N6264919R0031_V-22_SSN_Att_Maint_Fac.pdf

V‐22 Maintenance Facility Requirements

Item Description Requirement

Stall Size Minimum 2 stalls

The typical stall size is 39 meters wide (including 1.5 meter fire lane on each side) by 30 meters deep (including 3 meter fire lane in front and rear). For adjoining stalls, consideration shall allow a minimum of 4.7 meters for blade tip radial clearance for aircraft in flight ready position or, in the event the proposed facility does not provide adequate space for a minimum of 4.7 meters for blade tip radial clearance for aircraft in flight ready position, the Offeror shall provide the expected clearance for a 2, 3 and 4 aircraft arrangement and provide a plan and process to demonstrate how the Offeror will ensure safety of all Government assets (aircraft, etc.) and all personnel, fire lane access and all mitigation steps to further reduce the danger associated with the aircraft at less than 4.7 meters radial clearance.

Although the minimum facility requirement is for two stalls, the Contractor is still required to be able to support up to four aircraft in flow at one time.

Hanger Door Height & Width

Height 8.5 meters by width 27.4 meters with wings in helicopter mode or height 7.3 meters by width

7.3 meters in blade folded and wing stowed position.

Hoist Height & Load

For safety, it is recommended the minimum hook height be no less than 11.9 meters but shall be no less than 10.4 meters. Under an extreme case scenario, the load limit should be 5000 pounds. For any potential PMI requirement or unscheduled tasks, a minimum 2000 pound hoist can be used.

The V‐22 requirement is a 5 ton Bride Crane with a clear hook height with hook fully retracted of 39’. If a 5 ton crane could not be incorporated into the existing facilities then a mobile crane capable of lifting 5 tons could be used as a work a round.

Electrical Power

Each aircraft requires a 400 Hertz ground power source which is distributed by the Power Service Point (PSP). The PSP shall have visual indication that 400 Hertz power is available and power is being applied to the aircraft as stated in the Unified Facilities Criteria (UFC) Aircraft Maintenance Hangars: Type I, Type II and Type III (UFC‐4‐211‐01). A latching circuit shall be provided in the external ground power source output contactor so that it will not latch closed until the 400 Hertz power cable plug is fully inserted into the aircraft 400 Hertz receptacle. Although the aircraft monitors the 400 Hertz power source to prevent possible damage to the aircraft equipment, it is recommended that each power service point have provisions to monitor the 400 Hertz power to protect the aircraft. The power source is required to have the following voltage and frequency limits. Refer to Military Standard Aircraft Electric Power Characteristics (MIL‐STD‐704), Performance Specification Electric Power Monitors, External, Aircraft (MIL‐PRF‐24021), and Military Handbook Electrical Engineering Preliminary Design Considerations (MIL‐HDBK‐1004‐1), for additional information.

• Voltage: 112.8 to 118.2 Volts per phase

V‐22 Maintenance Facility Requirements

• Frequency: 393 to 407 Hertz

• Phase Sequence: A‐B‐C

• 175 Amperes

• Cable Assembly: NSN 6150‐01‐471‐8361; 30.5 meters (100.0 feet) with molded plug

Note:

Insure that voltage drop calculations are conducted to verify that the full load voltage will be less than

12.8 volts phase line to neutral (L‐N). As part of system acceptance testing, each PSP should be tested using a combination resistive and reactive load bank to confirm the allowable voltage drop at 37.5 Volt‐amperes (kVA) and 48.7 kVA at 0.8 power factor lagging prior to connecting.

Each aircraft parking location will also require one (1) 230/440/480 Volt, 3 Phase, 60 Hertz, 200 Amperes and one (1) Class 'L' receptacle for an external power source for the A/M27T‐7 Portable Hydraulic Power Supply. Proper static grounding, not to exceed 10,000 ohms will also need to be provided. Refer to UFC‐4‐211‐01 for grounding requirements.

Fire Protection

IAW the V‐22 Spec (NAVAIR CV/MV‐22B‐PMI), all aircraft will be defueled prior to a PMI event, thereby establishing that for Hangars wherein the PMI work will be performed as based on defueled, the requirement is based on fire protection for defueled aircraft. NAS 3306 and NFPA 409 apply. The Fire Protection System for all aircraft maintenance hangars containing defueled aircraft must consist of an overhead automatic sprinkler system designed, installed, and supervised according to NFPA 409 with 79°C (175°F) temperature, quick response sprinklers. The overhead system must be closed head, water only sprinklers. A pre‐action system can be used where the sprinkler pipes are subject to freezing. The system must activate automatically.