A Century Apart: Restored Ab-11 Biplane Meets Modern Skyfox Jet in Prague

Prague's Kbely Airport, home to the Czech Army's 24th Air Transport Base, played host to a remarkable meeting of two eras in Czech aviation history — a painstakingly restored 1926 Aero Ab-11 biplane and a modern L-39 Skyfox trainer/light combat aircraft built by AERO Vodochody AEROSPACE. The event marked the 100th anniversary of the Ab-11's record-setting flight, which in 1926 took it across 23 countries on three continents.

The Skyfox's arrival nearly didn't happen. Just before departure from the company's home airfield in Vodochody, a warning light came on in pilot Vladimír Továrek's cockpit, indicating a fault in the brake control unit. Rather than taking off, the aircraft was rolled back into the hangar. Technicians quickly traced and fixed the problem, but additional checks were needed, delaying the flight. As the pilot explained, this is a prototype under constant refinement — an unavoidable part of developing new aircraft.

According to Skyfox's chief designer, Jaroslav Lang, the company keeps two prototypes in continuous development, used to test new weapons systems and equipment. Aerodynamically, however, the aircraft remains unchanged — no modifications are made that would affect flight performance. Aero currently produces one Skyfox per month, but should demand pick up, the company is ready to ramp up output to one-and-a-half aircraft monthly — bringing annual production to 18 planes, up from the current 12.

One area of ongoing development involves adapting the Skyfox's cockpit and control systems to help train pilots for the F-35 fighter jets the Czech military is expected to acquire in the future. Every customer, the designer noted, requests its own specific configuration, so refinement work never really stops.

As for the historic Ab-11, despite having passed engine tests and being technically airworthy, it will never fly again. According to Prague's Military History Institute, it is the only surviving example of its kind in the world, and its preservation cannot be put at risk. The aircraft still retains its original Breitfeld-Daněk engine, propeller, and a few now-hidden fuselage parts — everything else has been rebuilt using components from other aircraft.

The restoration took two years, running from April 2024 to April 2025, and was carried out by specialist Petr Ježek along with two restorers surnamed Zimák. In effect, it was a "restoration of a restoration" — the plane had previously been worked on at aircraft repair workshops in Trenčín, Slovakia, back in the 1980s, but that earlier work no longer meets today's standards.

As the Military History Institute recalls, the original Ab-11 flight took place between May and July 1926, flown by pilot Vilém Stanovský (then a staff captain, later a general) and mechanic František Šimek. The pair visited 23 countries, covering 15,070 kilometers over 92 hours and 52 minutes of flight time. The journey carried diplomatic as well as promotional significance: the crew was received by Czechoslovak embassies along the route, and in London they were personally welcomed by Jan Masaryk, son of the republic's president and future foreign minister.

One curious detail: a spare propeller was mounted on the Ab-11's landing gear — an unusual precaution for the time, but one that proved well justified, as the institute notes that a propeller was indeed damaged during one landing and had to be replaced.

The modern-day counterpart to that historic flight took place between November 7 and December 23, 2025: the Skyfox, flown by pilots David Jahoda and Vladimír Továrek, visited 20 countries and covered 23,018 kilometers in 56 hours and 20 minutes of flight time. According to designer Lang, both expeditions — the one a century ago and last year's — were equally successful, showcasing to the world the enduring excellence of Czechoslovak and Czech aircraft design.

Around Prague, based on reporting by prazsky.denik.cz