14.3 Inspections After Lightning, Heavy Landing & Other Abnormal Events

14.3 Inspections After Lightning, Heavy Landing & Other Abnormal Events

Abnormal-event inspections are conditional maintenance tasks. Their purpose is to determine whether loads, electrical energy, heat, contamination, or motion outside normal assumptions caused damage that is not captured by a routine inspection. The approved aircraft maintenance manual or other applicable instructions define the trigger, inspection zones, sequence, limits, and escalation.

Establish the event

Do not start with a memorised generic checklist. Obtain the crew report and technical-log entry, including indications, sounds, odours, aircraft configuration, phase of flight, weather, and handling effects. Use recorded load, exceedance, or maintenance-system data when the procedure permits. For a heavy landing, aircraft mass, vertical acceleration, attitude, sink rate, side load, and touchdown sequence may affect the required inspection. For overspeed, overtemperature, or overtorque, the magnitude and duration matter.

Make the aircraft safe before opening access. Isolate damaged systems, address fuel or hydraulic leakage, cordon off unstable areas, and preserve evidence. Record initial condition before cleaning or moving parts.

Lightning and high-energy electrical events

Lightning commonly attaches and exits at extremities, antennas, control surfaces, or other conductive paths, but the actual inspection follows aircraft-specific zones and evidence. Look for burns, pits, melted material, punctures, delamination, damaged sealant, loose fasteners, degraded bonding, and effects at hinges, bearings, static dischargers, radomes, lights, probes, and antennas. Composite structure may hide subsurface damage, so tap testing, ultrasonic inspection, or another approved method may be required.

Check affected electrical, fuel, flight-control, and avionic systems as the procedure directs. Bearings or hinges may be examined where current passage is possible. A magnetic-compass check or swing is performed only when required by the applicable maintenance data or when evidence indicates a magnetic effect; it is not automatically mandatory after every strike.

Heavy landing and severe turbulence

The initial inspection usually looks for evidence of load transfer: wrinkling, buckling, cracks, paint disturbance, pulled fasteners, leaks, misalignment, unusual gaps, landing-gear or wheel damage, and damage at attachments. The scope may include wings, fuselage, pressure bulkheads, engine or pylon attachments, control surfaces, doors, and landing gear.

If a limit is exceeded or initial evidence meets an escalation criterion, the approved task may require access removal, dimensional or symmetry checks, jacking, rigging checks, component removal, or NDT. Terms such as phase 1 and phase 2 are not universal across all types; follow the terminology and decision points for the aircraft being maintained.

Other conditional events

Bird strike, hail, tyre burst, brake overheat, runway excursion, ground collision, fluid contamination, propeller strike, engine exceedance, or flight into volcanic ash each has a different damage mechanism. For example, a tyre burst may damage nearby structure, wiring, hydraulic lines, and sensors; an overheat may affect material strength or seals beyond the visibly scorched area. The event-specific procedure identifies secondary zones.

Findings and release

Describe findings with location, orientation, dimensions, photographs, and references to inspection zones. Compare damage with approved limits; do not blend, drill-stop, straighten, degauss, or return a part to service without authorised instructions. When data are ambiguous or incomplete, Part-145 procedures require the issue to be reported through the maintenance organisation so clarification can be obtained.

Complete all required follow-on inspections, functional tests, independent inspections, records, and deferred-item controls. Release to service depends on the authorised person being satisfied that the ordered work is complete and that any known incompleteness is handled under the applicable rules.

The exam discipline is to link action to mechanism and data: establish what happened, make the aircraft safe, inspect the paths and load-transfer areas specified for that event, escalate only at defined criteria, and document the evidence.

Coordinating a conditional inspection

A useful work package divides the aircraft into stated zones and gives each finding a traceable reference. One team should not close a zone while another team is still assessing a connected load path or system. If evidence crosses zone boundaries—for example, a lightning exit mark near a control surface or fluid leakage following a landing event—the coordinator applies the escalation logic and expands the work only as the approved procedure directs.

Measurements need context. Record datum, instrument, units, access condition, temperature where relevant, and the exact limit used. A photograph without a location or scale cannot by itself support a disposition. Likewise, a downloaded flight-data value should be tied to the correct flight and interpreted through the authorised process.

Before release, reconcile the event report, inspection task, findings, engineering instructions, rectification, tests, and technical record. Confirm that temporary protections and isolations are removed in the correct order and that any recurring inspection or operational limitation is entered into the continuing-airworthiness system. If the event cannot be bounded or the prescribed data are unavailable, the aircraft remains controlled while the organisation obtains competent support; schedule pressure is not an inspection criterion.

Event-Evidence Map