Japan in Northwest Thailand during World War II

Off Topic: Locating Loiwing airstrip(s), Yunnan, China
Page 3 of 6 : Loiwing Aerodrome

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Text Notes

Loiwing Aerodrome (Suili)

Little was known about the history of this air facility before WWII. It did exist in 1942[35a], when Dudley Wood seemed to define it as a separate air facility in a visit in April 1942. But, in that light, a re‑examination of the record of events during that period verifies its existence and strongly supports its importance, as a separate entity, distinct from Loiwing's Factory strip.

Dan Gourley, advance man with the duty to pick a site for the CAMCO factory, arrived in November 1938, apparently by car from Rangoon, and the factory manager, Mr "Chuck" Hunter, followed by the Burma Road from Kunming.[36] Had Suili existed at that date, in consideration of the importance of the CAMCO operation and the tight schedule for its relocation, both Gourley and Hunter presumably would have continued their flights from Rangoon and Kunming respectively, straight into Suili, rather than having taken the road.

Allied intel provided this late introduction in 1944 to the Suili air facility in its Airfield Report No 21:[37]

Suili appraisal 1

Suili appraisal 2

Partial transcription:


The main concern of this short appreciation is with enemy occupied airfields . . . in enemy occupied Yunnan. . . .

Loiwing (Suili) Airfield: This airfield, which is of Chinese construction in origin, came into Japanese occupation in May 1942 . . . .

. . . Reconnaissance on the 28th October 1942 . . . disclosed a possibility that the Japanese had laid out an extension of the WNW-ESE runway as its [p1→p2] western end though it was notable that a canalized stream which divided this extension from the main runway would require to be bridged before the extension could become effective. This can only be stated as of possible Japanese construction by reason of the Japs [?] to previous photographic cover. The drainage of the runways and land tracks had also been improved and three AA gun emplacements were located at the intersection of the runways. The runways appeared to be built up of local gravel and there was no indication of metalling or tarring of the surface.

By the 1st December 1942 the number of aircraft shelters completed or under construction had increased to forty-nine and some leveling of ground in the diagonal areas had taken place. In February 1943 dispersal facilities had been extended in the area north of the runways and there were fifty-one aircraft shelters only four of which were incomplete. Some surfacing had been done at both ends of the main runway. From this time up to the 21st July 1943 very little further activity was observed at the airfield. Photographs taken on the 18th September showed however, that since the 21st July considerable leveling had taken place and there had been some extension of taxi tracks.

On the 3rd November [1943] the airfield was attacked by the USAAF with excellent results and photographs taken the next day showed at least 50 bomb craters at the runways intersection. Photographs of the 19th November showed that those craters had been filled in and on the 2nd January 1944 both runways appeared to be serviceable. It was reliably reported that the airfield was in operational use during January and February 1944 and it is believed that it was used by both fighter and light bomber aircraft in operations against Allied airfields in Yunnan.

The airfield again received the attention of the USAAF at the beginning of March 1944 and photographs of the 6th March showed nearly 60 bomb craters on the field, at least 50 of which straddled the intersection of the runways rendering both runways unserviceable.

The latest report on the airfield in April, stated that the NE-SW runway appeared to be usable.

With regard to possibilities of development of this airfield the following considerations appear to preclude any large scale construction outside the immediate vicinity of the present landing area.

The airfield lies in the valley of the Shweli River which at this point runs approximately NE-SW and is enclosed by high hills on either side which make flying approach difficult except from the south and east. Numerous tributarial streams flow near the landing area to join the Shweli River to the south and in this connection it is worthy of note that the extension to the main runway first seen in October 9142, has not to date been made effective by bridging of the canalized stream which separates it from the rest of the runway.

In general, the text indicates that early on, the Japanese had made some improvements to the facility; the Allies saw the facility's potential and had targeted it more than once, with the Japanese responding with timely repairs. Particularly useful in the text above is a clue, however awkwardly stated, to Suili's origin: "This airfield, which is of Chinese construction in origin . . ."

The report provided an aerial photo[38]

Loiwing Airdrome aerial

High resolution image is available here.

And a text description of Loiwing Airdrome:[39]

Loiwing Airdrom descrip

Higher resolution image available here.


MAP REF 1/1,000,000
International Map of the World.


