ANC99FAMS2 · Piper PA-28R-200

The accident airplane departed as the lead airplane in a flight of two airplanes on a cross-country flight from Alaska to Canada. Both airplanes were listed on one VFR flight plan. The accident airplane is missing and presumed to have crashed in a remote area of mountains. The commercial pilot is presumed to have sustained fatal injuries. The last communication from the accident airplane was when the pilot reported '10 miles from the border' to the second airplane. When the pilot of the second airplane observed poor weather conditions in the area of intended flight, he diverted to an intermediate U.S. airport not listed on the original flight plan, and attempted to close his portion of the flight plan. Flight service station personnel at the intermediate U.S. airport did not find the two airplane flight plan in their computer system, and did not notify the departure or destination facilities of a change in the flight plan. Consequently, the flight plan remained open. The ETA of the flight passed, and flight service station personnel at the Canadian destination began initial search inquiries. Shortly after the ETA expired, the second airplane pilot filed a new VFR flight plan to a Canadian destination, and the original flight plan for both airplanes was then closed by Canadian personnel. The following day, the second airplane pilot did not locate the first airplane along the original plan route and alerted search personnel. A search for the missing airplane in Alaska and Canada was suspended after 21 days.

Verbatim NTSB analysis and probable cause from the NTSB dataset