Des Moines

N81589 was following a Boeing 727 on ILS approach in IFR conditions. Approximately 2.5 miles from runway, N81589 suddenly deviated left nearly 90°. 39 seconds later, pilot reported he encountered severe turbulences, then said he was trying to climb. N81589 subsequently flew thru tree tops on rising terrain for approximately 2 city blocks, then hit power lines and a pole and crashed against a tree. No evidence of turbulences due to weather at/near approach altitude. Investigation showed 4.7 miles separation between aircraft when the 727 passed the point of deviation (pod). At pod, the 727 was on the ILS glide slope at 850 feet; N81589's altitude was not determined. Wind was from 120° at 3 to 6 knots, shifting more southerly withalt. Prevailing visibility was 1/2 mile; RVR for runway 12L was 6,000 feet; light rime icing was reported. Witnesses heard power interruption of one engine at pod; but there was no indication of power loss where aircraft hit trees. Radar data showed aircraft slowed to 80 knots at pod, accelerated to 100 knots during deviation, slowed to 70 knots before impact; vmca was 74 knots. Safety board believes the pilot most likely lost control due to slow speed and light airframe icing; possibly encountered wake turbulences. No reason found for loss of engine power. All seven occupants were killed.

At 2015 the flight contacted ARTCC and requested Dubuque weather. They were advised that Dubuque was 500 feet indefinite ceiling, sky obscured, visibility 1/2 mi fog and they would be vectored for a back course runway 13 approach. The flight then requested the front course approach to runway 31 and the controller advised the flight that it would be vectored to the ILS front course approach to runway 31. Approximately 40 seconds later the flight advised the controller that it would take the back course approach to runway 13. The landing minima for a straight-in ILS runway 31 is 1/2 mile visibility and for a straight-in LOC/DME back course approach to runway 13 3/4 mile visibility. The aircraft's wreckage was found in a valley about 3/4 mile short of runway 13 and approximately 100 feet below the runway elevation about two days after the crash. Both occupants were killed.

On approach to Kansas City-Charles B. Wheeler-Downtown Airport, the pilot encountered very bad weather conditions with low ceiling, fog and windshear. In a zero visibility, he failed to realize his altitude was too low when the airplane struck trees and crashed in flames few miles short of runway 19 threshold. The aircraft was destroyed upon impact and all three occupants were killed.

The airplane crashed while landing on runway 09 at Detroit-Metropolitan-Wayne County Airport. The airplane was returning executives of Massey-Ferguson, Inc., to South Bend, Indiana, Detroit, Michigan, and Toronto, Canada, following a meeting at the company's headquarters in Des Moines, Iowa. During the descent, the aircraft flew in light to moderate, occasionally severe icing conditions. Shortly before the Learjet was to land, a McDonnell Douglas DC-9 was cleared for takeoff. Witnesses saw the Learjet cross the threshold in a normal landing attitude and seconds later roll violently. The airplane was in a steep right bank when the wing tip tank struck the runway 2,440 feet from the threshold and the airplane burst into flames. The two pilots and four passengers were killed.

On final approach, the crew failed to realize his altitude was too low when the airplane struck an embankment located 300 feet short of runway 03 threshold. Upon impact, the undercarriage were torn off, the airplane nosed down and crashed. Both pilots were injured and the aircraft was damaged beyond repair.

While cruising by night on a cargo flight from Des Moines to Chicago, the pilot encountered engine problems and decided to divert to Muscatine for an emergency landing. Due to lack of visibility, he was unable to locate the runway and completed three low passes then started an approach to runway 12. On final, the airplane struck the ground and crashed about 1,245 feet short of runway. The aircraft was destroyed and the pilot was killed.

During the takeoff roll, the pilot-in-command attempted to rotate when an unexpected situation was encountered. The captain decided to abort the takeoff and started an emergency braking procedure. Unable to stop within the remaining distance, the airplane overran and struck ditches before coming to rest in a field. While all four passengers were unhurt, both pilots were seriously injured. The aircraft was written off.

