Date: 201306
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Daylight
Aircraft: Gulfstream G200 (IAI 1126 Galaxy)
Operator: Air Taxi
Operating under: Part 135
Flight plan: IFR
Mission: Training
Flight phase: Landing
ATC / advisory: CTAF ZZZ
Aircraft component: Squat Switch
Component problem: Malfunctioning
Reporter organization: Air Taxi
Reporter function: Pilot Not Flying; First Officer
Reporter qualification: Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Flight Instructor; Flight Crew Air Transport Pilot (ATP)
Second reporter function: Pilot Flying; Captain
Anomaly: Aircraft Equipment Problem Critical; Ground Excursion Runway
Detector: Person Flight Crew
When detected: In-flight
Result: Aircraft Aircraft Damaged
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: I reported for duty for a flight to complete a Part 135.293 a (1) 4-8 and 135 299 line check. I was acting as SIC for the two legs. The first leg was completed without incident. The oral portions of the test were completed and administered by POI Mr. X and FAA Check Airman Mr. Y and these checks were satisfactory. The preflight portions; planning; weight and balance were observed by Mr. X. The second leg was observed by Mr. Y in the Jump Seat and as passengers were the company Chief Pilot and the POI. After an uneventful departure the After Takeoff; Climb and Cruise Checklists were completed. The ILS approach was reviewed again and confirmed that landing in 60% of runway was in accordance to company Ops Specs and FAR 135. Special Caution was taken to confirm that we were able to land and stop in the 60% of Runway 25. The flight was uneventful. The Approach and Before Landing [Checklist] was completed. [The Captain] performed a stabilized approach. I contacted the CTAF about 10-15 miles from the FAF and airport ops reported; there was communication on CTAF. I came back to Comm 2 and finished the Landing Checklist and reported crossing the FAF. Approach said to contact CTAF and I did. Again it appeared there was communication from the airport. We touched down at the 1;000 foot marker and the ground brakes reflected deployed in the EICAS; (after the fact; I cannot recall if the flight airbrakes were also deployed) I am very sure I saw the green ground brakes message on EICAS. It appeared that the thrust reversers were deployed but it did not feel like there was effective braking or thrust reversing power. I begun to count the speed and speed versus the distance of runway remaining and when it was obvious that the aircraft was not braking; I braced for impact. The airplane departed the runway end about 10-15 feet. I asked the passengers if everyone was okay or needed assistance. Passengers responded everyone was okay. I got up and opened the main cabin door after ensuring it was safe. Passengers and crew deplaned after aircraft was secured and Shutdown Checklist were completed. After ensuring there was no leaks or unsafe conditions. I noticed tire marks left of the runway centerline from the 1;000 to 1;500 foot markers. There was only one set of tire marks indicating that there was no braking on the right main wheels. The nose wheel left tire marks for about 3;000 feet along with tire tracks from locked wheel from the left main wheels. A go-around was not commanded due to uncertainty of the conditions of the brakes; antiskid and most important the thrust reversers. There was not sufficient runway left to execute a safe takeoff after it was suspected it that there was a malfunction with the aircraft. It appears there is a history of proximity switches failures and issues with the brake wear indicators not showing and representing the actual condition of the brake system. I feel the crew did everything to ensure no lives were endangered and minimum aircraft damage. I computed the performance several times and it reflected a [landing field Length] dry of 3;151 and with the 60 % factor an added margin of safety to 5;251 and the runway is longer. I feel in future; we as crewmembers should be able to decline flights to airports with such a short runway for an airplane like the G200 with a high Vref and stopping the airplane safely after a brake emergency is an issue. I feel the WOW switches did not command the airplane to be on the ground. It actually told the airplane that it was in the air; thus limiting thrust for the reverses and disabling the antiskid and the brake degradation.


Second narrative: The plan for the day was to ferry to ZZZ for an Oral and FAA Check Ride administered by the FSDO Office. The first flight of the day was uneventful. During the first flight of the day the crew was pilot flying; from the left seat (me) Captain; pilot not flying right seat First Officer; and in the jump seat was the Chief Pilot. Once we arrived at the FSDO Office; Oral Testing was successfully completed. All Weight and Balance and Performance for this flight were reviewed as OK. It was at this time that FAA Check Airman Mr. Y commenced the flight portion check of this 135.299 Check Ride. The crew placement was: Captain left seat; First Officer right seat and in the jump seat was FAA Check Airman Mr. Y. Passengers were FAA POI Mr. X and the company Chief Pilot. This next leg was from ZZZ to ZZZ1. After what was an uneventful flight segments of takeoff; climb; cruise; descent and approach; all regimes of flight were on profile and normal. During the normal stabilized approach to landing; I touched down on speed and on profile as a normal landing. The aircraft crossed the fence at 50 FT in the air and at Ref. speed. I touched down the aircraft at the 1;000 FT paint markings in normal configuration to land. At touchdown I lowered the nose wheel down to the ground and then applied thrust reverser levers and breaking action of steady brake pressure continually. At this point I further increased thrust reverser levers with no thrust reversing being able to be obtained. Also; at nose wheel touchdown I transferred the yoke to the pilot not flying. During rollout phase of the landing the breaking action and stopping ability was nil. I continued with increased max braking force; however I was never able to get any noticeable stopping control. Max breaking and full thrust reversers were used. I believe the thrust reversers deployed; but nothing more than that could be achieved. I felt no anti skid pulsing or any noticeable normal stopping action from my inputs. As a result the aircraft stopped off the end of the runway; approximately 10-15 FT beyond the pavement. After stopping; inspection of runway tire marks from our aircraft indicated that no braking action from the right main tires or the outer left main tire was archived.I believe this problem could have been prevented if the braking system had worked correctly. In addition; thrust reversers did not perform correctly in assisting stopping ability.


Synopsis: G200 flight crew experiences thrust reverser and brake failures during landing that result in a runway excursion causing minor damage to the aircraft. The aircraft had a history of proximity switch failures and issues with the brakes wear indicators.