Waco E series
Airworthy 1941-built Waco SRE at Poplar Grove Airport, near Belvidere, Illinois, in August 2010
Role	Four-seat cabin biplane Type of aircraft
National origin	United States
Manufacturer	Waco Aircraft Company
First flight	1939
Introduction	1940
Status	some still flying in 2011
Primary user	private owner pilots
Produced	1939–1942
Number built	30 [1]
Developed from	Waco C series[2]

The Waco E series is a small family of American-built cabin biplanes built between 1939 and 1942, which differed primarily by engine installation.

Development and design

The E series was the final development of the prewar Waco line of biplane designs. A full four-seater, it had the best performance of any of the Wacos. First flown in 1939, it had a much slimmer and more streamlined fuselage than earlier Waco C and S models and heavily staggered unequal-span parallel-chord wings with rounded tips. Wings were plywood-skinned, and also had wire cross-bracing between the wings in place of the solid struts used on previous models.^[3]

Engines varied in power from 285 to 450 hp (213 to 336 kW), giving the E series a high cruising speed for the period of up to 195 mph (314 km/h).^[4] Production ceased in 1942. Note: the Waco GXE of 1929/30 was an unrelated biplane design with non-staggered wings

Operational history

The E series was sold to wealthier private pilot owners who required the comfort of a fully enclosed cabin and a high cruising speed, combined with a longer range. Because of the type's good performance, 15 examples were impressed by the United States Army Air Forces during World War II for communications work as the UC-72. Several of the USAAF examples were returned to civilian use after the end of the war and five E series aircraft remained airworthy in 2001.^[5]

Variants

(Source : Aerofiles)

ARE Aristocrat

300 hp (224 kW) Jacobs L-6 (4 built, one impressed as UC-72A)

HRE Aristocrat

285 hp (213 kW) Lycoming R-680 (5 built, 2 impressed as UC-72C)

SRE Aristocrat

400 hp (298 kW) Pratt & Whitney R-985 Wasp Junior SB-2 (21 built, 12 impressed as UC-72)

WRE Aristocrat

420 hp (313 kW) Wright R-975 - model offered to potential customers, but none built

Impressed aircraft

UC-72

12 impressed Waco SRE for USAAF

UC-72A

One impressed Waco ARE

UC-72C

Two impressed Waco HRE

Specifications (SRE)

Data from Simpson p. 576

General characteristics

• Crew: 1 pilot
• Capacity: 3 passengers
• Length: 27 ft 10 in (8.48 m)
• Wingspan: 34 ft 9 in (10.59 m)
• Height: 8 ft 8 in (2.64 m)
• Empty weight: 2,734 lb (1,240 kg)
• Max takeoff weight: 4,200 lb (1,905 kg)
• Powerplant: 1 × Pratt & Whitney R-985 SB-2 nine-cylinder radial air-cooled piston, 400 hp (300 kW)

Performance

• Maximum speed: 202 mph (325 km/h, 176 kn)
• Cruise speed: 195 mph (314 km/h, 169 kn)
• Stall speed: 57 mph (92 km/h, 50 kn)
• Range: 1,070 mi (1,720 km, 930 nmi)
• Service ceiling: 23,500 ft (7,200 m)
• Rate of climb: 1,550 ft/min (7.9 m/s)