CHAPTER 5
NAVY AIRCREW COMMON EJECTION
SEAT (NACES)
Chapter Objective: Upon completion of this chapter, you will have a working
knowledge of the Navy Aircrew Common Ejection Seat (NACES), including
functional description, physical description, component identification, and
maintenance concepts.
The incorporation of the Navy Aircrew Com-
mon Ejection Seat (NACES) in Navy aircraft re-
presents a significant improvement in ejection-seat
design that takes advantage of the latest escape
system technology. The NACES system gives the
aircrew improved chances for escape in all ejection
situations, reduced potential for injury, extended
preventive maintenance intervals, and a significant
reduction in life-cycle costs. This Martin-Baker
ejection seat will be fitted to the new Grumman
F-14D Tomcat, the McDonnel Douglas/British
Aerospace T-45A Goshawk two-seat trainer, and
the McDonnel Douglas F/A-18C and D aircraft.
The purpose of the common ejection seat is
to ease the logistics and maintenance problems on
the Navy’s inventory of aircraft. The new seat will
increase the standardization and reliability of
aircraft emergency escape and aircrew and ground
crew training. The electronically controlled
NACES represents the state-of-the-art in escape
system technology, and it has been selected as the
future standard of the U.S. Navy. The NACES
series was engineered from the outset for future
growth potential. The ejection seat is designed for
simple reprogramming or modification to ensure
that it maintains current technology.
As a senior AME, you already have the prere-
quisite knowledge and experience to understand
ejection seat theory. New ideas have been
incorporated into the NACES. Now all that is
required is your willingness to learn these new
ideas so that NACES characteristics become as
familiar as previous Martin-Baker ejection seats.
SYSTEM DESCRIPTION AND
COMPONENTS
Learning Objective: Recognize the func-
tional and physical description of the NA-
CES and the components within the system.
The NACES system uses a flexible
configuration to meet the exact requirements of
the crew station designer. Although this is a
common ejection seat, the designator number for
the seat versus aircraft types are different, as
shown below.
SEAT
TYPE AIRCRAFT-LOCATION
1. SJU-17(V)1/A F/A-18C, F/A-18D, rear cockpit
2. SJU-17(V)2/A F/A-18D, front cockpit
3. SJU-17(V)3/A F-14D, rear cockpit
4. SJU-17(V)4/A F-14D, front cockpit
5. SJU-17(V)5/A T-45, rear cockpit
6. SJU-17(V)6/A T-45, front cockpit
Although the physical description may differ
between the seats used in the F-14D as compared
to the F/A-18 and T-45 (fig. 5-1), the functions
of all the seats are the same. In this chapter we
will use the F/A-18 ejection seat to discuss system
description, operation, function, and component
identification.
FUNCTIONAL DESCRIPTION
WARNING
The emergency escape system incorporates
several explosive cartridges and rockets
containing propellant charges. Inadvertent
firing of any of these may result in serious
or fatal injury to personnel on, or in the
vicinity of, the aircraft.
5-1
