Adopted: November 7, 1944

File No. 1191-44

REPORT OF THE CIVIL AERONAUTICS BOARD

of the

Investigation of an Accident Involving Aircraft During a Scheduled Flight

While proceeding under contact flight rules over snow-covered terrain which made visibility uncertain, a Pan American Airways plane on a schedules flight from Nome to Fairbanks, Alaska, crashed about 3:48 p.m., Bering War Time, April 6, 1944, approximately 10 miles east of the CAA field at Nome. All occupants, including the pilot, two crew members and three passengers, were fatally injured and the aircraft, a Pilgrim 190-B, was demolished.

CONDUCT OF INVESTIGATION

The Fairbanks Office of the General Inspection Branch, Civil Aeronautics Administration, was notified at 6:00 p.m., April 6, that NO 742N was overdue; and about 8:00 a.m., April 7 that office was notified by Pan American Airways, Inc. (hereinafter referred to as Pan American) that the wreckage had been found. Due to the unavailability of an Air Safety Investigator of the Civil Aeronautics Board (hereinafter referred to as the Board) the Civil Aeronautics Administration made the investigation for the Board. CAA Inspector D. M. Gretzer arrived at Nome at 3:05 p.m., April 7 to begin his investigation. At that time the bodies had been removed and such mail and cargo as could be handled without disturbing the airplane had been removed.

On the basis of the information furnished by the Civil Aeronautics Administration, the Board now makes its report in accordance with the provisions of the Civil Aeronautics Act of 1938, as amended.

SUMMARY AND ANALYSIS OF EVIDENCE

Air Carrier

At the time of the accident Pan American was operating under a certificate of public convenience and necessity authorizing it to engage in air transportation with respect to persons, properly and mail between various points in Alaska, including Nome, Moses Point, Nulato and Fairbanks.

Flight Personnel

Captain Robert Leslie Bullis of Yakima, Wash., held an airline transport certificate with 0-1200 h.p. single and multi-engine land and sea, and flight instructor ratings. He had logged about 3477 hours, 114 of which were on the type aircraft involved. He had flown on the Nome run since August 1943 and had made seven flights to Nome as captain.

Fred Moller of Fairbanks, described in the Pan American clearance as first officer, actually served as flight maintain and radio operator on this flight. He held an aircraft and engine mechanic certificate.

The third member of the crew, Theodore *** of Fairbanks, was on the flight for route familiarization. He held in aircraft and engine mechanic certificate.

The Aircraft

The aircraft, a Pilgrim 100-B, NC 742N, was equipped with a Wright R-1820F-31 engine of 670 h.p., with Hamilton Standard two-position controllable pitch propeller. It had been operated a total of *** including 258 hours since the last major overhaul of airplane and engine in January 1944. The take-off *** at the time of *** was 7539 pounds, which was within the authorized maximum of 7750 pounds. At the time of the accident the plane was operating on *** It as not equipped with de-icers

History of the Flight

NC 742N took off from the Nome CAA field about 3:35 p.m., cleared to Fairbanks with stops schedules at Moses Point, Nulato, Galena and *** No altitude was assigned since the clearance was for contact flight rules, but because of prevailing ceilings it was expected the flight would proceed at an altitude somewhere between 100 and 1500 feet. Wind was west 17 to 21 m.p.h., light snow was falling and two ceiling was variable.

The only radio contract with Captain *** after departure was an exchange of messages with regard to another Pan American Aircraft, a Lockheed coming in to Nome along the coast from the east. *** turned off his *** of east-southeast ***heading of northeast, toward the *** the time of this *** contact. It was *** and the Pilgrim passed each other between 3:40 and 3:43 p.m.

From the time of the turn toward the *** was discovered from the air, nothing certain is *** of the flight. The last person known to have seen the Pilgrim stated that it nosed down from a height of approximately *** turned off its heading, then quickly disappeared below his line of vision toward low hills directly ahead. HE said he thought the plane was critically low and that he climbed on top of a *** roof to continue watching, but had difficulty in seeing due to *** and *** snow at the ground level. He thought he saw the plane about a minute later but was not sure. However, he was certain it did not loud on the next up-slope. Apparently it passed over the admit of a hill *** feet high and struck on the down slope at an elevation of 125 feet. The wreckage was found parallel with the beam projection, *** mile south of the *** center line and 6 4/10 miles east of the ***

Examination of the Wreckage

Examination of the wreckage indicated that the plane struck the ground in a steeply banked attitude at a high rate of vertical descent and with great forward speed. Apparently power was on at the moment of impact. The right wing struck first and the airplane skidded along the ground 39 feet into a depression, bounced 20 feet beyond the hold and came to rest on the right side of the fuselage. There was no evidence found of mechanical failure of malfunctioning of any part of the aircraft prior to impact.

Weather

In Alaska, there are areas that are either rolling of flat and almost without contrast. such as trees, jutting rocks, buildings, etc. When complete snow cover exists, the landscape assumes an unbroken whiteness. During an overcast, particularly with haze or falling snow, the horizon completely disappears and, in effect, instrument conditions exist even when there would be five or six miles visibility if reference marks were available. It was established that Captain Bullis encountered such conditions from the time he left the coastline to the point of the accident. Even the existence of one cabin near the scene of the crash was not sufficient to establish the horizon or contour of the terrain, as was subsequently determined under similar conditions by a CAA Inspector.

It has not been determined why the pilot did not maintain sufficient altitude to clear any obstructions, as he undoubtedly was familiar with the height of the terrain and with the illusions brought about by the snow condition. The weather report at Nome showed a 2000-foot ceiling, light snow, temperature 32 degrees, and dew point 28 degrees. It is entirely possible that aircraft icing existed under these conditions, including the unheated *** which supply air pressure to operate the gyroscope instruments. Such an icing condition could have contributed to the pilot's confusion in conducting the flight.

Discussion

Ordinarily, under such conditions of visibility as prevailed at the time of the accident, pilots on the Nome-Fairbanks run stay near the coast if flying contact, because of the sharply defined reference line where land and water meet. Inland the blending of the snow-covered ground, haze and clouds makes it difficult for the pilot to determine where the plans is with reference to the surface. However, Captain Bullis was competent to fly either routs. Why he turned inland off his coastal heading could not be determined, but it is possible he did so either to avoid the lockheed which was flying toward Nome, or because he decided to fly the beam. If any emergency existed, it is apparent that the passengers were not aware of it as it was established that they were eating at the moment of impact.

PROBABLE CAUSE

The probably cause of this accident was failure of the pilot to recognize his proximity to the ground due to heavy snow which entirely covered the terrain.

BY THE BOARD

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/s/ Fred A. Toombs

Secretary