21 November 2009

Following General Billy Mitchell's dramatic demonstration of airpower in July 1921 with the sinking of the captured German battleship Ostfriesland by Martin MB-2 bombers, Rear Admiral William A. Moffett ordered that the US Navy expeditiously get aircraft on its battleships and get aircraft carriers as quickly as possible. Within a year of Mitchell's bombing demonstration, Moffett had organized the Bureau of Aeronautics (BuAer) with himself as its first chief. In the first ten years of BuAer's existence, the Glenn L. Martin Company would produce over 400 aircraft in over a dozen different types from scouts to patrol bombers. The first contracts for experimental aircraft to expand the Navy's aerial reach were awarded in 1922 and in 1923 Admiral Moffett and BuAer were even wanting a scouting aircraft for submarines.

The Martin MS-1, a submarine observation aircraft, was one of the more unusual designs of its day and one of the rarest of Navy aircraft. Measuring in right at seven and a half feet in height, the float-equipped biplane was only seventeen feet long and had a removable wing only eighteen feet in wingspan. A three-cylinder radial engine powered the MS-1 to top speed of 100 mph. It was rolled out on 17 April 1923 at Martin's Cleveland, Ohio, plant.

At sea, the submarine would surface underneath the alighted MS-1, lifting it up out of the water. The wings were then removed and stored with the scout plane in a watertight compartment on the deck. To launch the MS-1, the procedure was reversed. The Navy bought six MS-1 scouts.

Source: Raise Heaven and Earth- The Story of Martin Marietta People and Their Pioneering Achievements by William B. Harwood. Simon and Schuster, 1993, p99-102.

19 November 2009

In the 1980s as a response to the Strategic Defense Initiative (SDI), the Russians began work on a spaceborne laser system of their own under the name Polyus-Skif. "Polyus" was Russian for "pole" and "Skif" referred to the Scythians, an ancient tribe of warriors from Central Asia. As the work continued, Polyus-Skif would evolve into a spaceborne weapon to attack the American SDI satellites instead of American ICBMs. As the challenges in sending a megawatt-class laser into orbit mounted, the Russian scientists developed the Skif-D (for demonstrator) to test key technologies in orbit. Originally intended for the Proton rocket, the Skif-D was simply too large and would be launched by the larger Energia launcher.

The Skif-D was bigger than Skylab- it was 131 feet long, over 13 feet in diameter and weighed in at 210,000 pounds. It consisted of two sections- the "purposeful" module carried the carbon dioxide tanks and two turbogenerators for the laser as well as a turret for pointing the laser beam. The other section was the "functional block" which carried small rocket engines, the power generation system, solar panels and other control systems.

Though an interim flight test article designated Skif-DM that was launched on 15 May 1987 failed to reach orbit and Gorbachev eventually canceled the program, elements of the Polyus-Skif are alleged to live on in orbit today on the International Space Station.

According to a recent Air & Space article on the Polyus-Skif, the first component of the ISS, the Russian control module Zarya (meaning "dawn") and also called the Functional Cargo Block, was built under contract to NASA in the mid-1990s by the Khrunichev bureau, the same organization that was responsible for the Polyus-Skif. The engineers produced Zarya on time and on budget at a time when the Russian aerospace industry was in crisis. The role of the Zarya is the same as the functional block on the Polyus-Skif- to supply electrical power and for in-orbit stationkeeping. Some spacewatchers have indicated that the Zarya may even be more than just based on the Polyus functional block, it may have even started as a Polyus flight spare- if true, then today's ISS has as its heart a legacy of the Soviet space laser program from the Cold War!

Source: Air & Space Smithsonian, January 2010. "Soviet Star Wars- When the world was on the brink of laser weapons in space" by Dwayne A. Day and Robert G. Kennedy III, p55-60.

