Military Wiki
Register
Advertisement
L-23/U-8 Seminole
Beechcraft U-8D Seminole US Army in flight
US Army U-8D Seminole liaison version
Role Utility aircraft
Manufacturer Beech Aircraft Corporation
First flight 1949
Introduction 1952
Retired 1992
Primary user United States Army
Produced 1952-1961 (L-23A/E)
1958-1963 (L-23F/U-8F)
Number built 288 (including 71 L-23F/U-8F)
Developed from Beechcraft Twin Bonanza
Variants Beechcraft Queen Air
File:Militarytbone.jpg

US Army RU-8D during the Vietnam War

The Beechcraft L-23 Seminole (later designated U-8) was the United States Armed Forces designation for the Beechcraft Twin Bonanza and Queen Air aircraft in its inventory.

Design and development[]

In 1951 the United States Army evaluated a Twin Bonanza at Fort Bragg, North Carolina and subsequently ordered four 'off-the-shelf' Model 50s as YL-23s, these being delivered in early 1952.[1] Further examples of the Model 50 were ordered under the designation L-23A and Model B50s were also ordered under the designation L-23B.[1] These accounted for the majority of Twin Bonanza production during 1952 and 1953, the first L-23A being delivered in February 1953 and the last L-23B being delivered in April the following year.,[1] shortly before cessation of the Korean War.

In 1955 the United States Air Force ordered a single Model C50 Twin Bonanza under the designation XL-23C for evaluation; this was the only L-23 variant not delivered to the US Army as no further orders were placed by the Air Force.[1][2] In 1956 deliveries of L-23s to the Army recommenced when Beechcraft delivered six Model D50s under the designation L-23E. In January 1957 the first example of the L-23D was delivered, based on the Model E50 Twin Bonanza.[1] During 1958 the remaining L-23A and L-23B aircraft in service (a few had crashed) were returned to the Beechcraft factory, where they were remanufactured to a similar standard as new-build L-23Ds and then re-designated as such with new constructor's numbers and military serial numbers.[1][3][4] In 1958 the Army also ordered 11 RL-23Ds with further examples being converted from L-23Ds. These aircraft featured belly-mounted radar, either AN/APS-85 in a large pod or AN/APQ-86 in a long narrow pod mounted on brackets with a modified nose as well.[1]

Also in 1958 Beechcraft began to develop a variant with a larger cabin at the request of the US Army. The L-23F that emerged had the same wings and tail but up to ten people could now fit in the longer, wider and higher cabin compared to only five in earlier L-23s.[1] Beechcraft gave the type the in-house designation of Model 65 and developed it as a civilian aircraft as well, christening it the "Queen Air". The first two Model 65s built were retained by Beechcraft as prototypes and the third was delivered to the Army in 1960, with a further 23 being delivered that year and in 1961.[1][4][5][6]

Operational history[]

The first L-23As entered service in 1953 and the type served the US Army for almost forty years, the last U-8Fs being retired in 1992. When US military aircraft designations were revised in 1962, the remaining L-23D, RL-23D, L-23E and L-23F aircraft became U-8Ds, RU-8Ds, U-8Es and U-8Fs.[1] A further 47 Model 65s were ordered in 1962 and 1963 as U-8Fs; one of these was delivered to the Pakistan Army, the only delivery outside the US military[1][7] (although other nations bought Queen Airs as military aircraft). These were the final new-build aircraft in the series, however the unique Beechcraft Model 87 turboprop proof-of-concept aircraft used in developing the King Air was delivered to the Army as the NU-8F in 1964 (this was later re-designated the YU-21) and a few used Queen Airs were also taken by the Army. Many U-8Fs were modified during their service lives to a similar standard as civilian Excalibur Queen Airs. The most obvious modifications are more powerful Lycoming IO-720 eight-cylinder engines in place of the factory-fitted six-cylinder engines; and bulged main landing gear doors that fully enclose the wheels when the gear is retracted instead of the wheels partially protruding through the doors. Many L-23Ds/U-8Ds and U-8Fs have been registered as civilian aircraft since retirement from military service.

Variants[]

YL-23
Four Model 50 Twin Bonanzas evaluated by the US Army as Serial Numbers 52-1800 to 52-1803; 52-1801 subsequently converted to L-23A standard.[8]
L-23A
55 delivered to the US Army, many subsequently converted to L-23D standard.[8]
L-23B
40 delivered to the US Army, many subsequently converted to L-23D standard.[9]
XL-23C
One aircraft for evaluation by the US Air Force.[2]
L-23D
100 delivered new to the US Army plus 93 L-23As and Bs rebuilt to L-23D standard.[3][4][10][11]
RL-23D
variant with belly-mounted radar. Eleven new-build aircraft delivered to the US Army, plus 29 converted from L-23Ds.[4][11]
L-23E
Six delivered to the United States Army.[10]
L-23F
24 aircraft based on the Beechcraft Queen Air delivered to the US Army.[4][5][6]
U-8D
L-23D redesignated in 1962.
RU-8D
RL-23D redesignated in 1962, plus 15 U-8Ds converted after 1962.[3][4][10][11]
U-8E
L-23E redesignated in 1962.
Beechcraft U-8F

