Half Moon Bay, CA, USA
N517SW
Cirrus Design Corp. SR22
The pilot taxied the airplane from the parking area to the end of the runway for takeoff, which was about 1.5 miles, with the right brake on to maintain alignment with the taxiway. He had turned onto the runway, when the passenger saw flames coming from the right main landing gear brake area. The airplane sustained structural damage to the right wing from the fire. The pilot said that for the past several months, the airplane had been "pulling left," and he had to drag the right brake in order to taxi straight. Two weeks prior to the accident, the pilot informed maintenance of the issue. Maintenance personnel found that the left brake cylinder and assembly had been leaking fluid. They repaired the left brake assembly, and returned the airplane to service. Three days prior to the accident, there was a report to maintenance that the left brake was pulling excessively. Section 4 of the airplane's operating manual, contained a caution note, which directed pilots to taxi with the minimum power needed for forward movement. It stated that excessive braking could result in overheated or damaged brakes, which could result in brake system malfunction or failure.
On March 7, 2005, at 2040 Pacific standard time, a Cirrus SR22, N517SW, caught fire prior to the takeoff roll on runway 12 at Half Moon Bay Airport (HAF), Half Moon Bay, California. The pilot/owner operated the airplane under the provisions of 14 CFR Part 91. The airplane sustained substantial damage. The private pilot and one passenger were not injured. Visual meteorological conditions prevailed for the local area flight that was destined for Palo Alto Airport of Santa Clara County (PAO), Palo Alto, California. An instrument flight rules (IFR) flight plan had been filed. The pilot submitted a written report. He flew from Palo Alto to Half Moon Bay for dinner. He was on the return leg, and had taxied the airplane from the parking area to the end of the runway for takeoff, which was about 1 1/2 miles. As he turned the airplane onto the runway and began to align it with centerline, the right brake failed. He could not control the direction of taxi, so he cut the engine. He then noticed smoke and flames coming from under the right wing. Both occupants exited the airplane. He noted that the airplane had been pulling to the left for several months, and he had to "drag" the right brake in order to taxi straight. The National Transportation Safety Board investigator-in-charge (IIC) interviewed the pilot. The pilot stated that during the taxi, the airplane was pulling to the left so he applied a little extra power and right brake to maintain a forward/straight taxi. Once he had lined up on the runway for takeoff, his wife noted flames from the right main landing gear brake area. They exited the airplane and called 911. By the time the fire department arrived, the right wing had melted and collapsed. The pilot reported that, 2 weeks prior to the accident, the airplane had been pulling to the left. The airplane was leased back to and maintained by West Valley Flying Club, Palo Alto. He informed maintenance of the issue. Maintenance personnel found that the left brake cylinder and assembly had been leaking fluid. They repaired the brake assembly, and returned the airplane to service. A review of the airplane's squawk sheet noted several discrepancy reports for the brakes. Several reports noted that the airplane pulled left, and one noted that it pulled in both directions. A squawk sheet entry from 3 days prior to the accident noted that the airplane pulled hard left, and was not normal. On March 8, 2005, the northwest field service manager for Cirrus joined maintenance personnel to inspect and photograph the airplane without disturbing it. He returned to his office, and sent the photos to Cirrus. He examined the airplane again on March 30, 2005, intent on providing better photos detailing the right brake assembly. He noticed that the right brake caliper assembly was not installed on the airplane nor was it anywhere in the immediate vicinity. When he returned to his office and compared the photos he had just taken with those he had taken initially, he discovered that the right brake caliper assembly had not been present in the initial photos. The maintenance records contained an entry on November 1, 2004, for replacement of both main wheel rotor discs and brake pads at a tachometer time of 496 hours. An entry on February 2, 2005, indicated completion of a 100-hour inspection at 593 hours. The flying club flight log indicated a tachometer time of 612.1 on March 5. Section 4 of the Pilot's Operating Handbook (POH) discussed normal procedures. The section on taxiing contained a caution note, which directed pilots to taxi with the minimum power needed for forward movement. It continued that excessive braking could result in overheated or damaged brakes, which could result in brake system malfunction or failure. Section 7 of the POH discussed the brake system. It stated that brake system malfunction or impending brake failure might be indicated by a gradual decrease in braking action after brake application. Other indicators were noisy or dragging brakes, soft or spongy pedals, excessive travel, and/or weak braking action. It stated that any of the symptoms required immediate maintenance. As a result of this investigation and several similar investigations throughout the United States, both the FAA and Cirrus issued the following documents: FAA Airworthiness Directive 2006-24010 effective November 17, 2006. CIRRUS Owners Owner Service Advisory SA 05-04 regarding Proper Braking Practices issued on June 30, 2005. Service Bulletin 2X-32-13 titled Wheel Conversion and Brake Upgrade in December 2005. Several changes to the POH - (see current Cirrus POH for further details) Service Bulletin 2X-32-14 titled Main Landing Gear Fairing Modification. Associated POH changes for inspection of tele-temp stickers during preflight. Production SR20 serial number 1601 and subsequent, current SR22 brakes installed on the SR20, with new material O-ring installed as well. SR22 serial number 1740 and subsequent, new larger brake assemblies installed, with new material O-ring installed as well. Tele-temp stickers, inspections holes, and trimming of the lower fairing opening are made concurrent with new brake assemblies.
The pilot's excessive braking during taxi that resulted in the right brake overheating and a fire. A factor in the accident was the pilot's continued operation with known deficiencies.
Source: NTSB Aviation Accident Database
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