Co-ordinates N23°55'
Local position 4 1/2 miles ENE of LOIWING Factory Landing Ground and 8 1/2 miles NE of NAMHKAN suspension bridge.
Altitude 2480 feet above Mean Sea Level.
Landing Area Two strips:
     WNW-ESE 1730 x 340 yards
     NNE-SSW 1830 x 125 yards
intersection near the ESE end of the WNW-ESE strip. Extension of approx 500 yards to western end of WJW-ESE runway not yet connected up to main runway from which it is divided by a canalized stream.
Surface Runway gravel. Remainder paddy.
Serviceability Fair weather only.
Installations Living quarters, fuel storage, buildings, taxi tracks, dispersal areas, aircraft shelters, AA defences.
Communications Rail: Nil.
Road: Good roads to LOIWING Factory Landing Ground and thence to the BHAMO-NAMHKAN road which joins the Burma Road approximately 30 miles SW of CHEPANG.
River: SHWELI.
Landmarks This airfield lies in the valley of the SHWELI River which at this stage runs approximately NE-SW. Hills rise steeply on either side of the river valley which narrows into a gorge about 8 miles to the SSW where the SHWELI Bridge is located. NAMHKAN town situated approximately 6 miles south of the airfield.
Remarks Occupied by the Japanese in May 1942, who have since developed it considerably. Work has consisted principally of construction of taxi tracks and aircraft shelters. The Chinese name for this airfield is SUILI.


Page 5.


Items of particular interest:

• "Coordinates": for the intersection of the two runways,
   N23°54.78 E97°42.46. 
• "Local position": ties the field to "LOIWING Factory Landing
• "Landing Area": runway headings (actuals per Google Earth)
   • WSW-ENE: actual WNW-ESE, 099°-279°, or 10-28.
   • NNE-SSW: actual 029°-209°, or 03-21.
• "Communications": as with the Loiwing Factory airstrip, while
   the Road entries include "West to BHAMO-NAMHKAN Road", no    mention is made of the bridge needed to cross the Nam Wan
   to reach the road.


• The north arrow on the aerial photo was found to be only
   slightly off, with a rotation of +5° needed to make it true.
• However, the photo itself was not aligned to up-north,
   which required the image to be rotated +33°:[40]

Suili aerial tilted

To determine the alignment of the aerial photo:

The coordinates provided in the text description seemed to have been rounded to whole minutes: this broadened the possible location of the intersection of the runways to an area of about 1.9km x 1.7km (from N23°54.5' to N23°55.5' and from E97°41.5' to E97°42.5'). Ultimately, I found that the coordinates were almost spot on --- ie, in whole minutes; but of course I didn't know that until I had looked at Google Earth (GE) terrain for quite some time: evidence on the ground of the runway wasn't immediately clear. Eventually, I was able to match some distinctly aligned roads on the ground to old airport perimeter roads and I used them to align the aerial photo to GE:

Aerial photo:[41]

Suili aerial dist road tilted

High resolution image available here.

Google Earth:[42]

Suili distinctive road on GE

High resolution image available here.


Suili aerial on GE

High resolution image available here.

Final product:[44]

Final overlay

High resolution image available here.

It is not known if the perimeter roads (or taxi tracks, or whatever they might have been) that allowed this identification were constructed by the Nationalist Chinese or later by the IJA / IJAAF.

Lieuwe Montsma nicely summarized the result using an aerial photo found by Matt Poole:[44a]

Montsma rotation of 1943 aerial
Higher resolution image here.


More evidence on the ground

Dan Ford looked at the Suili location on Google Earth without my overlay obscuring the landscape and commented:

I can indeed see the ghost of the airfield main landing area immediately below N23°55' E97°42 on Google Earth! What a strange feeling. The area now seems to be fields, but fields laid out exactly in the pattern of the original airfield, including the wider area to the west of the stream.[44a1]

Dan Ford view

Lieuwe Montsma overlaid the 1943 aerial photo on the current Google Earth view and took a critical step farther, enlarging the result:[44b]

Montsma overlay of Suili
Higher resolution image available here.

and checking closely for evidence still on the ground. And he was rewarded, finding well-defined revetments in the fields immediately around N23°54.615 E97°42.560:[44c]

Montsma closeup of Suili revetments
Higher resolution image available here.



