By Utibe Inyang
A Non-Directional Beacon (NDB) was developed by a United States Air Force (USAF) Captain, Albert Francis Hegenberger, and was used to fly the world’s first instrument approach on May 9, 1932.
A Non-Directional Beacon is a ground-based, low frequency radio transmitter used as an instrument approach for airports. It transmits a signal of equal strength in all directions. NDB’s used for aviation are standardized by the International Civil Aviation Organization (ICAO) Annex 10, which specifies that NDB be operated on a frequency between 190 to 1800 kHz.
REFERENCE
wikipedia.org
thisdayinaviation.com
