Aviation Navigation Arrow 70-feet (circa 1924) and VOR “Omni” (Mormon Mesa, NV) Before GPS the U.S. Government built giant 70-foot concrete arrows, like breadcrumbs across America, for airmail pilots to find their way. Transcontinental airmail service began in 1920 when the U.S. Postal Service began coast-to-coast air mail service using old, army war surplus aircraft from World War I. Many of the planes were flown by former army pilots. However, some pilots got lost because they didn’t know the

What is VOR? What is DME?

¿Qué es el VOR? ¿Y el DME?