Every minute spend on the ground causes operational and financial damage. The direct costs associated to the inspection are hangar, equipment and inspectors, while the secondary costs associated with the inspection are lost income, flight cancellation and potentially replacement aircraft. For busy airports the additional runway movements to the hangar are also a safety consideration.
Unplanned inspections are disruptive for any airline schedule, as the whole inspection process causes up to a 10 hour downtime in operations. The most significant cause for unplanned inspections are lightning strikes, other causes are hail strikes or bird strikes.
In 80% of the cases – where the airplane was struck by lightning – it can continue the original schedule without repairs to the lightning strike damage. In these cases the damage is insignificant and can be repaired during the next maintenance series.