United States of America

The pilot reported that during a climb after takeoff, he engaged the autopilot. While making an entry on a trip sheet, he felt a bump and noted that the aircraft had started to descend. He disengaged the autopilot and the nose pitched down violently. Reducing power had an adverse effect, so he increased power again. He finally leveled the aircraft just prior to impacting in a field at cruise power. The elevator trim tab cables were found to have been crossed between the tab actuator and the pulley in the tail cone. The tab was also found fully trimmed nose down. The aircraft had just been given an annual inspection during which the elevator trim actuator had been removed, inspected and lubricated. This was the first flight since the inspection. All eight occupants escaped with minor injuries.

The aircraft collided with a utility pole and a large tree during a forced landing after a power loss on takeoff. Witnesses heard the aircraft backfiring and the ground run was excessively long. Immediately after takeoff the aircraft went through the tops of pine trees. The backfiring and smoke stopped after the collision with the pine trees and the aircraft started a descent toward a street. It maneuvered as if to avoid a collision with cars. After the accident the spark plugs from the right engine were tested and all but #5 front plug would not spark. However during a subsequent test the spark plugs, with the exception of #5, did test properly. A complete engine teardown did not reveal evidence of mechanical failure or pre-impact engine discrepancy.

After takeoff, the aircrew flew to the southern end of Lake winnebago where they made several uneventful water landings. They estimated that the wind was from the northeast at 5 to 6 knots. The water was described as smooth with only small ripples. On the 6th approach, the gear handle was checked in the up position and the amber gear up indicator light was illuminated. The amphibious aircraft touched down on the water with no bounce or porpoise. About 2 or 3 seconds after touchdown, the aircraft yawed violently to the right and rolled left. The left float and wing tip hit the water and the left wing separated. The hull rolled over, but the occupants egresed before the aircraft sank. A diver noted that the right gear was extended. After the aircraft was recovered, the right main gear actuator rod clevis was found to have fractured. The fracture surface had signs of overload failure. The lock nut had been screwed tightly against the clevis and the lock nut threads had produced gouge marks on the unthreaded portion of the shank of the clevis.

The aircraft crashed in a level, wooded area. The initial impact with trees occurred approximately 40 feet agl. Both wing tips and a portion of the left stabilizer and elevator were found at the bases of the trees that were first impacted. From the first impact point, the wreckage was disintegrated and scattered over an area that was 30 feet wide and 140 feet long. No known eye witnesses were reported. However, a short time before the accident, the aircraft was observed being flown in abrupt maneuvers and buzzing boats. A toxicological exam of the pilot's blood showed an alcohol level of 2,41‰. An exam of the wreckage was made, but no preimpact/mechanical malfunction or failures were found. The passenger was killed while the pilot was seriously injured.

At about 60 feet agl black smoke was observed coming from the left engine. The aircraft continued a climb in a nose high attitude and the nose pitched down and the aircraft rolled inverted. Engine teardown revealed extensive damage to the supercharger assembly. The impeller shaft was bent and its associated bearing damaged. The aircraft had not flown for about 14 years. Engine service instructions describe pre-oiling of the supercharger drive shaft bearing after any prolonged period of inactivity. The owner, a paraplegic, was seated in the left seat. The pilot seated in the right seat had a history of heart and pulmonary disease. The gear and flaps were in the down position. Prior to departure, a witness asked the owner 'are you doing the elevators and ailerons and is he your rudders.' the owner responded with 'we have an arrangement'. Both occupants were killed.

While turning from downwind to base leg, the aircraft was observed descending rapidly in a steep bank. Witnesses reported smoke was trailing from the aircraft. The aircraft crashed in an industrial area. An exam of the right engine revealed that the exhaust-to-turbo adapter, pn 641829, had fractured and separated. The fracture was a result of thermal fatigue and it had propagated across more than 95% of the area before final separation had occurred. Since an exam of the cowling and both engines showed no streaking heat or smoke patterns, the reported 'smoke' was attributed to exhaust gas. While there was a loss of power in the right engine, no other aircraft malfunctions were found that would have caused loss of control. All six occupants were killed.

The aircraft took off with 4 occupants and an estimated 596 lbs of cargo on board. After it took off, the ATC controller noted that it was climbing slower than expected. After climbing to about 4,200 feet msl, the aircrew reported a problem with the left engine and said they did not believe they could make it back to the departure airport. They expressed a desire to continue toward the southwest. ATC proceeded to vector them to the Weston Airport, but informed them that it had no instrument approach. After the reported engine malfunction, ATC personnel noted that the aircraft continued in a gradual left turn. About 8 minutes after takeoff, radio contact was lost. A witness on the ground saw the aircraft come over a hill with the sound of an engine at high power. At about that time, the aircraft collided with a power line cable, then crashed into two trees, impacted the ground and burned. An examination of the wreckage revealed no significant preimpact failures. The aircraft was estimated to be approximately 400 lbs over its max certificated gross weight. All four occupants were killed.

The copilot stated that when he began the approach to the destination airport, the weather condition was hazy and he delayed his descent slightly until he located the airport. When he saw the runway, he believed that they were a little too close, so he indicated to the captain that he would like to make a 360° turn. At that point, the captain assumed control of the aircraft and continued the approach to runway 04. According to witnesses, the aircraft touched down long. According to the captain, he tried several applications of the normal braking system, but got no response. He then tried the emergency brakes and asked the copilot to get on the brakes, but reported there was no braking. Subsequently the aircraft went off the end of the runway, went over an embankment and hit a fence. It came to rest on a second embankment where it exploded and burned. Tire marks with evidence of braking action were found starting 2,377 feet beyond the runway threshold. A required field length of approximately 2,600 feet was calculated for landing. No pre-impact part failure/malfunction was found. VASI lights were inoperative. Both pilots escaped with minor injuries.

Just after touchdown the aircraft rolled over a frost heave on the runway surface and began veering to the right. The pilot applied left brake and added power to the right engine but the aircraft continued going right until the right wing struck a hill adjacent to the right side of the runway. The aircraft came to rest in a ditch 110° to the right of the landing runway heading. Examination of the right main landing gear tire revealed a large jagged opening in the sidewall which extended into the tread area of the tire. This opening matched one of the sides of a rock found in the vicinity of the frost heave. The aircraft maintenance logbooks were reviewed and found to have no record of compliance with airworthiness directives. Both pilots escaped uninjured.

For unknown reasons, the seaplane landed hard on Walker Lake and came to rest. All three occupants were able to evacuate the cabin in time before the wreckage would sank by 200 feet depth.