Page:CAB Accident Report, Zantop Logair Flight 60-16.pdf/2

 Captain Laurence H. Wensel and First Officer Clarence B. Miller were originally assigned to fly C-46F, N 618Z. They departed McChord AFB in this aircraft but, 10 minutes after takeoff, they returned to McChord AFB because of a hydraulic malfunction. They were then rescheduled to fly N 616Z to Hill AFB via Malmstrom AFB. This aircraft had already been loaded with 9,471 pounds of cargo and 1,200 gallons of fuel. The weight and balance form signed by Captain Wenzel indicated that the takeoff gross weight was 46,751 pounds and the center of gravity (c.g.) was 29.3 percent Mean Aerodynamic Chord (MAC). Both the weight and c.g. were within limits.

The flight departed McChord AFB at 1813 on an Instrument Flight Plan to Malmstrom AFB via V-2, and V-120 airways, then direct to Malmstrom AFB. The crew requested and received radar vectors from McChord Departure Control to intercept V-2 airway. The departure was normal until 1820, at which time the aircraft was 13 miles east-northeast of McChord at approximately 4,600 feet m.s.l. climbing to 9,000 feet. At this point the crew requested a clearance to return to McChord AFB. The radar controller provided the flight with a vector to intercept the precision approach course for runway 16 at McChord. The flight was instructed to maintain 3,000 feet. The crew acknowledged the transmission and said they would descend to and maintain 3,000 feet. When the controller asked the crew the nature of their difficulty they advised that they had "feathered the left engine." The controller gave the flight the McChord weather as 2,600 scattered; estimated ceiling 7,000 broken; cirriform; visibility 15, temperature 48, dewpoint 43; wind calm; altimeter 30.07. At 1821:38 the crew reported a runaway propeller; at 1822:05 they reported it was under control; and at 1822:20 the crew radioed that the propeller had gone back to "flat pitch” again. The controller asked whether the flight was VFR and upon receiving an affirmative reply, advised the crew that the aircraft was "exactly five miles north of the runway at Thun Field." At 1822:59 the crew asked the controller to have "Thun Field flash their landing lights." At 1823:13 the crew requested "a Vector." The controller responded with "Roger, turn left heading 150 for Thun Field," which was acknowledged by the crew. At 18:23:35 the flight was advised that they were 4 miles north of Thun Field. The runway length was given to the crew by the controller as "five thousand three hundred," which was correctly read back. At 1824:05 the controller instructed the flight to "turn right heading one five five," and stated that they were 3 miles north of the airport. At 18:24:33 N 616Z was advised that it was one mile north of the field and possibly a little left of the runway. The field elevation was given to the flight as 520 feet which was acknowledged. At 1825:00 the crew made a transmission that was garbled in the beginning but ended "high we'll have to go around." This was the last radio contact between the aircraft and the controller. At 1825:40 and 1826:10 the controller made transmissions to the aircraft that were not answered.

An aeronautically qualified witness observed the aircraft an estimated three miles east of Puyallup, Washington. His attention was drawn to the aircraft when he " . . . heard the sound of one engine rev up at a high RPM just as though it had been changed to full low pitch." The witness noted that the aircraft appeared to maintain its altitude which he estimated to be 4,000 or 5,000 feet. A short time later, approximately two or three minutes, he heard the engine run up to high RPM, the sound level was quickly reduced and a flash of fire was seen coming from the aircraft. A "medium banked" turn to a southerly heading was noted, followed by a definite descent. The aircraft lights disappeared from sight. No crash or fire was seen or heard by the witness. He later learned of a crash near Thun Field and volunteered this information.

Another aeronautically qualified witness was standing midway down the west side of runway 17/35 at Thun Field. He observed a large aircraft on a long final approach. The aircraft appeared to be lined up with the runway and flying at an airspeed of approximately 110-120 knots. It passed over the north end of the asphalt portion of