Lavochkin La-17
| Lavochkin La-17 | |
|---|---|
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| Type: | Target and reconnaissance drone |
| Design country: | |
| Manufacturer: | |
| First flight: |
May 13, 1953 |
| Production time: |
1954-1993 |
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The Lavochkin La-17 ( Russian Лавочкин Ла-17 ) was the first target and reconnaissance drone of the Soviet Union and was mass-produced in many variants from 1954 to 1993.
history
In the early 1950s, the urgent need for a versatile target drone for fighter pilots and air defense was identified in the Soviet Union. With the introduction of the first ground and airborne anti-aircraft missiles, the use of towed target bags by manned aircraft for targeting became too dangerous. Because there was no separate design office for such unmanned drones at that time, the aircraft and anti-aircraft missile designer Lavochkin ( LaGG-3 , La-5 , SA-2, etc.) was commissioned with the development. The new target drone should have the same flight characteristics as a modern combat aircraft at that time and be as easy and inexpensive to manufacture as possible.
construction
The appearance of the La-17 (internal product 201) resembles a flying bomb with wings and a high tail unit. The ramjet engine RD-900, which was hung under the fuselage, was ultimately chosen as the drive . A ramjet is easy to manufacture, but it must be accelerated to a minimum speed before it can function reliably. Therefore, converted Tupolev Tu-4 bombers were initially used as carrier aircraft. After separating from the carrier aircraft, the autopilot or the operator in the ground station could control the drone over the training area. Although the La-17 was designed as a single-use product, it could land and be reused in the event of an unscathed operational flight. During the belly landing required for this, the ramjet engine, which was only designed for a few minutes of flight, served as a buffer and was replaced.
A propeller at the top drove the generator to power the on-board systems in flight. During the flight tests carried out in 1953, it was found that the radar cross-section was too small for the radar receivers of the time and had to be enlarged using radar-reflecting mirrors. This enabled the La-17 to be used very successfully for testing newly developed surface-to- air and air-to-air missiles .
After some time in operational use, serious disadvantages quickly became apparent. The biggest was the dependence on the Tu-4 carrier aircraft. The few converted machines were tied to airfields and were therefore inflexible and expensive to operate. The only alternative was a ground-launched variant. A converted mount of the 100 mm anti-aircraft gun served as a launch platform. Two PRD-98 solid rocket launchers launched the new version called La-17A (product 201A) before the main engine took over the climb.
Further developments of the target drone
The La-17A was only an insignificant intermediate version to the La-17M (product 202), which had many decisive improvements. The ramjet propulsion system used up to now turned out to be too fuel-hungry to be able to guarantee sufficient flight time and thus exercise time. Under poor conditions, the fighter pilots only had one approach for their attack because the drone then had to go into a landing glide flight. As an engine was in the La-17M jet engine of the type Tumanski RD-9 selected BK. It differed from the RD-9B version built into the MiG-19 by the lack of an afterburner , the fixed air inlet and a short lifetime. Further improvements concerned the radio control from the ground station, the autopilot and the energy supply of the systems by a turbine-driven generator.
From 1960 the La-17M was used very successfully as a target drone in the land, air and naval forces. The next stage of development differed only in the slightly modified RD-9BKR engine from its predecessors and was designated as La-17MA (product 202). The armed conflicts in the 1960s showed that warplanes are operating more and more often at low altitude in order to avoid detection by radar and to escape the threat of modern anti-aircraft missiles. These scenarios could not be practiced with the La-17M due to its minimum altitude of 3,000 m, which is why a more suitable successor was urgently sought.
The further development with the designation La-17MM (product 202M) could operate at heights of 500 m to 18,000 m. To this end, the engines that were still in use were retrofitted in such a way that the maximum speed near the ground was automatically limited, so that the structural loads in low flight remained low. In contrast to ramjet engines, turbine jet engines are, to put it simply, not just empty tubes, but have a massive inner workings with compressor and turbine stages. That is why the designers developed shock absorbers that can be mounted under the engine. If the target drone survived an operation undamaged, these absorbers reduced the force of the belly landing and could then be replaced. Other improvements included a new autopilot. For the La-17, however, it was not new, but converted and overhauled engines that had already reached the end of their service life in MiG-19 machines.
When the end of the MiG-19's use became apparent at the end of the 1960s, the engine source for the drones also dried up. The next generation was therefore equipped with the R-11K derived from the MiG-21 Tumanski R-11 engine. The afterburner was omitted. The new drone variant was given the designation La-17K by the designers, but was not officially renamed. In addition to the modified propulsion system, the airframe was also strengthened and numerous improvements were made to the electrics and autopilot, the fuel system and the ground station. The La-17K remained in production from 1978 to 1993. During this time only minor modifications were made in order to be able to use further developments of the R-11K.
use
As recently as 1999, a La-17 was used as a target drone in an exercise by the Russian military. However, it is unknown until when exactly the drones were used and how many copies were produced in total. There were probably a few thousand target and reconnaissance drones in total. The Dan system, developed as a successor model by the Sokol design office , flew for the first time in 1993 and replaced the La-17 as a target drone in the following years.
