SITKA, AK, USA
N357SX
Buesing SX-300
The homebuilt airplane was being operated as an IFR cross-country flight over mountainous/coastal terrain. While cruising at 14,000 ft, about 19 miles from the nearest airport, the pilot encountered a low engine power condition. He declared an emergency, & was given vectors to the airport. The airplane was capable of gliding about 24 miles from 14,000 ft, but was ditched in the ocean, about 5 miles from the airport. The occupants did not egress from the airplane before it sank. The airplane engine had a ram air/alternate air box attached to the fuel control servo which controlled the engine air source. Ram air was unheated & unfiltered, & was to be used when operating in clear/dry air conditions. Alternate air was heated & filtered, & was to be used during an engine emergency, takeoff & landing, when flying in dusty air, or when in conditions where inlet icing could be expected (visual moisture & temperatures of 40 deg F or below). The airplane's air control was found in the ram air position. Weather conditions near the accident site included a temperature & dew point of 35 deg with snow & ice pellets. Upper air conditions along the route of flight included temperatures between -28 to -45 deg C, & humidity levels between 69 & 81 percent. An AIRMET had been issued for the area. It included a caution for light & temporary moderate icing in clouds & in precipitation from 1,000 ft to 12,000 ft. The freezing level was 1,000 ft. The pilot was provided a PIREP that indicated a trace of ice had been encountered in the area.
HISTORY OF FLIGHT On March 7, 1997, about 1411 Alaska standard time, the pilot of an experimental homebuilt Buesing SX-300 airplane, N357SX, declared an emergency and ditched in the ocean about 5 miles south of Sitka, Alaska. The airplane was being operated as an instrument flight rules (IFR) cross-country personal flight to Soldotna, Alaska, when the accident occurred. The airplane, registered to and operated by the pilot, was destroyed. The certificated private pilot, and the sole passenger received fatal injuries. Visual meteorological conditions prevailed. An IFR flight plan was filed. The accident flight originated at the Ketchikan International airport, Ketchikan, Alaska, at 1310. At 1211, the pilot obtained a weather briefing at the Federal Aviation Administration's (FAA) Ketchikan Flight Service Station (FSS), as part of his continuing flight from Colorado Springs, Colorado, to Soldotna, Alaska. The pilot filed an IFR flight plan with the intended route from Ketchikan as; Annette VOR, Victor Airway 311 to the Biorka VOR, Victor 440 to the Yakutat VOR, Victor 319 to the Johnstone Point VOR, then direct to Soldotna. After departure from Ketchikan, the pilot contacted the FAA's Anchorage Air Route Traffic Control Center (ARTCC). The airplane climbed to 14,000 feet mean sea level (msl), and proceeded along Victor 311 toward the northwest. At 1406:00, the pilot declared an emergency by stating: "Ah center, this is experimental 7SX, I got ah loss of power on the engine, I need to land." The pilot was initially given a clearance to the Sitka Airport via the LDA/DME approach to runway 11. The pilot then requested a heading straight to Sitka, stating he was not going to be able to maintain altitude very well. The controller provided instructions to fly a heading of 280 degrees and maintain 5,000 feet. At 1406:47, the pilot inquired about his distance from the Sitka Airport. The ARTCC controller indicated the airplane was 13 miles from the airport, and asked the pilot to confirm the airplane had no power. The pilot replied, "nah, very low power." At 1407:34, the controller inquired about the flight conditions. The pilot replied, "I'm in the clear." At 1407:54, the controller provided the pilot with the current weather conditions at Sitka, which included a ceiling of 2,000 feet overcast conditions. At 1408:19, the pilot reported, "Ah kay, we're at 6,500, I don't think we're going to make it." The ARTCC controller provided a suggested heading to the Sitka Airport of 340 degrees, below the minimum enroute altitude (MIA), and began providing terrain elevations for the area. At 1408:57, the pilot reported, "I'm passing through five (unintelligible) five thousand, and I, um, I'm going down at about 2,000 foot a minute." At 1409:48, the ARTCC controller suggested a heading of 360 degrees, stating it would keep the airplane over water, all the way to the Sitka Airport, which was 8 miles away. The controller inquired if the