18 November 2009

After having flown as N616NA for NASA's Lewis Research Center in Cleveland for several years in supersonic transport-related studies, it was transferred to Langley Research Center and renumbered N816NA for a role it would serve for nearly six years starting in January 1979. The Convair NF-106B joined NASA's Storm Hazards Program to study the effects of lightning strikes on aircraft.

The program began the previous year in 1978 using De Havilland DHC-6 Twin Otter aircraft that would fly on the fringes of thunderstorms gathering lightning data to be used in planning the penetration flights of N816NA. The modified Delta Dart would be flown into thunderstorms to trigger lightning strikes. Mainly operating off the coast of Virginia and at various locations in the US Midwest, the Delta Dart would fly as low as 3,500 feet up to as high as 50,000 feet on its penetration flights. In its time with the Storm Hazards Program, N816NA made 1,496 thunderstorm penetrations and was struck by lightning 714 times. In a single flight in 1984 it was struck 72 times in the space of only 45 minutes while penetrating a thunderstorm at 38,000 feet!

The data collected during the course of the program proved to be extremely valuable to both commercial and military aviation and represented a significant step in aviation safety.

Source: Convair Deltas: From SeaDart to Hustler by Bill Yenne. Specialty Press, 2009, p151.

17 November 2009

The Germans weren't the only ones to fit sirens on their Junkers Ju 87 Stuka dive bombers for psychological effect when attacking troops on the ground. In 1943 the USAAF stationed Curtiss P-40 Warhawks in the Assam Valley in eastern India to protect departing transports headed north over the "Hump" to bases in China. As the heavily laden C-47 and C-46s left India, they had to travel over Burma and since the Japanese controlled the Burma railroad, prowling fighters preyed on the lumbering aircraft.

The 89th Fighter Squadron's P-40s were marked with a red spinner and a large white skull on the side of the nose. Knowing that many Japanese soldiers were superstitious and a good number of ground attack missions were flown, the squadron fitted 18-inch air raid sirens to the Warhawks and turned them on as they made their attack runs, calling them the "Banshee Wail".

Source: World War II Air Combat (Flight Journal supplement), Winter 2008. "Burma Banshee Brawl" by Colonel Philip R. Adair, USAF (Ret.), p72-77.

16 November 2009

In the summer of 1944 the German forces in Italy were holding a defensive position called the Gothic Line that ran across the Italian peninsula across the Apennine Mountains south of Bologna. Most of the Allied sorties of the MATAF (Mediterranean Allied Tactical Air Force) were focused on the Gothic Line itself but on July 11, a combined offensive headed by Martin B-26 Marauders of the MATAF codenamed Operation Mallory Major sought to break the logistical support of the Germans.

Named for Major William N. Mallory of the Twelfth Air Force who conceived of the plan, Operation Mallory Major was one of the first applications of what today war planners might call "shock and awe". The Germans had massive supply dumps north of the Po River and OSS agents had determined that 22 major bridges across the Po River were virtually undefended and it was across these road and rail bridges that the Germans were supplying the Gothic Line.

The genius of Mallory's plan was to hit all 22 bridges in short span of time before the Germans would realize what was going on and deploy anti-air assets to protect the bridges. With good weather, two B-26 Marauder bomb wings flew 300 missions a day and in the first two days, 11 of the 22 bridges were destroyed and four days after the start of the operation, all 22 bridges were knocked out, cutting off the Gothic Line from their supply bases north of the Po River. For another 12 days, the medium bomber force of the MATAF revisted several bridges to insure that they weren't repaired and put back into use. Although the Germans reinforced the bridge defenses, it was too late as the volume of traffic that could cross the Po had slowed to a trickle, hastening the defeat of the Germans in northern Italy.

Major William Mallory would be awarded the Legion of Merit for his plan but tragically he died when the plane returning him to the United States crashed.

Source: Aviation History, November 2009. "Operation Mallory Major- A Twelfth Air Force intelligence officer came up with a daring plan to cripple Axis supply lines in northern Italy" by Joseph Connaughton, p40-43.

