Tag Archives: Takhli RTAFB

26 March 1967

Republic F-105D-6-RE Thunderchief 59-1772, parked in a revetment. Colonel Scott flew this airplane 26 March 1967 when he shot down a MiG-17. (U.S. Air Force)
Republic F-105D-6-RE Thunderchief 59-1772, parked in a revetment. Colonel Scott flew this airplane 26 March 1967 when he shot down a MiG 17. (U.S. Air Force)

26 March 1967: Colonel Robert Ray Scott, United States Air Force, commanding the 355th Tactical Fighter Wing, was leading 20 Republic F-105 Thunderchief fighter bombers from Takhli Royal Thai Air Force Base, Thailand, on an attack against an enemy military barracks near Hanoi, North Vietnam. Colonel Scott’s airplane was Republic F-105D-6-RE, serial number 59-1772, and his call sign was “Leech 01.” As he came off the target, he shot down an enemy Mikoyan-Gurevich MiG 17 fighter with the 20 mm M61A1 Vulcan cannon of his fighter bomber.

Colonel Robert R. Scott, U.S. Air Force
Colonel Robert R. Scott, U.S. Air Force

The third MiG-17 destroyed during the month was credited to the 355th TFW, Colonel Scott, who was leading an F-105 flight on a strike mission not far from Hoa Lac airfield on 26 March. His account follows:

“I had acquired the target and executed a dive-bomb run, while heading approximately 250°, altitude approximately 4,000 feet, I observed a MiG taking off from Hoa Loc airfield. I began a left turn to approximately 150° to follow the MiG for possible engagement. At this time I observed three more MiG-17s orbiting the airfield at approximately 3,000 feet, in single ship trail with 3,000 to 5,000 feet spacing. MiGs were silver with red star. I then concentrated my attention on the nearest MiG-17 and pressed the attack. As I closed in on the MiG it began turning to the right. I followed the MiG, turning inside, and began firing. I observed ordnance impacting on the left wing and pieces of material tearing off. At this time the MiG began a hard left-descending turn. I began to overshoot and pulled off high and to the right. The last time I saw the MiG it was extremely low, approximately 500 feet, and rolling nose down.”

Aces and Aerial Victories: The United States Air Force in Southeast Asia 1965–1973, by R. Frank Futrell, William H. Greenhalgh, Carl Grubb, Gerard E. Hasselwander, Robert F. Jakob and Charles A. Ravenstein, Office of Air Force History, Headquarters USAF, 1976, Chapter II at Page 45.

This former Egyptian Air Force Mikoyan-Gurevivch MiG-17F in the collection of the National Museum of the United States Air Force is painted in the colors of the Vietnam Peoples' Air Force. (U.S. Air Force)
This former Egyptian Air Force Mikoyan-Gurevivch MiG 17F in the collection of the National Museum of the United States Air Force is painted in the colors of the Vietnam Peoples’ Air Force. (U.S. Air Force)

The pilot of the MiG 17, Second Lieutenant Vũ Huy Lượng, 923rd Fighter Regiment, Vietnam Peoples’ Air Force, was killed.

As a Northrop P-61 Black Widow pilot with the 426th Night Fighter Squadron during World War II, Colonel Scott had shot down two enemy airplanes. By destroying the MiG-17, he became only the second U.S. Air Force pilot, after Colonel Robin Olds, to achieve aerial victories during World War II and the Vietnam War.

Mikoyan Gurevich MiG-17F in Vietnam Peoples' Air Force markings at the National Museum of the United States Air Force, Wright-Patterson Air Force Base, Ohio. (U.S. Air Force).
Mikoyan-Gurevich MiG 17F in Vietnam Peoples’ Air Force markings at NMUSAF, Wright-Patterson AFB. (U.S. Air Force).

Robert Ray Scott was born at Des Moines, Iowa, 1 November 1920. He was the first of two children of Ray Scott, a railroad worker, and Elva M. Scott. He graduated from North High School in Des Moines, January 1939. He studied aeronautical engineering at the University of Iowa for two years before he enlisted as an Aviation Cadet in the U.S. Army Air Corps, 15 August 1941. Scott was 5 feet, 7 inches (1.70 meters) tall and weighed 144 pounds (65.3 kilograms). He was trained as a pilot and and was commissioned as a Second Lieutenant, 16 March 1942. He was assigned as an instructor pilot in California, and was promoted to 1st Lieutenant 15 December 1942.

