Aero Vodochody L-59

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The L-59's were never powered by AIDC F-124 engine. Two of remaining L-59 airframes (S /N 5831 and 5832) intended for some next business cases (Tunisia, Algeria, ... ), which never came, were finally re-constructed for prototypes or better to say flight demonstrators of the intended L-159 combat aircraft. Contrary to the real L-159 they remained two-seaters, but they did not get some military equipment, especially radar. They were the only L-159's with dual controls for long time and therefore after completing the development and testing programs they vere used for conversion of the Czech military pilots for the new L-159A ALCA model. Nowadays both of them are scrapped.

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Basic information concerning the L-59 models:
The aircraft is intended like a light attacker with 7 tons of maximum ramp weight (4 tons of empty weight). It is equipped by two-barrel Gš-23 cannon under fuselage belly and it can carry 2x 500 kg and 2x 300 kg of loads at its underwing pods, including 4x 350 l underwing tanks. It also has larger (230 l) wing-tip tanks. I am not sure about its range above, but I think that it is calculated with four underwing tanks. The cockpit is equipped with two Czech VS-2 zero-to-zero ejection seats with complete automatic system including rocket canopy jetissoning. The canopy is only one for both pilots, opened backward
by hydraulic jack. There is only simple acrylic glass shield between the pilots. The aircraft does not require longer runway than the L-39's, it is also able to operate from unpaved fields (with limited weight !).
Originally the model line was developed for East European Air Forces under designation L-39MS. This model was equipped by Czech and Russian avionics and military electronic devices including HUD. About 6 pieces were built and used in Czechoslovak (and then Czech and Slovak) AF's, at least one was scrapped and the remaining sold to the USA, at least one of them crashed there.
The L-59 models were equipped by Western avionic and military hardware (Bendix-King, Flight Vision). Egypt was the first foreign customer, 50 of L-59E were produced, one of them crashed before delivery and at least four other crashed in Egypt. The remaining L-59E have been out from operation for about 8 years and the Egyptian maintenance has been very poor all the time. All the aircraft have got very low sum of total flight hours and landings, but they are heavily corroded, deteriorated. I know them well, be VERY carefull, Akin !!
The last and best version was L-59T for Tunisia with some important improvements (OBOGS system avoids necessity of groung oxygen supply, new Allied Signal electronic engine regulation system decreased the engine problems). 12 pcs were delivered to Tunisia, three of them have crashed and the remaining nine passed through overhauls performed by Aero staff in mid-2000's. Tunisian servicing and maitenance are not perfect, but 100% better the Egyptian ones ! I could recommend only those 9 AC, but as far as I know, the Tunisian would never leave them away.
Concerning the L-59 servicing, I have an experience with US "experts" (and also Slovak, Russian, Ukrainian etc.), who do not hesitate to promise anything, but they do not know anything about the matter. From the European point of view, they are criminals, but there are different standards in Asia, Africa or America. The only cause of VS-2 seat failure, which happened during L-59 fatal crash in the USA, was caused by securing pin (normaly intended for ground manipulation or transportation), which was inserted into the seat rocket engine and blocked it from operation.
The DV-2 engine, though it is powerfull and low-consuming, is far from reliability and its original electronic control system has never been developed to full satisfaction. It has short operation period limitation and former extensions of the limits were done from marketing office, not from design ot technical office of the producer. Most of the AC losses and incidents were caused by engine problems. Numerous important aircraft systems need to be carefully serviced and periodically overhauled, some parts and components (sealings, rubber fuel tanks, hydraulic accumulator membranes etc.) have to be replaced. Not only flight utilisation, but also calendar age has to be considered, despite assurance of so called "experts".

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