Republic F-105

Republic F-105 Thunderchief
A fully loaded F-105D Thunderchief over Vietnam
Type:	Fighter bomber
Design country:	United States
Manufacturer:	Republic Aviation Company
First flight:	October 22, 1955
Commissioning:	May 27, 1958
Production time:	1955 to 1965
Number of pieces:	833

The Republic F-105 Thunderchief (also known as the Thud ) was a single-engine fighter aircraft made in the United States that was in service during the Cold War and Vietnam War . It belonged to the so-called Century series (F-100 to F-110).

development

Development of the F-105 began in 1951. The draft was the in-house designation AP 63FBX (AP for A dvanced P roject and FBX F ighter B omber (fighter-bomber), E x perimental). The plane was very big, but the top speed should still be Mach 1.5. The aircraft fuselage was designed for high-speed operations at low altitude . The responsible chief designer of Republic was Alexander Kartweli , who had already developed the P-47 Thunderbolt . In March 1952 the was of Defense of the United States submitted a draft which as driving a jet engine type Allison J71 envisaged. This proposal received a positive assessment.

There were a number of issues during development. One reason for this was that many innovations were introduced with the armament spurt at the beginning of the Cold War. Republic struggled to implement the complex technology used on the F-105. And the unclear attitude of the US Air Force towards the F-105 also led to problems in the development of the machine. Here are some key data from the development:

• April 1952: The US Air Force and Republic signed an initial development contract.
• September 1952: A contract was signed that provided for the delivery of 199 aircraft, with the first aircraft to be operational in 1955. The F-105 should have an internal bomb bay for atomic bombs .
• October 1952: Agreement with Republic for the procurement of tools and equipment to manufacture the F-105.
• March 1953: After the end of the fighting in Korea became apparent, the Air Force was not sure what characteristics a future fighter-bomber should have. The order was therefore reduced to 37 F-105A (fighter-bombers) and nine RF-105A (photo reconnaissance aircraft).
• October 1953: The mock-up of the design was inspected and approved, but the design had become so large and heavy that the new engine required was the Pratt & Whitney J75 , which had a thrust of 71.7 kN without an afterburner and a thrust with an afterburner of 112.1 kN. This made the Thunderchief the largest single-engine, single-seat fighter aircraft ever built. However, the J75 engine was not yet developed as far as necessary, and so the J57 was used as an interim solution for the F-105A and the J75 was intended for the further developed F-105B. As one of the other various effects of the size, a servo control was developed for the nose wheel control , which had to function as usual via the foot pedals.
• December 1953: Due to a delay in performance by Republic, the Air Force temporarily stopped procurement.
• February 1954: 15 machines (YF-105 with J57) should now be procured.
• August 1954: Four of the machines were to get the J75 engine from this order.
• September 1954: Due to delays in development, the procurement program was reduced to three machines.
• February 1955: Now 15 units (two YF-105A, four YF-105B, six F-105B and three YRF-105A) should be procured again.

commitment

Use in Germany

The F-105D was also stationed at the USAFE in West Germany, from May 1961 to 1966 at the 36th TFW in Bitburg and from October 1961 to 1967 at the 49th TFW at Spangdahlem Air Base . When the conversion to the F-4D Phantom II (36th TFW: 1966, 49thTFW: 1967) began, the F-105D and F-105F of the two squadrons were handed over to units in Southeast Asia. The 49th TFW relocated back to the USA.

Use in Vietnam

From 1964 to 1970, the F-105 flew 75% of all USAF attacks on North Vietnam during the Vietnam War . The F-105D were replaced in 1970 by the F-4 Phantom II and the F-111 Aardvark , but the F-105G " Wild Weasel " did not leave Southeast Asia until 1973. A total of 385 F-105s were lost in Vietnam: 312 were from anti-aircraft guns or missiles shot down, 22 from MiGs , 51 crashed in accidents. The F-105 pilots themselves shot down 27.5 North Vietnamese aircraft. The F-105D was used in Vietnam mainly until 1970 by the 355thTFW (Tactical Fighter Wing), 366thTFW and 388thTFW from the bases at Korat and Takhli in Thailand .

Versions

YF-105A

Republic YF-105A

The first YF-105A prototype ( registration number 54-0098 ) took off on October 22, 1955 from Edwards Air Force Base in California on its maiden flight . Republic's test pilot, Russell “Rusty” Roth, accelerated the machine to over Mach 1. On December 16, 1955, the machine was so badly damaged that it was no longer worth repairing.

The first flight of the second YF-105A (54-0099) took place on January 28, 1956.

Overall, the performance of the prototypes fell short of expectations, and the design was fundamentally revised.

F-105B

F-105B

The shape of the fuselage was adapted to the aerodynamic knowledge of the area rule . The air inlets received a new shape - this led to the characteristic air inlets of the Thunderchief. In addition, the vertical stabilizer was enlarged. This resulted in the F-105B.

The first B-Version machine (YF-105B-1-RE - 54-0100) took off on its maiden flight on May 26, 1956. 75 B-version machines were built in Farmingdale between May 1956 and December 1959. The F-105B cost approximately US $ 5.65 million.

In May 1958, the USAF's first task force received the F-105B. However, this unit was commissioned to test the F-105, which then dragged on for a very long time; only at the end of 1960 was the type declared ready for use. The problems lay in the susceptibility of various systems to failure and the inadequate supply of spare parts. The susceptibility to failure meant that up to 150 maintenance hours had to be spent on one flight hour. This may have been one reason why the B-Version was taken out of active service in the Air Force in early 1964. After that she was only in the Air Force Reserve and the Air National Guard until May 1981 in service. Only the D version was suitable for all weather conditions, which was an important step in the development of the F-105.

