Freezing behavior, pumpability, and temperature profiles for aviation turbine fuels were measured in a 190-liter tank, to simulate internal temperature gradients encountered in commercial airplane wing tanks. Two low-temperature situations were observed. Where the bulk of the fuel is above the specification freezing point, pumpout of the fuel removes all fuel except a layer adhering to the bottom chilled surfaces, and the unpumpable fraction depends on the fuel temperature near these surfaces. Where the bulk of the fuel is at or below the freezing point, pumpout ceases when solids block the pump inlet, and the unpumpable fraction depends on the overall average temperature.
incorporated unique methods to separate nozzle and airframe loads and to bridge the thrust-measuring balance with a highpressure air-supply system.Special test procedures involved 1) measuring the amount of bridging of the thrust balance not removed by the bellows system and making the necessary corrections to the data, 2) measuring the extent to which the afterbody-forebody seal bridged both balances, and again making the necessary corrections to the data, and 3) using a short-duration run to minimize temperature effects on the afterbody and seal. Test results were very satisfactory with excellent repeatability, and valid configuration comparisons could be made.The ability to operate from unimproved bases with minimum support equipment was a principal design objective for the Army AH-56A Cheyenne armed compound helicopter being built by Lockheed-California Company. An important element of this concept is the use of the aircraft's boost pump to fuel the ship from drums or other containers through the pressure fueling system. Pump electrical power is furnished by the aircraft's auxiliary power unit. The only ground equipment required is a suitable hose with disconnect fitting to match the ship and storage container. Tests to develop this capability were conducted on a full-scale fuel-system simulator as part of a complete fuel-system test program. With the resulting system, priming time through 38 ft of 1^-in. hose averaged 45 sec; steady-state fueling rate was approximately 50 gal/min. Fueling from large rather than small containers is more efficient because of fewer priming operations. DiscussionO NE of the most advanced combat aircraft to be developed in recent times is the Lockheed AH-56A Cheyenne being built for the U.S. Army. Its mission is to provide protection for troop-carrying helicopters and to furnish direct-fire support in combat zones. With a design speed of over 250 mph, it is considerably faster than armed helicopters now in Vietnam and carried much more fire power. Figure 1 is a photograph of the AH-56A in flight.The aircraft is 55 ft long, has a main rotor-blade diameter of 50 ft, and a stub wing with a 27-ft span. It is powered by a General Electric T-64-16 gas turbine engine connected to a main transmission that distributes engine power to the main rotor, the antitorque rotor on the left side of the aircraft, and the thruster propeller at the tail. The engine has a military rating for 30 min of 3400 hp to 76°F, and a cruise rating of 3230 hp. This arrangement provides a standard day hover ceiling, out of ground effect, of 10,600 ft. Maximum rate of climb is over 3400 ft/min. Maximum range with 10% fuel reserve, at design gross weight, is 760 naut miles (874 statute miles), while maximum endurance for the same reserve and gross weight condition is 5.4 hr. By employing short takeoff and landing runs at optimum altitude, with 10% fuel reserve, ferry missions can be flown to a maximum range of 2510 naut miles (2886 statute miles).Two men constitute the crew, a pilot in the aft seat and a copilot/gu...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.