Air navigation von Weems, Philip Van Horn 1889-

“… Weems System of Navigation …”

Star altitude curves Latitude 40° to 50° north, positioned for epoch 1 January 1945,(U.S. Papent No. 2,143,042) von Weems, Philip Van Horn 1889-

“… Weems system of navigation …”

Instrument flying von Weems, Philip Van Horn 1889-, Zweng, Charles A.

“… Weems System of Navigation <<[u.a.]>> …”

Instrument flying von Weems, Philip Van Horn 1889-, Zweng, Charles A.

“… Weems System of Navigation [u.a.] …”

Instrument flying von Weems, Philip Van Horn 1889-, Zweng, Charles A.

“… Weems System of Navigation [u.a.] …”

Instrument flying von Weems, Philip Van Horn 1889-, Zweng, Charles A.

“… Weems System of Navigation [u.a.] …”