Cessna 421C Golden Eagle III

Prior to the accident flight, the pilot indicated that he was aware of the thunderstorm activity along his route of flight and that he anticipated deviating around the weather as necessary. While enroute to his destination, the pilot requested and was provided both weather information and pilot reports from other aircraft by air traffic control (ATC). Upon encountering an area of thunderstorm activity that extended east-to-west across the route of flight, the pilot reported encountering significant turbulence, and then downdrafts of 2,000 feet per minute. He then requested a course reversal to exit the weather before he declared an emergency and advised ATC that the airplane was upside down. There were no further transmissions from the pilot and radar contact with the airplane was lost. Review of radar data revealed that the pilot had deviated south and then southwest when the airplane entered a strong and intense echo of extreme intensity. Visible imaging revealed that the echo was located in an area of a rapidly developing cumulonimbus cloud with a defined overshooting top, indicating the storm was in the mature stage or at its maximum intensity. Two debris fields were later discovered near the area where the cumulonimbus cloud had been observed. This was indicative that the airplane had penetrated the main core of the cumulonimbus cloud, which resulted in an inflight breakup of the airplane. Near the heavier echoes the airplane's airborne weather radar may have been unable to provide an accurate representation of the radar echoes along the aircraft's flight path; therefore the final penetration of the intense portion of the storm was likely unintentional.

Shortly after take off from Hamburg-Fuhlsbüttel Airport, the pilot informed ATC that he lost all his navigational instruments and was cleared to divert to Hamburg-Finkenwerder Airport. On final, he encountered difficulties to lower the gears and eventually ditched the aircraft in the Elbe River. The aircraft came to rest upside down in 0,8 meter of water and was destroyed. The pilot escaped with minor injuries.

The twin engine aircraft departed Madrid-Torrejón AFB on a charter flight to Pamplona with 4 businessmen and a crew of two on board. While descending to Pamplona-Noain Airport, the crew encountered marginal weather conditions. Unable to establish a visual contact with runway 15, the crew initiated a go-around procedure. Few minutes later, while flying at an insufficient altitude, the aircraft impacted ground and crashed in a hilly terrain located in the Sierra de Tajonar, near the village of Labiano. The copilot and a passenger were killed while all other occupants were seriously injured. The aircraft was totally destroyed by impact forces and a post crash fire.

During a cross country flight, the pilot was informed by air traffic control that adverse weather was along his route of flight for terrain obscurement in clouds, precipitation, fog or mist. Turbulence was reported below 12,000 feet and occasional moderate rime or mixed icing was reported from the freezing level to 14,000 feet. Further along the route, the pilot reported to another controller that he was at 13,000 feet and descending. The controller inquired if the pilot was aware of the center weather advisory and the reports of severe rime ice in the direction that he was heading. The pilot acknowledged the controller by reporting that he was aware of the weather and that the aircraft was "equipped." The controller continued to inform the pilot of pilot reports from commercial aircraft flight crews of the reports of icing conditions, however, the pilot continued on his routing and again reported that the aircraft was "equipped." During the last transmissions from the pilot, he reported that he was "turning on (de-ice) equipment now." The controller recommended to the pilot to stay clear of the clouds. The pilot responded, "roger." The controller then asked the pilot if he was "going to orbit there for awhile." The pilot responded, "yes," followed by a partially unintelligible transmission of "getting some weather here." The pilot's last transmissions were "Ah, I'm in a little trouble," followed by "Ah, standby 9KM." Radar tracking indicated that the aircraft had been cruising at 16,500 feet before starting a gradual descent. The aircraft descended to 12,700 feet and it began a turn to the right. During this turn, the aircraft's altitude changed rapidly beginning with an increase, followed by a rapid loss of altitude from 8,000 feet per minute descent to 10,600 feet per minute descent before radar contact was lost. The aircraft was found 6 months later in an area of mountainous terrain. On site evidence indicated that the aircraft collided with trees and terrain in a nose low attitude with the majority of the wreckage contained in a large deep crater.

Northrepps Airfield has a single grass runway, orientated 18/36, and 1617 ft (493 m) long, with a down slope of 1.8% on Runway 18. On the day of the accident, the short grass was wet and an aftercast indicated that the wind at Northrepps was from approximately 210º at 10 to 13 kt. The pilot first flew an approach to Runway 18 and touched down close to the threshold; he subsequently reported that, looking at the slope of the runway ahead of him, he decided to go around and re‑position for a landing on Runway 36, to take advantage of the up-slope on that runway. The pilot stated that, during the approach to Runway 18, he had assessed that the braking effect of the wind would be insignificant in comparison to the braking effect that would be afforded by the uphill slope when landing on Runway 36. The pilot recalled seeing a “shortened” and “non‑standard” windsock mounted on a caravan adjacent to the Runway 18 threshold, but he did not believe that it could be relied upon for an accurate wind strength determination. He did not recall having seen the airfield’s other, larger, windsock. The approach for a short field landing on Runway 36 was normal and the pilot closed the throttles just before the threshold. The aircraft touched down close to the threshold, and the pilot immediately retracted the flaps. The pilot reported that he had lost two thirds of his touchdown speed by about the mid-point of the runway, and that the braking was within his expectations. He subsequently stated that he “seemed to get to a point… when I realised that I was effectively getting no braking at all from the wheels and the uphill slope had petered away”; he then experienced a sensation which he described as being similar to aquaplaning, with all braking authority seemingly lost. The aircraft continued along the runway, crossed the grassed overshoot area, ran over an earth bank beyond the end of the runway and came to rest on a public road just north of this bank. The pilot shut the aircraft down and all three occupants vacated the aircraft without difficulty.

The twin-engine airplane sustained substantial damage when it impacted the top of a single story industrial building and then impacted a landscape embankment and trees during an attempted single-engine go-around. The pilot reported that the left engine failed during initial climb. He feathered the left propeller and returned to the airport to execute an emergency landing. The pilot reported that he had "excessive speed" on final approach and "overshot the runway." When the airplane was at mid-field, the pilot elected to do a go-around. He did not raise the landing gear and the flaps remained about 15-degrees down. The airplane lost altitude and impacted the terrain about .5 miles from the airport. A witness reported seeing the airplane attempt to land on the runway twice during the same approach, but ballooned both times before executing the go-around. The Pilot's Operating Handbook (POH) "Rate-of-Climb One Engine Inoperative" chart indicated that about a 450-foot rate-of-climb was possible during the single-engine go-around if the airplane was in a clean configuration. The chart also indicated that a 350-foot penalty would be subtracted from the rate-of-climb if the landing gear were in the DOWN position, and additionally, a 200-foot penalty would be subtracted from the rate-of-climb if the flaps were in the 15-degree DOWN position. Inspection of the left engine revealed that the starter adapter shaft gear had failed. Inspection of the engine maintenance logbooks revealed that the Teledyne Continental Motors Service Bulletin CSB94-4, and subsequent revisions including the Mandatory Service Bulletin MSB94- 4F, issued on July 5, 2005, had not been complied with since the last engine overhaul on July 17, 1998. The service bulletin required a visual inspection of the starter adapter every 400 hours. The engine logbook indicated that the engine had accumulated about 1,270 hours since the last overhaul. The service bulletin contained a WARNING that stated, "Compliance with this bulletin is required to prevent possible failure of the starter adapter shaft gear and/or crankshaft gear which can result in metal contamination and/or engine failure."