14 November 2009

Having built up its experience base with the local assembly of the Fouga CM-170 Magister jet trainer in the late 1950s, Israeli Aircraft Industries (IAI) used the Magister as the basis for its first jet design, the B-101 business jet. The B-101 combined the wings and V-tail of the Magister with a new fuselage and external jet nacelles on the aft fuselage. However, it was soon realized that the target cruise speed of Mach 0.8 wasn't possible with the wings of the Magister. Five different design configurations followed that included a T-tail, swept wings and at one point, a trijet, but the project was eventually cancelled in May 1963.

IAI would get back into bizjets again several years later when Rockwell Standard acquired Jet Commander of Oklahoma. As Rockwell already owned North American Aviation that produced the Sabreliner, the US Department of Justice required that Rockwell had to sell one of the two business jet concerns to comply with anti-trust statutes. As the US military was already operating the Sabreliner as the T-39, the complete Jet Commander program was offered for sale including 49 unsold airframes. In September 1967 IAI was the winning bidder and the Jet Commander evolved into the Westwind.

The Westwind led to the improved IAI Astra which first flew in March 1984 and in turn with cooperation with Yakovlev, led to the IAI Galaxy which first flew in December 1997. In 2001 General Dynamics' Gulfstream Aircraft purchased the Astra and Galaxy programs and they were were rebranded as the G100 and G200 with the G150 a further development that launched in 2002 of what was the IAI Astra.

Source: Air Enthusiast, September/October 2003. "Golden Heritage- Israeli Aircraft Industries at 50" by Shlomo Aloni, p17-30.

13 November 2009

One of the Most Important Missions of the C-133 Cargomaster: Transporting ICBMs

One of the principal missions planned for the Douglas C-133 Cargomaster was the transport of the ballistic missiles of the Strategic Air Command. With the Atlas ICBM in development and the Thor and Jupiter IRBMs already deployed in Europe, no other aircraft had the performance and capacity to move the missiles to air bases near the launch sites. With the entry into service of the Titan ICBM, the aft cargo doors of the C-133 had to be modified from the original configuration which consisted of the ramp and a single cargo door that hinged upward. As the Titan was a significantly wider missile, the single upward-hinging door was replaced by a three part unit that consisted of two doors than hinged outward to provide more clearance and a small section of the upward-hinging door at the very end of the tail. Not only did this give a wider opening, but it also added an additional 3 feet of space for the longer Titan missile.

The first Atlas missile was transported in 1959 and the first Titan and Minuteman missiles were transported on the Cargomaster in 1962. The thin skin of the Atlas was particularly challenging to protect during loading as the fit was extremely tight. A complex rail loading system was used for the Atlas and it had to be aligned within a tolerance of less than 2 mm with the cargo rails inside the Cargomaster, necessitating use of a surveryor's transit. Fuel load, tire pressure and landing gear strut compression were all closely monitoried and the loading and unloading could easily take a full day.

The solid-fueled Minuteman ICBM was easier to load but required a special cradle that had hydraulic translating jacks to align the cradle with the rails in the C-133's cargo hold. Since there was no integral winch on the Cargomaster, the Minuteman cradle had one of its own to facilitate loading. A portable winch was developed for missile loading, but it wasn't any easier for ground crews as it required a forklift to move and position.

NASA also found value in the ICBM transport capability of the C-133 Cargomaster as it was used to deliver launch vehicles to Cape Canaveral in Florida. Between 1966 and 1969, NASA operated a C-133 as tail number 928 from both Dover AFB and Ellington Field near the Johnson Space Center for over 200 flight hours. It also served in the development of the Apollo spacecraft by air dropping a boilerplate Apollo command module to test the recovery parachutes. The C-133 wasn't approved for air drops, but the cargo ramp and doors were removed and the boilerplate was dropped from a fixture in the opening. Thirty four drops were made at National Parachute Test Range at El Centro, California.

