Dan Heller 
Name: Mark V. Dennis (Middle initial stands for him being the fifth child of his parents)
Memorials: Find a Grave 1 2 Vietnam Wall Wall of Faces
Rank/Branch: Hospitalman (Corpsman) 3rd Class/USN
Unit: Assigned as Medic to “E” Company USMC Dong Ha South Vietnam
Date of Birth: 21 September 1946
Home of Record: Miamisburg OH
Date of Loss: 15 July 1966
Country of Loss: South Vietnam
Loss Coordinates: 174659N 1065984E (YD039648/YD038649)
Status in 1973: Killed in Action
Category:
Aircraft/Vehicle/Ground: CH-47 “Chinook” BuNo. 151015
Other Personnel In Incident: (none officially missing)
REMARKS: Not on official US Government List of POW/MIAs
SYNOPSIS: The Boeing Vertol CH-47 Chinook heavy lift helicopter arrived in Southeast Asia in September 1965 and could carry almost anything. Airlifting troops, supplies, artillery pieces and field equipment were routine tasks for “The Hook.” More important, with its two Lycoming T-55-L-7 turboshaft engines offering 5,700shp, it could salvage downed aircraft and return them for repair. Few helicopters were as powerful or as versatile as the Chinook.
Operation Hastings began as a search and destroy mission 55 miles northwest of Hue, Quang Tri Province, South Vietnam, to counter the NVA 324B Division located across the demilitarized zone (DMZ) that separated North and South Vietnam. Task Force Delta, initially consisting of three US Marine battalions, grew to six battalions with an additional five Republic of Vietnam (ARVN) battalions assigned to it. In addition to the ground troops, some of Marine Air Group (MAG) 16, including a detachment of eight UH-1Es from VMO-2, moved to Dong Ha Airfield in support of Operation Hastings.
On Friday, 15 July 1966, Operation Hastings began with the initial troop lift by 10 transport helicopters to Landing Zone (LZ) Crow located on the west side of the Ngan River Valley some 5 miles northeast of the Rockpile, 11 miles due west of Dong Ha, 12 miles south of the demilitarized zone and 19 miles west-northwest of Quang Tri City. Capt. Thomas C McAllister, pilot; 1st Lt. George Richey, Jr., co-pilot; Sgt. Robert R. Telfer, crewchief, and Sgt. Gary A. Lucas, door gunner; comprised the crew of a CH-46A helicopter (aircraft #EP-171). Also on board were at least 15 passengers. Known to be on board were 12 Marines and 3 Navy Corpsmen, including HM3 Mark V Dennis.
As the flight of helicopters approached LZ Crow, NVA anti-aircraft artillery (AAA) batteries opened up with a withering barrage of fire. Four of the Chinook helicopters were shot down or were involved in mishaps on the landing zone including EP-171. It was struck in the fuel cell by 12.7mm AAA fire. As the cockpit and passenger compartment filled with smoke, the aircraft’s fuel system continued to pump jet fuel into the fire. EP-171 lost an engine forcing Capt. McAllister and 1st Lt. Richey to put it into auto-rotation in an attempt to land. Ironically, news footage of this aircraft loss was aired on the nightly news 2 days later, and watched by the Dennis family. Of the men aboard EP-171, only Capt. McAllister, 1st Lt. Richey and Sgt. Lucas survived the crash.
The remaining 16 men believed to be on board were immediately declared Killed In Action. Three and a half weeks later, a casket purportedly containing the mortal remains of HM3 Mark Dennis arrived in Ohio. The family was warned not to open the casket “due to the condition of the body.” He was buried by his family with full military honors in their family plot in Hillgrove Cemetery, Miamisburg, Ohio.
The 30 November 1970, issue of Newsweek carried a photograph of an “unknown POW” along with the photos of four identified POWs who were all being held prisoner in Hanoi. Mark’s parents, brother and sisters all positively identified the unidentified Prisoner of War as being him. That photograph, combined with an earlier report from the US Navy that stated that “a couple of men could have gotten out of the helicopter” sparked Mark’s older brother to travel to Paris, Bangkok and Vietnam in search of the truth.