Dan Ford recently received this additional information clarifying the Loiwing Aerodrome's origins from Li-yan, Yunnan Museum Archives, via Wang Min and Lu Min email.[44d]

In May 1939, the Chinese Nationalist government ordered construction of an airport near CAMCO's test runway. That airport was completed in October 1941, and consisted of two runways. The main runway was 1900 m long and 300 m wide. The secondary runway was 1200 m long and 100 m wide. Warehouses plus underground fuel storage were also provided.

The dimensions roughly coincide with Allied intel information above.



The location of Namsham

Before Loiwing's Factory and Suili air facilities were rediscovered to be two separate entities, there had long been another bit of confusion:

Warbirdforum's The fall of Loiwing, April 1942 quotes a letter from RC Wertz to WD Pawley, both of CAMCO, which was dated 28 April 1942. In it, Wertz mentioned a place name, Namsham, twice, in describing events associated with Loiwing during April 1942 (emphasis added):

1. We had eight P-40's which had been strafed at Namsham . . . Field two weeks previous.

2. Col. Chennault was still operating two squadrons from Namsham . . . , strafing and trying to block the Jap drive up the Burma Road.

Wertz's Event 1 (from the list above) would have occurred around (26 April - 2 weeks) 12 April. There is no record of such an event; however, on 10 April, as described by a different source, there was an IJAAF attack on the Loiwing airfield complex:[45]

. . . the damage at Loiwing was trivial . . . . Of twenty-three fighters on the field --- thirteen Tomahawks, seven Kittyhawks, three Hurricanes --- only half were hit, and just one so badly that it was written off. . . .

Half of 23, call it 11, with one a writeoff: so 10 aircraft required repair. Wertz's eight P-40s or here, ten assorted --- close enough.

Wertz's Event 2, dealing with Chennault's whereabouts, appears to be contradicted by another source which records events, again in the Loiwing airfield complex (emphasis added):[46]

. . . Loiwing had become untenable. "Enemy reported in Lashio,"[46a] [Chennault] told the Generalissimo, requesting permission to quit Loiwing and set up a new base deeper into China. . . . Monday, April 27, . . . Madame Chiang: "Your urgent message of 26th just received. . . If by tomorrow enemy entrance into Lashio confirmed then Generalissimo consents that you change to whatever fields you think best."

That was good enough for Chennault. He told the 3rd Squadron to drive to Mangshi . . . and there prepare a fallback field for the AVG.

Tuesday, April 28 . . . After the Tomahawks and Kittyhawks had taken off from Loiwing, but before the Sallys came over, . . . Chennault ran across the runway . . . .

So, Chennault was still very much in Loiwing on 28 April.

And, as already noted, Chennault was operating out of Suili, not Factory.

With that as background, it was eventually realized that Wertz was using the place name, Namsham, as found on a foothill about 4km NNE of Suili, to identify Suili, and to differentiate it from Factory.[47] The name does not appear on the Survey of India Hsenwi map at the location discovered in later-dated maps:[47a]


On this 1967 US Army map, the location name does appear (circled in red):[48]


Wertz, amongst all the CAMCO and AVG staff, seems to have been the only one to have recorded the name Namsham in English narrative.

The mystery was ended by a letter from Wang Min and Lu Min to Dan Ford, which reads (paraphrased) in part:[49]

. . . In July1939, Loiwing's Central Aviation Manufacturing Company factory started production. The runway for testing newly assembled aircraft was completed at the same time.

In May 1939, the Government Aviation Committee also ordered the construction of another airport near Loiwing to be called Nanshan Airport. The straightline distance between the two air facilities was only few kilometers (Nanshan Airport was also called Ruili Field).

Nanshan Airport was completed in October 1941. The main runway was 1900 meters long and 300 meters wide while the secondary runway was 1200 meters long and 100 meters wide. There were 38 aircraft shelters. Northeast of airport apron, open on three sides, good drainage, underground oil tanks, warehouse facilities, etc. In the war against Japanese aggression, it was the second largest airport in Yunnan.

To restate the conclusion: Namsham was intended to identify the Suili airfield.







Reminder: Loiwing Aerodrome, Loiwing (Suili), Ei­Yun, Awlaw, Suili, Ruili, Juili, Shweli, Su-li, Ju-li, Namsham, Namshan, and Loping were all found to refer to the same airstrip, though the last, Loping, was later found to be in error.