NASA went as far as to do wind tunnel testing on a twin-finned C-133 that could carry Saturn rocket stages on its back similar to what the Russians did years later with Energia rocket components on the Antonov An-225 and Myasishchev M-4 Bison. NASA eventually settled on using the Aero Spacelines Super Guppy as a more economical approach.

Source: Air Enthusiast, March/April 2004. "Forgotten Airlifter- The Short-Lived Douglas C-133 Cargomaster" by Bill Norton, p45-51.

12 November 2009

With the shortest routes to attack American targets laying across the North Pole, Russian research efforts in the Arctic which began in the 1930s took on strategic urgency with the start of the Cold War. Work began in earnest on 23 April 1948 when the first Soviet expedition, designated SP-2, was airlifted to the North Pole. An even larger expedition followed using assets of the Soviet Polar Aviation (a civil aviation agency in the USSR that supported Arctic research) and that of Long-Range Aviation (DA, or Dalyniya Aviatsiya, the Russian version of the Strategic Air Command). Two Tupolev Tu-4 "Bull" bombers from the DA were seconded to Polar Aviation and used as cargo transports with supplies carried in the bomber's spacious bomb bays. Other aircraft were part of the early expeditions and even used at one point an ex-Luftwaffe Focke-Wulf Fw 200 Condor. Also accompanying the bombers and transports were Lavochkin fighters to assess the feasibility of fighter operations in the Arctic.

By the early 1950s a network of deployment airfields large enough to take heavy bombers of the DA like the Tu-95 "Bear" and the Myasishchev M-4 "Bison" had been built across the Russian Arctic along with a chain of radio navigation beacons. However, the DA general staff recognized the vulnerability of these forward bomber bases and in 1956 began investigating operating jet bombers off the polar ice pack itself. By 1958 a special unit of DA Tupolev Tu-16 "Badger" twin jet bombers was created to test the feasibility of operating off ice runways on the polar ice pack.

On 26 April 1958 Colonel Anton Alekhnovich landed a Tu-16 bomber at the SP-6 research station's ice runway. However, on takeoff, the port main gear hit an area of ice that wasn't fully frozen and the bomber veered off the runway and hit an Ilyushin Il-14 transport. Attempts to repair the bomber were unsuccesful and due to fears that the SP-6 ice floe was moving too close to the United States, the Tu-16 was destroyed. Due to the variable nature of ice stability on the polar ice pack, further DA bomber operations were conducted from land bases built in the tundra.

Source: Soviet Strategic Aviation in the Cold War by Yefim Gordon. Hikoki Publications, 2009, p75-82.

10 November 2009

In 1936 the RAF issued Specification T6/36 for an aircraft designed from the outset for crew training. At the time, air crew training was often carried out retired aircraft types. T6/36 required the new design be a monoplane with retractable undercarriage, side-by-side seating with dual controls, a radio compartment for the training of navigators and radio operators and a manually-operated gun turret. There was to even be provision for a forward firing gun and practice bomb carriage as well. The RAF indicated that well over 100 aircraft would be required.

De Havilland was selected to built its design, an elegant looking aircraft powered by a single 525-horsepower Gipsy King 1 12-cylinder engine. The De Havilland DH.93 Don made its first flight on 18 June 1937. Initial flight testing showed the need for several modifications, including the addition of auxiliary fins under the horizontal tailplane but an order for 250 aircraft went forth.

Once the training equipment including the gun turret was installed, it was found the DH.93 Don was underpowered and suffered from continued stability issues. The order was revised to only 50 aircraft which were to be fitted out as light transports seating four to six individuals. A "turtleback" was fitted in place of the radio compartment and the dorsal gun turret. Of the 50 aircraft delivered, only 30 were delivered as airworthy and distributed quietly across several RAF station flights. The remaining 20 went straight into service as engineless ground instructional airframes.