Beechcraft U-8F

U-8F
L-23F redesignated in 1962 and 46 new-build aircraft delivered to the US Army, plus single Beechcraft Model 87 delivered used as NU-8F in 1964[7][12] and one Queen Air purchased second-hand in 1966.[13] In addition, one U-8F was delivered to the Pakistan Army instead of the US Army[7] and two Queen Airs confiscated from drug runners were added to the US Army inventory in 1981 as U-8Fs.[14]
NU-8F
US military designation assigned to a modified commercial Queen Air converted as the protoype Model 65-90 King Air, and fitted with two 500 shp Pratt & Whitney PT6A-6 turboprop engines.[15] The aircraft was evaluated by the US Army in 1964.
U-8G
XL-23C, seven U-8Ds and four U-8Es modified with more powerful engines and enlarged cabin for six passengers.[2][3][4][10]

Military operators[]

Flag of Pakistan Pakistan
United States

Aircraft on Display[]

Specifications (L-23D)[]

[17] General characteristics

  • Crew: 1-2 pilots
  • Capacity: 5 passengers
  • Length: 31 ft 6 in (9.61 m)
  • Wingspan: 45 ft 3 in (13.78 m)
  • Height: 11 ft 6 in (3.51 m)
  • Wing area: 277 ft² (25.7 m²)
  • Empty weight: 5,010 lb (2,270 kg)
  • Max. takeoff weight: 7000 lb (3175 kg)
  • Powerplant: 2 × Lycoming GSO-480-A1A6 (Military designation O-480-1), 340 hp (253 kW) each

Performance

  • Maximum speed: 270 mph (235 knots, 432 km/h)
  • Range: 1,000 mi (870 nm, 1,600 km)
  • Service ceiling: 30,000 ft (9144 m)
  • Rate of climb: 1,614 ft/min (8.2 m/s)

See also[]

References[]

Notes
  1. 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 Phillips, Edward H. Beechcraft - Pursuit of Perfection, A History of Beechcraft Airplanes. Flying Books, Eagan, Minnesota 1992. ISBN 0-911139-11-7.
  2. 2.0 2.1 2.2 Baugher, Joe. "USAF/US Army 1955 Serials list." USAF Aircraft. Retrieved: 11 June 2011.
  3. 3.0 3.1 3.2 3.3 Baugher, Joe. "USAF/US Army 1957 Serials list." USAF Aircraft.Retrieved: 11 June 2011.
  4. 4.0 4.1 4.2 4.3 4.4 4.5 4.6 Baugher, Joe. "USAF/US Army 1958 Serials list." USAF Aircraft. Retrieved: 11 June 2011
  5. 5.0 5.1 Baugher, Joe. "USAF/US Army 1960 Serials list." USAF Aircraft. Retrieved: 11 June 2011.
  6. 6.0 6.1 Baugher, Joe. "USAF/US Army 1961 Serials list." USAF Aircraft. Retrieved: 11 June 2011.
  7. 7.0 7.1 7.2 Baugher, Joe. "USAF/US Army 1963 Serials list." USAF Aircraft. Retrieved; 11 June 2011.
  8. 8.0 8.1 Baugher, Joe. "USAF/US Army 1952 Serials list." USAF Aircraft. Retrieved: 11 June 2011.
  9. Baugher, Joe. "USAF/US Army 1953 Serials list." USAF Aircraft. Retrieved: 11 June 2011.
  10. 10.0 10.1 10.2 10.3 Baugher, Joe. "USAF/US Army 1956 Serials list." USAF Aircraft. Retrieved: 11 June 2011.
  11. 11.0 11.1 11.2 Baugher, Joe. "USAF/US Army 1959 Serials list." USAF Aircraft. Retrieved: 11 June 2011.
  12. Baugher, Joe. "USAF/US Army 1962 Serials list." USAF Aircraft. Retrieved: 11 June 2011.
  13. Baugher, Joe. "USAF/US Army 1966 Serials list." USAF Aircraft. Retrieved: 11 June 2011.
  14. Baugher, Joe. "USAF/US Army 1981 Serials list." USAF Aircraft. Retrieved: 11 June 2011.
  15. Harding 1997, p. 22.
  16. "Kansas Aviation Museum". http://kansasaviationmuseum.org/queen.php. Retrieved 17 April 2012. 
  17. "Beechcraft Model 50 Type Certificate." FAA. Retrieved: 11 June 2011.
Bibliography
  • Harding, Stephen. U.S. Army Aircraft Since 1947: An Illustrated Reference. Atglen, PA: Schiffer Publishing Ltd., 1997. ISBN 978-0-7643-0190-2.

External links[]

All or a portion of this article consists of text from Wikipedia, and is therefore Creative Commons Licensed under GFDL.
The original article can be found at Beechcraft L-23 Seminole and the edit history here.
Advertisement