TECHNOLOGY AREA(S): Materials/Processes

ACQUISITION PROGRAM: PMS 312 In-Service Aircraft Program Office.

OBJECTIVE: Develop a capability for passive cooling of Aircraft Carrier Jet Blast Deflectors.

DESCRIPTION: Commercial jet blast deflectors are raised and lowered by hydraulic arms; are actively cooled; and range in complexity from stationary concrete, metal, or fiberglass fences to heavy panels. The decks of aircraft carriers are presently equipped with pivotally mounted Mark 7 Jet Blast Deflector (JBD) Systems that function to dissipate jet exhaust of aircraft undergoing catapult launch. Aircraft Carrier JBDs are cooled by active cooling systems that tap the fire mains (i.e., fire suppression water systems) to circulate seawater through water lines within the deflector panel. This active cooling system imposes significant corrosion effects and burdensome maintenance problems as well as a complicated constructional design and increased associated costs. The cost of JBD maintenance on aircraft carriers is in the tens of millions of dollars for the fleet. There are additional operational and aging problems for the equipment involved because of the high temperatures and the flow speeds of exhaust plumes from the aircraft. Passively cooled JBD systems will reduce Carrier operating and maintenance cost by 40%.

Reducing operating and maintenance costs for Aircraft Carriers can be achieved through avoidance of maintaining the seawater cooling lines by reducing and burdensome maintenance problems due to corrosion caused by the seawater cooling lines.

The orientation of aircraft carrier catapults requires that the hot exhaust gases of the jet aircraft turning up to full power during launch operations are deflected so as not to cause heat and blast damage to other aircraft, equipment, and personnel on the flight deck. As such, the JBD must be capable of withstanding both the heat and pressure forces that impinge on its surface as a result of the aircraft blast. The JBD, which consists of a series of water cooled panels, achieves this purpose. The JBD, when in the flush deck position, allows an aircraft to be taxied over it and into launch position. As soon as the aircraft is forward of the JBD, the operation actuates the hydraulic system to raise the JBD for aircraft turn up. The JBD must allow for ease of maneuvering the aircraft on the flight deck (so as to position it for launch) as well as be capable of absorbing any landing or rollover loads. The final capability requires rapid dispersion of heat after an aircraft launch.

The Navy is seeking a passive JBD System (i.e., a system that does not require active water cooling) with physical dimensions (height 14 feet, width 36 feet) that allow for installation in a Flight Deck Pit identical in length, width, and depth to those that house the currently deployed Mark 7 JBD System. Electrical power is available for solutions that require it, but high voltage solutions will add safety concerns. The passive JBD System will consist of a heat deflector panel, a structural panel, and associated actuating mechanisms and control systems. The aircraft jet blast will impinge directly on the heat deflector. As such, the heat deflector panel will have a surface profile and inclination (in the fully raised position) that will be adequate to protect any Naval Aircraft (present and future) located behind the JBD, as well as protecting the structural panel. In addition, the heat deflector panel surface will prevent recirculation of the jet blast into the jet intakes of the aircraft located in front of the JBD. The heat deflector panel surface attitude to the Catapult Centerline (for each catapult installation) will be identical to that of the currently deployed Mark 7 Jet Blast Deflector Panel. The distance of the heat deflector panel hinge line to the Catapult Station �0� location will be identical to that of the currently deployed Mark 7 Jet Blast Deflector Panel. The structural panel will completely cover the Flight Deck Pit (and any system components located in it). The JBD System must withstand aircraft rollovers and landings, Foreign Object Debris (FOD) impingement, and any potential strikes from aircraft hook points or accidentally dropped equipment normally used by flight deck personnel. The JBD System will be exposed to thermal cycling, weather, sea states seawater spray, countermeasure wash-down, JP-5 spills, and other wear and tear. The passively cooled JBD system must not be subject to suffer structural damage under flight operations and must have a sufficiently high cool-down rate to achieve 200�F tire-