The RAF's crew training needs shifted over to a design that was not tendered for the T6/36 specification- the Avro Type 652A first flew the year before the issuance of Specification T6/36 and would go into production as the vastly superior Avro Anson while the DH.93 Don faded into obscurity.
Source: Air Enthusiast, May/June 2003. "Out-Moded Teacher- De Havilland's Don Crew Trainer" by Daniel Ford, p74-75.

09 November 2009

After a prolonged development phase that started in 1934, the Blohm und Voss BV 138 three-engined flying boat first appeared in the skies over the Bay of Biscay in 1940. The first flying boat from Blohm und Voss, the most unique but not seen feature of the BV 138 was its tubular main wing spar which was also sealed to form a large fuel tank in addition to the more conventional fuel tanks in the wings. The flying controls were all hydraulically assisted and the crew of five was housed in the short fuselage/hull which bestowed the BV 138 it's nickname of "Die Fliegende Holzschuh" or "Flying Clog". There were enough provisions in the hull to sustain the crew for a week which allowed deployment of the BV 138 to forward positions to await further orders.

The crew included the pilot and naval observer side by side in the flight deck- in the Luftwaffe, the naval observer was actually the mission commander and only had a rudimentary amount of flight training as most of the flying was entrusted to the pilot who sat on the left. The navigation and radio compartment was located below the central engine while behind the center engine and in the wing midsection was the flight engineer's cabin whose duties included operating the fuel transfer pumps as well as topping off the engine oil in all three engines via hand pumps every 60 to 90 minutes as well as mixing coolant to keep the engines topped off as well. Two gun positions included a 20mm cannon turret in the nose ahead of the flight deck and an aft machine gun mount at the rear.

In the summer of 1943 the deployed provisioning capability of the BV 138 was used to base the flying boats on the Russian island of Novaya Zemlya to prowl on Arctic convoys bound for the port of Murmansk.

But the most unusual use of the BV 138 was that of an aerial minesweeper with a 46.6 foot diameter degaussing loop attached to the aircraft and powered by a generator in the former nose turret. As the war drew to a close, BV 138s were used to land on lakes around Berlin to evacuate wounded soldiers to Denmark.

Source: Air Enthusiast, July/August 1999. "Flugboots from Hamburg- An Outline History of Blohm und Voss Flying Boats" by Ken Wixley, p42-47.

08 November 2009

During the Second World War, aircraft manufacturers Arado and Fieseler were asked to develop a carrier-borne aircraft for the under-construction carrier Graf Zeppelin that could deliver both bombs and torpedoes. The Arado Ar 195 was the less successful of the two- based on the Arado Ar 95 floatplane, it was underpowered with only an 830-horsepower engine. The Fieseler Fi 167, was a better performer as from the start as its engine was the same Daimler-Benz 1,100-horsepower engine that was used on the Messerschmitt Bf 109 and Bf 110 fighters.

Though a biplane design with fixed undercarriage, the Fi 167 was in the same class as the Fairey Swordfish and Albacore torpedo bombers that despite their antiquated appearance, were quite effective in the Second World War. Fieseler's experience in designing the Fi 156 Storch STOL aircraft resulted in the Fi 167 having an astoundingly low stalling speed. Leading edge slats on the wings made it possible to stop the Fi 167 in midair by pulling hard back on the stick and the aircraft would settle in a near vertical drop while still under full control. Such handling characteristics made it ideal for carrier landings.

In addition to folding wings that folded aft in a similar fashion to the wing fold of the Fairey Swordfish, explosive charges could sever the fixed landing gear from the wings in case the aircraft had to be ditched at sea.

At the end of 1938 Fieseler got a contract for the first 12 aircraft which would be pre-production prototypes. Designated Fi 167A-0, the were taken on by an experimental squadron and operated in Holland from 1942 to 1943 in various testing roles which also included camouflage trials. With the eventual cancellation of the Graf Zeppelin, the aircraft were returned to Fieseler and rumored to have been split up between nine being overhauled before being delivered to Romania and the remaining three were kept by the Luftwaffe for test work.

