At 19 Thatcher finished high school and enlisted in the US Army Air Corps on December 3rd, 1940. Thatcher was sworn in and sent to Washington for basic training. After training he was assigned to the 95th Squadron of the 17th Bomb Group. That was the first group in the US Army Air Corps that trained in B-25's. June 1, 1940 his group was transferred to an air base in Pendleton, Oregon. The facilities proved to be lacking so they were then shipped to Felts Field in Spokane, Washington. Thatcher was only in Washington about 2 weeks before he went to Lincoln, Nebraska to airplane mechanic school for 5 months. Thatcher grew up on a farm so he was familiar with some things that were mechanic. Thatcher was very thrilled to be working with airplanes. Thatcher received training in hydraulics, cooling systems, and just about every engine the military had in the air. Thatcher was in Lincoln, Nebraska starting in July 1941 up until war broke out. Thatcher was coming out of a movie when he found out about Pearl Harbor. Thatcher did not really expect war given that he was signed up for about 3 years. After the war broke out that term of duty was extended. During most of the summer of 1941 the 17th group was on maneuvers in North Carolina. When the war broke out they were sent back to Pendleton, Oregon where they immediately started flying submarine patrols in the Pacific Northwest. One of the pilots in the 17th was credited with sinking the first Japanese submarine off of the US coast in World War II. Thatcher was eventually transferred to Columbia South Caroline, from there they went to Eglin Field in Florida. Thatcher met his crew for the first time at Eglin. Thatcher met Lawson in Florida and was the only enlisted man on his crew.Thatcher received different types of training for the Doolittle Raid. He also witnessed firsthand the stripping of the aircraft and the modifications that had to be made so it was light enough. Thatcher remembers the guns on the bottom of the plane being removed because their plan was to fly so low that an enemy plane could not get below them. They also removed a lot of their radio equipment because once they got close to Japan they needed complete radio silence. A lot of the weight was made up with extra fuel. Thatcher volunteered for what was at the time a top secret mission. He was not aware of what kind of mission it was going to be until they got to Eglin Base in Florida and began training.

Thatcher watched and was actually in a few of the B-25's that were practicing taking off from a short runway. It gave Thatcher a little clue as to what they may be doing but he was not sure. One of the ways to make sure they could go fast enough was to lock the brakes at the start of the run, as soon as the engine was where it needed to be they would release the brakes so the plane would shoot off. Eventually they were able to take off on a simulated 400 foot runway with a full load of fuel and bombs. A few airplanes were washed out of the training because of crashes. They started with 24 airplanes. Thatcher and his crew did very well on the short takeoff scenarios. Thatcher met Jimmy Doolittle at Eglin. Thatcher's first impression was that he was very short, but he knew his stuff and was able to train the men effectively because of his knowledge of airplanes.Thatcher was instructed to not even talk with his men about the training they were going through. A week before they left Eglin, they flew down to Ft. Myers and then across the Gulf to Houston, then finally back to Eglin so they could get some open water flying experience. They then flew to Kelly Field in San Antonio and eventually ended up in Sacramento. From Sacramento they flew down to Alameda, California for final preparations. They loaded their planes on the USS Hornet. Thatcher stayed on the carrier, he did not take any leave. Thatcher and the 16 airplanes steamed underneath the Golden Gate Bridge and out into the open Pacific. After they were underway someone came over the P.A. system and announced that they were headed towards Japan and a big cheer went out among the men on the ship. Thatcher was on the Hornet for 18 days before the mission launched. They killed time by exploring the carrier. They also performed maintenance checks on all of the planes and made sure they were properly secured to the deck. If the ropes holding the planes were too dry they would loosen up and cause the planes to move; if the ropes were too wet, they would become tight and there would be too much pressure. They constantly had to keep an eye on the ropes so that the pressure was just right. They also had to keep an eye on exposure the planes were receiving due to the salt in the air.

The engines on the plane that Thatcher was working with were in phenomenal shape due to the diligence they displayed in keeping it maintained. The wind sweeping across the deck of the carrier was an issue, which is why they had steel beams that would come up from the side of the ship and block the wind. This was essential so that planes or personnel were not blown off of the carrier. Their task force consisted of 2 cruisers, 4 destroyers and a tanker. After about 9 days another task force headed by the Enterprise met up with them. All in all there were about 16 ships. There was an aura of confidence with Thatcher looking out and seeing all of the ships. The Navy pilots onboard the Hornet were a bit surprised to see B-25s sitting on their carrier deck and doubted that those planes were going to be able to take off from the carrier deck. Thatcher did not have any doubt in his mind that they could get those planes off the deck. The Hornet was turned into the wind the day they took off. The pretty stiff wind aided in creating lift quicker so the planes could get off of the deck in time. To keep busy and to keep sharp they had daily meetings on the deck discussing the routes they were going to take and different scenarios they would likely confront upon entering China. Thatcher remembers being told that if they were going to drink any water in China, they had to make sure that it was boiled first. Their target in Tokyo was a napalm and steel factory, as well as various docks and factories.The morning they took off Thatcher was issued his general orders just like any other day. Shortly thereafter Thatcher heard the guns on the ship going off followed by an announcement that said, "All Army pilots to their planes." Thatcher got into his plane number 7. He was handed a dozen 5-gallon drums of 100 octane fuel. Because the Japanese ship located their position they had to take off about 250 miles short of their planned launching point. Thatcher was a little nervous about takeoff. The pilot of Thatcher's plane said he was running the engines so high that he feared the flaps were going to blow off. So he raised up the flaps and failed to put them back down. Thatcher's plane took off with no flaps. Their plane dipped below the level off the deck, almost as if it were going to land in the ocean, but it recovered and joined up with the rest of the planes.

