MERRILL PASS, AK, USA
N5647N
MAULE M-6-235
THE PILOT-IN-COMMAND WAS ATTEMPTING TO FLY THROUGH MERRILL PASS IN WEATHER CONDITIONS THAT WERE FORECAST TO BE MARGINAL. OTHER PILOTS IN THE AREA REPORTED THE PASS WAS MARGINAL TO CLOSED. THE WRECKAGE WAS FOUND IN A BOX CANYON ONE VALLEY BEFORE REACHING THE PASS. THE TURN REQUIRED INTO THE BOX CANYON WAS THE SAME TURN REQUIRED TO GO THROUGH THE PASS. THE AIRPLANE CRASHED ON THE GLACIER AT THE 4000-FOOT-LEVEL, 90 DEGREES TO THE LONG AXIS OF THE BOX CANYON. THE GLACIER AND SURROUNDING MOUNTAINS WERE COVERED WITH FRESH SNOW.
HISTORY OF FLIGHT On October 2, 1993, at 1430 Alaska daylight time, a wheel equipped Maule M-6-235 airplane, N5647N, registered to the Pilot- in-Command, collided with glacier/terrain while maneuvering to reverse direction in a large box canyon located immediately southeast of Merrill Pass. The business flight, operating under 14 CFR Part 91, last departed Merrill Field, Anchorage, Alaska, and the destination was Bethel, Alaska. The Private Certificated Pilot-in-Command, the sole occupant, was fatally injured, and the airplane was substantially damaged. A visual flight rules flight plan was filed, and according to witnesses on the west side of Merrill Pass, marginal visual meteorological conditions prevailed. PERSONNEL INFORMATION The 53 year old Pilot-in-Command was the holder of a Private Pilot certificate, number 1618778, with airplane single engine land and sea ratings. He was also the holder of a Federal Aviation Administration class 3 medical certificate, with no limitations, dated 4/22/93. Examination of the Pilot-in-Command's logbook showed that he met the requirements for a biennial flight review based upon the issuance of his Airplane Single Engine Sea Rating on April 25, 1992. The records show that the Pilot did not possess an instrument rating and his logbook showed only 5.4 hours of simulated hood time, only 4.1 hours of simulator time, and no actual weather experience. AIRCRAFT INFORMATION The airplane, N5647N, was registered to the Pilot-in-Command and the aircraft logbooks show that the airplane had been removed from floats and placed on wheel landing gear on 9/28/93 at tach time 1384.8. The tach time at the accident site read 1386.0. The logbook records show that the Emergency Locator Beacon battery was to be replaced in Jul, 1994. The engine, serial number L-21934-48A, capable of producing 230 horsepower had received an oil and filter change at tach time of 1384.8. It was last inspected on June 21, 1993, in accordance with a 100 hour inspection. The engine had a total time of 1386.0 hours since new and had not been overhauled. METEOROLOGICAL INFORMATION The Pilot-in-Command received a full weather briefing from the Kenai Automated Flight Service Station. The Pilot's route of flight would have taken him through Merrill Pass, Sparrevohn,and on to Bethel, Alaska. The weather briefer told the Pilot that the weather had been below VFR in the Sparrevohn area for the last three hours and that VFR flight was not recommended. The pilot received this briefing twice, once at 0806 adt and 1127 adt. Sparrevohn is located approximately 40 miles west of the Alaska Range and beyond the western exit of Merrill Pass. The general area forecast, received by the Pilot the day before the accident, called for marginal conditions with snow and the possibility of low level wind shears. Merrill Pass was forecast to be VFR but turbulent. The Bethel area forecast, the Pilot's destination, called for worsening conditions due to ceilings and snow showers. The accident site was covered with fresh fallen snow with a light dusting of snow on the airplane. The site was located in a box canyon and the surrounding mountains shadowed the wreckage. The surrounding terrain was also covered white with snow. There are no weather reporting facilities within Merrill Pass. WRECKAGE AND IMPACT INFORMATION The airplane wreckage was found in a box canyon that was 1/4 mile wide and 3.25 miles long. The slope in the canyon was 10 degrees down slope from the wreckage. The canyon floor was covered with a glacier and was completely snow covered. There were no open crevasses visible, however, there were snow bridges visible from on the ground near the wreckage. The canyon walls on all three sides were near vertical and the lowest point along the canyon wall was 1300 feet above the wreckage site (5300 feet above mean sea level). The magnetic path into the canyon was 184 degrees. The airplane wreckage was found at the 4000 foot level of the glacier in the canyon approximately .25 mile from the rear canyon wall. The airplane's wreckage path and heading were 269 degrees. The first impact mark was a scar in the snow cause by the left wing. The fuselage impacted the snow approximately 10 feet beyond the left wing ground scar. The airplane came to rest 55 feet beyond the left wing ground scar. The engine remained attached to the right side of the firewall and was skewed to the right. The propeller separated from the engine and was located 10 feet beyond the engine and slightly left of the crash path. Examination of the propeller blades showed that both blades were bent, one forward and one rearward. Both blades had chordwise scoring and damage. The left wing was folded rearward with the leading edge pointing downward. The left wing tip was crushed more severely than the right wing tip and the leading edge of the left wing tip was rolled under the wing. The forward wing attach point of the left wing separated from the cabin top. The wing struts were bent. The right wing was also bent rearward slightly and downward. Both wing attach points remained attached to the cabin top. The wing struts were bent. The empennage was twisted slightly and the horizontal stabilizer, elevators, vertical fin, and rudder were not damaged. The bottom of the cockpit and cabin were pushed upward into the fuselage. The amount of crush was not measured due to the snow coverage of the lower fuselage. ADDITIONAL INFORMATION Merrill Pass is a widely used pass that transects the Alaska Range on an East/West course. The Eastern end of the pass is wide and continually narrows until reaching the actual pass. The actual pass requires the accomplishment of a left 70 degree turn and then a right 45 to 50 degree turn to successfully negotiate the pass. Once those turns are made the pass begins to widen. The terrain slowly rises along the flight path until passing through the two turns. The maximum elevation necessary to clear the pass is approximately 3400 feet above mean sea level. The terrain begins to descend once passing through the turns in the pass.
THE PILOT-IN-COMMAND'S ATTEMPT TO FLY VFR INTO IMC CONDITIONS. A FACTOR WAS THE WHITEOUT WEATHER CONDITION.
Source: NTSB Aviation Accident Database
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