Flight 329 departed Des Moines on a VFR (Visual Flight Reed) night plan at 1608 for Omaha, Nebraska. The gross weight of the aircraft was 45,215 pounds 1,685 pounds less than the allowable 46,900 pounds. According to company records, the load was properly distributed with respect to the canter of gravity of the aircraft. The climb to 5,000 feet was uneventful but at that altitude the crew noticed vibration and a slight fore-and-aft movement of the control column. The climb was continued to 6,000 feet, where the aircraft was leveled off and power was reduced. As the vibration was still present at this time, the captain attempted to dampen it by engaging the autopilot; however, this was unsuccessful and it was immediately disengaged. The first officer next lowered the flaps, first to 5 degrees and then to 15 degrees, without any noticeable effect. The “Fasten Seat Belt" sign was turned on and the captain told the first officer to advise the company of their difficulty via radio. About this time a sudden failure in the control system was felt and it was with extreme difficulty that any semblance of elevator control was maintained. The first officer again tried lowering the flaps, this time to the 24-degree position, but as this did not help to maintain control he returned them to the 15-degree position, where it was found the most favorable results were attained. Accordingly, the first officer transmitted "Mayday” (distress call) on the radio and said that they were attempting to return to Des Moines but were experiencing control trouble. The buffeting became so severe it was then necessary for the copilot to help the can hold the control column. However, the buffeting lessened and the captain advised the first officer to depressurize the aircraft and tell the stewardess to prepare the passengers for an emergency landing. This was done. By that time the aircraft had descended below 3,000 feet. Both throttles were retarded in turn to see if the trouble could possibly be caused by one of the engines. This also proved to no avail. The vibration built up to high level and suddenly another failure in the control system was felt and the air-plane went into a steep climb. As it seemed that a stall was imminent, the captain quickly moved the propellers to a high r. p. m. and pushed the throttles forward until about 50 inches of manifold pressure was seen on the gauges. The airplane then nosed over and began to dive at a very steep angle. During this rapid descent the captain reduced power and headed toward open country to his right. When the aircraft reached 500 feet above the ground the captain was successful in flaring the aircraft and it struck the ground in a flat attitude. All occupants were quickly deplaned as soon as the aircraft stopped.

The aircraft arrived at Cheyenne, Wyoming at 0038, May 22, on a Civil Air Movement flight (military contract) from New York International Airport. The incoming pilots had no mechanical or radio discrepancies to report. After the aircraft was serviced, Captain Bowen F. Marshall and Copilot Samuel B. Aronson relieved the incoming crew for the purpose of ferrying the aircraft to Chicago, at which point, the pilots were to turn it over to another crew. Both pilots visited the U. S. Weather Bureau Airport Station at Cheyenne for weather briefing; all current weather information through 2330 (including three severe weather warnings) was on file and available to them. The aircraft departed Cheyenne at 0132, on an instrument flight plan to O’Hare Airport, Chicago, via Green Airway 3 and Red Airway 42 at 7,000 feet. Neither passengers nor cargo was carried and the center of gravity was within permissible limits. Routine position reports were made over Sidney, North Platte, Grand Island, and Omaha, Nebraska. In the last position report, at 0337, the flight reported to Omaha INSAC (Interstate Airways Communication Station) that it was over Omaha at 7,000 feet, estimating over Des Moines at Ohio. Three minutes later, the pilot again contacted Omaha INSAC and requested a change of altitude to 3,000 feet. Air Route Traffic Control, through Omaha INSAC, advised the flight that the 3,000-foot altitude was unavailable until arrival over Des Moines owing to a westbound flight proceeding at 2,600 feet between Des Moines and Omaha, and the request for descent would have to be disapproved. The flight was given the latest weather information between Omaha and Chicago, and the Des Moines 0327 weather, and there were no further radio contacts after this. Des Moines tower personnel received a telephone call at 0517 notifying them of the crash. The aircraft was destroyed and both pilots were killed.