Photo Reconnaissance and Analysis Over The Ho Chi Minh Trail During the Vietnam War.

Photo Reconnaissance and Analysis Over The Ho Chi Minh Trail During the Vietnam War.

Above: Reconnaissance photo of the result of intensive bombing at a choke point on the Ho Chi Minh Trail in Laos. (USAF)

Peter Alan Lloyd talked to Les Halfhill.

“I arrived in Thailand in July 1970 and was assigned to the 11th Tactical Reconnaissance Squadron (TRS), Udorn RTAFB, just south of the city of Udorn Thani. I had been trained in the field of Aerial Reconnaissance Photo-Processing in Denver, Colorado, and at Udorn I began working in the 11th TRS Photo Processing and Interpretation Facility (PPIF) as a film processor.

The 11th TRS PPIF, and its sister squadron, the 14th TRS PPIF, were located side-by-side on a concrete pad on the west side of the air base.

Udorn Air Base 1969-1970 (Jim Burns)

Udorn Air Base 1969-1970 (© Jim Burns)

The PPIF was a mobile grouping of aluminum modules with detachable wheels that were interconnected, and which could be quickly dismantled and air-lifted or towed to another location.

Entrance to the 11th TRS PPIF at Udorn Air Base.

Entrance to the 11th TRS PPIF at Udorn Air Base. (David Ramsey, Flikr)

 Their function was to process and interpret the photographic film taken by the reconnaissance aircraft based at Udorn.

An F-4 Phantom II at Udorn Air Base in 1973.

An F-4 Phantom II at Udorn Air Base in 1973. (USAF)

In the five-year period I spent at Udorn (1970-1975), the primary reconnaissance aircraft was the McDonnel Douglas RF-4C Phantom II.  It carried several cameras, some that were static and pointing in various fixed directions, and one that moved on an axis from left-to-right and back, taking panoramic images from horizon to horizon.

Example of aerial photographic coverage.

Example of aerial photographic coverage (

When aircraft returned from a mission, they were met by a van with two or three airmen who would remove the film from the cameras on board. The film was then delivered to the PPIF.

My job was to process the film in a Kodak Versamat processor, which could run two rolls of 5in-x-500ft film (or one roll of 9.5in-x-500ft film).

Kodak Versamat film processor in a PPIF.

Kodak Versamat film processor in a PPIF (David Ramsey, Flikr).

After the film was processed, it was a negative image. It was then taken to another module to have a positive-image copy made. This involved running the negative film and a blank roll of positive film through a machine that shined a light through the negative film onto the positive film. This new positive-image roll of film was then processed in the Versamat just as the negative film had been.


 The positive film was now ready for “interpretation”, which is the process of examining the images to search for predetermined targets, and also any obvious “targets of opportunity” (unexpected targets of interest). This was done on “light tables”, which had illumination and special optics that allowed for the detailed examination of the film.

A more modern image of a Photo-Interpretation Light-Table, identical to the one Les used during the Vietnam War.

A more modern image of a Photo-Interpretation Light-Table, very similar to the one Les used during the Vietnam War. (US Navy)

After the film had undergone interpretation, a report of findings was generated and sent to higher command authorities for their action. This was for time-sensitive target response.

A reconnaissance photo of trucks on the Ho Chi minh Trail in Laos detouring around a bombed bridge.

A reconnaissance photo of trucks on the Ho Chi minh Trail in Laos detouring around a bombed bridge.

After six months with the 11th TRS, it was shipped out and most personnel went with it. However, I stayed at Udorn and was assigned to the 14th TRS. In July 1972,

I came back to the U.S., returned to Udorn in October 1973 and I was then assigned to the 432nd Reconnaissance Technical Squadron.

In that position I created/transcribed and electronically transmitted two different types of reports; the IPIR (Initial Photo Intelligence Report), and the SUPIR (Supplemental Photo Intelligence Report). This squadron did not do any film processing on its own, but only did photo-interpretation. The film from the 14th TRS would be sent to us after their initial review, and we would then examine it in greater detail.

Burned out vehicles on the Ho Chi Minh Trail in Laos, following an air strike (Corbis)

Burned out vehicles on the Ho Chi Minh Trail in Laos, following an air strike (Corbis)

Using the same light-tables as the 14th TRS personnel, we would look for potential targets that were not part of the initially-tasked group. For instance, in following a road through the jungle I discovered a truck convoy on the Ho Chi Minh trail that consisted of 20+ Soviet ZIL-131 trucks carrying supplies from North Vietnam through Cambodia to South Vietnam.

On others, we might notice increased activity at a formerly defunct fuel storage depot. All these findings would be reported for consideration for future targeting.

Vehicles and fuel drums at a fuelling station on the Ho Chi minh Trail in Laos.

Vehicles and fuel drums at a fuelling station on the Ho Chi Minh Trail in Laos.