Scott was transferred to the 426th Night Fighter Squadron, 14th Air Force, flying the Northrop P-61 Black Widow in India and China. He was promoted to captain, 3 May 1944, and to major, 16 August 1945. Major Scott was credited with shooting down two enemy aircraft. He was awarded the Distinguished Flying Cross and the Air Medal.

Captain Robert Ray Scott (back row, second from left) with the 426th Night Fighter Squadron, 1944. The airplane is a Northrop P-61 Black Widow. (U.S. Air Force)

Following World War II, Major Scott returned to the University of Iowa to complete his bachelor’s degree. He also earned two master’s degrees.

In 1952 he graduated from the Air Force test pilot school at Edwards Air Force Base, then served as a project pilot on the North American F-86D all-weather interceptor. Later he was a project officer at Edwards AFB on the Republic F-105 Thunderchief Mach 2 fighter-bomber.

Scott flew the North American Aviation F-86F Sabre during the Korean War. From January to July 1953, he flew 117 combat missions. From 1953 to 1956, Lieutenant Colonel Scott commanded the 405th Fighter Bomber Wing, Tactical Air Command, at Langley Air Force base, Virginia.

Lieutenant Richard Hill and Lieutenant Colonel Robert R. Scott (in cockpit) after their record-breaking transcontinental flight. (Unattributed)

On 9 October 1955, Scott set a transcontinental speed record by flying a Republic F-84F Thunderstreak fighter bomber from Los Angeles International Airport, California, to Floyd Bennett Field, New York, in 3 hours, 46 minutes, 33.6 seconds. Later he was a project officer at Edwards AFB on the Republic F-105 Thunderchief Mach 2 fighter-bomber.

Scott was promoted the rank of Colonel in 1960.

During the Vietnam War, Colonel Scott commanded the 355th Tactical Fighter Wing, flying 134 combat missions in the Republic F-105 Thunderchief.

Colonel Scott’s final commanding was the 832nd Air Division, 12th Air Force, at Cannon Air Force Base, New Mexico. He retired 1 September 1970 after 29 years of military service.

Colonel Robert Ray Scott flew 305 combat missions in three wars. During his Air Force career, Colonel Scott was awarded four Silver Star medals, three Legion of Merit medals, six Distinguished Flying Crosses and 16 Air Medals. He died at Tehachapi, California, 3 October 2006 at the age of 86 years. He is buried at the Arlington National Cemetery.

Republic F-105D 59-1772 is credited with another air-to-air victory. Just over a month after Colonel Scott’s Mig-17 shoot-down, on 28 April 1967 Major Harry E. Higgins, 357th Tactical Fighter Squadron, shot down another MiG-17 with the fighter bomber’s cannon, for which Major Higgins was awarded the Silver Star.

The Thunderchief, though, met its own end when it was shot down by 37 mm anti-aircraft gunfire 10 miles (16 kilometers) west of Ko Hinh, Laos, 27 January 1970. The pilot was rescued.

Colonel Robert R. Scott, commander, 355th Tactical Fighter Wing, checks the bombs loaded on a multiple ejector rack while preflighting his Republic F-105 Thunderchief. (U.S. Air Force)
Colonel Robert R. Scott, commander, 355th Tactical Fighter Wing, checks the bombs loaded on a multiple ejector rack while preflighting his Republic F-105 Thunderchief. (U.S. Air Force)

The F-105 was the largest single-seat, single-engine combat aircraft in history. It was designed as a Mach 2+ tactical nuclear strike aircraft and fighter-bomber. Republic Aviation Corporation built 833 F-105 Thunderchief fighter bombers at its Farmingdale, New York factory. 610 of those were single-seat F-105Ds.

The F-105D Thunderchief is 64 feet, 5.3 inches (19.642 meters) long with a wingspan of 34 feet, 11.2 inches (10.648 meters) and overall height of 19 feet, 8.4 inches (6.005 meters). The total wing area was 385 square feet (35.8 square meters). Its wings were swept 45° at 25% chord. The angle of incidence was 0° and there was no twist. The wings had 3° 30′ anhedral. The F-105D-31 has an empty weight of 26,855 pounds (12,181 kilograms) and a maximum takeoff weight of 52,838 pounds (23,967 kilograms).

