A modified Boeing 707 fuselage section is being tested to verify structural changes planned for the US Navy E-6B airborne command post fleet as part of its recently expanded mission role. The E-6B fleet will be modified to take a large, roof-mounted antenna radome as part of the Milstar programme.
The associated structural changes to the fuselage centre section are being evaluated in tests on a 20m-long section at the National Technical Systems Rye Canyon site in California. Strain surveys have been completed, and the first of two lifetime fatigue load tests is presently under way.
Each lifetime will consist of up to 502,150 load cycles and will be followed by an ultimate load test of the new section which involves the design of new stiffeners, stringers and skin between fuselage stations 600 to 800.
Milstar-related modifications are also planned for the E-4B Advanced Airborne Command Post Aircraft. Boeing Defense and Space Group is now manufacturing four 8m-long, wedge-shaped radomes for the fleet.
The radome will contain an extra high-frequency antenna to enable communications with ground stations and other aircraft through the Milstar secure satellite network. The tri-band radome will replace the current unit, which houses two main communications antennas, on top of the fuselage.
Source: Flight International
