LET L-13 BlanÃk
The L -13 Blanik is a two-seater glider Czech LET. The nickname Blechnik goes back to his building material.
History
The design from 1956 comes from Karel Dlouhy and his team. The former state-owned Czech Aircraft Works LET Kunovice, South Moravia, presented to 1978 produces about 2,700 units of this pattern. Since 1981, the successor model L -23 Super Blanik is built, tried with the LET to build on the successes of the L-13. The glider - index is 78
Construction
The Blanik L -13 is a two-seat, cantilever high-wing, all-metal construction with standard tail. The pilot seats are arranged in series, the canopy consists of several parts, the middle part can be opened for boarding to the right. The control surfaces are covered with fabric. The wings have a trapezoidal plan with a slight negative sweep ( Vorpfeilung ). They are provided with simple trailing-edge flaps and spoilers DFS.
Use
The Blanik was originally designed as a basic trainer for the air forces of the Warsaw Pact. By using a spring-loaded landing gear was the Blanik a popular training aircraft in gliding clubs, as well as hard landings will be compensated. An entity known as TG -10B Merlin version of the L -23 Super Blanik is since 2002 the Air Education and Training Command of the United States Air Force Academy as a beginner trainer aircraft in use.
Fatigue on the wing spar
In the years 2010 to 2012, a large part of the world yet approved Blanik aircraft was subject to a series of official start of prohibition, they were Earth-bound. On June 12, 2010, near Ferlach Carinthia in an accident in which a wing is broken off in flight on a Blanik L-13 occurred. After it soon turned out in accident investigations that the Holmuntergurt had failed on the trunk port due to fatigue cracks and such a lack of other Blaniks also can not be excluded, was approved by the EASA first on 18 June 2010 a review of the spars of all operating Blaniks and a ban on aerobatics arranged on September 5, 2010 was followed by a general grounding of all L -13 and L- 13. This official order is now canceled, unless the individual airplanes meet certain requirements. For this it is usually necessary to examine the affected areas on the wings thoroughly for cracks and install a structural reinforcement kit. After these modifications the Blanik obtained either a maximum flight hour service life of 3,750 hours with 2 % aerobatic content ( according to the original EASA certification ) or 5,000 flight hours in normal operation without aerobatic certification.
Specifications
NACA 63 ² A- 612 wing tip