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 in 1986 under the Gulfstream Aerospace name. The initial production version was the , 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 , 11-seat Model 695B/Jetprop 1000B turboprop.
As of recent, the Aero Commander is known as the Twin Commander.
Design and development
thumb|The first model, the five-seat 520, was certified in January 1952 with two 260 HP [[Lycoming GO-435s]]
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. 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. 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.
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 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.
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.
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. and 2A4
! model || name || approved || TC || engines || power || MTOW || ceiling || seats || fuel || built
|-
! L-3805
| || || || || || || || || || 1
|-
! 520
| || 1952-01-31 || 6A1 || 2× GO-435-C2/C2B || 2× 260 || 5500-5700 || || 5 || 145 || 150
|-
! rowspan=2 | 560
| || 1954-05-28 || 6A1 || 2× GO-480-B/B1C || 2× 270 || 6000 || || 7 || 145 || 80
|-
| colspan=10 | 520 with more power, increased weight, swept tail, plus revised wing, landing gear, fuselage, and primary control system
|-
! rowspan=2 | 560A
| || 1955-07-01 || 6A1 || 2× GO-480-D/C/G || 2× 275 || 6000 || || 7 || 156 ||
|-
| colspan=10 | 560 with longer fuselage, revised engine installation, wing, landing gear, fuel and oil systems
|-
! rowspan=2 | 560E
| || 1957-02-21 || 6A1 || 2× GO-480-C/G || 2× 295 || 6500 || || 7 || 223 || 93
|-
| colspan=10 | 560A with Larger wings and greater payload, revised engine installation, wing, wheel and brake installation, fuel system with outboard tanks, and landing gear location
|-
! rowspan=2 | 560F
| || 1961-02-08 || 2A4 || 2× IGO-540-B || 2× 350 || 7500 || || 7 || 223 ||
|-
| colspan=10 | 680F with normally aspirated engine and reduced gross weight
|-
! rowspan=2 | 360
| || || || || 2× 180 || || || 4 || || 1
|-
| colspan=10 | Lightened 560E
|-
! rowspan=2 | 500
| || 1958-07-24 || 6A1 || 2× O-540-A2B || 2× 250 || 6000 || || 7 || 156 || 101
|-
| colspan=10 | 560E with decreased gross weight, powerplants, and 560A landing gear
|-
! rowspan=2 | 500A
| Aero Commander || 1960-04-07 || 6A1 || 2× IO-470-M || 2× 260 || 6000 || || 7 || 156 || 99
|-
| colspan=10 | 500 with new nacelles, fuel injected Continental engines and new landing gear
|-
! rowspan=2 | 500B
| || 1960-07-13 || 6A1 || 2× IO-540-B/E || 2× 290 || 6750 || || 7 || 156 || 217
|-
| colspan=10 | 500A with Lycoming engines and 3-bladed props.
|-
! rowspan=2 | 500U
| Shrike Commander || 1964-12-11 || 6A1 || 2× IO-540-E ||2× 290 || 6750 || || 7 || 156 || 56
|-
| colspan=10 | 500B with pointed nose and squared off tail.
|-
! rowspan=2 | 500S
| Shrike Commander || 1968-03-15 || 6A1 || 2× IO-540-E || 2× 290 || 6750 || || 7 || 156 || 316
|-
| colspan=10 | 500U with minor changes
|-
! rowspan=2 | 680 Super
| L-26C → U-4B<br />L-26C → U-9C || 1955-10-14 || 2A4 || 2× GSO-480-A1A6 || 2× 340 || 7000 || || 7 || 223 || 254
|-
| colspan=10 | supercharged 560A
|-
! rowspan=2 | 680E
| || 1958-06-19 || 2A4 || 2× GSO-480-B1A6 || 2× 340 || 7500 || || 7 || 223 || 100
|-
| colspan=10 | 680 with Lightened 560E/560A type undercarriage, extended wing and increased maximum weight
|-
! rowspan=2 | 720
| AltiCruiser || 1958-12-05 || 2A4 || 2× GSO-480-B1A6 || 2× 340 || 7500 || || 6 || 223 || 13
|-
| colspan=10 | Pressurized 680-E, structural modifications to the fuselage, extended wing and increased maximum weight
