V-22 ATTACH 11 Airfield Requirements DRAFT.docx

DRAFT RFP N62649-20-R-0032

Attachment (11) 11 February 2020

Attachment (11): Airfield Requirements For V-22 Integrated Maintenance Concept (IMC) Planned Maintenance Interval (PMI) Airfield Capability: Functional Requirements

Turn-up Areas Due to the MV-22's unique Tiltrotor design and nacelle location, the area directly under the aircraft will be subject to extreme heat that can cause damage to the concrete over a period of time. This area should be* constructed out of heat resistant concrete or an application of a Sodium Silicate solution should be applied over the existing concrete, and heat resistant joint sealant to provide added protection from spalling and cracking, which can be caused by these excessive temperatures (see details below).

A. Chloroprene (Neoprene) or fluorocarbon adhesive joint seals are used for locations where the V-22 takes-off vertically or performs ground runs for operations or training. Chloroprene (Neoprene) joint seals are already routinely used in airfield pavements. Neoprene has shown good chemical resistance and heat resistance up to 550F.

B. Fluorocarbon adhesive has shown excellent chemical resistance and heat resistance up to 750F.

C. Silicones joint seals are used for general applications areas where the MV-22 does not take-off vertically or perform ground runs.

These recommendations* are based on laboratory tests of the joint seal materials that were conducted by the Research Structural Engineer, NAVFAC Pavements SME, at Port Hueneme, CA.

In addition to the Chloroprene (Neoprene) or fluorocarbon adhesive joint seal is highly recommended* that the concrete where the aircraft will be performing those ground turns have a Sodium Silicate Solution applied over the old or new concrete. This Sodium Silicate solution will help to mitigate heat issues on the concrete.

*NOTE: The recommendation to use higher heat resistant concrete and sealants are recommendations, not requirements. These recommendations are for the purpose of preventing or reducing damage to the Contractor’s facilities. The Government is not responsible for any damages or degradation to the Contractor’s facilities regardless of whether or not the Contractor undertakes to implement these recommendations. The Government also notes that has used a steel plate work-around in some applications. Two areas of 20’x18’ (360 sq ft) (35’ apart, one for each nacelle) are overlaid with half-inch thick steel plates are bolted into the deck to protect the concrete.