Northwest Airlines Flight 421 Crashes, Killing 37

Northwest Airlines Flight 421 was a domestic scheduled passenger flight from Chicago, Illinois to Minneapolis, Minnesota that crashed on 29 August 1948.

The Martin 2-0-2 aircraft, operated by Northwest Airlines, suffered structural failure in its left wing and crashed approximately 4.1 miles (6.6 km) northwest of Winona, Minnesota, approximately 95 miles (153 km) southeast of Minneapolis. A Civil Aeronautics Board investigation determined that the crash was caused by fatigue cracks in the wings of the aircraft, and recommended lower speeds and frequent inspections of all Martin 2-0-2 aircraft. All 33 passengers and four crewmembers onboard were killed. The crash was the first loss of a Martin 2-0-2, and remains the worst accident involving a Martin 2-0-2.

Northwest Airlines' Flight 421 departed from Chicago for Minneapolis at 15:50. At 16:55 the flight reported over La Crosse, 125 miles southeast of Minneapolis, and was at that time cleared to start an en route descent from its cruising altitude of 8,000 feet. Four minutes later the flight reported passing through the 7,000-foot altitude level. The flight proceeded in the direction of Winona where it encountered a thunderstorm. Flight 421 was seen flying below the overcast. As it passed over Winona, the aircraft appeared to enter the roll cloud or the leading edge of the thunderstorm at which time it was lost from view. Seconds later parts of the airplane were observed falling. It was later found that the flight had crashed approximately 4 miles northwest of Winona on a bluff on the east side of the Mississippi River.

When an airliner crashes, the airlines and manufacturers scramble to find out what happened and why, but they seldom accuse each other in public of laxity. They prefer to sweep the accident under the rug and out of sight. Last week Croil Hunter, boss of Northwest Airlines, took another course. His airline sued the Glenn L. Martin Co. for $725,000, charging that five Martin 2023 which it had bought in 1947-48 were defective. The wing of one of them, said Northwest, "tore off in flight," during a storm, killing 36 passengers and crewmen near Winona, Minn., last Aug. 29. Another 202 broke a wing spar the same day but landed safely.

In Chicago on that Aug. 29, Northwest Airlines flight 421 took off at 3:50 p.m. with 34 passengers headed to Minneapolis.

The captain was Robert Johnson, a 30-year-old South Dakota native. Like his co-pilot, David Brenner, he had joined Northwest in the early 1940s and had served as a civilian pilot during the war. Their hostess was a 26-year-old nurse, Mary Ungs, who had joined the airline after serving in the Army.

They flew in a new Martin 2-0-2, a fast, "ultramodern" twin-engine plane designed to replace the DC-3, the commercial airlines' workhorse since the mid-1930s. They would have enjoyed luxuries like "cloud-soft seats," reading lights and air conditioning.