Historic California Posts, Camp, Stations and Airfields
Los Angeles Defense Area Site LA-09
(California Air National Guard Radio Relay Site, Mt. Disappointment)

On 26 July 1955, the U.S. Forest Service (USFS) issued a special use permit, No. LA891, to the U.S. Army for 12 acres of land for construction, maintenance, and use as a Nike-Ajax air defense missile battery integrated fire control (IFC) on Mt Disappointment know as LA-09C. A use permit was also issued for the construction, maintenance, and use of a three-mile access road to the site located at Barley Flats.. This site was the location of the launch and administration portions (LA-09L and LA-09A) of the battery

In 1955, the U.S. Army constructed a generator, corridor, ready room, and concrete pads for radar at the upper site. A barracks and mess hall were constructed at the lower site. water, sewer, and fuel storage facilities were also constructed at the control area.

In 1960, the U.S. Army determined that the site was excess to their needs. On 15 January 1963, the special use permits for the 12-acre site and the access road were terminated, and the improvements were transferred to the USFS. In 1961, the USFS issued special use permits to federal, state, and Los Angeles County agencies to construct, operate, and maintain radio
repeater equipment on the site.

On 19 August 1963, the USFS issued a special use permit to the U.S. Air Force to allow the California Air National Guard (CA ANG) to construct, operate, and maintain radio repeater equipment on the site. The responsibility for restoration of the 12 acre site was transferred from the U.S. Army to the CA ANG at the termination of the special use permit for the U.S. Army. In 1963, the CA ANG demolished the buildings on the lower site due to vandalism. The concrete slabs still remain and there are pieces of floor tiles and wall board on the slabs.

The project area is owned by the USFS and is being used by federal, state, Los Angeles County, and the CA ANG for radio repeater equipment. The CA ANG maintains the site and the USFS maintains the access road. The remaining Army site improvements are being used with the exception of the tanks and piping. The USFS requested that the concrete slabs, asphalt paving, and septic tanks be removed. Launch site magazines have been destroyed, the site is currently utilized by the Los Angeles County Sheriffs Department. The administrative buildings remain in good shape. They were used as a probation camp until 1992.
In 2009, the Station Fire (26 August–16 October 2009) destroyed the launch and administrative portions of the site.
The site was garrisoned by the following Regular Army units:
Source: Los Angeles District, US Army Corps of Engineers
Posted 15 February 2015

The Western Electric SAM-A-7/M1/MIM-3 Nike Ajax

The Nike Ajax was the world's first operational surface-to-air guided missile system. Its origins lay in the immediate post-war time, when the U.S. Army realized that guided missiles were the only way to provide air-defense against future fast high-flying bombers. Western Electric became the prime contractor for the XSAM-G-7 Nike missile system and Douglas as the primary subcontractor was responsible for the missile airframe.

The first unguided Nike missiles were fired in 1946, but problems with the original multi-rocket booster (eight solid-fuel rockets wrapped around the missile tail) soon led to delays in the program. In 1948, it was decided to replace this booster pack with a single rocket booster, attached to the back of the missile. The main propulsion of the missile was a Bell liquid-fueled rocket motor, and the flight path was controlled by the four small fins around the nose. In November 1951, the first successful interception of a QB-17 target drone succeeded. The first production Nike (which had been redesignated SAM-A-7 in 1951) flew in 1952, and the first operational Nike site was activated in 1954. By this time, the missile had been designated by the Army as Guided Missile, Anti-Aircraft M1. The name had changed to Nike I, to distinguish it from the Nike-B (later MIM-14 Nike Hercules) and Nike II (later LIM-49 Nike Zeus). On 15 November 1956, the name was finally changed to Nike Ajax.

The Nike Ajax missile used a command guidance system. An acquisition radar called LOPAR (Low-Power Acquisition Radar) picked up potential targets at long range, and the information on hostile targets was then transferred to the Target Tracking Radar (TTR). An adjacent Missile Tracking Radar (MTR) tracked the flight path of the Nike Ajax missile. Using tracking data of the TTR and MTR, a computer calculated the interception trajectory, and sent appropriate course correction commands to the missile. The three high-explosive fragmentation warheads of the missile (in nose, center, and aft section) were detonated by ground command, when the paths of target and missile met.

One of the major disadvantages of the Nike Ajax system was that the guidance system could handle only one target at a time. Additionally, there was originally no data link between different Nike Ajax sites, which could lead to several sites engaging the same target. The latter problem was eventually solved by the introduction of the Martin AN/FSG-1 Missile Master command-and-control system, with automatic data communication and processing. Other problematic features of the Nike Ajax system were the liquid-fuel rocket motor with its highly toxic propellants, and the large size of a complete site with all components, which made Nike Ajax to all intents and purposes a fixed-site air defense system.

By 1958, nearly 200 Nike Ajax sites had been activated in the United States. However, the far more advanced MIM-14 Nike Hercules soon replaced the Nike Ajax, and by late 1963, the last Nike Ajax on U.S. soil had been retired. In 1963, the Nike Ajax had received the new designation MIM-3A. Despite the use of an MIM (Mobile Intercept Missile) designator, the mobility of the Nike Ajax system was more theoretical than actually feasible in a combat situation.

The MIM-3A continued to serve with U.S. overseas and friendly forces for many more years. In total, more than 16,000 missiles were built.

Source: Directory of U.S. Missiles and Rockets, http://www.designation-systems.net/

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Updated 8 February 2016