Source: Air Enthusiast, March/April 2001. "Graf Zeppelin Afloat" by Henk van Willigenburg, p59-62.

06 November 2009

Within the Manhattan Project was a sizable scientific and technical effort to determine the progress of the Nazi atomic bomb program. One of the key scientists in this effort was future Nobel Laureate Luis W. Alvarez who in 1944 was working at Los Alamos in New Mexico when he was asked by General Leslie Groves, the head of the Manhattan Project, if there were a way to detect from the air if the Germans were operating plutonium-fueled reactors. Given only a week by Groves, Alvarez proposed an airborne collection system to detect Xenon-133, a by-production of reactor fission with a five-day half life which had distinctive patterns of gamma and beta radiation making it an ideal marker for German reactor activity.

General Groves' idea was to determine the locations of potential German reactors and then disrupt their atomic bomb effort via airstrikes.

With the help of General Electric, Alvarez designed an activated charcoal-based filter system that would fit in the nose compartment of a Douglas A-26 Invader that would fly several hundred feet above the ground. In the fall of 1944, three A-26s carrying Alvarez's Xenon-133 detector scoured three possible areas where intelligence analysts thought a German reactor might be operating. Fast and agile enough to evade AAA-gunfire but large enough to carry the bulky detector, no Xenon-133 was ever found.

Source: Spying on the Bomb- American Nuclear Intelligence from Nazi Germany to Iran and North Korea by Jeffrey T. Richelson. W.W. Norton, 2007, p40-41, 49-50.

05 November 2009

Dr. Forrest Bird, head of a biomedical engineering corporation based in Palm Springs, bought a Consolidated PBY Catalina (specifically it was a Canadian-built PBY-5 Canso) that in 1968 he had modified into a four-engined configuration called the Bird Innovator. Outboard of the existing radial engines were added nacelles accommodating 360-horsepower Lycoming piston engines driving Hartzell three bladed propellers. Though the speed increase from the Lycomings was modest, the real improvement came from the propwash of the new additonal engines which, in effect, acted to energize the airflow across the outer wings of the Catalina which were notorius for being sluggish particularly in engine out situations.

The Bird Innovator also had strengthened wings and a taller fin and rudder as well. The engineer's controls were also moved to the cockpit to allow the aircraft to be operated by a single pilot. After passing through various owners, the aircraft in 1997 was returned back to its original layout.

Source: General Dynamics Aircraft and their Predecessors by John Wegg. Putnam Aeronautical Books/Naval Institute Press, 1990, p78.

04 November 2009

On 11 July 1951 the USAF selected Beechcraft to design and build a new high-performance twin-engine transport-trainer aircraft to replace the Beech C-45s then operated by the Air Training Command. The new aircraft was designated the T-36A and would have been powered by two 18-cylinder 2300-horsepower Pratt & Whitney R-2800 radial engines driving three-bladed propellers for a cruising speed over 300 mph. In the training role, the T-36A would have carried three students and an instructor or as a light transport, it would have carried 12 passengers and a crew of 2.

By November 1951 the Air Force Inspection Board reviewed the full-scale mockup at Beech's facilities in Wichita. By that summer Beech began construction of a new production facility at Beech Field for T-36A production. In January 1953 the final details were fixed and production planned to start for the first batch of 195 aircraft for the USAF with Canadair in Montreal as the main subcontractor.

On 10 June 1953 with the maiden flight of the prototype only an hours away the Department of Defense canceled the T-36A contract and ordered all development activities to cease. Two aircraft were complete, the prototype that was being readied for its maiden flight and a complete static test airframe. Both airframes were scrapped on site in major blow to Beechcraft.

