Phillip DeLong was given his aviation wings and commissioned a Second Lieutenant in the Marine Corps. He then attended advanced fighter training at NAS Miami and became carrier qualified at NAS Glenview, Illinois on the USS Wolverine.
 
He was assigned to VMF-212 and sent to the Solomon Islands. After arriving on the Solomons he was promoted to First Lieutenant. Phillip gained his first aerial victories on January 9, 1944, with two confirmed Zero’s, damaging a third over Kabanga Bay. It happened with a flight after lunch, when Phillip and the squadron's skipper pulled in behind five Zero's. He was flying wing on this mission with the commanding officer of the squadron, Hugh Elwood. Elwood fired first and knocked out the first enemy fighter. Phillip was able to hit and burn another to make his first aerial victory. The flight broke up and Phillip pulled in behind another Zero who was trying to sneak up on a Navy F6F Hellcat. Phillip fired into the Japanese fighter, mortally damaging the aircraft and pilot. Just eight days later on January 17th, Phillip claimed two more Zeros over Blanche Bay.
 
During a morning escort mission on January 23rd, Phillip helped two fellow pilots shoot down two Zeros, giving him 1/3 victory for each enemy fighter. The flight of Corsairs had broken up during the midair duel when Phillip found himself alone with five Zeros on his tail. The Corsair was faster so he decided to outrun his pursuers. The chase took them along the coast of New Britton. Phillip kept looking back watching the Zeros. He decided that, if the enemy fighters started to turn away, he would give chase to them. As Phillip expected, one by one, the Zeros broke away and headed back to their base. Only one Zero remained and, after a few more moments, it turned. Immediately Phillip swung his Corsair around. Apparently the Zero’s pilot was expecting such a move and turned back onto Phillip. Head on, both fighters bore down on each other until they both fired. Phillip's six 50-caliber machine guns split the Zero, turning it into a fireball with Phillip flying through the explosion.
 
Later that afternoon, Phillip was on a fighter sweep when he and another squadron mate shared in shooting down a Zero, giving them both 1/2 credit. These shared victories gave Phillip 2 1/2 credits for the day. Before January was over, Phillip scored two more times. Phillip was flying on the 29th when he shot down another Zero. He added a Hamp fighter on the 31st.
 
 
Phillip’s best day was February 15th. He was part of an umbrella of Marine Corsairs, covering troops from New Zealand landing on Green Island. Disregarding heavy anti-aircraft fire from the invasion fleet, He shot down three Val dive-bombers, which were attacking the allied invasion.
Phillip DeLong was the "Top Gun" of VMF-212, credited with 11.166 aerial victories, one probable and two damaged. He flew a total of 69 combat missions. During the Bougainville Campaign, he was promoted to Captain.
 
 
During his service Phillip DeLong earned the Silver Star, Legion of Merit, along with the Distinguished Flying Cross with 6 Gold Stars. He also received the Air Medal with 16 Gold Stars and the Navy Commendation Medal. Phillip's total aerial victories were 11.166 victories in the Pacific during WW II, flying a total of 69 combat missions. He also scored 2 in the Korean War where he flew 127 combat missions. Phillip DeLong is the 13th highest scoring Marine Ace.