F-105C

The Republic F-105C was designed as a two-seat training version of the F-105B. The airframe should have received the same armament and equipment as the B version. A second seat behind the original pilot seat was to be installed instead of the 1264 liter tank, which would have limited the range of the aircraft. The instructor and his student should find space under a one-piece cockpit hood made of plexiglass . A mock-up was made in 1956, followed by an order for five aircraft in June 1956, which was canceled in October 1956 due to the increasing costs of the project.

F-105D

F-105F and F-105D of the 465th TFS, Tinker Air Force Base , 1978

F-105G of the 561st TFS, 388th TFW, 1972

The F-105D had its maiden flight on June 9, 1959. This version featured greatly improved electronics. The first task force, the 335th TFS of the 4th TFW, received it in June 1960. 610 of the F-105D were built.

F-105F / G

The two-seat version of the F-105D was designated as the F-105F, of which 143 were built. During the Vietnam War, 61 F-105Fs were converted into F-105G “Wild Weasel” machines (to combat enemy radar positions) and remained in service until 1973.

After the Vietnam War, the remaining F-105G were concentrated at George AFB in California. The last machines were taken out of service with the Air National Guard in May 1983.

production

Acceptance of the F-105 by the USAF:

version	1955	1956	1957	1958	1959	1960	1961	1962	1963	1964	1965	TOTAL
YF-105A	1	4th										5
F-105B		2	2	11	60							75
JF-105B			1	2								3
F-105D					1	76	183	169	180	1		610
F-105F									14th	128	1	143
TOTAL	1	6th	3	13	61	76	183	169	194	129	1	836

Between July 1, 1969 and June 30, 1972, 61 F-105F were converted into F-105G.

Incidents

From the first flight in 1955 to the end of operations in 1984, the Republic F-105 suffered 616 total losses of aircraft; 320 of them were shot down in combat. With 833 units built, this is by far the highest loss rate for a military aircraft after the Second World War .

In Germany, between 1961 and 1967, when the F-105 was withdrawn, 18 total aircraft losses occurred. In 4 of them, 5 crew members were killed. Examples:

• On 10 December 1964, came up with an F-105D (Code 61-0141 ) when pulling out of the low-level flight at a stall . The machine crashed near Würzburg ; the pilot was killed.

• On July 14, 1966, an F-105F (registration number 63-8310 ), launched from the Spangdahlem Air Base in Rhineland-Palatinate , crashed near the Baden-Württemberg town of Fichtenberg (about 14 kilometers south-southwest of Schwäbisch Hall ). Both inmates were killed.

Technical specifications

cockpit

Parameter	F-105B data	F-105D data
Type	Fighter bomber
crew	1 pilot
length	19.23 m	19.63 m
span	10.65 m
Wing area	35.80 m²
Wing extension	3.17
height	5.99 m
Empty mass	12,474 kg	12,980 kg
Max. Takeoff mass	18,144 kg	23,834 kg
Top speed	Do 1.9 or 2,018 km / h	Do 2.08 or 2,208 km / h
Service ceiling	15,850 m
Use radius	1,252 km
Transfer range	3,550 km
Armament	Gun load up to 6,351 kg
Engine	a Pratt & Whitney J75-PW jet engine	a Pratt & Whitney J75-PW-19W jet engine
Thrust	up to 104.57 kN (with afterburner)	up to 109.02 kN (with afterburner)

literature

• Jack Broughton: Thud Ridge. St. Paul, Minnesota: MBI Publishing Company, 2006. ISBN 978-0-85979-116-8 .
• Republic F-105 Thunderchief Pilot's Flight Operating Instructions. Los Angeles: Persiscope Films LLC, originally published by the United States Air Force, 2008 (reprint). ISBN 1-935327-36-4 .
• R. Frank Futrell et al. Aces and Aerial Victories: The United States Air Force in Southeast Asia, 1965–1973 . Washington, DC: Office of Air Force History and the Albert F. Simpson Historical Research Center, 1976. ISBN 0-89875-884-X .

Web links

Commons : Republic F-105  - Album with pictures, videos and audio files

Individual evidence

1. ↑ Power Steering on Jet Plane Aids Pilot on Ground , Popular Mechanics, Volume 111, Number 3, March 1959, p. 249
2. ^ Accident report Republic F-105 54-0098 , Aviation Safety Network WikiBase , accessed on July 27, 2019.
3. ↑ Statistical Digest of the USAF 1955, p. 80; 1956, p. 91; 1957, p. 97; 1958, p. 72; 1959, p. 68; 1960, p. 62; 1961, p. 70; 1962, p. 72; 1963, p. 71; 1964, p. 58; 1965, p. 60
4. ↑ Statistical Digest of the USAF 1969–1972, table "US Aircraft Gains and Losses"
5. ^ List of accidents involving Republic F-105 , Aviation Safety Network WikiBase , accessed on July 27, 2019.
6. ↑ List of accidents in Germany with Republic F-105 , Aviation Safety Network WikiBase , accessed on July 27, 2019.
7. ^ Accident report Republic F-105D 61-0141 , Aviation Safety Network WikiBase , accessed on July 27, 2019.
8. ↑ http://www.swp.de/gaildorf/lokales/gaildorf/14.-juli-1966_-zwei-tote-bei-absturz-eines-duesenjaegers-13329835.html July 14, 1966: Two dead in a jet fighter crash
9. ^ Accident report Republic F-105F 63-8310 , Aviation Safety Network WikiBase , accessed on May 13, 2017.