We would also look at film from other sources. These included drones flown in a program called “Buffalo Hunter”. This film was only 70mm wide, but the image quality was superb since the drones, not having a pilot, could fly at much lower altitudes than the Phantoms without risking lives.

The drones were launched (and controlled, if required) from C-130 aircraft, and flew a pre-programmed course to find requested targets.

A Lightning Bug drone over Vietnam.

A Lightning Bug drone over Vietnam.

Occasionally we would also receive film from SR-71’s, which flew out of Kadena AB, Okinawa. These images covered areas in North Vietnam, South Vietnam, Laos, Cambodia and south-eastern China.

Three months before I arrived at Udorn, in 1970, an RF-4C crashed during landed. There were nine U.S. military personnel killed and 30 other people injured at the Armed Forces Thailand Network radio station and vicinity when the aircraft crashed, the pilot and copilot having bailed out.

The fire from the burning RF-4C Phantom which crashed at Udorn. (Tommy Spahr,

The fire from the burning RF-4C Phantom which crashed at Udorn. (Tommy Spahr,

I left Udorn in May 1975, just after the fall of Saigon. That event marked the end of the use of tactical reconnaissance in South East Asia. All further aerial reconnaissance would be conducted by U-2, SR-71 and satellite craft.”

Les Halfhill.

Our new film, M.I.A. A Greater Evil. Set in the jungles of Laos and Vietnam, the film deals with the possible fate of US servicemen left behind after the US pulled out of the Vietnam War.

MIA button

See the trailer for our new film, M.I.A. A Greater Evil. 

For POWs left behind in Laos, see:

© Peter Alan Lloyd

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Front cover of BACK Part 2.

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  1. Gene Rivers

    I was stationed with the 11th TRS (The Yellow Submarine) ffrom 68 to 69. We flew sorties both day and night. I finished up my 20 + years at Kadena AB, Okinawa.

  2. John Sroufe

    I was a “23450” stationed at Udorn, working at the 11th TRS Black and White lab July 20, 1969-July 20, 1970.

  3. Ivan Taylor

    I was one of the last photo troops to close the 432nd operations. I shipped the equipment out in 1975 only to discover some of it in a warehouse on Kadena AFB in 1981.

  4. albert gangolf

    Welcome home to all my brothers and sisters. I was assigned the 14th TRS PPIF from Oct 70 to Feb 71 and then got orders to the 12thRITS at TonSonNhut AFB,RVN Feb71 to Oct71. I worked in distribution,Versamats , and the still lab.Obert,Mohr,Toliver,Farthing,Nunn,Newman and Major George were some of the guys I worked with and stay in touch with today. I Read The Raid its about theSonTay POW raid which launched from Udorn 20 Nov 71 and how the 14th did much recon in prep for the raid. On a helpful note if someone needs a letter substansiateing exposure to agent orange please contact me by email .. We must stand together !! GOD BLESS YOU ALL. !!

  5. Patrick Morgan

    Thanks for the great photos. I did photo interpretation with the 432nd at Udorn in 72/73 leaving in October of 1973. Also with SAC on Guam during the bombing of North Vietnam. Your site brings back a lot of memories.

    • Ernie Mills

      I was there as a PI also the exact time. I left in November 73. We had to have worked in the same room. I worked on the “Bug” recon for the CIA (Air America). Remember a guy named John Behuniak? I’m sorry I don’t remember you Pat. You have any problems from Agent Orange?

  6. Roy Ellam

    I was stationed at Udorn 71-73, with the 14th TRS/PPIF. I took care of the generators out back, and had an office at the left rear of the compound. I was the guy on the AGE tractor during the Photo van replacement project. I pulled the old vans over to the flight line and onto a C5A, for return for overhaul. and pulled the replacement vans to the compound to be installed for operation. I was also involved in painting the tops of the vans white, so that they would reflect the heat of the sun instead of absorbing it. I left Thailand as an

  7. Ivan Taylor

    I was a 23350 photo processor assigned to the 601st and was transferred to the 432nd RTS 1974-1975. I worked in the Select Print Section. I worked to support the evacuations of Laos, Cambodia and Saigon. I also provided prints for the Mayaguez operation. Later in my career, I would cross train into the 206 photo interpreter career field. I obtained my Commission and became an 8045. I ran the Photo School in Denver and taught an officers photo class.

  8. Phil Wujek

    I was at TSN ’69 to’70 with the 12th TRS. I was “Select Photo” and did a lot of titling on mission film, more than actual select print work. I am about to continue my blog regarding the PPIF’s, sometimes referred to as “Tippies,” and reviewed this article as a memory jogger. Many thanks!

  9. Tom Campbell

    I was at Utapao in 69 as a 204×0 Air Intel and in Udorn 71-72 as 206xo photo interpreter. Great memories here thanks for documenting them.


    I was a 70250 with the 14th TRS assigned to the PPIF in Nov 67 to Nov68. I received the information from the interpreters and typed the messages to be sent to the 7th for possible strikes.

