The Lockheed OP2E Neptune was used for a wide variety of missions including it's primary function of patrolling the Vietnamese coast in search of contraband carrying junks in Operation Market Time. Several OP2E aircraft were assigned to Task Force Alpha, a special unit organized under US Air Force command employed to deliver Air Delivered Seismic Detection Sensors (ADSID) along the Ho Chi Minh Trail in Laos and Cambodia. The twin-engine Neptune dropped the sensors to aid intelligence in pinpointing the heaviest traffic for fighters and gunships assigned to attack enemy targets on the trail. The anti-infiltration detection system program had a succession of code names including "Igloo White," the name most recognized and used the longest.
On 17 February 1968, Cmdr. Glen M. Hayden, pilot; Lt. Curtis F. Thurman, co-pilot; Lt. JG James Kravitz, flight officer; Ensign James Wonn, navigator; ATN1 Paul Donato, 1st technician; AO2 Clayburn Ashby, Jr., ordnance; ADJ2 Chester Coons, plane captain; AN Frank A. Dawson, 2nd mechanic; and AN James Martin, aerial gunner; comprised the crew of an OP2E Neptune conducting a sensor seeding mission over the Ho Chi Minh Trail. The target location was along Highway 19, the primary road running from the Mu Gia Pass through the Steel Tiger sector of eastern Laos, then into South Vietnam near the major US base of Khe Sanh.
After completion of the first target pass, Cmdr. Hayden reported to the accompanying fighter escort and Forward Air Controller (FAC) that the Neptune had sustained hits by small arms fire, but would continue with a second target run. During the second pass, the pilots of fighter escort reported the starboard engine of the Neptune was on fire.
The crew acknowledged the report, aborted the rest of its mission and started to climb into an overcast of clouds at 4000 feet in its attempt to return to home base. In the meantime, the fighter escort climbed to the top of the cloud overcast to await the damaged OP2E in order to escort it back to base. The Neptune never emerged above the clouds. The last radio transmission from the crew was, "We're beat up pretty bad."
When the Neptune failed to rendezvous with its escort aircraft, the FAC dropped below the clouds to search for the OP2E and found burning wreckage. As the FAC visually inspected the area; he saw no parachutes, heard no emergency radio beepers and saw no other evidence of survivors on the ground. Aerial search and rescue (SAR) efforts were immediately initiated, but found no signs of life in or around the wreckage.
No ground search of the crash site was possible due to the heavy enemy presence in the area. Because there was no direct witness to the crash of the OP2E and the enemy was already close by; there was no way to determine if any of the crew of nine survived their loss incident. The Navy assumed that they did not survive, and on 6 March 1968 changed the status of all crewmembers from Missing in Action to Killed/Presumptive Finding of Death.
The crash site was located in rugged jungle covered mountains approximately 6 miles west of the town of Ban Namm which was located next to Highway 19; 11 miles south of the demilitarized zone (DMZ) that separated North and South Vietnam, 19 miles northwest of the major communist city of Tchepone and 58 miles south-southeast of Mu Gia Pass, Savannakhet Province, Laos. The crash site was also located 9 miles west-northwest of Binh Tram 34, an NVA way station used for a variety of purposes and 56 miles northwest of Khe Sanh, South Vietnam.
During 1992 and 1993, the Joint Task Force Full Accounting (JTFFA) actively investigated this crash site first with a site survey, then four joint field excavations. The first excavation was conducted in 1992 and three excavations in 1993. There was also one unilateral turnover of some partial remains/wreckage/personal affects to US personnel during this same timeframe.
The excavation resulted in the recovery of over 400 bone and teeth fragments, 1 gold crown for a tooth and 1 anterior permanent dental bridge. Also recovered were personal items including Lt. Thurman's Military Identification Card and his Sears Roebuck Credit Card. Additionally, other crewmen's ID cards and dog tags were recovered along with parts of 9 parachutes and other pieces of the Neptune's wreckage.
The bone and teeth fragments were sent to the Central Identification Laboratory, Hawaii (CIL-HI) for examination. They were able to match two of the teeth fragments to the dental records of Chester Coons and he was identified on the basis of those teeth. The bridge and the gold crown were possibly attributable to specific individuals, but it was decided to keep them as part of the group identification.
After examining the bone fragments, CIL-HI personnel were only able to identify them as human/possibly human. Further, because they are so small and fragmented, no DNA testing was possible and no individual identifications for any of the Neptune's crew could be made based upon the bone fragments. All the remains were considered to be a "group identification" and they were all buried together in one grave with a headstone bearing all nine names.