The planes did not form up, instead they headed out one by one. They also did not go up to their normal cruising height but rather they stayed low to the ocean. Before they got to Japan they used the gasoline out of the turret tank. Thatcher then emptied the rest of the 5-gallon tanks into the turret tank. He then cut holes into the bottoms of the tanks and kicked them out the window. The holes were cut so that when they landed in the ocean they would sink and not leave a trail that could potentially hint at which direction they came from. The flight from the Hornet to the coast of Japan was approximately 3 hours. They reached Japan at noon. The sun was out and there was a lot of people on the beach. Thatcher remembers looking down and seeing people cheering on the beach because they must have thought they were Japanese planes and not American. Before they got to Toyko they saw a formation of about 6 Japanese planes. They were flying higher and kept on going. The planes were spread out just enough that it was tough to see the other planes in the group but Thatcher notes that every once in awhile they caught sight of another plane they were with. This aided in confusing the Japanese because they could not get an accurate count of how many planes there were and what direction they were coming from. Once they got to Tokyo they could see anti-aircraft fire and they also had to jump up to 1500 feet so that the concussive blasts from the bombs would not knock their planes out of the sky. The anti-aircraft fire was heavy but not accurate. After they dropped their bombs they went back down low over Tokyo Bay and started on a southwest bearing. After they cleared the southern portion of Japan they turned west and headed towards China. Once they made that westward turn the weather took a turn for the worse with rain and wind. When they headed west Thatcher had no clue if they were going to crash land, land successfully, parachute, or just flat out crash. Their plan was a bit askew because of the Japanese patrol ship that discovered them and caused them to launch prematurely. They were supposed to bomb Japan at night and arrive in China in the morning. Instead they arrived in China in the dark. Thatcher's pilot tried to land the plane on a beach. With the landing gear down the pilot miscalculated ever so slightly and once the landing gear hit the water the plane flipped. Thatcher was knocked unconscious and once he woke up he realized he was upside down and water was coming in. Thatcher was able to open an escape hatch and crawl out. The plane was in about waist deep water and the other 4 men were on the beach. Thatcher noticed some people on a bluff overlooking the beach. The villagers came down to them and they could not understand each other. They helped Thatcher and his crew up to the village and they stayed there that night. After a couple hours in the house Thatcher took a lantern and a couple of his new friends to go see if there was a first aid kit in the plane but at that point the tide had made things impossible. Thatcher went out again before dawn and was able to walk up to the airplane but since it was upside down it was impossible to get the kit.

Thatcher was able to get his tool kit from the plane. Later in the morning there was a Chinese underground member who helped Thatcher make some makeshift stretchers because the other 4 men from Thatcher's plane could not walk. They started across the island. They found out that 4 hours after they had left to cross the island 65 Japanese soldiers landed where the plane crashed to look for the crew. Thatcher was not seriously injured when the plane crashed, just bumps and bruises. The Chinese led Thatcher and his men across Nantien Island. The other guys from his plane were in a lot of pain. Thatcher had his pistol belt with him from the plane and there was a decent sized first aid kit attached to that. Thatcher distributed the bandages and what was left of the kit to his guys who needed it the most. It was the first aid kit plus the dirty rags the Chinese gave him for his friends' wounds. Part of the time they walked across the island and for the rest of the time they were in a flat bottom boat that meandered its way across the island via canals. One time walked across a levee and to their left was a harbor. At one point the guide made a motion for everyone to get down. As Thatcher peered over the side of the levee he saw a Japanese patrol boat. It eventually left the harbor and they were able to get up on the levee and continue their trek. Thatcher and his men were transferred to the mainland of China where they received medical attention. The first hospital they went to had an English missionary and they were able to speak English with someone. It was here they received their first information regarding what had happened to the other planes. Number 15 crew made a good water landing. The plane stayed afloat for 8 minutes so they were able to exit into a raft. Number 15 ended up on the same island as Thatcher. They eventually caught up with Thatcher and his group. After 3 days in the hospital Thatcher was no use to his crew, and with the Japanese advancing he ended up moving on with a crew that consisted of Don Smith, Griff Williams, and Sesler the navigator, and Ed Saylor. Thatcher left Lawson and Davenport at the hospital. The Chinese had blown up the roads along the coast to hinder the Japanese so most of the travelling that Thatcher did was through rice paddies. Finally they got inland far enough and were able to hop on a main road, then a train, and then finally on to a big city on the Yangtze river. From there they were to wait for a plane to pick them up. Thatcher waited 3 days there for a plane. The Japanese continually bombed and strafed the city and the airport. The Chinese had minimal defenses. For 3 days Thatcher went up on a knoll near the airport to spot incoming planes. On the 4th day the same spot he had been standing at was strafed because spies realized what Thatcher was doing. Thatcher eventually met with Chiang Kai-shek, who had a banquet for them. They were each awarded a medal from the Chinese at this banquet. They landed in Calcutta and it was during the dry season and they could not see much so they overshot the airport and landed in a field. They were there for the last ten days of May 1942. From there they went to by train to New Delhi for about 3 days. Then they went to Karachi and from there Thatcher received his orders to head back to the United States.