by Thomas Girke
Mi-8 Variant Briefing
In the second half of the 1980s, several aircraft of the Czechoslovak Air Force were converted for SIGnals INTelligence (SIGINT) along the western border of Czechoslovakia -
on the dividing line between the Warsaw Pact and NATO.
These aircraft were intended to intercept a wide range of military radio frequencies and radio conversations on behalf of the Czechoslovak security forces and the Czechoslovak army.
Specifically, it involved one An-26 transport aircraft and two Mi-17 transport helicopters.
While the An-26 aircraft became known as the An-26Z-1 (Zástavba-1) (Zástavba - Modification), the Mi-17s received the designation Mi-17Z-2 (Zástavba-2).
The planned conversion of one L-610 transport aircraft, which was to be designated L-610Z-3 (Zástavba-3), could not be implemented.
The Mi-17s were converted into the SIGINT version at LOM Praha in the late 1980s. The two helicopters that were converted into the SIGINT version were the helicopters with the construction numbers 108M07 and 108M08. The Mi-17Z-2s were operated by the 1st Reconnaissance and Command Squadron from the Líně airbase near Plzeň. At the end of 1992, both Mi-17Z-2s were assigned to the Slovak Air Force as part of the division of aircraft from the Czechoslovak air force.
At the end of the 1990s, there was a demand in Slovakia for further development of the Mi-17 for SIGnals INTelligence on the eastern border with Ukraine. Slovakia became a candidate for NATO membership in 1999. The project was developed by the Military Research Institute in Liptovský Mikuláš and the Slovak Military Aviation Technical and Testing Institute in Kosice. The technical implementation took place in the overhaul plant LO Trenčín. The “Zastavba – 2M” was installed into only one Mi-17 with the construction number 108M24 in mid 2000. The helicopter was presented to the public for the first time on June 9, 2002 as part of the Slovak International Air Fest. The Mi-17Z-2M was operated by the Helicopter Wing from the Prešov Airbase. The SIGINT version was only used for a short time. The “Zastavba – 2M” equipment was disassembled in the second half of 2005 and the helicopter returned to the home base in Prešov in December 2005 in standard transport configuration.
Technical Details - Outside
Technical Details - Inside
Inside the cargo compartment, four working stations for four operators (two stations on each side) were installed. Two stations have been used for wiretapping and gathering signals namely the Work Station 1 (Commanding Post) and the Work Station 2, both connected to all three Chelton antennas located on the belly of the helicopter. The Work Station 4 was connected to the Thomson-CSF ANT 184-A for signal searching and direction finding/targeting, the Work Station 3 was for storage and transmitting data to the ground station. The planned ground station for signal reception and evaluation was most likely not realized.