Caravan 208B
Flight Crew Commercial; Flight Crew Instrument
Flight Crew Last 90 Days 80; Flight Crew Total 750; Flight Crew Type 110
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Excursion Taxiway; Inflight Event / Encounter Loss Of Aircraft Control
Flight Crew Took Evasive Action; General Maintenance Action
Aircraft
After picking up passengers for skydiving operations during the final load of the day; I began to taxi the aircraft as I have done numerous times before; crossing the threshold and turning right onto the taxiway. As I approached the taxiway; I applied right rudder to turn the aircraft and tapped the right brake to assist. I was taxiing at a safe and slow speed as I had done twelve times previously that day. On this occasion; I noticed the aircraft was not turning normally and began to drift left of centerline. At this point; I had already pushed full right rudder and had the brake pressed full down. The aircraft continued to drift further left of centerline as I began to assess the problem more. A skydiver was seated up front in the right seat and I assumed he may have inadvertently had his foot on the pedals; although all passengers are briefed not to touch controls. I informed the passenger to get off the pedals. He said that he was not on them and I quickly glanced down to see that he was not and to check if an object had found its way to the pedals. It was clear. I continually held full right rudder and brake attempting to turn the aircraft to no avail.The aircraft continued drifting left and I felt immediate action was further warranted. The taxiway is narrow and the ground slopes downward toward a fence. There is also a sign next to the fence which is wing height. I observed these objects previously and was aware of them. As the aircraft continued drifting left; while still on taxiway; I immediately put the power to idle and entered full Beta reverse attempting to utilize the prop and engine to slow the aircraft down. However; the momentum of the aircraft at only a few knots taxi speed continued to carry the aircraft off the narrow taxiway. I knew that if I went off the taxiway diagonal onto the slope the aircraft could possibly tip wing down and strike the fence. Therefore; I added left brake and it immediately brought the nose of the aircraft around and perpendicular to the fence. I attempted to use the emergency brakes while depressing both brakes and having the prop in Beta and full reverse.As the aircraft came closer to the fence; I feathered the prop in order to slow it down in case a strike would occur. The aircraft came to a stop approximately 6-8 feet from the fence line and did not strike any object or the ground. I continued with normal shut down procedures and informed passengers to disembark after shutdown. There were no damages or injuries as a result of this. The plane was pushed back onto the taxiway and taxied and the brakes were checked.I was informed by one of the passengers that another pilot stated that he had a similar issue with the brakes 'a few days ago.' After calling the Chief Pilot; I was informed that both he and another pilot had experienced similar issues with the right brake not working after picking up passenger. The Chief Pilot also stated that he believes it occurred after depressing the brakes for a couple of minutes during passenger pick-up. He informed me that no one had brought this issue to the attention of the mechanic because it had been intermittent and 'a couple of months' since happening.I called the Mechanic and informed him of the intermittent failure. I later met with the Mechanic and spoke with him and he grounded the aircraft. Some considerations from the outcome of this incident are communicating any factors that others pilots experience with all pilots that fly the aircraft. I; being a part-time pilot; fly only once a day during the week. I believe it is paramount that a strong level of communication is present between all pilots that operate the aircraft and conveyed this to the Chief Pilot. I always do brake checks during start-up and after every shutdown and had done them that day. The brakes worked throughout the day and I had not experienced any issues with the brakes previously that day or while flying this aircraft. It is my perception that communication between pilots could improve and I hope to work with the Chief Pilot in doing this.
Cessna 208B pilot reported directional control problems during taxi.