On which date did the 56th Guards Air Assault Brigade secure the major mountain pass connecting northern Afghanistan with Parwan Province?
56th Guards Air Assault Brigade:  On 27 December, the brigade's 4th Airborne Battalion crossed the Afghan border and secured Salang Pass. Salang Pass: The Salang Pass (Persian: كتل سالنگ‎ ‎ , el.
27 December