airplane, at its present rate of descent, could make the 8 miles. The pilot replied that he did not think so. At 1411:07, the controller advised the pilot, "And ah NSX, radar contact is lost, say flight conditions." The pilot replied, "We're in the clear." The controller suggested a heading of 350 degrees, and indicated it was 6 miles to go from the last known position. The controller also inquired about the airplane's altitude. The pilot replied, "We're at 1,300 feet." The controller inquired if the pilot could see the water and/or land. The pilot replied to the affirmative. At 1411:42, the controller inquired, "N7SX, you going to ditch in the water or do you think you can make the land." The pilot replied at 1411:45, "Ah ditch in the water if I have to ditch." At 1411:54, an unknown voice was heard on the radio frequency, saying: "Check your crossfeeds, check your cross fuel crossfeeds." There was no further radio contact with the pilot. The accident occurred during the hours of daylight at latitude 56 degrees, 58.79 minutes north, and longitude 135 degrees, 23.11 minutes west. CREW INFORMATION The pilot held a private pilot certificate with airplane single-engine land, and instrument airplane ratings. In addition, the pilot held a repairman certificate, with an experimental aircraft builder rating, for the accident airplane. The most recent third-class medical certificate was issued to the pilot on November 11, 1996, and contained the limitation that the pilot must wear corrective lenses. No personal flight records were located for the pilot. The aeronautical experience listed on page 3 of this report, was obtained from the NTSB form 6120.1/2 submitted by the pilot's spouse, and from an application for aircraft insurance, dated April 9, 1996. AIRCRAFT INFORMATION The airplane and engine both accumulated a total time in service of 1020.62 hours. Examination of the maintenance records revealed that the most recent inspection was accomplished on August 31, 1996, 43.15 hours before the accident. Fueling records at Ketchikan, Alaska, established that the aircraft was last fueled on the accident date with the addition of 62.3 gallons of 100LL octane aviation fuel. The airplane is a high performance, single-engine, home built airplane. The normal operating speed for the airplane is between 92 and 249 knots indicated airspeed. The maximum airspeed limitation is 280 knots. At gross weight, the airplane's power off stall speed is 82 knots. With full flaps, the stall speed is 72 knots. The airplane was approved for day and night VFR operations, and day and night IFR operations. It was not approved for flight into known icing conditions. The airplane is equipped with a 300 horsepower, fuel injected, non-turbocharged engine. The airplane's pilot operating handbook (POH), Section VII, Systems Descriptions, 7.5 Induction System, states, in part: "Air for the engine induction system is available from two sources, the ram-air inlet located below the spinner on the front of the cowling or the alternate air source from inside the cowling. The ram air inlet lets unfiltered air directly into the engine induction system, whereas the alternate air provides warm, filtered air. The door position controlling the source of the inlet air is selected manually with a lever that is located on the control quadrant. The alternate air control should be in the HOT position when filtered, warm air is required - such as during takeoff or landing, when flying in dusty air, or when in conditions where inlet icing could be expected (visual moisture and temperatures of 40 degrees F or below). Otherwise, it should be the RAM position." The accident airplane's ram/alternate air control is controlled by a lever on the engine control quadrant. The pilot labeled the ram air position as "OPEN", and the alternate air position as "CLOSED." Section III, Emergency Procedures, 3.11 Engine Power Loss in Flight, of the POH, states, in part: "An airspeed of at least 125 knots should always be maintained. Altitude permitting, switch the fuel selector to another tank containing fuel and turn the electric fuel pump ON. Move the mixture control to RICH and the alternate air to HOT." The designer of the airplane reported the airplane's rate of climb data, contained in Section V of the POH, established performance figures at 130 knots. He utilized the performance data to calculate the airplane's anticipated descent rate at 130 knots, and the airplane's glide ratio, also at 130 knots. The designer indicated at 130 