Now comes Original Vintage NPL-M AF Pilot Flight Knee Computer/Recorder. Measured 6" x 4.5". Nothing broken or missing. . Circa 1970s-80s. What you see on the scans is what you are going to get.
Tablet knee-high military pilot. Used condition (no rubber strap). With skilled hands, everything is possible to make :) Designed for the convenience of writing / reading basic flight data (navigation, airfield call signs, wind drift calculation, etc. etc. .....) To whom in more detail how to use, I will unsubscribe the entire algorithm. Well, to start with: 1 - fixed - percentage 2 - moving ring - distances and speed - kilometers, kilometers per hour 3 - fixed - time (min-sec or hour-min). On the scale are also available; round red index on the number 36 - designed to convert speeds from m / s to km / h and vice versa; a square red index at 10 and a triangular red index at 60. 4 - fixed scale with plotted diverging drift angle lines (in degrees) and arcs of ground speed (in percent) 5 - movable transparent limb with degrees from 0 to 360 applied along the perimeter. Scales 2 and 3 are used for calm calculation of the flight, similarly to the same scales on the NL-10M ruler, when, according to the available length of the route section S and the air (indicated) speed of the aircraft V, we calculate the passage time of the section t = S / V Key: Opposite the red triangle of scale 3, set the air (indicated) speed of the aircraft (for example, 180 km / h), after which on scale 2 we find the length of the route section (for example, 27 km) and opposite it on scale 3 we read the flight time in minutes ( 9 minutes). Thus, all sections of the route are calculated, a calm calculation is performed and the corresponding tables are filled in on a tablet or on paper - in the Navigation Flight Plan.