Source: Beech Aircraft and their Predecessors by A.J. Pelletier. Putnam Aeronautical Books/Naval Institute Press, 1995, p111.

03 November 2009

First flying on 27 May 1970, the Boeing Vertol 347 testbed was a modified CH-47A Chinook (aircraft 65-07992) used for Boeing's HLH (Heavy Lift Helicopter) program. The helicopter featured just over 9 foot extension of the forward fuselage cabin, a raised aft rotor pylon, four bladed rotors that were two feet longer than a standard Chinook blade, fly-by-wire controls and retractable landing gear.

But the most unique feature of the Model 347 was a variable-incidence wing that created extra lift to offload the main rotors. There was also a retractable gondola in the forward fuselage that had a full set of flying controls during flying crane operations. As the twin rotors no longer overlapped, some degree of noise reduction was also achieved. The Model 347's performance was greater than that of the standard Chinook, but flight testing ended in 1975 with the cancellation of the HLH program.

The BV-347 is currently on outdoor static display at the US Army Aviation Museum with sixty other aircraft at Fort Rucker, Alabama.
Source: Air International, October 2009. "Fort Rucker- Home of Army Aviation" by Kees van der Mark and Arnaud Boxman, p80.

02 November 2009

One of the unique features of the Mikoyan MiG-23/27 Flogger fighter aircraft is that compressed air for the pneumatic systems is stored inside the main undercarriage legs and axles. The main pneumatic system fed off a 12.1 liter "bottle" inside the right undercarriage leg to operate the cabin pressurization, canopy operation, moving the sliding panels that cover the gaps on the variable-geometry wings, the main wheel brakes, main fuel valve, braking parachute deployment, activating the emergency drive for hydraulic system and closing the air vents in the avionics bays. A smaller 1.75 liter "bottle" inside the right wheel axle supplied compressed air to the radar bay and avionics heat exchanger which used fuel as coolant.

A 12.1 liter "bottle" in the left main undercarriage leg supplied compressed air for emergency lowering of the landing gear, folding of the ventral fin and operation of the brakes. A smaller 1.75 liter "bottle" in the left wheel axle supplemented the emergency systems on the Flogger. The main valve to fill the compressed air circuits in both main landing gears was located in the left main wheel well.

Source: MiG-23/27 Flogger- Soviet Swing Wing Fighter/Strike Aircraft by Yefim Gordon and Keith Dexter. Midland Publishing/Aerofax, 2005, p52.

01 November 2009

The most numerous aircraft in the US Army's fixed-wing aircraft fleet is the Hawker Beechcraft King Air which is used in over 165 aircraft over 13 different version from utility transport (such as the C-12 Huron) to special mission aircraft (like the RC-12 Guardrail). By mid-2009 the utilization of this diverse fleet of King Air variants had already reached approximately 173,000 flight hours.

Approximately 113 C-12s are in use operationally and fly an average of 48.2 hours monthly with an operational readiness rate of 91.1%. The more complex RC-12s fly 38.6 hours monthly and have an average readiness rate of 89.9%. Both fleets of aircraft have an average age just over 20 years old.

The Army's first King Air was delivered on 16 May 1967 in the form of the U-21A Ute that was an unpressurized hybrid of the Beech Queen Air fuselage with the wings and tail of the newer King Air 90 series. The newer C-12A based on the Super King Air 200 was first deployed by the Army in July 1975. The newest Army King Airs are modified C-12C/D/V aircraft for Task Force ODIN (TF ODIN- Observe, Detect, Identify, and Neutralize) created at Fort Hood, Texas in August 2006 to conduct airborne intelligence and surveillance in support of anti-IED efforts in Iraq. The TF ODIN aircraft have an underfuselage Lynx hi-resolution SAR, EO/IR sensor turrets and other communications/sensor equipment to assist in the counter-insurgency efforts.

Source: Air Forces Monthly, November 2009. "US Army King Airs" by Tom Kaminski, p84-89.