approach to Minneapolis. The last reported altitude was 7,000 ' . One item of important evidence was known immediately...parts of the aircraft were separated by over two miles, indicating an in-flight problem. Before an official investigation began another incident occurred. A second NWA M2o2 had flown through the same area about an hour later, encountered some turbulence including a couple of severe jolts, and landed at MSP with no problem. The plane continued with a flight to Duluth and return. On the ground, at MSP, a mechanic noticed a discontinuity with one wing. Further investigation showed a failure in the step-splice, which joined the outer wing panel to the center section. All of the remaining 24 NWA M202 's were immediately grounded. Later on in the investigation it was determined that 5 other planes had fatigue cracks in this critical area, three of which had minute cracks in both wing joints! Another wing, which had been-used for the factory static tests, was found to have small cracks that had been covered by chrome paint. This wing had been cycled 1,885 times with a load from 30 to 100% over designed maximum strength. The airplane that crashed had 1,321 flying hours, which was about the average in NWA's fleet of 202s. The immediate "fix" was to beef up the wing root fitting or splice and frequent inspections of the affected areas. This was considered temporary, until 3,000 hours of flight. The CAA added: "After 3,000 hours of flight have been accumulated on the aircraft or before, the airplane will be modified at the Martin plant with a permanent correction which involves extensive structural changes to the wing." After the preliminary modification, the 202S were in the air again, one month after the accident. The stigma, however, remained. Ironically, on the same day as the crash, another NWA 202 experienced a serious problem when the front cargo door blew off. A safe landing was made at Spokane, although extensive damage was done to the fuselage, center wing and stabilizer. During the "teething" period with a new airplane there were always some initial "bugs" which needed correction. If safety was involved there was an "AD" (a CAA Airworthiness Directive), which would mandate a correction or modification within a specified period of time. Some of the early AD's for the M2o2, which the NWA pilots experienced the hard way (flying the line), had to do with cracks in the cabin heater system, problems with the propellers, autopilot servo system and excessive hydraulic leaks. One AD ordered the removal of all fiberglass (or rubberized) and vinyl lining from both the forward and aft belly cargo compartments as this was acting like a blotter for leaking hydraulic fluid. Oxygen tanks or lines were also located in these areas, which added to the potential fire hazard. One NWA flight experienced such a fire. There were a number of cases where a failure of the nose gear centering cam made it impossible to lower the nose gear for landing (another ` AD ' ). One very enterprising pilot had this situation and, before landing, ordered all passengers to sit or stand as near to the rear of the cabin as possible. With this tail-heavy load he was able to hold the plane in a nose-high attitude during the rollout to a stop after landing (no brakes were used) on the runway. The engines were then stopped. The nose remained high, and a flatbed truck was positioned to where the nose wheel would normally be supporting the plane. One by one a passenger would move forward and the nose gradually settled on the truck's bed. The truck then towed the plane to the ramp. There the passengers deplaned without further incident. The only damage to the plane was where the tail had scraped the runway due to the nose-high attitude.
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