B737 Undifferentiated or Other Model
Flight Crew Last 90 Days 212.7; Flight Crew Type 448.6
Situational Awareness; Fatigue
Ground Excursion Runway; Inflight Event / Encounter Weather / Turbulence
General None Reported / Taken
Human Factors; Weather
Landing during a snowstorm; we encountered NIL Braking due to ice and unplowed snow and slid past the end of the runway; stopping in the overrun. No aircraft damage or injuries. Aircraft was repositioned on the runway using a tug and then taxied to the gate.Approach was hand-flown by myself (Captain) on FD with Auto Throttle (AT) off. Approach and touchdown were normal and on-speed; in the touchdown zone. Autobrakes (3) and full reverse thrust were activated at touchdown. Reverse thrust was kicking up a lot of blowing snow so it was secured and the autobrakes were kicked-off; using normal manual braking. Approaching the last 2;000 feet remaining; both the First Officer (FO) and myself noticed that wheel braking was not effective and the aircraft was not decelerating. We both applied max manual braking and I re-engaged full reverse thrust although there was some difficulty getting the reversers to fully deploy. Braking action was Nil and I concentrated on keeping the aircraft aligned with the runway as we entered the overrun. We stopped the aircraft short of the end of the overrun and the aircraft remained on the prepared surface. We advised the tower controller that we were stopped and he sent around the aircraft on short final.We contacted station ops and coordinated (over the next 2 hours) to have a tug reposition us on the runway. This required extensive coordination and effort as the runway and overrun were covered in ice and snow; making it difficult to walk or drive equipment without slipping. Station ops finally brought a de-ice truck out to where we were and sprayed de-ice fluid all over the overrun to break-up the ice and snow and allow the super-tug access and traction. The ground team really did a great job.The primary factor leading to this incident was the runway condition. Braking action at the end of the runway was nil and there had not been any plowing or sanding since a snow-shower had moved in. On approach; the tower reported RVR went from 'greater than 6000' to '6000' to '4000' and I believe even lower; so snow was accumulating on an already contaminated surface. We had tried to pull the runway condition using ACARS and there was 'no data.' The Notams had no indication of less than a clean and dry runway. Preceding aircraft on frequency reported braking action 'good;' although I recall that these were RJ aircraft that may have had an easier time stopping due to lower weight and approach speed.An additional factor is the imperative to maintain arrival rates. A FAA waiver allows 2.5 miles of separation between arriving aircraft and we were closely following the preceding aircraft and were aware that there was an aircraft close behind us. We handled the airspeed assignments and energy management well (I briefed these considerations) but all of these impact our deceleration rates and runway exit plan as we can't come to a dead stop on the runway and then power-up to clear; the trailing aircraft will get sent around. We had planned to exit at the high speed and I imagine I thought we'd be slowed to 25kts or so and have an easy coast-off. The runway is one of the shortest in the system and is designed with one high-speed turnoff at each end with no options to exit early. The aircraft was planned within 3000 lbs. of max allowable landing weight requiring a high VREF and VTGT. As noted; airspeed and touchdown point were precise and on target. Regardless; this is a very high-energy state; on a short runway; with few other options to mitigate the situation. I considered using Flaps 40 and max auto-brakes but I wanted to also manage our runway exit due to the factors previously mentioned. And; let's face it; I was tired. Legal; but tired.Our trip had been modified three times due to aircraft availability following a mid-west storm event. We had to wait for aircraft each day and the planned rest opportunities were disrupted. Specifically; we were scheduled to operate to ZZZ and layover before our Red Eye; but instead went to the hotel in ZZZ1 and the following day; deadheaded to SEA to operate. This disrupted our sleep patterns and exposed us to a longer duty day (within a couple of hours of FDP limits); into a Red Eye flight arriving at a low-visibility approach on a (un-advised) contaminated runway.
On final; approach was stabilized; on speed and on glide path. ATC had announced braking action good. RVR was first observed prior to starting the approach at 6;000 feet then 5;000 feet; then 4;000 feet and on short final 3;500 feet; well above the published minimums of 1;800 feet. Special ATIS called for flight visibility 1 sm with -sn. Clearly; that was not the case on short final; but still above minimums; in fact broke out at 964 feet; above field elevation. This was my first noted sign of fatigue; as I incorrectly called out; 'approaching minimums'. However; the Captain verbalized my mistake; and correctly continued with the approach. (Other signs of fatigue were noted after the fact).The touchdown was in the first one third of the runway; and very smooth. Thrust reversers were deployed; and as a habit; I mentally noticed the orange enunciation lights. Also noted at some point the auto brakes were disengaged. At approximately the half way point of the 7;500 feet runway I noted to myself we weren't stopping normally; so I verbalized (a non-standardized call) '100 kts'; that was followed by 'We're not going to make it' meaning; stopping before the end of the runway. At that point; I applied full braking on my brake pedals. We came to a full stop in the overrun area.
B737 flight crew experienced nil braking after landing on a 7;500 foot runway which had reported good braking. The aircraft is unable to stop and rolls onto the overrun; requiring the aid of a tug to be extricated. Tight spacing on approach led the reporters to use flaps 30 and auto brakes 3 for the landing. Snowfall was increasing during the minutes leading up to the landing.