B747-400 flight crew discovered enroute that the aircraft shipset does not contain approach plates for the enroute alternate BGTL.

Narrative

We had the usual northerly route placing us 231 miles south of THULE Greenland and 354 miles north of SFJ (the Old Sondrestrom); the First officer and I were reviewing the plates and information available to us in the new shipset publications; we were particularly interested in reviewing BGTL and BGSF as for a considerable period of time these would be our go to diversion airports (e.g. uncontrollable cabin smoke and fire) we were pulling out these plates after departure and to our surprise found BGTL missing from both shipset bags. This is a very serious omission; I am assuming it was an omission due to the critical role BGTL would potentially play during an in-flight emergency when operating at high latitudes. I have had BGTL plates in my personal flight bag for years. It is my suspicion that NO 400 Shipsets contain BGTL; I truly hope that I am not correct in this. Please investigate this situation immediately; many of our polar and high latitude flights to and from Europe will potentially be affected. Fortunately we found BGSF plates in BOTH shipset bags; but unfortunately; it was further away from our flight track and a less adequate facility. I fly this same trip again in a few days and I certainly hope the shipsets are corrected by then. In any event I will carry my personal BGTL plates and information.