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Aero Commander twins
690C Jetprop 1000
General information
Type	Utility and business aircraft
National origin	United States
Manufacturer	Aero Design and Engineering Company Aero Commander Rockwell-Standard Corporation North American Rockwell Rockwell International Gulfstream Aerospace
Status	Active
Number built	~2,902 (1951 piston-engined, 951 turboprops)
History
Manufactured	1951–1986
Introduction date	October 1952
First flight	23 April 1948 (Model L3085)

The Aero Commander 500 family is a series of light-twin piston-engined and turboprop aircraft originally built by the Aero Design and Engineering Company in the late 1940s, renamed the Aero Commander company in 1950, and later a division of Rockwell International in 1965. Final production occurred under the Gulfstream Aerospace name. The initial production version was the 200 mph (320 km/h; 170 kn), seven-seat Aero Commander 520. An improved version, the 500S, manufactured after 1967, is known as the Shrike Commander. Larger variants are known by numerous model names and designations, ranging up to the 330 mph (530 km/h; 290 kn), 11-seat Model 695B/Jetprop 1000B turboprop. As of recent, the Aero Commander is known as the Twin Commander.

Design and development

The idea for the Commander light business twin was conceived by Ted Smith, a project engineer at the Douglas Aircraft Company. Working part-time after hours throughout 1944, a group of A-20 engineers formed the Aero Design and Engineering Company to design and build the proposed aircraft with a layout similar to their A-20 bomber. Originally, the new company was going to build three pre-production aircraft, but as the first aircraft was being built, they decided to build just one prototype. The final configuration was completed in July 1946 and was designated the Model L3805.

Registered NX1946, the prototype first flew on 23 April 1948. The L3805 accommodated up to five people and was powered by two Lycoming O-435-A piston engines., it was an all-metal high-wing monoplane with retractable undercarriage using components from a Vultee BT-13 Valiant. The market segment planned for this aircraft to be sold to small feeder airliner firms and was originally designed to carry seven passengers, but instead found use in the private business aircraft and military market. Walter Beech test flew the aircraft in 1949 and expressed interest in buying the project, but passed on it, to instead develop the Beechcraft Twin Bonanza. Fairchild Aircraft also evaluated the prototype at its Hagerstown, Maryland, headquarters.

The prototype flew successfully and the company leased, at no cost, a new 26,000 square feet (2,400 m) factory at Bethany near Oklahoma City to build a production version, certified on 30 June 1950. Nearly 10,000 hours of redesign work went into the model, including more powerful Lycoming GO-435-C2 engines, with a combined rating of 520 horsepower (390 kW). The production model was named the Commander 520. The first Commander 520 was rolled out of the new factory in August 1951. Serial number 1 was used as a demonstrator, then sold in October 1952 to the Asahi Shimbun Press Company of Tokyo.

Operational history

In military service it was initially designated the L-26, though in 1962 this was changed to U-4 for the United States Air Force and U-9 for the United States Army.

Under ownership of Rockwell in the 1960s, World War II pilot R. A. "Bob" Hoover demonstrated the Shrike Commander 500S for decades in a variety of "managed energy" routines, including single-engine and engine-out aerobatics. His Shrike Commander is displayed in the colors of his last sponsor, Evergreen International Aviation, at the Steven F. Udvar-Hazy Center of the Smithsonian National Air and Space Museum. Bob Odegaard continued the tradition in 2012, flying a 1975 Shrike 500S in a Bob Hoover tribute routine.

One U-4B became a presidential transport aircraft for Dwight D. Eisenhower between 1956 and 1960. This was the smallest "Air Force One", and the first to wear the now-familiar blue-and-white livery. This aircraft is now owned by the Commemorative Air Force.

As of 2004 Shrike Commanders remained in service with the United States Customs Service, United States Coast Guard, and United States Forest Service.

A single 560F was operated by the Belgian Air Force as the personal transport of the late king Baudouin of Belgium from 1961 to 1973.

According to the July 1, 1968, Frontier Airlines system timetable, series 500 aircraft were being operated on scheduled passenger flights by Combs Aviation on behalf of Frontier via a contract agreement with service to several smaller communities in Montana and Wyoming at this time.

