DAVID J. GAUTHIER MEMORIAL COLLECTION
No. 10038. Boeing 727-22 (N7007U c/n 18299) United Air Lines
No. 10038. Boeing 727-25 (N8102N c/n (18253) Eastern Air Lines
Photographed at Boeing Field, Seattle, Washington, USA, source unknown

Boeing 727-22, Boeing 727-25

09/30/2010. Studies for an entirely new short to medium-range transport to serve routes uneconomical for the Model 720 were initiated in 1956 and achieved project status in 1959. In spite of the major configuration change, economy was achieved through extensive use of 707/720 equipment and components, notably the upper fuselage structure. Passenger accommodation was 70 first-class or up to 129 tourist, or 28 first-class and 66 tourist in the mixed configuration. Flight crew was three.

All 727s were equipped with hydraulically operated self-contained aft loading stairs and additional stairs could be installed forward of the cabin on the port side of the fuselage. Exceptional low-speed and short-field performance was obtained by use of new triple-slotted trailing edge flaps, retractable leading edge slats outboard of the taper break, and Krueger flaps inboard on the clean 32°-sweep wing.

Boeing did not originate the most noticeable feature of the 727-the aft-mounted engine installation. Jet pods on the side of the fuselage were tried on the German Junkers Ju-287 late in WW-II but were first used in regular production on the French Sud-Aviation Caravelle of 1955, which originated the aft location. This arrangement had three major advantages-increased ground clearance for the engine, reduced noise level in the cabin during take off, and reduced trim problems with one engine inoperative. Several other manufacturers followed the French in adopting this arrangement.

The use of a third engine installed in the aft end of the fuselage originated with the Martin XB-51 of 1948. Since it was desirable from the economy and reliability standpoints to use three engines on the 727, Boeing chose to cluster all three near the tail, two in pods and one under the vertical tail on the pattern developed for the British de Havilland D.H.121 Trident, a directly competitive aircraft. All three 14,000 lb (6,350 kg) st Pratt and Whitney
JT8D-1 turbofan engines, developed specifically for the 727, were fitted with thrust reversers but did not use sound suppressors.

Special design features mix bypass air with the exhaust to reduce exit velocities and effectively reduce noise. The quiet operation of the 727 compared to larger jets enabled it to overcome the jet ban at La Guardia and became the first jet to operate from that close-in terminal. To eliminate the need for starting equipment at small airports, a gas turbine in the right wheel well of the 727 served as an auxiliary power unit for starting, air conditioning, and other power requirements while the aircraft was on the ground.

First flight of the 727 was on February 9, 1963, and TC A3WE was issued December 24, 1963. Launch customers were United Air Lines, which bought 95 727-22s, and Eastern Air Lines, which bought 50 727-25s. The latter differed from other 727s in having self-contained hydraulic airstairs fitted to the forward entry door.

Created September 30, 2010