35a.^ It was recently found to have been completed in October 1941. See below.

36.^ Seagrave in Burma Surgeon, ibid, pp 95-96.



37.^ Airfield Report No 21, April 1944, pp 1, 2 (USAF Archive microfilm roll A8055 pp 0627-0628). Enhanced with IrfanView by author.



































































38.^ Airfield Report No 21, April 1944, photo date 08 Oct 1943, following numbered p 5 (USAF Archive microfilm roll A8055 p0631). Enhanced with IrfanView by author.

















39.^ Airfield Report No 21, April 1944, p 5 (USAF Archive microfilm roll A8055, p 0631). Enhanced with IrfanView by author.


































































40.^ Coordinates and realignment per Google Earth.

Airfield Report No 21, April 1944, photo date 08 Oct 1943, following numbered p 5 (USAF Archive microfilm roll A8055 p0631). Image tilted 33 degrees clockwise and enhanced with IrfanView by author.




















41.^ Airfield Report No 21, April 1944, photo date 08 Oct 1943, following numbered p 5 (USAF Archive microfilm roll A8055 p0631). Image tilted 33 degrees clockwise and enhanced with IrfanView, and annotated using Microsoft Publisher, by author.














42.^Google Earth view of N23°54.90 E97°41.90 at eye alt 7.22km. Image captured with Gadwin PrintScreen, enhanced with IrfanView and annotated using Microsoft Publisher, by author.








43.^ Google Earth view of N23°54.90 E97°41.90 at eye alt 11.56km. Underlying image captured by Gadwin PrintScreen, enhanced with IrfanView and annotated using Microsoft Publisher, by author. Overlay by author using Adobe PrintShop.







44.^ ibid.













44a.^ Image dated 29 Jan 1944, provided by Matt Poole from NARA records (image MP9416,FrD14,Suili,dark-1 by email of 1004 hrs 09 Dec 2014). Image realigned so that north is up-page and annotated by Lieuwe Montsma. Image enhanced with IrfanView by author.


















44a1.^ Dan Ford post on Warbirds Forum 1810 23 Dec 2014. Image enhanced with IrfanView by author.









 44b.^ 29 Jan 1944 aerial photo (provided by Matt Poole from NARA records (image MP9416,FrD14,Suili,dark-1 by email of 1004 hrs 09 Dec 2014)) overlaid on Google Earth view of Suili area (using GE historical imagery dated 13 Nov 2009 which best shows revetments) by Lieuwe Montsma (per att to email of 1453 11 Jan 15).









 44c.^ Lieuwe Montsma, ibid, and Dan Ford post of 1639 13 Jan 2015. Image enhanced with IrfanView by author.

The Mins (see below) caution that what are here termed "revetments" were called something they felt were very different in Chinese: "aircraft shelters".















44d.^ Per description by Li‑yan, Yunnan Museum Archives, to Wang Min and Lu Min by email. Document was subsequently forwarded to Dan Ford, who passed it to me (att to Ford email of 0340 17 Jan 2015).

















45.^ Ford, Daniel, Flying Tigers (Washington: Smithsonian, 2007), pp‑259‑260.





46.^ Ford, ibid, pp 276-282.

46a.^ The IJA entered Lashio on 29 Apr 1942 (Greenlaw, ibid, p 159).










47.^ "ick53993" on Yuku Warbirds' Loiwing thread seems first to have associated Namsham with the Loiwing's eastern component, ie, Suili --- (post of 06 Oct 2007 0534 hrs).

47a.^ Hsenwi, ibid, excerpt, extracted and enhanced using IrfanView and annotated with Microsoft Publisher, by author.








48.^ Extract from Hsenwi, Burma, China map, NF47-2 (St Louis: US DoD, June 1967); part pdf image captured with Gadwin PrintScreen, enhanced with IrfanView, and annotated with Microsoft Publisher, by author. The name, Nam-sham, also appeared in the previous map issue: Hsenwi map, NF47-2 (Washington: Army Map Service (AMS) (GUVLB), 1958). However, as noted, it doesn't appear on the pre-WWII UK Hsenwi map, F-47B (Provisional GSGS 4218 (Survey of India, third edition); reprinted by Washington: Army Map Service, 1944).


49.^ Letter of 12 January 2015 from Wang Min and Lu Min to Dan Ford (copy provided by Ford).