The unpressurized, long-fuselage 680FL was operated as a small package freighter by Combs Freightair in the 1970s and 1980s, and by Suburban Air Freight in the 1980s and 1990s. The aircraft was popular with pilots, because it was extremely "pilot friendly" and with its 380 hp (280 kW) supercharged engines did well in icing meteorological conditions. A number are still operated on contracts for cargo and fire control applications, as their piston engines offer good fuel specifics at low altitudes and longer loiter times. Suburban retired their last 680FLs in the first half of 2024.

Wing spar fatigue

Beginning in June 1991, senior engineers met with FAA officials to discuss concerns over the Aero Commander's main wing spar, which was believed to be susceptible to stress fatigue and subsequent cracking, and was believed to have resulted in a number of fatal crashes. From approximately 1961 to 1993, 24 aircraft crashed when spar failures caused the loss of the wing in flight. 35 more spars were found cracked during inspections.

Single-engine safety

In 1950, when the developers were working to satisfy Civil Aeronautics Authority (CAA) regulations for certification of the 500, they chose a novel method of demonstrating its single-engine safety and performance: they removed one of the two-bladed propellers, secured it in the aft cabin, and flew from Bethany to Washington, D.C., on one engine. There they met with CAA personnel, then replaced the propeller and returned to Oklahoma in the conventional manner. The flight received nationwide coverage in the press.

In 1979, the National Transportation Safety Board reviewed light-twin engine-failure accidents, involving the 24 most popular model-groups of light twins between 1972 and 1976. They found that the piston-engined twin-Commanders had averaged slightly over 3.4 engine-failure accidents per hundred-thousand hours, the second worst number of all aircraft under review. The most engine failures were suffered by the small-engine versions of the Piper Apache, at 6.9 failures per hundred thousand hours; the third-worst, the Beechcraft Travel Air, averaged 2.9 failures; the average for all models was only 1.6.

Countering the statistical evidence, Rockwell demonstration pilot Bob Hoover's famous airshow stunt routine, with the Shrike Commander, included a full aerobatic routine performed first with both engines, then with one engine out (and the critical engine, at that), then both engines out, and gliding. Then in his final airshow performance, in a supreme demonstration of conservation of momentum, he did all that, then landed the Shrike Commander dead stick (engines off), coasted the airplane down the runway then from the runway down the taxiway and silently let the craft roll slowly to a full stop right in front of the crowd.

The turboprop twin-Commanders—with much more powerful engines (and most with longer bodies, allowing greater rudder leverage, critical for single-engine control) – came out on the opposite end of the rankings, with one of the lowest rates of engine-failure accidents of all "light" twins examined, at only 0.4 per hundred-thousand hours.

Variants

• Certified from 1954, the seven-seat 560 is powered by two 270–295 hp (201–220 kW) Lycoming GO-480s.
• From 1955, the 680 has Supercharged 340–380 hp (250–280 kW) Lycoming GSO-480s.
• From 1958, the lighter 500 is powered by two 250–290 hp (190–220 kW) Lycoming O-540s or Continental IO-470s.
• From 1963, the stretched 680-FL offered up to eleven seats.
• It gained two 575 hp (429 kW) AiResearch TPE-331 turboprops from the 680-T in 1965.
• From 1971, the heavier 690 has a larger wing and more powerful 717.5–748 hp (535–558 kW) TPE-331s.
• From 1979, the final 695 Jetprop 980/1000 is powered by 733–820 hp (547–611 kW) TPE-331s.

Operators

Government operators

 United States

• Texas Highway Patrol

 Indonesia

• Indonesian National Police

Military operators

 Algeria

• Algerian Air Force – 1 x 680E survey aircraft in 1986

 Angola

• Angolan Air Force – 1 x 690A VIP aircraft in 1986

 Argentina

• Argentine Air Force – 1 x 500B, 27 x 500U and 1 x 680
• Argentine Army Aviation – 680V, 690A

 Bahamas

• Royal Bahamas Defence Force – 500S (no longer operated)

 Benin

• Benin Air Force – 1 x 500B

 Bolivia

• Bolivian Air Force – 1 x 690 in 1986

 Burkina Faso

• Burkina Faso Air Force – 1 x 500B in 1986

 Colombia

• Colombian Aerospace Force
• National Army of Colombia

 Costa Rica

• Public Force of Costa Rica

 Cuba

• Cuban Air Force – 1 × 560 acquired in late 1956.

