R. B. Underdown

Ground Studies for Pilots: v. 3: Navigation, General and Instruments

By R. B. Underdown, R.B. Underdown

Ground Studies for Pilots, Volume 1: Radio Aids

By R. B. Underdown

Ground Studies for Pilots: v. 2: Plotting and Flight Planning

By R. B. Underdown, R.B. Underdown

Ground Studies for Pilots: Meteorology v. 4

By R. B. Underdown