A periodontist is a dentist who specializes in the prevention, diagnosis, and treatment of periodontal disease, and in the placement of dental implants. Periodontists are also experts in the treatment of oral inflammation.
Ground speed. Ground speed is the horizontal speed of an aircraft relative to the ground. An aircraft heading vertically would have a ground speed of zero. Information displayed to passengers through the entertainment system often gives the aircraft ground speed rather than airspeed.
The speed of any aircraft over the ground is a function of both its. airspeed, and any local winds that may be blowing. In calm air, the airplaneaâ¬â¢airplaneÃ¢ s ground speed equals the. Airspeed when flying. into a, headwind the ground speed is the difference between the. airspeed and wind. speed