Martin M130 accident at Near Ukiah, California, 21 Jan 1943

Accident narrative

On January 21, 1943, at about 7:30 a.m. Pacific War Time, a Pan American Airways Martin M130 flying boat crashed in mountainous terrain about seven miles south-southwest of Ukiah, California. The aircraft, operating as Flight V-1104, was completely destroyed by impact and subsequent fire. All 19 people on board—nine crew members and ten passengers—were fatally injured.

### The flight

Flight V-1104 (also identified by the carrier as Trip No. 62100) departed from Pearl Harbor in Honolulu, Hawaii, at 5:30 p.m. PWT on January 20, destined for San Francisco, California. The aircraft was fueled for an estimated 24.2 flying hours, which provided ample fuel to reach an alternate destination such as San Diego if necessary.

The crew was properly certificated for the flight. Captain Robert M. Elzey had accumulated 3,359 flying hours while in the employ of Pan American. First Officer Orven K. Judd had completed 21 trips from San Francisco to Honolulu and 20 trips on the return route.

### Sequence of events

The flight proceeded normally across the Pacific, maintaining two-way radio contact. Favorable tailwinds put the aircraft about three and a half hours ahead of its originally estimated arrival time. At 6:16 a.m. on January 21, satisfactory radio telephone communication was established with the Pan American Flight Watch Office at Treasure Island, San Francisco.

At 6:22 a.m., Treasure Island transmitted a surface weather report indicating heavy rain, strong south winds, a ceiling of 900 to 1,000 feet, and visibility of one to two miles. Treasure Island advised the flight that landing conditions in San Francisco were impossible before daylight, suggesting San Diego as the only possibility unless the flight could hold. The flight acknowledged the message. When the flight asked what surface conditions would be at daylight, Treasure Island provided an anticipated 9:00 a.m. forecast of light rain, a 900- to 1,000-foot ceiling, and two miles of visibility.

At 6:50 a.m., Treasure Island gave the flight a new position plot approximately 43 nautical miles west-southwest of San Francisco. The flight subsequently reported being over the Farallone Islands at an altitude of about 5,000 feet and proceeding toward the KPO transmitting station in San Francisco.

At about 7:15 a.m., Flight V-1104 advised Treasure Island that it had "been over the area but -- now taking a course due west." Treasure Island confirmed, asking if they were taking a course due west to sea, to which the flight answered, "That's correct." When asked about flying conditions, the flight reported them as very poor and stated they required a change of altitude to 7,000 feet.

At 7:20 a.m., the flight called Treasure Island again, stating, "We are not interested in setting up on Oakland quite yet. We would like to have a fix, please, so would you arrange that? Go ahead." This was the last message received from the aircraft. At 7:26 a.m., Treasure Island attempted to contact the flight to provide the requested fix, but received no response.

### What the investigation found

An extensive search located the wreckage on January 30 at an elevation of approximately 2,500 feet, just below a mountain ridge and about 22 miles inland from the Pacific coast.

Examination of the wreckage showed that the aircraft had sheared small trees about 75 feet before impact, indicating it struck the ground on a downward angle of approximately 10 degrees while headed in a northerly direction. The instruments were completely shattered, but the ignition switches were in the normal "on" position, the automatic pilot was "off," and all four propellers indicated that power was being applied at the time of impact. The Board found no evidence of failure in any part of the aircraft prior to impact, with the possible exception of carburetor ice.

The Board noted that slight power interruptions had affected some radio aids in the San Francisco area between 7:03 a.m. and 7:14 a.m., but concluded these were of no real consequence since the flight's last transmission at 7:20 a.m. gave no hint of radio difficulty.

Weather analysis revealed an intense low-pressure area with steep pressure gradients and extremely strong winds aloft. The Board estimated that south-southwest winds aloft ranged from 80 m.p.h. at 3,000 feet to over 100 m.p.h. at 10,000 feet in the Bay district. The Board noted that the intensity of the storm had not been realized, and the strength of the winds would not have been anticipated by the crew.

Witnesses on the ground who observed the aircraft between 7:15 and 7:20 a.m. reported that the engines sounded normal and the plane was flying very low, just above the trees, in a generally northerly direction. The Board determined that while Captain Elzey reported taking a course "due west" (a true heading of 288 degrees), the extremely strong south-southwest winds caused the aircraft to travel on a track closer to 350 degrees.

The Board considered potential factors that might have forced a descent, such as carburetor ice, wing ice, power plant failure, or structural failure, but found no evidence of any of these. The Board concluded that the aircraft was in controlled flight when it crashed. The fact that the captain reported proceeding due west to sea indicated to the Board that he believed he was over the ocean and therefore free to descend to a lower altitude. However, due to the unusually high wind velocity, the flight had been carried a considerable distance farther northward and eastward than the pilot realized.

### Probable cause

The Board determined that the probable cause of the accident was "the failure of the captain to determine his position accurately before descending to a dangerously low altitude under extremely poor weather conditions during the hours of darkness."