550th Strategic Missile Squadron

550th Strategic Missile Squadron
Convair SM-65F Atlas #532, Site 02 Abilene KS, 1963
Active	1942-1949; 1961-1965
Country	United States
Branch	United States Air Force
Type	Squadron
Role	Intercontinental ballistic missile
Garrison/HQ	Shilling AFB, Kansas
Engagements	World War II (EAME Theater)
Decorations	Distinguished Unit Citation (2x)
Insignia
550th Strategic Missile Squadron emblem

The 550th Strategic Missile Squadron (550 SMS) is an inactive United States Air Force unit. It was last assigned to the 310th Strategic Aerospace Wing, stationed at Shilling AFB, Kansas

The 550 SMS was equipped with the SM-65F Atlas Intercontinental ballistic missile (ICBM), with a mission of nuclear deterrence. The squadron was inactivated as part of the phaseout of the Atlas ICBM on 25 June 1965.

History

World War II

Activated in late 1942 as a B-17 Flying Fortress heavy bomb squadron, trained under Second Air Force. Deployed to England in the European Theater of Operations (ETO) during June 1943, assigned to VIII Bomber Command as a strategic bombardment squadron. Participated in the air offensive over Nazi Germany and Occupied Europe until German capitulation in May 1945. Personnel demobilized in England and returned to the United States; squadron reassigned to Second Air Force and was programmed to be re-equipped with B-29 Superfortresses for deployment to Pacific Theater. Japanese capitulation led to units inactivation in September 1945, being neither manned or equipped.

Effective 15 September 1947, the squadron was activated at Selfridge Field, Michigan. Having been allotted to the organized reserves, with assignment to Second Air Force, Air Defense Command, it was redesigned as a B-29 very heavy bombardment unit on 25 August. In August 1948, the squadron was assigned to the Tenth Air Force, which in December, became a part of the Continental Air Command. On 1 December 1948 it was again reassigned to Air Defense Command where it remained on reserve service until being inactivated on 27 June 1949 due to budget restrictions.

Intercontinental Ballistic Missile Squadron

Reactivated in 1961 as a Strategic Air Command SM-65F Atlas ICBM launch squadron, stationed at Shilling AFB, Kansas and assigned to the 310th Bombardment (later Strategic Aerospace) Wing on 1 July 1961. The activation of the 550th SMA along with the 551st Strategic Missile Squadron at Lincoln AFB, Nebraska, on April 1, 1961, marked the first standing up of Atlas F units. The squadron was assigned twelve missiles, based in a 1 x 12 configuration: twelve independent widely dispersed launch sites comprised the missile squadron. In June 1962, the first operational sites for the Atlas F ICBMs were accepted by SAC and in September the squadron was declared operational. In the following month during the Cuban missile crisis, the 550th received orders to maintain all 12 missiles on alert status.

The Atlas F was the final and most advanced version of the Atlas ICBM and was stored in a vertical position inside underground concrete and steel silos. When stored, the Atlas F sat atop an elevator. If a missile was placed on alert, it was fueled with RP-1 (kerosene) liquid fuel, which could be stored inside the missile for extended periods. If a decision was made to launch the missile, the missile was raised to the surface and the liquid oxygen tank was filled. The launch would occur shortly after completion of this process. (see below for site details).

The exposure on the surface that this procedure entailed was the great weakness of the Atlas F. It was exposed and vulnerable during this time. The Titan II and Minuteman missiles could be launched from within their silos, thereby eliminating this vulnerability. Also, since the Titan did not use a cryogenic fuel or oxydizer, and the Minuteman was a solid fuel rocket, they could be stored fully fueled and ready to launch within a very few minutes.

On December 1, 1964, the first Atlas F missile at Shilling was removed from alert status in favor of the more advanced LGM-25C Titan II; squadron was inactivated on 25 June 1965. Missile sites were later sold off to private ownership after demilitarization.

Lineage

Emblem of the World War II 550th Bombardment Squadron

• Constituted as 550th Bombardment Squadron (Heavy) on 25 November 1942

Activated on 1 December 1942

Inactivated on 28 August 1945

• Re-designated 550th Bombardment Squadron (Very Heavy) on 25 August 1947

Activated in the reserve on 15 September 1947

Inactivated on 27 June 1949

• Re-designated 550th Strategic Missile Squadron, and activated, on 22 July 1960

Organized on 1 April 1961

Inactivated on 25 June 1965

Assignments

• 385th Bombardment Group, 1 December 1942 – 28 August 1945

ETO Fuselage Code: HG

• Second Air Force, 15 September 1947
• Tenth Air Force, 1 July 1948
• First Air Force, 15 August 1948
• Tenth Air Force, 1 December 1948 – 27 June 1949
• Strategic Air Command, 22 July 1960
• 310th Bombardment (later Strategic Aerospace) Wing, 1 April 1961 – 25 June 1965

Stations

• Davis-Monthan Field, Arizona, 1 December 1942
• El Paso Army Airfield, Texas, 4 January 1943
• Geiger Field, Washington. 1 February 1943
• Great Falls Army Air Base, Montana, 11 March – 7 June 1943

• RAF Great Ashfield (AAF-155), South Dakota, 29 June 1943 – 6 August 1945
• Sioux Falls Army Air Field, 14–28 August 1945
• Selfridge Field, Michigan, 15 September 1947 – 27 June 1949
• Shilling AFB, Kansas, 1 April 1961 – 25 June 1965

Aircraft and missiles

SM-65F Atlas Missile Sites

• B-17 Flying Fortress, 1942–1945
• B-29 Superfortress, 1947-1949.
• SM-65F Atlas Missile, 1961–1965

Operated twelve missile sites of one missile at each site (12 total):

550-1 2.8 mi S of Wells, KS

550-2 3.2 mi W of Abilene, KS

550-3 2.5 mi WNW of Chapman, KS

550-4 5.1 mi W of Elmo, KS

550-5 7.0 mi SSE of Lindsborg, KS

550-6 1.8 mi ENE of Mitchell, KS

550-7 1.5 mi NW of Carneiro, KS

550-8 2.3 mi ENE of Wilson, KS

550-9 4.4 mi NNW of Beverly, KS

550-10 1.5 mi ENE of Tescott, KS

550-11 8.7 mi WSW of Aurora, KS

550-12 3.7 mi NE of Minneapolis, KS

See also

• List of United States Air Force missile squadrons

References

 This article incorporates public domain material from websites or documents of the Air Force Historical Research Agency.