Platforms — E-3 Sentry & E-6 Mercury

E-3 Sentry

AWACS · rotodome ship

Rotodome ~30 ft diameter, roughly 11 ft above the fuselage
Supported by two struts (forward and aft)
Hydraulic systems operating near ~5000 psi for mission equipment
EMP hardening throughout the design
Metallic work often touches strut interfaces, upper fuselage, and mission-related structure around the dome

E-6 Mercury

TACAMO · trailing-wire ship

Last new 707 derivative built; CFM56-2A-2 engines from birth
No rotodome — dual VLF trailing-wire antennas instead
Wingtip pods and extra aft structure for the wire systems
Additional hardening vs commercial 707 baseline
SLEP: service life extended roughly 27,000 → 45,000 hours; ~15,000 wing fasteners with cold work

Shared 707-320 structure

What both ships inherit from the commercial airframe family.

Element	Typical material / note
Skins	2024 aluminum (Alclad where specified)
Stringers	7075 extrusions / formed sections
Frames	~20-inch spacing common on fuselage
Tear straps	Crack-arrest / fail-safe fuselage design
Joinery	Riveted fail-safe construction — not welded primary structure

Work today

This is sustainment, repair, remanufacture, and DMSMS — not new greenfield production like a 787 line. Expect:

Skin and stringer replacement / patch per SRM
Hole cold-work and fastener substitution on life-extension programs (especially E-6 wing SLEP heritage)
Fixture and form-block remakes when OEM tooling is gone
Chem mill, heat treat, and NDI as special processes under approved sources

Accuracy note

Figures above are publicly cited platform characteristics for orientation. Always verify dimensions, pressures, and life numbers against current technical orders and engineering data before shop use.