knots, the airplane would descend at 1,256.2 feet per minute. The glide ratio, at 130 knots and the landing gear retracted, would be 10.41 to 1. The cockpit area is enclosed by a canopy that is hinged along the upper edge of the firewall. The canopy is retained in the closed position by two latches located adjacent to each seat. The mating surface between the canopy and fuselage is equipped with an inflatable seal. METEOROLOGICAL INFORMATION The closest official weather observation station is Sitka. On March 7, 1997, at 1353, an Aviation Routine Weather Report (METAR) was reporting in part: Wind, 100 degrees (true) at 4 knots; visibility, 10 statute miles; clouds, few at 1,200 feet, 2,000 feet overcast; temperature, 02 degrees C; dew point, 02 degrees C; altimeter, 29.57 inHg; remarks, unknown pellets began at 1326, ended at 1328, snow ended at 1326. During the accident airplane's emergency descent, an Anchorage ARTCC controller contacted Sitka, Alaska, FSS personnel to obtain the local weather conditions. The Sitka FSS controller commented that the area around the airport consisted of a solid overcast; however, the weather conditions appeared better to the south of the airport, with areas of sunlight appearing through the overcast. Search personnel in Sitka, Alaska, reported areas of isolated rain and snow showers under overcast sky conditions. During the pilot's weather briefing at the Ketchikan FSS, the briefer reported he provided the pilot with a full route briefing, current weather conditions, area forecast, AIRMETs, NOTAMs, winds aloft, and pilot reports along the route. The area forecast for Sitka, issued on March 7, 1997, at 1019, and valid until March 8, 1997, at 0900, stated, in part: "Wind, 170 degrees at 6 knots; visibility, greater than 6 miles in light snow showers; clouds, 1,500 feet scattered, 2,500 feet broken. Temporary conditions from 1000 to 2300: Visibility, 3 miles in light snow showers and mist; clouds, 800 feet scattered, 1,500 feet broken, 2,500 feet overcast. From 2300: Wind, 240 degrees at 7 knots; visibility, greater than 6 miles in light snow showers; clouds, 1,500 feet scattered, 2,500 feet broken. Temporary conditions from 2300 to March 8, 1997, at 0900: Visibility, 5 miles in light snow showers; clouds, 1,000 feet scattered, 1,500 feet broken, 2,500 feet overcast." An Airmet for IFR conditions and mountain obscuration, issued on March 7, 1997, at 1145, for southeast Alaska coastal waters, and valid until March 8, 1997, at 0000, stated, in part: "Temporary ceilings below 1,000 feet, visibility below 3 statute miles with light snow, and ice pellet showers. No change. Otherwise, scattered clouds at 1,500 feet, broken clouds at 4,000 feet, and 8,000 feet. Layers above. Tops at 24,000 feet. Temporary conditions of broken clouds at 1,500 feet, visibility 3 statute miles in light rain, ice pellets, and snow showers. After 1500, surface winds from the southwest, gusting to 25 knots. Outlook, valid from March 8, 1997, at 0000 to 1800, marginal VFR conditions with ceilings due to rain, and snow showers. Turbulence: Isolated moderate turbulence below 6,000 feet. Icing: Light, with temporary moderate mixed icing in clouds and in precipitation, 1,000 to 12,000 feet. Freezing level: 1,000 feet. No change." When the pilot was taxiing for takeoff from Ketchikan at 1307:52, a Ketchikan FSS specialist informed the pilot of an in-flight weather advisory received at 1301 from the crew of a Boeing 737 airplane. The pilot report (PIREP), indicated that during descent, the Boeing airplane encountered a trace of ice, and the sky condition was 17,000 feet overcast. A National Transportation Safety Board, senior meteorologist, conducted an examination of the weather conditions around the accident scene. Between Ketchikan and Sitka, at 1400, infrared temperature data revealed that radiative temperatures ranged from about -12 to -47 degrees C. During the previous 25 nautical miles prior to the airplane's position at 1406 along V311, radiative temperatures ranged from -39 to -45 degrees C. Winds and temperatures aloft are recorded at radiosonde locations around the area. The 1500 upper air data from Annette Island, Alaska, located 175 miles southeast of the accident site, was recording, in part: At 14,002 feet, temperature, -28.4 degrees C; dew point temperature,-32.3 degrees C; humidity, 81 percent. The 1500 upper air data from Yakutat, Alaska, located 198 miles northwest of the accident site, was recording, in part: At 14,002 feet, temperature, -31 degrees