This Republic F-105D-10-RE Thunderchief, 60-0504, served with the 355th TFW at Takhli AB, Thailand. It shot down two enemy fighters. Similar the the F-105D flown by Colonel Scott, 26 March 1967, it is in the collection of the National Museum of the United States Air Force, Wright-Patterson AFB, Ohio. (U.S. Air Force)

The Thunderchief was powered by one Pratt & Whitney J75-P-19W engine. The J75 is a two-spool axial-flow afterburning turbojet with water injection. It has a 15-stage compressor section (8 low- and and 7 high-pressure stages) and 3-stage turbine section (1 high- and 2 low-pressure stages.) The J75-P-19W is rated at 14,300 pounds of thrust (63.61 kilonewtons), continuous power; 16,100 pounds (71.62 kilonewtons), Military Power (30-minute limit); and Maximum Power rating of 24,500 pounds (108.98 kilonewtons) with afterburner (15-minute limit). The engine could produce 26,500 pounds of thrust (117.88 kilonewtons) with water injection, for takeoff. The J75-P-19W is 21 feet, 7.3 inches (6.586 meters) long, 3 feet, 7.0 inches (1.092 meters) in diameter, and weighs 5,960 pounds (2,703 kilograms).

Republic F-105D Thunderchief 60-0504 at the National Museum of the United States Air Force. (U.S. Air Force)

The maximum speed of the F-105D was 726 knots (835 miles per hour/1,345 kilometers per hour) at Sea Level (Mach 1.09) and 1,192 knots (1,372 miles per hour (2,208 kilometers per hour) at 36,089 feet (11,000 meters) (Mach 2.08). The combat ceiling was 51,000 feet (15,545 meters). The F-105D’s combat radius varied with the type of mission from 277 to 776 nautical miles (319–893 statute miles/513–1,437 kilometers). The maximum ferry range was 1,917 nautical miles (2,206 statute miles/3,550 kilometers).

The F-105D was armed with one 20 mm M61A1 Vulcan rotary cannon and 1,028 rounds of ammunition. It has an internal bomb bay and can carry bombs, missiles or fuel tanks on under wing and centerline hardpoints. The maximum bomb load consisted of 16 750-pound (340 kilogram) bombs. For tactical nuclear strikes, the F-105D could carry one B57 or three B61 nuclear bombs.

Two Air Force sergeants load belts of linked 20-millimeter cannon shells for the F-105’s M61 six-barreled Gatling gun. (U.S. Air Force)

The F-105 Thunderchief was a supersonic tactical fighter bomber rather than an air superiority fighter. Still, during the Vietnam War, F-105s shot down 27 enemy MiG fighters. 24 of those were shot down with the Thunderchief’s Vulcan cannon.

Of the 833 F-105s, 395 were lost during the Vietnam War. 334 were shot down, mostly by antiaircraft guns or missiles, and 17 by enemy fighters. Another 61 were lost due to accidents. The 40% combat loss is indicative of the extreme danger of the missions these airplanes were engaged in.

Republic F-105D Thunderchief at Takhli TRAFB. (U.S. Air Force)

© 2021, Bryan R. Swopes

25 March 1968

General Dynamics F-111As of 428th Tactical Fighter Squadron, 1968. (U.S. Air Force)

25 March 1968: A U.S. Air Force General Dynamics F-111A, 66-0018, flown by Colonel Ivan H. (“Ike”) Dethman and Captain Richard M. Matteis, completed the type’s first combat mission when it attacked a munitions dump on Tiger Island (Cồn Cỏ), off the coast of North Vietnam. The precision strike mission was flown at night with heavily overcast skies. The fighter bomber carried twelve 750 pound (340 kilogram) M117 bombs on hard points under its wings, and approached the target from the west at 500 knots (575 miles per hour/926 kilometers per hour) at just 500 feet (152 meters) above the ground.

Colonel Dethman later told news reporters that, “the computers clicked over, crosshairs on target, bombs away.” The weather prevented a post-strike damage assessment, but the mission was considered successful.

Three additional single-aircraft combat missions were flown by F-111As that night.