|-
! rowspan=2 | 680F
| || 1960-08-23 || 2A4 || 2× IGSO-540-B || 2× 380 || 8000 || || 7 || 223 || 126
|-
| colspan=10 | 680E with fuel injection engine, new nacelles, new main gear and increased maximum weight
|-
! rowspan=2 | 680FP
| || || || || 2× 380 || || || || 223 || 26
|-
| colspan=10 | Pressurized 680F
|-
! rowspan=2 | 680FL
| Grand Commander|| 1963-05-24 || 2A4 || 2× IGSO-540-B || 2× 380 || 7000-8500 || || 11 || 223 || 157
|-
| colspan=10 | 680F with larger tail, 2 built for the US Army as the RL-26D → RU-9D with , Courser Commander after 1967; stretched
|-
! rowspan=2 | 680FL(P)
| Grand Commander || 1964-10-08 || 2A4 || 2× IGSO-540-B1A/B1C || 2× 380 || 8500 || || 11 || 223 || 37
|-
| colspan=10 | pressurized 680FL
|-
! rowspan=2 | 680T
| Turbo Commander || 1965-09-15 || 2A4 || 2× TPE-331-43 || 2× 575 || 8950 || 25,000 ft || 11 || 286.5 || 56
|-
| colspan=10 | 680FL/P turboprop
|-
! rowspan=2 | 680V
| Turbo Commander || 1967-06-13 || 2A4 || 2× TPE-331-43 || 2× 575 || 9400 || 25,000 ft || 11 || 286.5 || 36
|-
| colspan=10 | 680T with slightly improved cargo capacity
|-
! rowspan=2 | 680W
| Turbo II Commander || 1968-02-05 || 2A4 || 2× TPE-331-43BL || 2× 575 || 9400 || 25,000 ft || 11 || 286.5 || 46
|-
| colspan=10 | 680V with pointed nose. squared off fin, one panoramic and two small cabin windows and weather radar
|-
! rowspan=2 | 681
| Hawk Commander || 1969-03-20 || 2A4 || 2× TPE-331-43BL || 2× 575 || 9400 || 25,000 ft || 11 || 286.5 || 43
|-
| colspan=10 | 680W with improved pressurisation, air conditioning system and nose
|-
! rowspan=2 | 681B
| Turbo Commander || || || || || || 25,000 ft || || || 29
|-
| colspan=10 | Marketing designation for economy version of the 681
|-
! rowspan=2 | 685
| Commander || 1971-09-17 || 2A4 || 2× GTSIO-520-F/K || 2× 435 || 9000 || 25,000 ft || 9 || 256-322 || 66
|-
| colspan=10 | 690 powered by piston engines
|-
! rowspan=2 |
| Commander 690 || 1971-07-19 || 2A4 || 2× TPE-331-5 || 2× 717.5 || 10250 || 25,000 ft || 11 || 384 || 79
|-
| colspan=10 | 681 with new wing centre section and engines moved further outboard
|-
! rowspan=2 |
| Commander 690A || 1973-04-25 || 2A4 || 2× TPE-331-5 || 2× 717.5 || 10250 || 31,000 ft || 11 || 384 || 245
|-
| colspan=10 | 690 with changed flightdeck layout and increased pressurisation
|-
! rowspan=2 |
| Commander 690B || 1976-10-05 || 2A4 || 2× TPE-331-5 || 2× 717.5 || 10325 || 31,000 ft || 10 || 384 || 217
|-
| colspan=10 | 690A with improved soundproofing and internal lavatory
|-
! rowspan=2 |
| Jetprop 840 || 1979-09-07 || 2A4 || 2× TPE-331-5 || 2× 717.5 || 10325 || 31,000 ft || 11 || 384 || 136
|-
| colspan=10 | 690B with increased wingspan, wet wing fuel tanks and winglets
|-
! rowspan=2 | 690D
| Jetprop 900 || 1981-12-02 || 2A4 || 2× TPE 331-5 || 2× 748 || 10700 || 31,000 ft || 11 || 425-474 || 42
|-
| colspan=10 | 690C with internal rear cabin extension, improved pressurisation and five square cabin windows
|-
! rowspan=2 | 695
| Jetprop 980 || 1979-11-01 || 2A4 || 2× TPE-331-10 || 2× 733 || 10325 || 31,000 ft || 11 || 425-474 || 84
|-
| colspan=10 | more powerful 690C
|-
! rowspan=2 |
| Jetprop 1000 || 1981-04-30 || 2A4 || 2× TPE-331-10 || 2× 820 || 11200 || 35,000 ft || 11 || 474 || 101
|-
| colspan=10 | more powerful 690D with higher takeoff weight, built for the NOAA
|-
! rowspan=2 |
| Jetprop 1000B || 1984-02-15 || 2A4 || 2× TPE-331-10 || 2× 820 || 11750 || 35,000 ft || 11 || 474 || 6
|-
| colspan=10 | 695A with minor changes
|}
Operators
thumb|[[Islamic Republic of Iran Army Aviation 690A]]
thumb|[[Argentine Air Force 500U]]