Juutilainen entered the Finnish military on 9 September 1932 for his compulsory military service, serving as a pilot in the Finnish Air Force starting from 1935. On 1 May 1935, Juutilainen was promoted to sergeant. He was transferred to LeLv 24, operating from Utti, on March 3, 1939. In October 1939, with the situation worsening, the squadron moved to Immola, closer to the Finnish-Soviet frontier. During the Winter War (that broke on 30 November 1939) he flew the Fokker D.XXI. Juutilainen scored his first victory on 19 December 1939, shooting down an Ilyushin DB-3 bomber and damaging two more. At the end of the Winter War, he had achieved one shared and two individual victories. During the Continuation War, he served in 3/LeLv 24, flying a Brewster B-239 "Buffalo". On 21 July 1941, he and five other Buffaloes scrambled to intercept Soviet fighters from 65th ShAP that were strafing Finnish troops near Käkisalmi. During that sortie, he destroyed a Polikarpov I-153 'Chaika', making him an "ace" on the Brewster Buffalo. Few days later, on 1 August, seven fighters under command of Ist Lt Karhunen destroyed six I-16s near Rautjarvi, and Juutilainen (having been promoted to Warrant Officer in the meantime) claimed two of them. On the morning of 6 February 1942, while reconnoitring the Petrovkiy-Jam region with other LLv 24 pilots, he intercepted seven Tupolev SB bombers escorted by 12 MiG-3s. Juutilainen claimed two SBs. Finnish Air Force's Brewster B-239 formation during the Continuation War. Flying this type of aircraft, Juutilainen scored 34 out of 94 kills He later recalled: “ I noticed the bombers at 3000 metres, and radioed the boys about them. As we intercepted the Soviet aircraft, I spotted a formation of three SBs heading for a nearby railway line and dived after them. Targeting the aircraft to the left of the formation, my fire set its port wing aflame. The SB crashed next to the railway line. Just as I started after the lead bomber, I observed a MiG fighter closing in on me. In spite of the threat posed by the latter, I managed to hit the bomber in the starboard engine, which poured out smoke and oil. Moments later the aeroplane rolled over to the right and plunged into the forest close to the railway line. Turning my attention to the MiG, which was above me, I managed to shoot at it as we raced towards each other. My aim was good and the fighter started to trail black smoke from the engine. He banked away to the east, losing altitude as it went. ” On 27–28 March 1942, 3/LLv 24 moved to Immola in preparation for a Finnish Army offensive on Suursaari, in the Gulf of Finland. Although being grossly outnumbered over the Gulf of Finland, LeLv 24 pilots were more experienced than their Soviet opponents from Red Banner Baltic Fleet. Even when they had the advantage of surprise and height, Soviet pilots did not succeed in shooting down Finnish pilots. On 28 March, WO Juutilainen, in patrol with Sgt Huotari, attacked some "Chaikas" of 11 IAP over the Suurkyla shoreline, at Gogland, and shot down two of them. These air victories took Juutilainen's tally to 22. A month later, on 26 April, he became his unit's first recipient of the Mannerheim Cross. On 20 September, he took off with Capt Jorma Karhunen and 3/LeLv 24 pilots for a patrol of the Kronstadt-Tolbukhin[disambiguation needed]-Seiskari region. Near the Estonian coast, they were bounced by ten Soviet fighters. But the Finnish quickly reacted and managed to down three of their opponents. WO Juutilainen was credited with two kills. All in all, Juutilainen scored 34 victories in Brewster B-239, 28 of them (including three triple kills) between 9 July 1941 and 22 November 1942, in his BW-364 "Orange 4". In 1943, he was transferred to LeLv 34, which used new Messerschmitt Bf 109G-2s. With the Bf 109, he shot down a further 58 enemy planes. He refused an officer commission, fearing it would keep him from flying. His 94th and last victory was a Li-2, the Russian version of the Douglas C-47, shot down on 3 September 1944 over the Karelian Isthmus. After the wars, he served in the air force until 1947. He worked as a professional pilot until 1956, flying people in his De Havilland Moth. His last flight was in 1997, in a double-seated F-18 Hornet of the Finnish Air Force. Juutilainen died on his 85th birthday on 21 February 1999.