Vmu is the minimum unstick speed.

It is the calibrated airspeed at and above which the airplane can safely lift off the ground and continue the takeoff. Lift-off is not possible prior to reaching this speed.

Vmu is not an operational speed and is established in flight testing only.

NDB errors:

Interference from other NDB’s

• Static, especially near thunderstorms

• Night effect Coastal refraction

• Mountain effect

• Aircraft quadrantal error

Reduced Vertical Separation Minima (RVSM) is the reduction, from 2,000 feet to 1,000 feet, of the standard vertical separation required between aircraft flying between flight level 290 (29,000 ft) and flight level 410 (41,000 ft).

anhedral is the downward inclinitation of the wing from the root to the tip.

Drag penalties (additional weight)

Less controllability

The angle between between the chord line and the aircraft's longitudinal axis. It's a fixed angle for wings, but variable for variable incidence tailplanes.

Taxi, trip, contingency, reserve and extra fuel.

a line extending from the leading edge to the trailing edge equidistent from the upper and lower surface of the aerofoil.

Dihedral provides:

Lateral stability (during a roll) Wing clearance, wingtip to ground has more space

Frequency range from 200-1750kHz, medium and low range frequency bands.