On 9 July 1971, the questionable remains of Mark V Dennis were exhumed, and exhaustive tests made by both very reputable private sector experts hired by the family and US government experts representing the Navy. The results proved to Mark’s family beyond a shadow of a doubt that they did not bury Mark Dennis, but someone else, unknown to them. The Navy disputed some of the findings made by the family’s experts, while admitting others and ignoring still others. The results in comparing the body to Mark and his incident were as follows:
1. Mark was 5′ 11″, the body was no more than 5′ 5″, and more likely to be only 5′ 3 1/2′ to 5′ 4
2. Only tooth #14 remained in the skull; the Navy extracted tooth #14 from Mark Dennis 1 year prior to the crash.
3. The Chinook helicopter uses JP-4, non-leaded kerosene fuel; the body was blown up with US grenades and burned
with regular, leaded gasoline; a dog tag found in the casket had been burned with book matches
4. Mark was tall and thin; the body was short and stocky.
5. Mark was 19 years old; the body was of a 30 year old.
6. According to a written statement by the US Government mortician, Mr. Lugo, regarding how he identified the body: “Identification was established by a thorough check of all units concerned in regard to the actual passengers aboard the aircraft. Complete identification was made on all the other deceased with only HM3 Dennis remaining and one cadaver. Identity was established in that manner.”
7. Dr. Papucci, metallurgist and director of a distinguished laboratory in Ohio, stated after examining the body: “Two things prove the man in the casket was killed on the ground – and the helicopter could have landed on the body which was already there – grenade fragments and lead deposits. Further, he stated he “determined the fact that fragments of grenades were imbedded in the body and skull – on the left side and lower parts of the legs.” The Navy offered to take the body from the family plot and bury it in a national cemetery with a headstone bearing the name Mark V Dennis if the family did not accept their official explanation. On 24 August 1971, the Dennis family had the body re-buried by the American Legion in the Hillgrove Cemetery as an unknown soldier.
Over a period of years after going public with this information, the Dennis family made contact with several survivors of this incident/operation. Through them, the family learned what really happened
On 12 July 1966, a group of Marines were dropped by helicopter at the DMZ in an attempt to hold back NVA regulars from crossing into South Vietnam. Instead, they were off-loaded in the middle of the NVA troops in the Ngan River Valley. Over the next 3 days, they set up a perimeter and secured a landing zone that was designated “LZ Crow” while sustaining heavy casualties. The second designated LZ carved out by the Marines was LZ Dove and it was located some 2 miles to the southeast of LZ Crow at coordinates YD 08577 60641.
In the early morning hours of 15 July 1966, Marine air strikes and artillery prepped the two designated landing zones selected for Operation Hastings. Beginning at 0800 hours, 24 CH-46 helicopters from HMM-164 and HMM-265 airlifted the first wave of Marines into L Crow. The 24 aircraft were divided into six divisions of 4 aircraft each since the LZ appeared to be large enough to accommodate four Chinook helicopters landing together. Each aircraft was slated to carry 14 fully armed Marines plus its 4-man aircrew.
Since numerous enemy automatic weapon positions were located to the northeast, the final approach heading was generally southeast with the downhill slope to the terrain toward the LZ. There was also a tailwind of roughly 5 knots that the pilots had to contend with along with the enemy ground fire and the continuing ground battle while entering and exiting the area.The first two divisions landed without incident. One of the aircraft in the third division overshot the landing point and hit a tree line causing strike damage to the airframe plus minor injuries to the crew and passengers. The Chinook was smoking when it came to rest to the right and outside of the landing zone’s perimeter. The smoke continued to drift across the LZ adding an additional hazard for the remaining divisions to contend with.
The fourth division was able to discharge its passengers without mishap, however, the 5′ division experienced major problems Major Tom Reap was the division commander and pilot of the lead aircraft (aircraft #YT-15). The flight approached the LZ in a free-trail formation. In the “Report of Aircraft Mishap,” Major Reap stated he believed he was slightly high and fast on his final approach. Rather than flare his helicopter to rapidly drop his airspeed and place his wingman in an awkward position, he picked a clear area about 75 feet east of the LZ itself. He came to a hover and the crew helped him avoid a small ridge that was already occupied by Marines. The Chinook started losing rotor RPM as he pulled power to move over the ridge. The CH-46 dropped the last 8 to 10 feet to the ground, landed hard, but remained upright.
Capt. W. J. Sellers, the pilot of the #2 aircraft (aircraft #YT-18), was roughly four rotor diameters behind the lead aircraft and a little higher. He flared to about 20 degrees nose up to get rid of his excess airspeed and moved abeam of Major Reap as he came to a high hover. Capt. Sellers’ touchdown choices were limited by some trees located near the stream a stand of 20-foot high bamboo and troops already on the ground. He started loosing RPM in the hover and set down on the uneven ground to the left of the flight leader. Major Reap had already lowered the rear ramp and Marines were offloading as Capt Sellers touched down.
Capt. Sellers’ helicopter was on the ground only about 4 seconds when it meshed aft rotors with Major Reap’s aircraft. Both Chinooks began to shake and vibrate violently, then broke at the splice just forward of the aft pylon. The pylon dropped injuring some of the men inside. Further, as the aircraft rocked back and forth from the force of the contact, the rotor blades of the lead aircraft struck and instantly killed two Marines who had just exited YT-15.
