Air carrier flight crew reported braking action nil on their landing at JAC; and were unable to stop on the runway; overshooting a few feet into the overrun area.
Synopsis
Air carrier flight crew reported braking action nil on their landing at JAC; and were unable to stop on the runway; overshooting a few feet into the overrun area.
Narrative
Our flight arrived at JAC approximately 40 minutes late. We began our landing preparation duties approximately one hour prior to landing. Multiple ACARS messages were sent between Dispatch and our flight for coordination. Items discussed amongst the flight deck were airfield conditions; weather; MAP climb gradients; and special engine out procedures. We used data provided by Dispatch; as well as the ATIS. We also coordinated with Dispatch to ensure that we were authorized to land after XA:30L hours; which dispatch confirmed. Reported braking action was medium to good; 4/4/4. Dispatch also provided their landing data calculations; which we verified using the XX-X page (Max Brakes). After reaching a comfortable place with the data review the briefing was conducted per the FOM and the descent checklist was completed prior to TOD (top of descent). Center cleared our flight direct to DNW at 14000' and the approach to 19 via ILS Z. The approach was flown with automation on. The aircraft was appropriately configured on-speed; during the approach; with the aircraft fully configured; flaps 40; and the checklist complete prior to YUSGU. Tower was closed so the PM made appropriate position reports and turned on the pilot controlled lights. When the position report for ZIBIV was given; the plow team stated that they were complete with plowing the runway on UNICOM. At approximately 500 feet AGL we broke out and had the runway lights in sight and continued. It was actively snowing throughout the approach and landing. Just below 500 feet AGL the autopilot was turned off. The aircraft was on-speed; stable; and slightly left of the centerline. At 50' below DA; the auto-throttle was turned off. The aim point was the 500' marker; but the touchdown was made at the 1000' marker due to the correction for centerline and narrow plowing. Initial aircraft braking was satisfactory; however as we neared the last 1/4 of the runway braking action. Thrust reverse was full. Approximately 3 to 4 inches of snow was covering the runway. The PM announced 3000' and I stated that the plane doesn't want to slow down. I disengaged the auto brakes and stood on the brakes around 80 to 70knots. The aircraft slowly decelerated to a stop; however due to the snow covered runway it appeared that the nose on the aircraft went approximately several feet into the overrun. We could not confirm this because the area did not look to have been plowed. The aircraft was turned on to A1 by using gentle asymmetric braking and thrust. The taxiways were not plowed so our aircraft was taxied no faster than 5 knots and we still slightly overshot alpha taxiway. The aircraft was parked with the appropriate checklist and configuration for RON in adverse weather; without further incident. Landing assurance to ATC was missed during the ground operations and a phone call was later made to Dispatch to ensure that the flight plan was indeed closed.
Second reporter narrative
Approaching 200 NM from final approach fix for ILS Z 19 in to JAC. Crew discussed and briefed thoroughly the approach threats of high altitude; short run way; snow and ice conditions and go around procedures Included in the 10-7 pages. Runway conditions and breaking action reported by ATIS was medium to good. Crew ran break calculations internally and externally with Dispatch.Selecting Flaps 40 and max brakes; we completed descent checklist prior to top decent.Making position reports on Unicom for closed Tower operation. The approach was stable with landing checklist complete prior final approach fix and stable at 500 feet where we broke out with run way in sight.Aircraft touchdown at the 1000 foot markers and had a good breaking action with full reverses through 80 KTS. After slowing the aircraft to a slow taxi speed straight ahead on runway before making turn on to taxiway Alpha.Braking action became nil allowing the nose wheel to slide slightly past the Alpha taxiway turn off and in to the overrun pad before stopping.Aircraft made turn onto Alpha taxi way and return to gate with no other issues.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.