Kenneth Oscar Chilstrom (April 20, 1921 – December 3, 2022) was a United States Air Force officer, combat veteran, test pilot, and author. He was the first USAF pilot to fly the XP-86 Sabre, chief of fighter test at Wright Field, commandant of the U.S. Air Force Test Pilot School, and program manager for the XF-108 Rapier. Chilstrom was a pilot in the first jet air race and delivered the first air mail by jet. He flew over eighty combat missions in the Italian Campaign of World War II and tested over twenty foreign models of German and Japanese fighters and bombers to evaluate their strengths and weaknesses.

Chilstrom was born on April 20, 1921, in Zumbrota—a small town in the southeast part of Minnesota. He developed an interest in aviation at an early age and began building model airplanes while still in grade school in Chicago, Illinois. After graduating from high school in 1939, Chilstrom went to a military recruiting office to sign up for pilot training. Since he did not have the two years of college needed to enter the air cadet training program, Chilstrom enlisted in the United States Army Air Corps to train as an aircraft mechanic.

Chilstrom completed the aircraft mechanics school at Chanute Field in Rantoul, Illinois, and eventually became an instructor. Still yearning to fly, he attended night school to earn the needed college credits. But the Army Air Corps now faced a shortage of pilots, and Chilstrom was accepted into the pilot training program anyway. In October 1942, he earned his wings and a second lieutenant's commission when he graduated with class 42I at Lake Charles, Louisiana. Chilstrom was assigned to the 58th Fighter Group at Bolling Field whose mission was to guard the nation's capital in Washington, D.C.

In February 1943, the 58th Fighter Group received new Curtiss P-40 Warhawks and took them to North Africa aboard the USS Ranger. Chilstrom and his fellow aviators arrived at an airfield near Casablanca shortly after the Allied defeat at Kasserine Pass. The 58th Fighter Group was forced to turn over their P-40s to a combat-experienced unit that lost their aircraft when German troops overran their airfield. Chilstrom transferred to the 27th Fighter Bomber Group and flew eighty missions in the North American A-36 over Sicily and Italy. At the end of his tour in November 1943, he returned home to the United States.

Chilstrom strongly desired a position in flight test at Dayton, Ohio's Wright Field—the dream job of many fighter pilots. Although no flight test positions were open at the time, he was able to secure a position as maintenance officer for Major Chris Petrie, Chief of Fighter Test. Flight test at Wright Field expanded rapidly and provided Chilstrom with the opportunity to realize his dream. He tested a number of P-47 Thunderbolt variants including the XP-47E with a pressurized cockpit and the XP-47J—one of the fastest piston engine fighters ever built.

During his seven years in flight test, Chilstrom flew 147 different aircraft including X, Y, and production models from the United States, Germany, and Japan. Many German and Japanese aircraft captured during World War II were sent to Wright Field, and Chilstrom had the opportunity to fly and evaluate over twenty different models including the Focke-Wulf Fw 190, the Messerschmitt Me 262, the A6M Zero, and the Kawasaki Ki-45 Nick. He flew the Fw 190 extensively and during his tenth flight on February 24, 1945, a malfunctioning trim switch nearly killed him. Chilstrom was landing at Wright Field when the elevator trim switch malfunctioned causing the nose to pitch up while the Fw 190 was dangerously close to the ground. After regaining control and climbing to a safe altitude, he identified the problem and determined the trim could also be driven to a full nose-down position. With full nose-down trim, Chilstrom had just enough control to successfully land the aircraft. Other Fw 190 pilots were not as fortunate as electrical problems in the trim switch caused or were suspected to have caused a number of crashes.

Chilstrom flew the United States' first twin jet engined fighter aircraft—the Bell P-59 Airacomet. In February 1945, while delivering a P-59 to Langley Field, he experienced an engine failure during take off that resulted in a runway excursion. Unable to stop or take off, Chilstrom crashed into a stand of trees just past the end of the runway. Although the P-59 was destroyed, Chilstrom survived one of the first major jet accidents in a U.S. military aircraft with only minor injuries.

Chilstrom graduated in the first group, class 45, of the recently formed Flight Performance School (now known as the United States Air Force Test Pilot School) with his friend and roommate Glen Edwards, who would later become the namesake of Edwards Air Force Base. Chilstrom was highly regarded by his superiors and in September 1946 succeeded Gabby Gabreski as chief of the Fighter Test section. He was in charge of a very select group of pilots including Richard Bong, John T. Godfrey, Bob Hoover, Don Gentile, Steve Pisanos, and Chuck Yeager. In 1947, Lieutenant Colonel Fred Ascani, deputy of the Flight Test Division, recommended Chilstrom fly the Bell X-1 on the historic mission to break the sound barrier, but division commander Colonel Al Boyd wanted Chilstrom as project officer for the XP-86 Sabre. Chilstrom was the first Air Force officer to test the XP-86, and by December 1947 had completed the XP-86 Phase II performance, stability and control tests pushing the aircraft to 45,000 feet (14,000 m) and Mach number 0.9.