During landing neither F-20 normal nor alternate brakes operated normally so near the runway's end; ...

Narrative:

I operated the flight that night. We were cleared for the visual approach and cleared to land runway 6. We completed all checklists prior to landing. The aircraft touched down on runway 6 at a normal speed; vref or so and was firm in nature. Airbrakes were deployed and indicated normal. I felt a light brake grab and the captain called out 'good brakes' as per SOP. After a few moments I realized that we were not decelerating properly and the captain was in some distress trying to apply the brakes. He reached up and attempted to disarm the antiskid and the airplane seemed to lurch and momentarily grab. He then tried the secondary brake system with no change in performance; he then commanded me to assist and try my brakes. I pressed my brake pedals and found some braking action to be (1/4 of normal at the most) and found that I had to press extremely hard to get that amount of braking action. We then saw the end of the runway coming with a significant cliff/drop off directly off the end of the runway and we had considerable speed left. The captain turned the airplane to the right with an attempt to stay on the taxiway area as we knew that there was flat ground in that direction. We departed the runway with the right main gear only prior to the intersection in attempt to make the turn. That slowed us down considerably and the captain was able to continue the right turn. We departed the north side of the taxiway with all 3 wheels and hit several taxi lights. The captain continued to turn right to avoid the cliff. The aircraft decelerated in the mud to a controllable speed and with the continued right turn we ended up on the parallel taxiway. We let air traffic controller know of our emergency; that we were ok and the aircraft appeared to be ok; but that we had departed the pavement and damaged several lights.

Original NASA ASRS Text

Title: During landing neither F-20 normal nor alternate brakes operated normally so near the runway's end; the Captain turned the aircraft off the runway across a muddy grass area; contacting several taxi lights and the re-entering a taxiway where it stopped with little apparent damage.

Narrative: I operated the flight that night. We were cleared for the visual approach and cleared to land Runway 6. We completed all checklists prior to landing. The aircraft touched down on Runway 6 at a normal speed; Vref or so and was firm in nature. Airbrakes were deployed and indicated normal. I felt a light brake grab and the Captain called out 'good brakes' as per SOP. After a few moments I realized that we were not decelerating properly and the Captain was in some distress trying to apply the brakes. He reached up and attempted to disarm the antiskid and the airplane seemed to lurch and momentarily grab. He then tried the secondary brake system with no change in performance; he then commanded me to assist and try my brakes. I pressed my brake pedals and found some braking action to be (1/4 of normal at the most) and found that I had to press extremely hard to get that amount of braking action. We then saw the end of the runway coming with a significant cliff/drop off directly off the end of the runway and we had considerable speed left. The Captain turned the airplane to the right with an attempt to stay on the taxiway area as we knew that there was flat ground in that direction. We departed the runway with the right main gear only prior to the intersection in attempt to make the turn. That slowed us down considerably and the Captain was able to continue the right turn. We departed the north side of the taxiway with all 3 wheels and hit several taxi lights. The Captain continued to turn right to avoid the cliff. The aircraft decelerated in the mud to a controllable speed and with the continued right turn we ended up on the parallel taxiway. We let Air Traffic Controller know of our emergency; that we were OK and the aircraft appeared to be OK; but that we had departed the pavement and damaged several lights.

Data retrieved from NASA's ASRS site as of July 2013 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Attributes
ACN	1133387
Time
Date	201312
Local Time Of Day	1801-2400
Place
Locale Reference	ZZZ.ARTCC
State Reference	US
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Make Model Name	Falcon 20FJF/20C/20D/20E/20F
Operating Under FAR Part	Part 91
Flight Phase	Landing
Flight Plan	IFR
Component
Aircraft Component	Normal Brake System
Person 1
Function	Pilot Not Flying First Officer
Qualification	Flight Crew Air Transport Pilot (ATP)
Person 2
Function	Captain Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Aircraft Equipment Problem Critical Ground Event / Encounter Object Ground Excursion Runway Inflight Event / Encounter Loss Of Aircraft Control Inflight Event / Encounter Object

During landing neither F-20 normal nor alternate brakes operated normally so near the runway's end; the captain turned the aircraft off the runway across a muddy grass area; contacting several taxi lights and the re-entering a taxiway where it stopped with little apparent damage.