Allison T78-A-2 Turboprop Engine

Object Details

Physical Description: Type: Turboprop with regenerator; Power Rating: 3,654 kW (4,900 eshp); Compressor: 14-stage axial; Combustor: Cannular; Turbine: 4-stage axial; Weight: 709 kg (1,564 lb)
Summary: The T78-A-2 was originally designed as a potential replacement for the Allison T56 turboprop in the Lockheed P-3A ASW aircraft. It was also adaptable to airborne early warning aircraft based on Navy carriers, for large transports, and other applications where long endurance or low fuel consumption was of prime importance.; The T78 incorporated a regenerator system that was intended to reduce specific fuel consumption at low power settings and, thus greatly extend long-range and "on station" capabilities. The basic principle of regeneration involved reclamation of turbine exhaust heat to increase the temperature of compressor discharge air, thus reducing the amount of fuel required for the most efficient engine operating temperature.; By the spring of 1965, Allison had run the T78 at up to 85% of rated power during a one-hour test. Testing continued for a short period, but the engine was not put into production. Apparently some people in the Navy were opposed to increasing time on station for the P-3 because of crew fatigue problems.

Credit Line: Transferred from the U.S. Navy, Naval Air Systems Command, Washington, D.C.

Circa 1964

Materials: HAZ MAT: Cadmium; Aluminum Alloys; Ferrous Alloys; Non-Magnetic White Metals; Paints; Plastics
Dimensions: 3-D: 433.1 × 97.2 × 157.5cm (14 ft. 2 1/2 in. × 3 ft. 2 1/4 in. × 5 ft. 2 in.); Storage (Wooden Crate): 121.3 × 459.7 × 213.4cm (3 ft. 11 3/4 in. × 15 ft. 1 in. × 7 ft.)

National Air and Space Museum

GUID (Link to Original Record): http://n2t.net/ark:/65665/nv96c2521e0-2a8b-47d1-8328-288efe555c3c