Figure 5-1.General arrangement of jet blast deflectors.
There are various modifications of JBDs in use.
Each type of JBD is identified by a model number,
such as Mk 6 Mod 1, Mk 6 Mod 2, and Mk 7 Mod
0. The most common types of JBDs in use are the
Mk 6 Mod 2, Mk 7 Mod 0, and Mk 7 Mod 1.
However, since Mk 6 Mod 1, Mk 6 Mod 3, and Mk
7 Mod 2 JBDs are also in use, you will need to
consult the specific NAVAIR technical manual for
the type of JBD installed on your ship. The Mk 7
Mod 0 JBD is discussed in this chapter to
familiarize you with the general operation and
maintenance of JBDs.
MK 7 MOD 0 JET BLAST DEFLECTOR
The Mk 7 Mod 0 JBD consists of six
water-cooled panels and three operating gear
Each operating gear assembly is
connected to a pair of panel assemblies. The panel
assemblies operate in pairs and may be raised or
lowered independently or simultaneously with others
in the same installation.
This allows for deck
The electrical, hydraulic, and mechanical
equipment needed to operate the panels are located
under the panel installation. When the panel is
lowered, the JBDs serve as part of the deck over
which an aircraft passes on its way to the catapult.
When the panel is raised behind the aircraft, the
panels deflect the heat and high-velocity exhaust
gases generated by the aircrafts engines upward and
away from personnel and other aircraft.
All Mk 7 JBD installations are electrically
controlled by a deckedge control panel or a portable
control box. Each control panel (fig. 5-2) has its
own electrical installation and is independent of the
other installations. Most JBD assembly installations
are controlled by a portable electrical system
consisting of portable control boxes and umbilical
cables (fig. 5-3). Each portable control box operates
independently and will only control the JBD
installation identified on its faceplate. An auxiliary
control panel and transfer switch are provided for
emergency operations, and they are located in the
retraction-engine machinery room.
Operating Gear Assembly
The JBD panel assemblies are raised and
lowered by an operating gear linkage assembly and
a hydraulic cylinder located just under each panel
cutout in the deck. The operating gear linkage