For his conspicuous gallantry at the risk of his life above and beyond the call of duty, Capt. Dethlefsen was awarded the Medal of Honor. President Johnson made the presentation at the White House on Feb. 1, 1968.
By March 1967, Operation Rolling Thunder had been going on for two years with no signs of North Vietnam backing down. The US and North Vietnam engaged in a gradual escalation of the conflict.
As US air strikes increased, the Hanoi regime increased its anti-air defenses from AAA to the more deadly SA-2 surface-to-air missiles as well as MiG fighters. The skies over North Vietnam would be the most dangerous and difficult skies for American pilots to operate in since World War 2.
At the start of Rolling Thunder, defense suppression was assigned to two-seat F-100F Super Sabres known as the Wild Weasels. The F-100 was an interim solution for the Wild Weasel role, though, as it had a limited payload and wasn’t fast enough to keep up with the F-105 Thunderchiefs that were shouldering the burden of strike missions at the time for the USAF.
In June 1966 the first Wild Weasel Thunderchiefs arrived in Southeast Asia. One of the Wild Weasel units at the time was the 354th Tactical Fighter Squadron (TFS) at Takhli Royal Thai Air Force Base (RTAFB) Takhli which was home to the F-105s of the 355th Tactical Fighter Wing (TFW). The 355th TFW had been operating the Thunderchief since 1962 at McConnell AFB in Kansas before being deployed for Rolling Thunder.
Like the F-100Fs, the Wild Weasel F-105Fs had two crew, the pilot and the electronic warfare officer in the back, the EWO or “Bear”.

On Mar. 10, 1967, the target portfolio was finally expanded to include the large Thai Nguyen steel works.
As explained by James Geer in his book The Republic F-105 Thunderchief Wing and Squadron Histories, on that day, Capt. Merlyn H. Dethlefsen took off from Takhli on an Iron Hand (SAM suppression) mission against the air defenses around the Thai Nguyen steel works. This was his 78th combat mission, and he had the number three position in a flight of four Thuds made-up of two EF-105Fs and two F-105Ds operating as hunter-killer teams.
As the flight approached the target area, they encountered intense AAA fire. Amidst the bursting shells, Dethlefsen trailed the two lead aircraft by some 3,000 to 5,000 feet as the flight pressed the attack. The lead aircraft had identified a SAM site and launched a Shrike missile, but it missed. The enemy gunners were more accurate. The flight leader was shot down, and his wingman had suffered heavy damage and was forced to abandon the effort.
Taking command of the flight, Dethlefsen circled the target area and repositioned his aircraft for a second pass on the target. Just as he and his backseater, Capt. Kevin “Mike” Gilroy, located the SAM site, he spotted two MiG-21s taking aim behind his Thud. He fired a Shrike missile at the SAM site and dove into a mushroom of flak just as the one of the MiGs fired a missile at his aircraft. His evasive maneuver worked as the MiGs failed to follow him into the barrage of AAA fire.
Dethlefsen reversed his course to gain visual contact on the SAM site to see if he had successfully knocked it out. By this time, the first elements a the strike force were bombing the steel mills, creating a cloud of debris and smoke over the target area. Through the cloud, Dethlefsen was able to see enemy missiles streaking up toward the strike force just as he encountered two MiGs attempting to gain position behind his aircraft. After shaking the MiGs with a Light left break, Dethlefsen realized that he had sustained damage from the AAA fire on his second pass.

While the strike force was completing its attack, Dethlefsen pulled off his run and checked over his damaged Thud. Fortunately, the engine and flight control systems were all right, even though the 57-mm gunner had knocked a hole in the bottom of the fuselage. Knowing that he had missed the SAM site and that the steel complex was a critical target that would require additional bombing over the next few days, he decided to re-engage the missile defense system.
Maneuvering around the flak pattern, Dethlefsen spotted the SAM site directly in front of him. He fired his second Shrike missile, and the site went promptly off the air. With the cloud of debris and smoke still hanging over the target area, Dethlefsen dropped is Thud on the deck to put the finishing touches on the site. Finding the SAM’s radar van, he dropped his bombs squarely on it and followed it with a strafing pass with his 20-mm cannon, effectively destroying the site.
For his conspicuous gallantry at the risk of his life above and beyond the call of duty, Capt. Dethlefsen was awarded the Medal of Honor. President Johnson made the presentation at the White House on Feb. 1, 1968.
The Republic F-105 Thunderchief Wing and Squadron Histories is published by Schiffer Publishing and is available to order here.
Photo credit: U.S. Air Force
