Date: 201601
Local time of day: 0001-0600
Location: ZZZ.Airport, US
Flight conditions: Marginal
Weather elements / visibility: Icing; Turbulence; Windshear; 8
Light: Night
Aircraft: Small Transport; Low Wing; 2 Turbojet Eng
Operator: Air Taxi
Operating under: Part 135
Flight plan: IFR
Mission: Cargo / Freight / Delivery
Flight phase: Landing
ATC / advisory: TRACON ZZZ
Reporter organization: Air Taxi
Reporter function: Pilot Flying; Captain
Reporter qualification: Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP); Flight Crew Flight Instructor
Human factors: Communication Breakdown; Situational Awareness
Second reporter function: Pilot Not Flying; First Officer
Anomaly: Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Loss Of Aircraft Control; Ground Excursion Runway; Inflight Event / Encounter Unstabilized Approach; Inflight Event / Encounter Weather / Turbulence
Detector: Person Flight Crew
When detected: In-flight
Result: General Evacuated
Contributing factors: Airport; Weather
Primary problem: Weather

Narrative: Enroute to ZZZ we got weather from the ATIS and requested the ILS XX with [ATC]. As we came down the approach we encountered turbulence and wind shear. Airspeed indications were rapidly changing by 10 to 15 knots. Nearing DA; I did not feel we could make a stabilized landing and called for a 'go around' which I performed and the go around checklist was completed. We requested vectors back for another ILS to Runway XX. Due to the wind shear we had encountered; we agreed to increase the ref speed by 5 knots. On the second approach we again had very rough air but remained stable. I brought the power to idle at the runway threshold. We touched down approximately 1500-2000 feet down the runway. During or just prior to touchdown the First Officer (FO) called go around. I made the decision that with the wind shear and turbulence we were experiencing and our proximity to the ground that it would be safer to land. At touchdown I applied maximum brakes and deployed airbrakes. I could hear the antiskid cycling. The aircraft departed the far end of the runway into the Engineered Materials Arresting System (EMAS). I did the shutdown and the FO opened the door for egress. While walking the runway immediately after the event I noticed that it was incredibly slick with a glazed ice. Ground crew told me that it was warmer and had rained during the evening and that temperatures then dropped; freezing the water on the runway.


Second narrative: Weight for landing was figured to be at 24;800 LBS so 25;000 LBS numbers were used; Vref was set to 130 knots. Approach cleared us for ILS XX descent was normal we encountered wind-shear starting at about 1100 feet MSL; loss and gain of airspeed of 5 to 15 knots approach was terminated at the decision height; missed approached was executed and ATC was contacted and we requested another approach. After stable missed approach check list was performed. Due to the wind-shear we bumped ref to 135 and started the ILS to XX; we broke out of the clouds at 1800 MSL I went visual at that point. Wind-shear was encountered about 1100 MSL till we entered ground affect. We crossed the end of the approach end of the runway at about 35 feet with proper VASI light indications. We passed the 1000 feet markings with no signs of slowing I called for PIC to go missed shortly after that we were on the ground; PIC deployed the boards and applied maximum brakes; and I was outside calling out runway distance remaining. We departed end of runway coming to rest in EMAS. Upon stopping PIC instructed me to evacuate the aircraft and he would perform the shutdown. I walked the runway and noted it was iced over.


Synopsis: The flight crew of a small transport aircraft reported a runway excursion during landing after an un-stabilized approach with windshear conditions. When the crew exited the aircraft; they noted that the runway was covered in glazed ice.