  11. O. P. Ditch

    Greeting fellow PIs. I was at the 13th RTS Aug 65 to Sep 66. I ran the out country PI shop and towards the end I was the photo briefer for the 7th Air Force. I’m trying to find the photos we used to help 7th AF put the smackdown on some trucks in a big truck park in North Vietnam while I was there. RF4s and RB66s flew some Night Photo (cartridges) and Infrared one night and caught a convoy pulling into a truck park just north of the ferry crossing. We walked the info and photos over to 7th AF HQ and they struck it at first light. Big time hit on those NVA dudes. Also, I sure would like to get my hands on the BumpyAction photo I used to identify an SA-2 missile on a camouflaged transporter near the DMZ during one of the TET stand downs.

    • Peter Alan Lloyd

      Very interesting comment. Was the SA-2 you identified in North Vietnam or Laos? I’m guessing North Vietnam in ’65 – ’66 but wanted to check.

      • Opditch

        In NOrth Vietnam in or near the DMZ.

        • Peter Alan Lloyd

          Thanks. I asked because I have just been reading an incredible account of the PAVN’s deployment of SA-2s in Laos along the Ho Chi Minh trail, to counter the threat of AC-130s decimating southbound truck convoys.

    • Thomas Lyons, Sgt USAF

      I was with the 13th RTS at Ton Son Nhute when some of our people flew to Udorn to set up modular photo labs (1966). The 13th moved some of its people to Udorn and the rest of us were loaned to the 6470th RTS. Yours is the first mention of the 13th. What happened to it?

  12. John Behuniak

    Hello. Just happened on this site. Really enjoyed your pics. I was a PI in the 432RTS from Jan. – Dec. ’73. I remember working with S/Sgt. Taylor and Ernie Mills (still stay in touch w/Ernie). Worked mainly with Cambodia/Laos missions. Some drone (Bug) missions over Vietnam too. I agree the drone missions were great quality images. One in particular showed a fully operational N. Viet. artillery site (after the “truce” was signed). Great memories, and think of my time at Udorn often and all the guys I served with.


  13. Donald Jones (Duck)

    I was stationed at Udorn from 1969 till 1970. I ran the color versamat in the YELLOW SUBMARINE section, 23450. In fact that was my baby, pushed a lot of film through that machine. We worked until the mission was done. 12hr. shifts which we always worked longer. Sorry I forgot to tell you I was in the 11th. TRS, Lived in the last hooch along the along the Security fence line, use to be the 11th. day room area, until they needed the room. And to answer someone earlier post about Agent Orange. I developed prostrate cancer and YES THE VA IS GIVING ME THE RUN AROUND NOW. so much for them honoring their word. I’m so glad I found this page, brought back many memory. I left Udorn about a month before the plane crash.

    • John Behunaik

      I was a PI at the 432 RTS in ’73. Our squadron area was on the perimeter pretty much at the end of the road on the working side of the base. Lived in the big pole barn barracks (also on the perimeter). I too developed prostate cancer. Found the VA letter admitting AO use at the Thailand bases. Filed a claim with proofs of Thailand service, photos showing unit location, etc. First claim rejected. Filed my disagreement. Long story short, many, many months later later was notified claim was approved for compensation. Persistence is key. Buddy letters help if you haven’t done that. Good Luck!


    I was with the 12th TRS of he 460th Wing at Tan Son Nhut. PPIF as a Still Photo Specialist. Spent most of my time titling film from the Phantoms.’69 to ’70. Anyone same time?

  15. Peter Alan Lloyd

    This is a bit of a long-shot but would anyone know where to find BDA videos and photos from the Spectre AC-130 missions over Laos and the Ho Chi Minh Trail nowadays?

    • Les Halfhill

      Hi, Peter. This is Les. I really couldn’t think of ANY PLACE that would have systematically maintained such media. There might be traces within the Library of Congress in D.C. You could always call or write with an inquiry. Good luck!

      Les Halfhill

    • O. P. Ditch

      You also might try the Air University Library at Maxwell AFB. I worked on a photo book that was spearheaded by Gen H.P. Smith in the 70s that documented some of the results of the US air raids along the Ho Chi Minh Trail. I’m pretty sure it covered North Vietnam and Laos. I have a letter I kept from Gen HP Smith that thanked me for our work and that he said he donated a copy to the Air University before he retired. There were lots of photos in the book. I can’t seem to find the letter right now to give you the exact name of the book. I will keep trying to find it.

  16. Brian Matthews

    I was assigned to the 14th TRS/PPiF in 73 /74. I worked the back up power for the PPiF which was easy since it was MB teen EMUs generators on an automatic transfer panel. But I also worked on the Aircraft Arresting Systems on the runways. I got there during the time that little Playboy bunny heads began popping up all over the base. I remember the daily bus to work going from the 3 story barracks (yep I was on the 3rd floor) from one end of the runway clear around past the ready birds and Air America up the other side past the power plant to work.


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