General Dynamics F-111A 66-0018 at Takhli RTAFB, 1968. (U.S. Air Force)

66-0018 was one of six “Combat Lancer” F-111As assigned to Detachment 1, 428th Tactical Fighter Squadron, under the command of Colonel Dethman, which had deployed to Takhli Royal Thai Air Force Base in Thailand from Nellis AFB in the United States just a few days earlier. (Colonel Dethman had previously commanded “Harvest Reaper,” an Air Force project to train pilots to fly the F-111A.)

Two F-111As were lost in the next five days. The aircraft and their crews have never been found. A third went down the following month, but its crew were able to use the escape module and were rescued. Their aircraft had suddenly pitched up and rolled over out of control. It was later determined that a hydraulic actuator valve in the stabilator control system had failed.

General Dynamics F-111A at Takhli RTAFB, 1968. (U.S. Air Force 090810-F-1234O-003)

The General Dynamics F-111A is a large twin-engine strike fighter with variable-sweep wings produced for the U.S. Air Force. A second variant, the F-111B, was intended for the U.S. Navy as an interceptor, but proved to be too heavy to operate from aircraft carriers and was not put into production. The F-111A made its first flight at Carswell AFB, Texas, 21 December 1964.

The F-111 was a result of Secretary of Defense Robert S. McNamara’s controversial “TFX” program which would use a single aircraft for both the Air Force and Navy as a fighter, interceptor, tactical fighter bomber, and strategic nuclear-armed bomber. Trying to make a single aircraft perform these different missions resulted in very high cost overruns, and the aircraft gained a negative perception in the news media. The F-111A and its follow-on, the FB-111, however, proved to be very effective in precision strike missions.

Det. 1, 428th Tactical Fighter Squadron personnel at Takhli RTAFB, 1968. Left-to right: Front row (kneeling): Major Tom Germscheid; Captain Joe Hodges; Colonel Ivan H. (“Ike”) Dethmann; Lieutenant Colonel Dean Salmeier; Lieutenant Colonel Ed Palmgren; Commander Bruce Ashley, USN; Major Roger Nunemaker. Back row (standing): Captain Mac Armstrong; Major Charlie Arnet; Captain Rick Matteis; Captain Joe Keene; Major Les Holland; Major Sandy Marquardt; Major Bill Coltman; Major Hank (“Mac”) MacCann; Captain Bill Sealy; Captain Denny Graham, USN; Lieutenant Commander David “Spade” Cooley, USN; Captain Ken Powell; Captain Norm Rice; and  Major Charlie Tosten. (U.S Air Force)
The crew escape module of General Dynamics F-111A 66-0017, which went down 22 April 1968. Major “Sandy” Marquardt and Captain Joe Hodges are seated inside. (Key.Aero)

The F-111A was flown by two pilots seated side-by-side in the cockpit. Pre-production aircraft were equipped with ejection seats, but production aircraft had a crew escape module which protected the pilots from the effects of supersonic speed. The airplane incorporated a state-of-the art terrain-following radar and and inertial guidance computer system that allowed it to fly at a constant height above the ground. The radar searched ahead and to the sides of the aircraft’s flight path and the computer calculated pitch angles to clear obstacles ahead. The system could be programmed to fly the aircraft as low as 200 feet (61 meters) above the ground. These “nap of the earth” profiles allowed the F-111A to avoid detection by radar.

The cockpit of General Dynamics F-111A 67-0067 at the National Museum of the United States Air Force. (U.S. Air Force 070703-F-1234S-019)

The F-111A is 73 feet, 10.6 inches (22.520 meters) long. With the wings fully extended, their span is 63 feet, 0.0 inches (19.202 meters), and fully swept, 31 feet, 11.4 inches (9.738 meters). The airplane has an overall height of 17 feet 1.4 inches (5.217meters). The wings are capable of being swept from 16° to 72.5°. Roll control is transferred to the stabilators when the wings sweep to 42°.  It has an empty weight of 46,172 pounds (20,943 kilograms) and maximum takeoff weight of 92,657 pounds (42,029 kilograms).

