PARIS — Czech company Aero Vodochody has announced three customers who have signed up to enter the L-39 Next Generation upgrade program, which will equip their L-39 jet trainers with new engines and systems.

The Breitling Jet Team, Draken International and Czech state firm LOM Praha will together order around 20 upgrades, said Ladislav Simek, CEO of Aero Vodochody, which manufactures the venerable L-39 trainer.

LOM Praha is a Czech state firm which offers jet training to the Czech Air Force and those of other countries, while Florida-based Draken has a fleet of 70 ex-military fighter aircraft which are used for training.

Draken and the Breitling Jet Team have signed letters of intent for their purchases.

A LOM Praha owned subsidiary is also working on a simulator for the new L-39, which will be ready by the end of 2016.

The three customers will have new Williams International FJ44-4M engines installed on their existing L-39s, as well as upgraded systems.

The Czech firm is meanwhile marketing the L-39NG as an all-new aircraft to new buyers, offering new avionics, a new airframe with five hard points, a glass cockpit and a new engine.

The low cost of the aircraft would be a major attraction, Simek said. "We are offering below $2,500 per flight hour."

There are currently around 400 L-39s in use, and Simek said he was talking to air forces about the L-39NG.

"We are talking to existing users and a few new customers," he said. "We are in advanced talks with two government customers which could be finalized in the coming months."

An official said the firm would pitch the L-39NG to France, which is seeking to replace its Alpha jets.

The first flight of a re-engined jet will be this summer in the Czech Republic, while the all-new aircraft will be certified in 2017 and ready for delivery in 2108.

"Customers who take a new engine for their aircraft now can subsequently transfer that engine to a new aircraft when they come to buy that," Simek said. "We would sell them a new aircraft with no engine in it."