A Flustered Falcon
When Orličan’s LD-40 first flew in late March of 1956, it was more than just the prototype of the L-40 Meta Sokol aircraft; it was the successful culmination of great effort to improve upon the Mráz M-1 Sokol (Falcon).
Just as Orličan was a descendant company of the Mráz company, so was the Meta Sokol intended to be a descendant of the M-1 Sokol. In both cases, neither company nor aircraft was a direct descendant of their forbear and the corelation to their respective ancestors is rather convoluted as a result.
Orličan had its roots in the pre war Beneš-Mráz company. During World War II, the company was annexed by the Germans and forced to do work for the Luftwaffe; it emerged from the conflict simply as Mráz. Through a series of nationalisations and mergers of Czechoslovak companies in the late 1940s, Mráz was merged into and passed through several other companies before it emerged as the independant Orličan in 1955. One result of this is that Orličan aircraft are sometimes credited to other manufacturers in some references.
Mirroring the evolution of its creator, the L-40 Meta Sokol ended up being a much greater departure from the M-1 Sokol than originally intended. What was envisioned as a refined and improved version of the M-1, ultimately emerged as a completely new arcraft with little in common with the M-1 save the Sokol name and the same designer, Zdeněk Rublič.
A Delayed Successor
Designed by Zdeněk Rublič in secret during the Second World War, the M-1 Sokol was Czechoslovakia’s first post war aircraft design. It was a very clean touring and sport aircraft of laminated wood construction and, by most accounts, a pleasure to fly. Nearly 300 M-1 aircraft were produced across five variants and successful enough to justify further exploration of the design and development of a follow on to it.
Work began on the Sokol’s successor in October of 1949. Changes included full metal construction as opposed to the M-1’s wood construction, a new cabin design and wing refinements. Additionally, the new aircraft design incorporated a V-tail design; famously used by the Beech V-35 Bonanza and the Fouga Magister jet trainer, and a distinctive reversed tricycle landing gear configuration.
The new aircraft, designated XLD-40 Mír, flew for the first time in July of 1950 and exhibited quite unfavourable handling characteristics; These handling problems were traced to the V-tail configuration. At the same time, Czechoslovakia’s Socialist regime ordered a shift in industry priorities to favour projects which benefited the military; as a result, the XLD-40 was put to low importance and any adjustments and developments to it were done on a volunteer basis as time allowed.
By 1953, the Czechoslovak government had adjusted its priorities once more and work on the XLD-40 was officially reauthorized. With the aircraft back to higher priority, developments were accelerated and a revised XLD-40 took to the air in August of 1954 with the V-tail replaced with a conventional tail arrangement.
The reborn XLD-40 was still not perfect from a handling standpoint, though much had been learned in its development and these lessons were applied to the LD-40 pre production prototype which flew in March of 1956.
Into Production and Around the World
Production of the L-40 Meta Sokol commenced in December of 1957 and concluded in December of 1959 after a total of 106 aircraft had been completed; 60% of these aircraft were exported and found use in nearly 20 countries outside of Czechoslovakia. The most significant export customers of the type were Australia, Great Britain and the former West Germany.
In the main, the aircraft was marketed as a light touring aircraft and navigation trainer with accomodation for three passengers plus the pilot. Like the M-1 Sokol that went before it, the L-40 had pleasant flying characteristics. However, it could present a challenge in ground handling when crosswinds were present.
The L-40 was of lightweight construction and possessed quite respectable range for an aircraft of it engine class. It also had several design features which set it apart from other aircraft of its period.
The reverse tricycle landing gear arrangement, so distinctive to the type, was adopted primarily to improve the pilot’s view of the runway during taxiing, take offs and landings. Unusually, rather than having a traditional tricycle landing gear configuration equiped with a nose landing gear, the Meta Sokol’s design was derived by replacing the M-1 Sokol’s traditional tail wheel with a more robust gear leg located located to a position just aft of the aircraft’s cabin.
Aside of the improved visibility for the pilot, the relocated tailwheel was able to be fully retracted into the fuselage for better aerodynamics in flight. The trade off of the reverse tricycle landing gear arrangement was that it reduced the aircraft’s wheel base and made it much more sensitive to crosswinds during ground handling and during take offs and landings. Such qualities required the pilot to be particularly attentive with the aircraft during these phases of flight.
The L-40 was also designed to incorporate a degree of component commonality. The wing flaps and ailerons were not handed nor were the horizontal tail surfaces. This allowed not only greater ease of maintenance when replacing parts, but also it reduced the amount of tooling required at the factory for the manufacture of those components.
One of the few design features that the L-40 inherited from the M-1 was main landing gear legs which intruded minimally into the wing construction. With the exception of a small percentage of the tires retracting into unobtrusive hollows in the wing, the remainder of the main langing gear legs simply retracted against the wing surface. This arrangement had the added advantage of reducing structural damage if the aircraft was force to make a belly landing.
Owing to the short period the type was in production and the modest number made, the L-40 only ever existed in one basic version.
In contexts of time frame, development, dimensions and performance, the Italian designed Piaggio P.149 could be considered one of the Meta Sokol’s closest contemporaries despite the fact that the Italian aircraft outnumbered the L-40 in production numbers and spent most of its time in military service while the Meta Sokol was exclusive to civil aviation.
The Meta Sokol Today and Learning More
Due to a relatively small production run, the L-40 Meta Sokol is not a common sight today and has a fairly sporadic distribution worldwide. Happily, as of 2015, there were at least 20 of the type listed as active between Australian, Czech, German and Slovak civil registers as well as technical support still available for it.
If you see a Meta Sokol, take some time to enjoy the sight and take some pictures if you can, it might be a while before you see another.
This link will take you to a brief write up of the type in Czech and some photos of one of the pre production prototypes which is on display at the Kbely Air Museum in Prague, Czech Republic. It responds reasonably well to online translators
This link at goodall.com.au will give you insights into Meta Sokols that were exported to Australia.
Pickled Wings 