Douglas DC-7C accident at Manila, Philippine Islands, 14 Jul 1960

Accident narrative

At approximately 0430 Manila Time on July 14, 1960, a Northwest Airlines Douglas DC-7C ditched in the Pacific Ocean about 67 nautical miles northeast of the Manila Airport. Operating as Flight 1-11 from Okinawa to Manila, the aircraft experienced an engine failure, the loss of a propeller, and an in-flight fire. All 58 occupants successfully evacuated the aircraft in darkness and rough seas. Forty-four suffered minor injuries, and one passenger died.

### The flight

Flight 1-11 originated in New York on July 11 and arrived in Tokyo on July 13 after weather diversions. A new crew took over in Tokyo, including Captain David G. Rall, who had 17,780 flying hours with 1,071 in the DC-7, and First Officer Travis E. Everett.

The flight departed Okinawa at 1700 Greenwich Mean Time (GMT) on July 13, operating on an instrument flight plan at 18,000 feet. The aircraft's gross weight was 115,429 pounds, well below the maximum allowable, and all engines performed satisfactorily on takeoff.

### The emergency

At approximately 1915 GMT, the No. 2 engine experienced a considerable loss of power, indicated by a drop in manifold pressure. Suspecting carburetor icing, the crew applied alcohol and carburetor heat, and adjusted the throttle and mixture. The engine ignition analyzer appeared normal, but the No. 2 engine oil quantity had dropped to 30 gallons, a loss of 22 gallons since departure.

The oil-out temperature then began to rise, and the analyzer showed irregular patterns on several cylinders. The captain and flight engineer attempted to feather the propeller, but it failed to feather. Instead, the engine speed increased from 2,350 to 2,900 rpm, and the oil quantity indicator dropped to empty.

At 1925, the flight advised Manila Radio of the runaway engine and requested a lower altitude. Cleared to 10,000 feet, the flight engineer tried transferring reserve oil to force the propeller to feather, but this also failed. The engine remained stuck in high blower, with rpm fluctuating between 2,150 and 2,350 after airspeed was reduced.

The crew began descending to 10,000 feet at 130 knots with the landing gear and flaps extended. The cabin attendants prepared the passengers for ditching, distributing lifevests, positioning liferafts, and moving passengers away from the cabin area in line with the propellers.

At 1940, Captain Rall declared an emergency. Shortly afterward, sparks and white smoke appeared from the No. 2 engine. The crew actuated the firewall shutoff valve to deprive the engine of lubricant and stop its rotation. This resulted in sparks, loud thumping noises, and a fire warning. The fire extinguishing system was discharged without effect.

The propeller then wrenched free from the engine, slashing a 15-inch hole in the fuselage above a passenger seat. A red glow on the engine's front casing rapidly turned into a white-hot magnesium fire. A second fire extinguisher bottle was used, again without effect. At 2020, the flight informed Manila Radio that the propeller was gone, the wing was on fire, and they were ditching.

### The ditching

The captain initiated a 3,000-foot-per-minute descent in darkness and moderate rain showers, which intensified the magnesium fire. At 1,000 feet, power was applied, the gear was retracted, and flaps were set to 30 degrees. The descent was slowed to 100 to 200 feet per minute at approximately 100 knots. When the first officer spotted the water, he shouted to pull up. The captain started the flaps up, the first officer started them down, and the captain pulled the control wheel all the way back. The aircraft struck the water at 2030 GMT, about five miles northeast of Polillo Island.

Upon impact, the aft fuselage broke free and sank immediately. The right wing tore off, taking its two engines, and floated for about three hours, serving as a temporary raft for several passengers. The remainder of the fuselage and the left wing sank within ten minutes.

The evacuation was orderly, with the purser noting no panic among the passengers. Smoke and burning gas entered the cabin, prompting the crew to direct passengers to the main cabin door and a left window exit. Survivors boarded liferafts or clung to floating debris. Coast Guard and Navy aircraft landed in the rough seas—which featured four-foot swells and a two-foot wind-driven chop—four to six hours later, rescuing the survivors. The Board noted that one-cell flashlights permanently attached to the lifevests materially aided the rescue in the darkness.

### What the investigation found

Because the wreckage sank in 2,100 feet of water, the Board based its analysis on crew testimony and maintenance records. Records showed no prior abnormal operation for the engine or propeller.

The Board concluded that the initial power loss was caused by a failure in the engine's two-speed impeller drive system. Because the crew initially suspected carburetor ice, the engine continued to run, allowing metal particles to circulate and contaminate the bearings and bushings. This internal disintegration caused the rise in oil temperature and the eventual loss of the oil supply, as oil was pumped overboard and the scavenger pump failed.

The attempt to feather the propeller failed because metal contamination likely jammed the propeller governor's pilot valve in the "up" position, causing the overspeed. The Board noted that the propeller's pitch lock assembly functioned as designed, preventing a much more severe overspeed that could have reached 4,500 rpm.

Ultimately, the lack of lubrication caused the propeller to separate from the engine. Friction heat at the propeller thrust bearing and reduction gear assemblies then ignited the magnesium nose case. The crew elected to ditch because the intense fire threatened the structural integrity of the wing.

### Probable cause

The Board determined that the probable cause of this accident was "the internal failure of No. 2 engine, resulting in oil contamination, loss of oil supply, subsequent loss of the No. 2 propeller assembly, and fire-in-flight, which necessitated a ditching."