 Dominican Republic

• Air Force of the Dominican Republic

 Greece

• Hellenic Army – 2 x 680FL

 Guatemala

• Guatemalan Air Force

 Honduras

• Honduran Air Force

 Indonesia

• Indonesian Army Aviation Command – 2 x 680FL

 Iran

• Islamic Republic of Iran Air Force – 3 x 681B
• Islamic Republic of Iran Army Aviation – 3 x 690, 2 x 690A
• Islamic Republic of Iran Navy Aviation – 2 x 500S, 2 x 690, 6 x 690A

 Ivory Coast

• Ivory Coast Air Force – 1 x 500B

 Kenya

• Kenya Air Force – 1 x 680FP (no longer operated)

Kingdom of Laos

• Royal Lao Air Force – 1 x 560 (no longer operated)

 Republic of Korea

• Republic of Korea Air Force – 3 x 520, 2 x 560F

 Mexico

• Mexican Air Force – 20 x 500S

 Nicaragua

• Fuerza Aérea de la Guardia Nacional

 Niger

• Niger Air Force – 1 x 500B

 Pakistan

• Pakistan Air Force – 1 x 680E (with radar nose), 1 x 680F
• Pakistan Army Aviation – 1 x 690B

 Panama

• Panamanian Air Force

 Philippines

• Philippine Air Force - 2 Units for ELINT.

 Thailand

• Royal Thai Air Force

 United States

• United States Air Force as the L-26 and U-4
• United States Army as the L-26 and U-9

 Venezuela

• Bolivarian Navy of Venezuela

Civil operators

 Samoa

• Talofa Airways

Notable accidents

• On 19 June 1964 Senator Ted Kennedy was a passenger in an Aero Commander 680 airplane flying in bad weather from Washington, D.C., to Massachusetts. It crashed into an apple orchard in the western Massachusetts town of Southampton on the final approach to the Barnes Municipal Airport near Westfield. The pilot and Edward Moss, one of Kennedy's aides, were killed. Kennedy suffered a severe back injury, a punctured lung, broken ribs and internal bleeding.
• World War II hero and actor Audie Murphy died in an Aero Commander 680 crash while flying as a passenger on 28 May 1971. The aircraft was flying in bad weather at night and was on approach to Roanoke, Virginia when it flew into the side of Brush Mountain outside Blacksburg, Virginia, West of Roanoke. Four others and the pilot were also killed.
• On 11 August 2002 photographer Galen Rowell, his wife Barbara Cushman Rowell, pilot Tom Reid and Reid's friend Carol McAffee were killed in an Aero Commander 690 crash near Eastern Sierra Regional Airport in Bishop, California.
• On Sunday 2 October 1994, an Aero Commander 690 operated by Seaview Air as flight CD111 departed for from Williamtown, NSW, on a flight to Lord Howe Island. Eight passengers, including honeymooners and a family with two children, boarded the single-pilot aircraft. 30 minutes after departure a distress call was made by the pilot with no future communications made. Only some minor wreckage was ever recovered. During the investigation a number of safety breaches by the operator were discovered including regular operations with overweight aircraft, inaccessible safety equipment & illegal regular public transport operations when the operator was only approved to operate charter flights. The incident was a significant one to occur in Australia & lead to a $20 million royal commission which resulted into fundamental changes to the governing aviation body in Australia.

Specifications (Rockwell Aero Commander 500S)

Data from Jane's all the world's aircraft 1976–77.

General characteristics

• Crew: Two
• Capacity: four passengers
• Length: 36 ft 9.75 in (11.22 m)
• Wingspan: 49 ft 0.5 in (14.95 m)
• Height: 14 ft 6 in (4.42 m)
• Wing area: 255 sq ft (23.69 m)
• Aspect ratio: 9.45:1
• Airfoil: NACA 23012 modified
• Empty weight: 4,635 lb (2,102 kg)
• Max takeoff weight: 6,750 lb (3,062 kg)
• Powerplant: 2 × Lycoming IO-540-E1B5 air-cooled flat-six piston engines, 290 hp (216 kW) each