A Pratt & Whitney TF30 turbofan engine at NASA’s Propulsion Systems Laboratory in Cleveland, Ohio, 1967. Left-to-right are engineers Fred Looft and Robert Godman. (NASA Glenn Research Center)

Early production F-111As were powered by two Pratt & Whitney TF30-P-1 afterburning turbofan engines, with following aircraft powered by the TF30-P-3. Both are two-spool axial-flow engines with a 3-stage fan section, 13-stage compressor (6 low- and 7 high-pressure stages) and 4-stage turbine (1 high- and 3 low-pressure stages). Both engines are rated at 10,750 pounds of thrust (47.82 kilonewtons), and 18,500 pounds of thrust (82.29 kilonewtons) with afterburner. Both the -1 and -3 engines are 19 feet, 7.5 inches (5.982 meters) long, 4 feet, 0.0 inches (1.219 meters) in diameter, and weigh 3,869 pounds (1,755 kilograms).

The F-111A had a maximum speed of Mach 1.2 at Sea Level, (913 miles per hour/1,225 kilometers per hour), and Mach 2.2 (1,452 miles per hour/2,336 kilometers per hour) at 60,000 feet (18,288 meters). With 5,015.5 gallons (18,985.7 liters) of internal fuel, its range was 3,165 miles (5,094 kilometers). The aircraft could carry external fuel tanks and was capable of inflight refueling.

A General Dynamics F-111A carrying 16 cluster bombs. (U.S. Air Force 120920-F-DW547-001)

The F-111A was designed to carry either conventional or nuclear weapons. It has an internal bomb bay, one hardpoint under the fuselage, and four hardpoints under each wing. With the wings swept to 72.5°, it could carry 18 M117 bombs, but when extended to 26°, it could carry as many as 50. A General Electric M61 Vulcan 20 mm rotary cannon could be installed in the bomb bay.

The F-111A returned to Vietnam in 1972 and flew more than 4,000 combat sorties during Operations Linebacker and Linebacker II. Attacking heavily defended airfields and surface-to-air missile sites, only six additional F-111As were lost in combat.

159 F-111As were built, including 18 pre-production aircraft. 66-0018 (s/n A1-36) was later converted to an EF-111A Raven electronic warfare aircraft. It was sent to The Boneyard at Davis-Monthan Air Force Base, Tucson, Arizona, 11 June 1998.

General Dynamics EF-111A Raven 66-0018, photographed in October 1984. (Dan Stilovich/AirHistory.net)

Ivan Harry (“Ike”) Dethman was born 19 March 1919 at Mansfield, South Dakota. He was the sixth of eleven children of Henry H. Dethman, a carpenter, and Marie D. Christianson Dethman. He grew up in Seattle, Washington.

Dethman registered for the draft (conscription) 6 November 1940. He was described as being 5 feet, 10½ inches (1.791 meters) tall, 158 pounds (71.7 kilograms) with a ruddy complexion, brown hair and blue eyes.

On 1 March 1942, shortly after the United States entered World War II, Dethman enlisted in the United States Army. He was trained as a pilot and flew 161 combat missions in the Douglas A-26 Invader over Italy, France and Germany.

Ivan H. Dethman, 1948.

Following the War, Dethman returned to the United States where he attended the University of Washington, graduating in 1948. While there, he worked on the staff of Forester’s Quarterly.

He remained in the Air Force. His date of rank as a first lieutenant is 30 August 1946. He was assigned to the 27th Tactical Wing at Carney, Nebraska, and from 1948 to 1950 was an instructor in the Air Training Command. In 1950, he attended the Air Force Institute of Technology at Wright-Patterson Air Force Base in Ohio.

Dethman commanded the 55th Tactical Fighter Squadron, 20th Tactical Fighter Wing, at RAF Weathersfield, England, and then the 474th Tactical Fighter Wing, 1966 to 1967.

Ike Dethman was married to Beverly Jane Smith, later to Anita Eveland, and finally, Marita A. Romson.

During his military career, Colonel Dethman was awarded the Legion of Merit, the Distinguished Flying Cross with one oak leaf cluster (two awards), and the Air Medal with 14 oak leaf clusters (15 awards). He retired from the Air Force 29 December 1972 after thirty years of service.

Colonel Ivan H. Dethman, U.S. Air Force (Retired), died at Escondido, California, 24 March 2004, at the age of 85 years. His remains are interred at the Arlington National Cemetery.

© 2023, Bryan R. Swopes