CANOPY SYSTEMS

Terminal Objective: Upon completion of this chapter, you will be able to identify the types of canopy systems; recognize cartridge and cartridge-activated devices (CAD), service life, and expiration dates; identify CAD maintenance policy; and identify the reason for the ordnance certification program.

The canopy on modern high-performance air-craft serves several purposes. It protects the crew, provides enhanced visibility, and serves as an avenue of escape in case of emergency.

The canopy system includes the canopy itself, plus all the components used in opening and closing the canopy for normal entrance and exit, as well as those used in jettisoning the canopy during an emergency. Inspection and maintenance of canopy actuating systems are important responsibilities of the AME. Three types of canopies are present on naval aircraft. Two types of canopies- the clamshell

type and the sliding type- are commonly used on naval aircraft. The clamshell type used on the F-14 aircraft is hinged aft and opens at the forward end like a clamshell. The sliding type used on the A-6 aircraft rests on tracks on the fuselage and opens and closes by a sliding action. Figure 2-1 illustrates these two types of canopies. A third canopy type, the frangible canopy, is less common, is used on the S-3 aircraft, and has many unique features. All three types will be presented in this chapter. Aircraft manufacturers have designed various methods of actuating the canopy. Normal opening and closing may be accomplished pneumatically (compressed air), electrically, manually, or hydraulically. Emergency opening (jettisoning) is done pneumatically or explosively.

In most instances, more than one method is provided for normal opening and closing of the canopy; thus, if one system fails, the other may be used. The same holds true for jettisoning the canopy.