Performance

• Maximum speed: 215 mph (346 km/h, 187 kn) at sea level (TAS)
• Cruise speed: 203 mph (326 km/h, 176 kn) at 9,000 ft (2,750 m), 75% power, TAS
• Stall speed: 68 mph (109 km/h, 59 kn) flaps and landing gear down, CAS
• Minimum control speed: 75 mph (121 km/h, 65 kn)
• Range: 1,078 mi (1,735 km, 936 nmi)
• Service ceiling: 19,400 ft (5,913 m)
• Rate of climb: 1,340 ft/min (6.8 m/s)

See also

• Bob Hoover
• Beechcraft King Air
• Partenavia P.68

References

Notes

1. ^
2. 2 built for the US Air Force
3. 4 built for the US Army

1. ^ "Rockwell U-9A Aero Commander". March Field Air Museum. Archived from the original on 18 August 2007. Retrieved 1 August 2007.
2. ^ Collman, B.J. (May–June 1973). "The Aero Commander Twins". Air-Britain Digest. 15 (3): 79–86.
3. ^ Williams, Nicholis M (Spring 1990). "The Aero Commander 520". AAHS Journal.
4. "What's New in Aviation: Feederliner Makes Debut". Popular Science. Vol. 153, no. 2. August 1948. p. 90.
5. "Shrike Commander". Flying. July 1972. pp. 72–73, 76.
6. Collins, Richard L. (January 1999). "Grand Renaissance: The rebirth of the tough bird". Flying. Vol. 126, no. 1. pp. 80–83.
7. "missing". Sport Aviation: 30. June 2011.
8. "President Eisenhower's Twin-Engine Air Force One". Ike's Bird. Archived from the original on 27 October 2020.
9. "Aerocommander 560f". Archived from the original on 17 February 2010.
10. "fl6807-1 JPG file".
11. "fl6807-4 JPG file".
12. ^ Swift, S. J. (1 May 1995), The Aero Commander chronicle (PDF), Civil Aviation Safety Authority, retrieved 1 August 2007
13. Harris, Richard. "The Aero Commander Line – A short history". Archived from the original on 13 July 2011. Retrieved 13 August 2011.
14. ^ Smith, Thomas Motley (1981). Multiengine Airplane Rating: A Guide to the FAA Oral and Flight Tests. Pan American Navigation Service. ISBN 0-87219-003-X. OCLC 7958067.
15. ^ "Special Study: "Light Twin-Engine Aircraft Accidents Following Engine Failures, 1972–1976 NTSB-AAS-79-2" (PDF). Washington, D.C.: National Transportation Safety Board. 1979. Retrieved 16 May 2017.
16. ^ Ibold, Ken, ed. (2001). Aviation Consumer's Used Aircraft Guide. Vol. 2 (9 ed.). Greenwich, Connecticut: Belvoir Publications.
17. Cochrane, Dorothy (20 February 2014). "Robert A_ "Bob" Hoover, The Greatest Stick and Rudder Man, is Honored in Hollywood". Smithsonian National Air and Space Museum. Washington, D.C. Retrieved 16 May 2017.
18. "Bob Hoover flies west". GeneralAviationNews.com. 25 October 2016. Retrieved 29 August 2020.
19. "Bob Hoover's Last Air Show". 15 June 2015 – via YouTube.
20. "Checkout in a Multiengine Airplane". Flight Training Handbook Advisory Circular 61-21A. Federal Aviation Administration.
21. "Type Certificate data sheet No. 6A1" (PDF). FAA. 25 September 2015. Archived from the original (PDF) on 19 June 2022. Retrieved 27 January 2022.
22. "Type Certificate data sheet No. 2A4" (PDF). FAA. 25 September 2015. Archived from the original (PDF) on 2 November 2016.
23. Simpson 1995
24. "TxDPS – Aircraft History". dps.texas.gov. Archived from the original on 28 August 2018. Retrieved 27 August 2018.
25. Seymour, Paul (28 December 2018). "AERO COMMANDER 560A, P-2001 / 310-73, INDONESIAN POLICE / POLISI". abpic.co.uk. Retrieved 1 April 2021.
26. Flight International 29 November 1986, p. 32
27. Flight International 29 November 1986, p. 33
28. Andrade 1982, p. 12
29. Andrade 1982, p. 13
30. "Royal Bahamas Defence Force (RBDF) – Air Wing". LA MILITARY. 9 April 2016.
31. Andrade 1982, p. 26
32. Flight International 29 November 1986, p. 37
33. Flight International 29 November 1986, p. 39
34. "World Air Forces 2022". FlightGlobal. 2022. Retrieved 17 July 2022.
35. "División de Aviación Asalto Aéreo incorpora nuevo avión Turbo Commander 690D". webinfomil.com. 10 March 2014. Retrieved 19 December 2016.
36. Hagedorn 1993, p. 128
37. Hagedorn 1993, p. 18
38. Flight International 29 November 1986, p. 49
39. Andrade 1982, p. 94
40. Hagedorn 1993, p. 55
41. ^ "World Air Forces 2021". FlightGlobal. 4 December 2020. Retrieved 10 August 2021.
42. Andrade 1982, p. 106
43. Andrade 1982, p. 107
44. Andrade 1982, p. 109
45. Andrade 1982, p. 110
46. Andrade 1982, p. 126
47. Andrade 1982, p. 141
48. "Royal Lao Air Force Aircraft Types". aeroflight.co.uk. Retrieved 19 December 2016.
49. Andrade 1982, p. 143
50. Andrade 1982, p. 156
51. Hagedorn 1993, p. 42
52. Andrade 1982, p. 167
53. Andrade 1982, p. 172
54. Andrade 1982, p. 173
55. Hagedorn 1993, p. 120
56. "World Air Forces 2025". Flightglobal Insight. 2024. Retrieved 10 December 2024.
57. Flight International 29 November 1986, p. 92
58. ^ Andrade 1979, p. 134
59. "When in Samoa, fly with Talofa and its Twin Commanders". Flight Levels Online. 21 (3). 2016.
60. "Teddy's Ordeal". Time. 26 June 1964. Archived from the original on 4 February 2013. Retrieved 23 May 2008.
61. "The Luck of the Kennedys". Check-Six.com. 8 May 2008. Archived from the original on 1 February 2009. Retrieved 24 February 2009.
62. "John F. Kennedy Jr. – Timeline: Misfortunes of a Family". CNN. July 1999. Archived from the original on 23 March 2008. Retrieved 23 May 2008.
63. Swidey, Neil (16 February 2009). "Chapter 2: The Youngest Brother: Turbulence and tragedies eclipse early triumphs". The Boston Globe. Archived from the original on 22 February 2009. Retrieved 24 February 2009.
64. "Biography for Audie Murphy". IMDb. 1 August 2007. Retrieved 1 August 2007.
65. Delgado, Ray (12 August 2002). "Galen Rowell 1940–2002". San Francisco Chronicle. Hearst Communications Inc. Retrieved 27 November 2016.
66. "INVESTIGATION REPORT 9402804 Rockwell Commander 690B VH-SVQ en route Williamtown to Lord Howe Island New South Wales 2 October 1994" (PDF). Bureau of Air Safety Investigation. Retrieved 12 October 2024.
67. Taylor 1976, pp. 346–347

