Letort was born on 18 September 1889 in Pire-sur-Seiche, Brittany, the youngest of four brothers and four sisters from a wealthy family in the textile business.

He was educated in Rennes at the School of Brothers of Christian Instruction at Parc du Thabor and the College of St. Martin.

His main interest was in mechanical things, so on leaving school aged 18 he started in the automotive and aviation industry.

[4] In an attempt to win the Coupe Pommery prize for long-distance flight, he flew 1,300 km (810 mi) from Paris to Danzig, stopping at Berlin, on 23 August 1913.

After departing from Buc with the intention of flying to Bordeaux and back, he flew 1,050 kilometres (650 mi) until he had to make a forced landing at Barbezieux, during which the aircraft ran into a ditch and overturned.