, and access to approved data (AMM, SRM, IPC) on site must be confirmed - 'we can look it up when we get back' is not acceptable.
- Staff: the certifying engineer must be type-rated, currently experienced on type and hold a certification authorisation covering this work; the mechanics must be competent for the tasks. Human factors: a single-shift, long-distance recovery with no supervision on site needs to be planned.
- Commercial/administrative: a work order and contractual arrangement with a new customer, clear definition of who provides what, and confirmation from the operator's CAMO of the approved data and of which document they will accept for release.
Only when all four are satisfied can Nordic sign the work order.
2. The SRM allows a dent up to 0.5 mm on the slat skin. The measured dent is 1.2 mm and the SRM directs the damage to the manufacturer. What are Nordic's options, and what changes on the release?
Read the worked answer
The damage is outside the approved data Nordic holds, so it cannot be rectified in-house under the SRM.
Option 1 - repair design. The repair becomes a major repair requiring design approval (Part-21: TC holder, or an approved design organisation), producing approved repair data, and eventually a part/repair released on an EASA Form 1. Nordic may embody it only if the repair is within its approval and capability and the data are complete. This is usually days, not hours.
Option 2 - replace the slat with a serviceable unit carrying a valid EASA Form 1 (or accepted equivalent), using the AMM removal/installation data. This is within Nordic's approval and is normally the fastest airworthy route. The unserviceable slat is quarantined and tagged.
What changes on release: the CRS can only be issued once the aircraft conforms to approved data. A dent that is 'probably fine' is not a release basis. If the operator wants the aircraft at base for the repair, that is a ferry/permit-to-fly matter, handled by the operator with its authority - not a normal CRS. The engineer must also record the damage assessment in the technical log so the CAMO and any subsequent organisation see the history.