Bibliography

• Andrade, John (1979). U.S. Military Aircraft Designations and Serials since 1909. Midland Counties Publications. ISBN 0-904597-22-9.
• Andrade, John (1982). Militair 1982. London: Aviation Press Limited. ISBN 0-907898-01-7.
• Hagedorn, Daniel P. (1993). Central American and Caribbean Air Forces. Kent, UK: Air-Britain (Historians). ISBN 978-0851302102.
• Hatch, Paul F. (29 November 1986). "World's Air Forces 1986". Flight International. Vol. 130, no. 4039. pp. 30–104. ISSN 0015-3710.
• Simpson, R.W. (1995). Airlife's general aviation. Airlife publishing. ISBN 1-85310-577-5.
• Taylor, John W.R. (1976). Jane's all the world's aircraft 1976–77. London: Jane's yearbooks. ISBN 0-354-00538-3.

External links

• Media related to Aero Commander 500 at Wikimedia Commons
• "Twin Commander aircraft, LLC". (Legacy Support)
• Bergqvist, Pia (2 November 2012). "Grand Renaissance Commander". Flying magazine. A rugged high-performance airplane with more than just a face lift
• Cook, Leroy (16 April 2015). "The Twin Commander turboprops". Twin & Turbine. Archived from the original on 17 May 2021. Retrieved 17 May 2021.
• Huber, Mark (February 2016). "Twin Commander 1000". BJT online. Decades after its introduction, it remains rugged, capable… and cool

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