C; dew point temperature,-38.4 degrees C; humidity, 69 percent. COMMUNICATIONS A transcript of the air to ground communications between the airplane and all involved FAA ATC facilities is included in this report. Continuous Data Reduction (CDR) radar data from Anchorage ARTCC, was reviewed by National Transportation Safety Board investigators to determine the flight track of the accident airplane. During the last 11 minutes of the flight, the radar data revealed the accident airplane was proceeding along V311 at altitudes between 14,000 to 14,200 feet msl. The CDR data was recorded every 12 seconds. At 1405:03, the altitude was recorded at 14,000 feet. The airplane was about 19 miles south of Sitka. At 1405:15, the airplane's altitude had dropped to 12,700 feet and thereafter, continued to descend. When the pilot declared an emergency at 1406:00, the airplane was descending between 10,700 and 10,000 feet, and was about 15 miles south of Sitka. A copy of the radar data is included in this report. WRECKAGE AND IMPACT INFORMATION The National Transportation Safety Board investigator-in-charge (IIC) examined the airplane wreckage in Sitka, Alaska, on March 14, 1997, after the airplane was recovered from the ocean. The airplane was observed in a hanger, resting upright, on its landing gear. All of the airplane's major components remained attached to the airplane. The right wing exhibited an upward bend and chordwise buckling of about 15 degrees, about 4 feet inboard from the tip. The right wing tip fairing was missing. The wing was crushed upward and aft along the lower surface of the leading edge, from the inboard attach point, to the point of chordwise bending. The wing had several tears, exposing the interior, wet wing tank, portion of the wing. The left wing was crushed upward along the underside of the leading edge. The wing was bent upward about 30 degrees, about 4 feet inboard from the tip. The wing tip fairing was missing. The pitot tube, mounted on the underside of the wing, was bent inboard about 45 degrees. Tears in the wing structure exposed the interior portion of the wing fuel tank. The fuselage displayed upward crushing on the underside of the cockpit area. Additional upward buckling of the underside of the fuselage was noted from the forward edge of the vertical stabilizer, extending in an aft direction. The outboard fairing of the left horizontal stabilizer was missing. A tail cone fairing, normally attached to the fuselage between the horizontal stabilizers, was missing. The flight control surfaces remained connected to their respective attach points. The flaps remained attached to their respective wings, and appeared retracted. The continuity of the flight control cables was established to the cockpit area. The instrument panel was buckled along the lower, right edge of the pilot seat position, in an aft direction. The alternate air control was found in the "OPEN" (RAM) position. The three bladed propeller assembly remained connected to the engine crankshaft. All of the blades were loose in the hub and exhibited aft bending of about 30 degrees, about mid-span. The forward nose of the propeller spinner appeared undamaged. The engine cowling sustained impact damage to the underside portion of the assembly. The crankshaft could be rotated by the propeller. Gear and valve train continuity was established, and thumb compression in each cylinder was noted, when the crankshaft was rotated by hand. The oil filter was free of contaminants. The alternate air box, normally attached to the forward portion of the engine induction fuel servo, was observed hanging below the engine. It was connected to the alternate air cable. The alternate air door was observed in the open, ram air position. The magnetos did not produce spark upon hand rotation. The interior of the magnetos was extensively damaged by salt water corrosion. The bottom, fine wire sparks plugs, were coated with water and oil. An auxiliary fuel tank was installed behind the two cockpit seats. The capacity was estimated about 10 gallo
the pilot's failure to properly evaluate the presence of icing conditions, and his failure to comply with procedures to use alternate engine air in icing conditions. Factors relating to the accident were: icing (weather) conditions, the pilot's improper application of emergency procedures to maximize available glide distance, and the lack of suitable terrain for a forced landing.
Source: NTSB Aviation Accident Database
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