At 1815 hours, while inserting a reaction company to guard the three Chinooks in LZ Crow and treat the wounded, Capt. Tom McAllister’s aircraft was at 1,500 feet when it was struck by communist 12.7mm machine gun fire. Photos taken from the ground show smoke coming from the cockpit windows and flames from the rear of the aircraft. When the crew tried landing on LZ Crow, smoke filled the cockpit and no one could see. They overshot the LZ and crashed on the edge of the Battalion’s command post and 81mm mortar pits, which were located to the northeast of the LZ. Tom McAllister, stated later that three things happened at once:
1. The lead aircraft radioed, “Pull out. The ground fire is too intense!”
2. The third aircraft radioed, “Tom, you are on fire
3. The cockpit quickly began to fill with heat and smoke, both of which blinded the pilot and co-pilot
Within seconds the aircraft dropped from 1500 feet to approximately 20 feet above the ground over a sandy creek bed. At this point they actually were touching the tree tops. The co-pilot jettisoned his half of the canopy and crawled halfway out in order to see. He sat back in his seat and said, “Let me have it, Tom. I think I can land it.” The Chinook missed the landing zone by about 75 yards, instead landing hard in the midst of a Marine mortar emplacement on a hillside, then rolled on its right side and, shortly thereafter, begin to burn.
Tom McAllister was pinned in the wreckage for 4 to 5 minutes before he was able to work himself free. The co-pilot and pilot exited the aircraft and warned everyone in the area to run. The gunner either climbed into, or was thrown into, the rear passenger compartment. The crew chief had been standing in the right-hand doorway when the helicopter hit. Sgt. Lucas, the gunner, found Sgt. Telfer lying in the doorway with his leg pinned under the aircraft. Before he could be freed, the first explosion occurred, and the crewchief was struck in the back and killed. The gunner was eventually able to free himself, exit the aircraft with severe burns over most of his body and wandered through the jungle for approximately 30 minutes before finding friendly forces.
Most of the Marines who viewed the crash from the ground were on the backside of a small rise when the Chinook hovered over the creek bed and could only see its rotor blades. From that vantage point no one could see how many men jumped from it. Sgt. Lucas “glanced” up during the action and saw 2 men as they jumped. He is the only eyewitness from within the aircraft, and he did not focus on the doors the entire time so he was unable to say whether or not others also exited in this manner. However, a Marine forward observer, Larry W. Nelson, who was located 200 to 300 meters upslope on a hillside to the west of the crippled CH46A, witnessed 5 or 6 men jumping from the burning Chinook before it crash landed roughly the same distance away from his position.
The wreckage continued to burn and explode a second time. The survivors reported there were rounds within the aircraft “cooking off” from the heat. When the fire burned out and the wreckage cooled, a search and recovery (SAR) team was able to enter the crash site, find and recover 6 or 7 sets of remains from the wreckage. Two days later the Marines on the ground were able to fight their way out bringing with them EP-171’s 3 aircrew survivors. When they departed the area through the creek bed where the Chinook wreckage lay, they saw no bodies in or near it.
The Dennis family filed a lawsuit in Fifth District Federal Court in Dayton, Ohio in 1972 for violation of Mark Dennis’ Constitutional Rights. The Court immediately issued a Restraining Order, which ordered his status changed to Missing in Action “for purposes of recovery” as the negotiations for a peace settlement were in the final stages. The Navy never complied with the order. The case was dismissed after the POWs came home in 1973. As a result, Mark Dennis has never been negotiated for in requests to the Vietnamese government from the US government.
If HM3 Mark Dennis died in the loss of the Chinook, he has a right to have his remains returned to his family, friends and country. However, if he safely exited the helicopter, enemy forces in the area certainly could have captured him and his fate like that of other Americans who remain unaccounted for in Southeast Asia, could be quite different.
Since the end of the Vietnam War well over 21,000 reports of American prisoners, missing and otherwise unaccounted for have been received by our government. Many of these reports document LIVE American Prisoners of War remaining captive throughout Southeast Asia TODAY/
The American military in Vietnam were called upon to fly and fight in many dangerous circumstances, and each was prepared to be wounded, killed or captured. It probably never occurred to them that they could be abandoned by the country they so proudly served.
The family of Mark Dennis request Americans include him as an unaccounted for serviceman, and fight for a righteous accounting of him in the same manner they fight for the rights of their missing countrymen who our government officially recognize as POW/MIAs.
After Operation Hastings, American forces referred to the Ngan River Valley as “Helicopter Valley.”
