WPR13LA310

The pilots reported that, during the approach, the main hydraulic system lost pressure. They selected the auxiliary hydraulic system "on," continued the approach, and extended the landing gear using the emergency landing gear extension procedures. During the landing roll, about two-thirds down the runway, the pilots noticed that the brakes were not working normally and then turned onto a taxiway to clear the runway. The captain reported that, once on the taxiway, he was unable to stop or steer the airplane as it proceeded across a parallel runway and into an adjacent field where it subsequently struck a metal beam. A postaccident examination of the airplane revealed brake system continuity with the cockpit controls. The tires, brake assemblies, and brake pads were intact and undamaged. The hydraulic lines from the hydraulic pump to the wheel brakes were intact. No hydraulic fluid was observed leaking on the exterior or interior portions of the airplane. The hydraulic fluid reservoir was found about 1/4 full. Further, testing of the two hydraulic pumps revealed that they were both functional, and no mechanical failures or anomalies that would have precluded normal operation were noted. The airplane's hydraulic system failure emergency procedures state that, if hydraulic pressure is lost, the electrically driven hydraulic pump should be reset and that, if the hydraulic pressure was not restored, that the primary hydraulic system should be disengaged and the landing gear should be lowered using the emergency landing gear extension procedures. After the gear is extended, the auxiliary hydraulic system should be selected "on" for landing. However, the pilots stated that they did not attempt to reset the electric hydraulic pump and that they performed the emergency landing gear extension procedures with the auxiliary hydraulic pump engaged. It is likely that the pilots' failure to select the auxiliary hydraulic system "off" before extending the landing gear caused the hydraulic pressure in the auxiliary system to dissipate, which left only the emergency brake accumulator available for braking during the landing. The number of emergency brake applications that can be made by the pilots depends on the accumulator charge, which may be depleted in a very short time. The airplane's emergency braking procedures state that, as soon as the airplane is safely stopped, the pilots should request towing assistance. However, the pilots did not stop the airplane on the runway despite having about 3,900 ft of runway remaining; instead, they turned off the runway at an intersection, which resulted in a loss of directional control.

On July 5, 2013, about 1845 Pacific daylight time, a Rockwell International Corporation NA-265-65, Mexican registered XB-RSC, sustained substantial damage following a reported loss of control while taxiing at the McCarran International Airport (LAS) Las Vegas, Nevada. The airplane was registered to and operated by Eseasa Contrucciones, S. A. de C. V., under the provisions of Title 14 Code of Federal Regulations Part 91. The captain, first officer, and four passengers were not injured. Visual meteorological conditions prevailed and an instrument flight rules (IFR) flight plan was filed for the personal flight which originated from Brownsville, Texas about 1755, central daylight time. The pilots reported that about 20 miles from the airport, the main hydraulic system lost pressure. They selected the auxiliary hydraulic system and continued the approach. During the landing roll, about two thirds down the runway, the pilots noticed that the brakes were not working normally and turned onto a taxiway to clear the runway. Once on the taxiway, the captain reported he was unable to stop or steer the airplane as it proceeded across a parallel runway and then into an adjacent grass field where it subsequently struck a metal beam located within a drainage area. Examination of the airplane wreckage by a Federal Aviation Administration Inspector revealed that the left wing was substantially damaged. The airplane was recovered to a secure storage facility for further examination. A review of the airplane's emergency procedures for Hydraulic Pressure or Hydraulic Caution Light On, revealed that the electrically driven hydraulic pump should be reset and if the hydraulic pressure does not return to normal, to select the hydraulic pump to "off," and use the emergency gear lowering procedures to extend the landing gear. After the gear is emergency extended, the hydraulic auxiliary pump should be selected "on" for landing. The flight crew stated that they did not attempt to reset the hydraulic pump and accomplished the emergency landing gear extension procedures with the auxiliary hydraulic pump engaged. Upon landing, the flight crew stated that they activated the emergency brake switch on the runway. The airplane's emergency procedures state when using emergency braking, as soon as the airplane is brought safely to a stop, that the flight crews should request towing assistance. The procedures also state that the number of brake applications available to the crew is dependent on the accumulator charge and may be depleted in a very short time. The landing runway was 10,525 feet in length, 150 feet wide, and had a 0.9 % uphill gradient. The flight crew did not bring the airplane to complete stop on the runway but taxied off the runway at an intersection, with about 3,900 feet of runway remaining. A postaccident examination of the airplane, revealed brake system continuity with the cockpit controls. The tires, brake assemblies, and brake pads were intact and undamaged.The hydraulic lines from the hydraulic pump to the wheel brakes were intact. No hydraulic fluid was observed leaking on the exterior or interior portions of the airplane. Further, the external portions of the brake assemblies were not contaminated with hydraulic fluid. The hydraulic reservoir quantity was observed low in fluid and about ¼ full. According to the airplane's maintenance manual, the reservoir maximum capacity was two gallons. The reservoir fluid was observed to be dark red/brown in color and had a musky burnt scent. A sample of the reservoir hydraulic fluid was sent to the National Transportation Safety Board Materials (NTSB) laboratory for analysis. The analysis of the hydraulic fluid revealed that the acid level was degraded beyond the normal range expected for this type of fluid but not to a critical level. Reference the Material Laboratory Factual Report in the public docket for additional information. The two hydraulic pumps were removed and sent to their respective manufacturer for a functional check. Examination and functional checks of both hydraulic pumps revealed that they operated normally. No mechanical failures or anomalies that would preclude normal operation were noted. The airplane's cockpit voice recorder (CVR) was sent to the NTSB Vehicle Recorder Division for readout. The recording of the accident flight was not present and consistent with the CVR being inoperative prior to the accident.