25th Fighter Squadron The 25th Fighter Squadron ( 25 FS ) is part of the 51st Fighter Wing at Osan Air Base , South Korea . It operates the A - 10 Thunderbolt II aircraft conducting close air support missions . History . The 25th Fighter Squadron began was originally created as the 25th Pursuit Squadron and activated at Hamilton Field , California , on 15 January 1941 . By March it was assigned to the 51st Pursuit Group at March Field , California . In July the squadron received P - 40 Warhawk aircraft . World War II . The 25th sailed to combat operations in the Pacific Theater aboard the SS " President Coolidge " on 11 January 1942 . The squadron was part of the first deployment of U . S . forces leaving the mainland after the declaration of war . The journey to Melbourne , Australia , took 20 days . By late March the 25th Pursuit Squadron had arrived in Karachi , India , and set up wartime operations . The 25th flew its first aerial combat mission over " The Hump " on 25 September 1942 , flying a combat escort mission . After the squadron moved to Dinjan in Assam , India , combat activity increased . Due to the terrain , the pilots would usually " drag in " on their passes . It was there that the 25th picked up the name " Assam Draggins . " Operations from Dinjan were concentrated against the Japanese in northern Burma along the upper Chindwin and Irrawaddy Rivers . In February 1943 the 25th Fighter Squadron was tasked to defend Fort Hertz near Myitkyina . Fort Hertz was a vital cog in air operations near " The Hump . " The 25th bombed and strafed enemy troops , concentrations , supply dumps , bridges , and enemy communication lines for twelve consecutive days , but failed to slow the Japanese advance on Fort Hertz . B - 25 heavy bombers were needed to halt the Japan ' s drive , but none were available . Lieutenant Colonel John E . Barr , the executive officer for the 51st Fighter Group , modified a P - 40 to carry 1 , 000 pound bomb s , and by May 1943 , the Japanese offensive had been halted . The 25th Fighter Squadron encountered more combat activity than any other unit within the 51st Fighter Group during the war . The squadron returned to the United States and was inactivated on 12 December 1945 . Postwar . On 15 October 1945 , the 25th was re - activated at Naha Air Base , Okinawa , where the squadron was assigned P - 47 Thunderbolt and P - 80 Shooting Star aircraft . As part of the occupation force , the 25th provided defense for the Ryukyu Islands . Korean War . The 25th was placed on alert when hostilities erupted in Korea in June 1950 . The unit was reassigned to Itazuke Air Base , Japan , in September , and to Kimpo Air Base , Korea , by October . The Chinese People ' s Volunteer Army intervention in December 1950 forced a retreat of U . N . forces from North Korea iinto the South . The 25th flew more than 21 sorties each day that month to save the 2nd Infantry Division , which had been cut off by the enemy near Kunuri , from being overrun . Air cover was officially credited with preventing disastrous losses to the division . On 20 November 1951 , squadron pilots received their new F - 86 Sabre aircraft and went to face the Chinese , North Korean , and Soviet pilots in their MiG - 15 aircraft . Major William T . Whisner Jr . got his fifth MiG kill on 23 February 1952 , becoming an Ace . When the 51st Group adopted a checkered design for its F - 86 tail markings , it also received the designation " Checkertails " . The red squadron colors appeared in the design . Thus , the Assam Draggins of World War II became known as the " Checkertails " of the Korean War . Post Korean War . After the war , the 25th was assigned to the 51st Fighter - Interceptor Wing at Naha Air Base , Okinawa . While there , the pilots were deployed for one week at a time to Kadena Air Base , Okinawa . From 1960 – 1965 , the 25th Fighter Squadron remained in a state of suspended animation with virtually no mission and only 20 percent manning . On 17 June 1965 , the unit was re - designated the 25th Tactical Fighter Squadron and assigned to the 33d Tactical Fighter Wing at Eglin Air Force Base , Florida . Vietnam War . On 31 May 1968 , the 25th was assigned to the 8th Tactical Fighter Wing and stationed at Ubon and Udorn Royal Thai Air Force Base s , Thailand , once again seeing combat in the skies of Vietnam . Flying F - 4 Phantom II aircraft , the 25th received the Presidential Unit Citation ( 1971 ) , the Republic of Vietnam Gallantry Cross with Palm ( 1967 – 1973 ) , and five Air Force Outstanding Unit Award s ( 1967 – 1973 ) . Post Vietnam War - Present . When the Air Force began its withdrawal from Thailand , the 25th was reassigned the 18th Tactical Fighter Wing at Kadena Air Base , Okinawa , where it remained until 1 February 1981 . On that date , the 25th was relocated without personnel or equipment to Suwon Air Base , Republic of Korea , and assigned to the 51st Composite Wing ( Tactical ) . On 28 January 1982 , the 25th received its first A - 10 Thunderbolt II aircraft . The squadron ' s presence helped maintain a peaceful armistice between North and South Korea until 2 October 1989 . It was during that time that the 25th began transferring aircraft to the 19th Tactical Air Support Squadron and other stateside units and inactivated on 1 July 1990 . On 1 October 1993 , the 25th Fighter Squadron was activated under the 51st Wing at Osan Air Base , Republic of Korea , under the command of Lieutenant Colonel Syd McPherson . It has since added six A - 10 aircraft to its fleet , making it a dual qualified A / OA - 10 squadron . Motto . The official motto of the 25th FS is " PILSUNG ! " meaning certain victory in Korean . It is customary / mandatory that any time the number 25 or any variation of 25 ( 2 . 5 , . 25 , etc . ) is said , every ATTACK pilot will shout a hearty " PILSUNG ! " under any circumstance , regardless of who said it or who was briefing . Mascot . The Squadron is unofficially known as the " Flying Elvis ' s " and have unlimited knowledge on everything regarding the King . Many stories are out there in regards to how this name came about , but the best and 10 % true story is as follows : About 25 years ago , a group of 25th ATTACK pilots took a helicopter up north near the DMZ and parachuted out for fun . Since this was around the time that " Honeymoon in Vegas " had just came out , the Commander at the time is to have said . . . " Tell those flying Elvises they are grounded ! " The name stuck .