Section 8 Aircraft landing

8.1.1 For ships that operate aircraft with the mandatory AIR notation, there are additional survey requirements.

8.1.2 The ship’s flight deck is divided into landing, parking and manoeuvring areas, and for each of these areas, different loadings are assumed. Manoeuvring areas should not be used for landing or parking, landing areas for parking and vice versa. The parking areas may be as small as a few frame spaces in way of the wheels, which are specially strengthened. To avoid damage, the marking of these areas must be maintained in accordance with the approved plan.

8.1.3 The rules require that suitable fire-fighting equipment and services should be provided for the flight deck. These may or may not come within the scope of classification as defined in the annex to the classification certificate. Even if they are not within the scope of classification, evidence for a suitable certification and inspection system should be sought. Records of survey to a nominated standard, plus evidence that those surveys have been carried out, are to be reported.

8.1.4 A landing guide should be on board which lists the aircraft for which the flight deck is approved. The document may also contain guidance in the form of a diagram to assess the flight deck capability for visiting aircraft. Any incidences of landing outside the limits of this guide should be reported and the area examined for damage.

8.2.1 Structural damage to flight decks will mainly be deformation of the structure due to overloading or fracture due to fatigue.

8.2.2 Structural overloading can occur in the landing or parking areas where loads in excess of the design load have been experienced. In moderate cases it will consist of plate deformations in excess of the design values, and in extreme cases, deformation of the surrounding stiffening. Deformation is of most concern in areas that are subject to high in-plane stresses such as the main strength deck amidships.

8.2.3 Deformations will be hidden by flight deck coatings and it may be necessary to remove representative samples of lagging under the deck to determine the amount of deformation. This can be restricted to a few frame spaces around the probable landing points and fixed parking areas.

8.2.4 Where deformations are in excess of the large deflection given in Table 16.8.1 Allowable maximum deformations for survey purposes, the plating is to be replaced. Any deformation of stiffening or support structure is to be replaced.

Table 16.8.1 Allowable maximum deformations for survey purposes

Case	Deflection (mm)
Small
Moderate
Large
Symbols
s = stiffener spacing in mm σo = Yield stress in N/mm2 E = Young’s modulus of the steel in N/mm2

8.2.5 Fatigue is likely to occur around frequently used tie down points and in welded joints around the parking areas, particularly if they are local patches. These areas should be subject to a close up examination using NDE where appropriate and consideration should be given to the fitting of removable lagging.