Hawthorne

The airplane veered off the runway during a rejected takeoff, overran an airport sign, and impacted a hangar. The captain stated that during the after start checklist he moved the power levers to disengage the start locks on the propellers. Post accident examination found that the left propeller was still in the start lock position, while the right propeller was in the normal operating range. The captain was the pilot flying (PF) and the second-in-command (SIC) was the non flying pilot (NFP). After receiving their clearance, the PF taxied onto the runway and initiated the takeoff sequence. The SIC did not set and monitor the engine power during takeoff, as required by the company procedures. During the takeoff acceleration when the speed was between 40 and 60 knots, the captain released the nose gear steering control switch as the rudder became aerodynamically effective. When the switch was released, the airplane began immediately veering left due to the asymmetrical thrust between the left and right engine propellers. The PIC did not advise the SIC that he had lost directional control and was aborting the takeoff, as required by company procedures. The distance between where the PIC reported that he began the takeoff roll and where the first tire marks became apparent was about 630 feet, and the distance between where the marks first became apparent and where the airplane's left main landing gear tire marks exited the left side of the runway was about 220 feet. Thereafter, marks (depressions in the dirt) were noted for a 108-foot-long distance in the field located adjacent to the runway. Medium intensity tire tread marks were apparent on the parallel taxiway and the adjacent vehicle service road. These tread marks, over a 332-foot-long distance, led directly to progressively more pronounced marks and rubber transfer, and to the accident airplane's landing gear tires. Based on an examination of tire tracks and skid marks, the PIC did not reject the takeoff until the airplane approached the runway's edge, and was continuing its divergent track away from the runway's centerline. The airplane rolled on the runway through the dirt median and across a taxiway for 850 feet prior to the PIC applying moderate brakes, and evidence of heavier brake application was apparent only a few hundred feet from the impacted hangar. No evidence of preimpact mechanical failures or malfunctions was found with the propeller assemblies, nose wheel steering mechanism, or brakes.

The aircraft collided with the ground in a steep nose down descent angle while maneuvering to return to the runway during the takeoff initial climb from the airport. Pilot and mechanic witnesses on the airport described the engine sounds during the takeoff as abnormal. The takeoff ground roll was over 3,000 feet in length, and the airplane's climb out angle was much shallower than usual. Two other witnesses said the engine sounded "like a radial engine," and both believed that the power output was lower than normal. One mechanic witness said the engine was surging and not developing full power; he believed the symptoms could be associated with a fuel feed problem, a turbocharger surge, or an excessively lean running condition. The ground witnesses located near the impact site said the airplane began a steep left turn between 1/4- and 1/2-mile from the runway's end at a lower than normal altitude. The bank angle was estimated by the witnesses as 45 degrees or greater. The turn continued until the nose suddenly dropped and the airplane entered a spiraling descent to ground impact. The majority of these witnesses stated that they heard "sputtering" or "popping" noises coming from the airplane. Engineering personnel from the manufacturer developed a performance profile for a normal takeoff and climb under the ambient conditions of the accident and at gross weight. The profile was compared to the actual aircraft performance derived from recorded radar data and the witness observations. The ground roll was 1,300 feet longer than it should have been, and the speed/acceleration and climb performance were consistently well below the profile's predictions. Based on the radar data and factoring in the winds, the airplane's estimated indicated airspeed during the final turn was 82 knots; the stall speed at 45 degrees of bank is 82 knots and it increases linearly to 96 knots at 60 degrees of bank. No evidence was found that the pilot flew the airplane from December until the date of the accident. The airplane sat outside during the rainy season with only 10 gallons of fuel in each tank. Comparison of the time the fueling began and the communications transcripts disclosed that the pilot had 17 minutes 41 seconds to refuel the airplane with 120 gallons, reboard the airplane, and start the engine for taxi; the maximum nozzle discharge flow rate of the pump he used is 24 gallons per minute. Review of the communications transcripts found that a time interval of 3 minutes 35 seconds elapsed from the time the pilot asked for a taxi clearance from the fuel facility until he reported ready for takeoff following a taxi distance of at least 2,000 feet. During the 8 seconds following the pilot's acknowledgment of his takeoff clearance, he and the local controller carried on a non pertinent personal exchange. The aircraft was almost completely consumed in the post crash fire; however, extensive investigation of the remains failed to identify a preimpact mechanical malfunction or failure in the engine or airframe systems. The pistons, cylinder interiors, and spark plugs from all six cylinders were clean without combustion deposits. The cockpit fuel selector lever, the intermediate linkages, and the valve itself were found in the OFF position; however, an engineering analysis established that insufficient fuel was available in the lines forward of the selector to start, taxi, and perform a takeoff with the selector in the OFF position.

During departure, the pilot climbed in IFR conditions to 6,000 feet. After leveling, a frequency change was made and he was cleared to 8,000 feet, which he acknowledged. About 2 minutes later, the controller radioed to the pilot that he was about 4 miles north of the airway, but there was no reply from the pilot. Shortly after that radar contact was lost and the plane crashed in mountainous terrain. Several residents in the area reported hearing extremely loud engine noises followed by complete silence. An investigation revealed that both wings had separated outboard of their respective engine nacelle assemblies. An examination of the fractures revealed the wings had separated from positive overload. The leading edges of both wings had ballooned upward, indicative of extreme airspeed. The empennage had separated in a yaw and from right torsional overload. Parts of the aircraft were found within a 1 mile arc, north of the main impact area. The pilot's recent instrument experience could not be verified. All three occupants were killed. Turbulence was forecasted below 8,000 feet.

While cruising by night under VFR mode, the crew changed his route from 170° to 195° direction Palmdale as they thought flying over the valley. Shortly later, the airplane struck a ridge and crashed down the slope of Mt Whitney (11,770 feet high) located about 12,5 miles west of Lone Pine. SAR operations were quickly conducted but eventually suspended few days later as no trace of the aircraft nor the 35 occupants was found. The wreckage was located in a very hazardous area on August 8, 1969 and was not detectable till this date due to snow accumulation on the ground. The accident was unsurvivable.

The DC-3 was cruising at FL115 between Burbank and Hawthorne when a no. 2 engine failure forced the crew to shut the engine down and feathered the propeller. At 20:50 EDT the crew radioed Tonopah, NV and said they wanted to make an emergency landing there. At 20:58 EDT the no. 1 engine lost power. The propeller couldn't be feathered and an emergency glide was initiated towards Mud Lake airfield. A 2000 feet/min rate of descent was necessary to maintain a 110 knots airspeed. All electrical and hydraulic power was lost during the descent. The DC-3 struck the ground in a 10-20 degree nose down attitude during the flareout and overturned. It appeared that there were numerous maintenance irregularities, a.o. improperly adjusted valve clearances, improperly adjusted voltage regulators and improperly installed cylinders. The plane was equipped with 2 28V dc generators and one 12V battery. All electrical components other than the starters were designed for 12V dc operation. It also appeared that all maintenance was performed by companies other than the operator. In many instances inadequate and incomplete records failed to reflect work accomplished.

The aircraft was completing a charter flight from Hawthorne, California, to Santa Maria, with a crew of two and six employees of the Martin Aircraft Group. During the final approach completed by night, one of the engine lost power. The airplane lost height, struck trees and crashed, killing all eight occupants.

The crew left Reno-Stead Airport on a classified mission with six other similar aircraft. While cruising in limited visibility at an altitude of 6,000 feet, the airplane hit the slope of a mountain located in the Gillis Mountain Range, about 12 miles northeast of Hawthorne. The wreckage was found few feet below the summit and all seven crew members were killed.