Portland, OR (PDX/L-33)

Contributed by Mark Morgan, TSgt, Washington ANG

505th AC&WG/636th AC&WS/761st AC&WS/136th AC&WS/689th AC&WS

– Excerpts from command histories



27 March 1948 - Fourth Air Force headquarters notified the 505th Aircraft Control & Warning Group (McChord Field) that it would begin immediate 24-hour operations with a view of providing an “air defense radar net” in the Pacific Northwest.  A TWX followed, stating:

   The Arlington detachment will go on immediate 24 hour operation, and immediate action will be taken to locate and operate radar installations near Neah Bay, Spokane, Hanford and Portland which will be integrated into an aircraft control and warning system covering the Seattle-Pasco area.


   Within three days, the S-4 section was supporting the activation of radar detachments at Neah Bay, Spokane, Pasco and Seaside.  Equipment included AN/TPS-1Bs and SCR-399 HF radios.  All stations on the air and operating by 1 April; additional equipment and personnel dispatched to Walla Walla and Portland.[1]


Note: Portland is one of a number of sites – including Colville and Oroville – that is identified as receiving radar equipment and personnel in late March 1948.  There is no further information on or mention of the Portland facility in the 505th AC&WG histories or the 25th AD histories until March 1950.  It is possible the 505th AC&WG briefly operated a radar at Portland through a detachment.

   The Online Air Defense Radar Veterans Museum (www.radomes.org/museum/) states that an AN/TPS-1B was installed in March 1948 and placed in 24-hour-a-day operations as an “interim” site to protected the approaches to Hanford, WA.  The site was incorporated into the Lashup network in August 1950.


7 Dec 49 – 636th AC&WS reactivated at McChord AFB.  The squadron transferred from Twelfth Air Force to Fourth Air Force effective 8 December with its personnel at Kirtland AFB transferring to the 690th AC&WS.[2]


1 Jan 50 – The 636th AC&WS at McChord started the year without a commander, personnel or equipment.[3]


Mar 50 – 636th AC&WS established a detachment at Portland Air Base, designated Det 2.[4]


1 May 50 – Det 2 636th AC&WS formally activated.  AN/CPS-5 placed in the operational area at the end of May but suffered some difficulties due to power fluctuations.[5]


23 Oct 50 – Site identified as a GCI facility located at Portland Airport in building T-1401 with station designator of No. 139.[6] 

7 Feb 51 – Per ADC historical information, the 761st AC&WS activated at Reedsport, OR and was assigned to the 505th AC&WG.  At this point operations at the Portland Lashup site apparently passed to the 761st AC&WS.


11 Aug 51 – Per the history of the 505th AC&WG, Det 1, 761st AC&WS occupied the Lashup installation at Portland.  The group history further states the headquarters of the 761st moved to North Bend on 11 August.[7]


1 Oct 51 – Beaumont’s 136th AC&WS, TXANG, called to active Federal service for the Korean War.[8]


Feb 52 – Site summary lists the calibration date of the site’s original AN/TPS-1B as August 1950; changed to AN/CPS-5 in 1951; and ceased operations in February 1952 with replacement by Permanent site P-12, North Bend, OR.[9]


31 Mar 52 – Portland site (L-33) listed as operational with an AN/CPS-5 under the 136th AC&WS.  No height-finder or IFF equipment at the site, date of Air Force acceptance “unknown.”[10]


30 Jun 52 – The 136th AC&WS currently occupied the site.  According to the 25th Air Division history, the squadron activated at Portland Airport and had a planned move date of October 1953 to Mount Hebo AFS, OR (M-100).[11]


1 Oct 53 – 136th AC&WS returned to state control, 689th AC&WS activated at Portland. 


31 Dec 53 – The 25th AD’s year-end summary identifies Portland (L-33) as the last operational Lashup site in the division, equipped with an AN/CPS-5.  The site tied into the ADDC at McChord AFB (P-1) along with Blaine AFS (P-46), Makah AFS (P-44), Naselle AFS (P-57) and North Bend AFS (P-12).[12]


Jul 56 – The 689th AC&WS moved to its permanent site (M-100) at Mount Hebo AFS, OR.  The move concluded Air Defense Command radar operations at Portland International Airport.[13]


[1] History (S/DECL-downgraded at 3-year intervals, declassified after 12 years.  DOD DIR 5200.10), History of 505th Aircraft Control and Warning Group,28 March thru 30 June 1948, Ch. I, “Activities of Staff Sections – S-4,” pp. 19-20.

[2] History (S/DECL-per DOD DIR 5200.30 by USAFHR, n.d.), 505th Aircraft Control and Warning Group Historical Data December,1949.

[3] History (S/DECL-per DOD DIR 5200.30 by USAFHR, n.d.), 505th ACWGP. Monthly Historical Data, January – 1950.

[4] History (S/DECL-by Dep Sec Def Memo 12 Apr 74, by AFSHRC, dtd 7 Mar 80), 25th Air Division (Defense) Historical Data (Monthly Edition), 1 March 1950-31 March 1950.

[5] History (S/DECL-by Dep Sec Def Memo 12 Apr 74, by AFSHRC, dtd 7 Mar 80), 25th Air Division (Defense) Historical Data, Quarterly Edition, 1 April 1950-30 June 1950.

[6]  Memorandum (S/DECL- AF/IGSPB ltr., 13 Dec 73, by AFSHRC, Dtd 7 Mar 80), “Communications Operations Instructions – Code Designation of Air Defense Facilities, COI 17-4,” HQ 25th Air Division (Defense), Everett, Washington, 23 October 1950.

[7] History (S/DECL- per AF/IGSPB 13 December 1973, by AFSHRC, 14 March 1979)., History – Headquarters, 505th AC&W Group, August 1951.  Reedsport/North Bend redesignated as North Bend AFS on 1 December 1953.

[8] “Air National Guard Korean War Mobilizations 1950-1953 - Air Control & Warning and Aircraft Control Units.”  Compiled by: NGB-PAI-H, 31 May 2000.

[9]  Historical Date of the Aerospace Defense Command (U), 1946-1973 (Ent AFB, CO: Headquarters, Aerospace Defense Command, n.d.), 39.

[10]  Historical Report, 1 January ’52-31 March ’52, 25th Air Defense Division (formerly secret; declassified per AF/IGSPB 13 December 1973, by AFSHRC, 7 March 1980).

[11] Encl 1 to WADF Ltr WDOPR-2 322, Subj: (Uncl) Revision of First Phase Mobile Radar Program, 1 May 1953.  Cited in history (S/DECL-AF/IGSPB ltr, 13 Dec 73, by AFSHRC, Dtd 7 Mar 80), History of the 25th Air Division (Defense), McChord AFB, Washington, 1April – 30 June 1952 (Formerly secret and restricted; declassified

[12] History (S/DECL- AF/IGSPB ltr, 13 Dec 73, by AFSHRC, Dtd 7 Mar 80), History of the 25th Air Division (Defense), McChord AFB, Washington, 1 July – 31 December1953.

[13]  Historical Data, 24.