Avia BH-5 (c/n 02, OK-BOS), flying display during Točna Airport open day, Prague, September 2022.
On 14th June 1923, new Czechoslovak aircraft, designated Avia BH-5, took-off for its maiden flight. The aeroplane was created by two Czech engineers – Pavel Beneš and Miroslav Hajn – and developed from their earlier designs, BH-1 from 1920 and BH-3 from 1923.
Similarly to its predecessors, the BH-5 was a two-seat, low-wing monoplane of wooden construction, although this time not only linen but also plywood was used to cover its wings. Initially, the aircraft was powered by Anzani A3 engine, but shortly after the first flight that powerplant was replaced for Walter NZ-60.
The NZ-60 was a five-cylinder radial engine – and the first aviation powerplant fully designed and produced in Czechoslovakia. Therefore, after being equipped with the Walter powerplant, the Avia BH-5 became the very first all-Czechoslovak made aircraft.
Shortly after the maiden flight, the BH-5 won its first trophy. The aircraft participated in the Belgian Touring Aircraft Contest and, flown there by Zdeněk Lhota, was awarded both the overall prize and the challenge cup of the King of Belgium. Later that year, during the domestic competition for the Award of the President, the BH-5 won the first prize in D-category.
Both the aforementioned successes attracted attention of the Czechoslovak armed forces. The BH-5 was evaluated by the Ministry of Defence, resulting in an order for series of approximately forty modified aircraft, successively designated Avia BH-9, BH-10 and BH-11. Following the civil registration of the first BH-5, L-BOSA, that aeroplane and its derivatives received a nickname ´boska´.
It should be mentioned here that also the BH-5 was finally bought by the armed forces and then used as a liaison aircraft.
At the beginning of 2000s the idea of making a true-to-life replica of the BH-5 appeared. The project was based on a part of original documentation that survived, as well as existing photos of the original aircraft. Reconstruction was launched in 2003 and, after seventeen thousand hours of work, was completed in 2007. As much as possible of the original materials, techniques and spare parts were used. And what is the most interesting, the aircraft was powered by one of the still existing, original Walter NZ-60 engines.
As a consequence, there is no exaggeration in saying the aircraft made in the 2000s is not an ordinary replica, but practically the second-build example of the BH-5 series.
The replica of the BH-5 performed its maiden flight on 1st June 2007, at Mladá Boleslav airfield. After eighty-four years from the first flight of the original aeroplane, the Avia BH-5 appeared again in the sky.
Over the next years, the replica of ´boska´ participated in many air shows and other aviation events all over the Czech Republic, always attracting the look of aviation enthusiasts and general public. The aircraft is now a part of Točna airport collection and is being based there on daily basis.