At the end of the 1950s, the People's Republic of China received some La-17 target drones from the Soviet Union. After the political break between the two states, the Chinese designers developed their own generation of target drones called the ChangKong-1 (CK-1) based on the La-17 .
The first Soviet reconnaissance drone
The vulnerability of reconnaissance aircraft to the newly developed anti-aircraft missiles at the end of the 1950s led to the development of unmanned reconnaissance drones in the Soviet air forces, as in the USA. Shortly after the first variant of the La-17 target drone was ready for use, the armed forces command decided to develop a reconnaissance variant from it. It should have the ability to detect targets that are heavily protected by air defense or contaminated by the use of NBC weapons. The first version with the designation La-17R (product 204) was based on the La-17M with ramjet engine, in the tip of which an AFA-BAF-40R camera was installed. With a range of 170 km and the dependence on the Tu-4 carrier aircraft, however, it did not meet the requirements in terms of depth of reconnaissance and flexibility. The extended range variant La-17BR was still dependent on the Tu-4.
In 1958, the development of a new reconnaissance system based on the La-17M began. The drone, stretched by half a meter, was again named La-17R and the entire system, including the launch and command vehicles, was named TBR-1 (Taktitscheski bespilotny raswedtschik - tactical unmanned reconnaissance aircraft). Externally, the La-17R is easy to recognize through the flattened fuselage floor in the front part. There was room for reconnaissance technology, which was too large for a circular trunk cross-section. The wings and the rear fuselage section of the drone could be folded in for transport.
The cameras used were identical to the types used in manned reconnaissance aircraft. The cameras ranged from the ASchtschFA-5E and ASchtschFA-5M for panoramic recordings, through the high-resolution AFA-20, AFA-BA-40, AFA-BAF-21 to a TV camera or a measuring device for ionizing radiation .
The reconnaissance flight could be completely autonomous or remote controlled. For the autonomous flight, the flight path, the flight altitude and the use of the camera were programmed via a timer. The ground guidance radar enabled the drone to make course corrections while the autopilot controlled the flight direction and attitude. In remote-controlled operation, the radar transponder SO-129-P sent encrypted signals to the ground station. This enabled the operator on the ground to monitor the flight and send control signals for the drone and cameras. A typical reconnaissance mission took place at altitudes between 600 and 7000 meters in a radius of up to 250 km. The first operational systems came to the armed forces in 1962, stayed for 20 years and were deployed with two squadrons in Ukraine and one each in Belarus and Latvia.
At the beginning of the 1980s, the unmanned WR-3 Rejs reconnaissance systems from the Tupolev design office took over their tasks.
Versions
- La-17 - first version with ramjet engine RD-900, carrier aircraft Tu-4,
- La-17M - ground-launched further development with RD-9BK Turbojet as a drive
- La-17N - La-17 with ramjet engine converted for ground launch
- La-17MA - further development based on La-17M with programmable autopilot
- La-17MM - further development with RD-9BKR Turbojet and further improvements
- La-17K - version with Tumanski R11K engine and other modifications
Enlightenment versions
- La-17R - first reconnaissance version based on the Tu-4 launched La-17
- La-17BR - extended range reconnaissance drone based on the La-17
- La-17R - second use of the name for the drone of the TBR-1 system based on the La-17M
- La-17RM - advanced reconnaissance drone based on the La-17MM
- La-17RU - La-17RM reconnaissance drone modified to reduce costs
- La-17UM - like the La-17RU reconnaissance drone, without cameras and with an RD-9BK MkII
Technical specifications
| Parameter | La-17 | La-17M | La-17K |
|---|---|---|---|
| length | 8.435 m | ||
| span | 7.5 m | ||
| height | nb | 2.98 m | nb |
| Takeoff weight | 1810 kg | 3065 kg | 3100 kg |
| Top speed | 900 km / h | 880 km / h | 900 km / h |
| Service ceiling | 10,000 m | 17,000 m | 17,500 m |
| Range | nb | 490 km | nb |
| Max. Flight duration | 40 min | 60 min | 60 min |
| Engine | RD-900 | Tumanski RD-9BK | Tumanski R-11K |
| thrust | 19.12 kN | 24.02 kN | |
See also
literature
- Jefim Gordon : Red Star Volume 20 - Soviet / Russian Unmanned Aerial Vehicles , 2005, Midland Publishing, Hinckley, England pp. 5–26
- Steven J. Zaloga: Unmanned Aerial Vehicles . In: Osprey New Vanguard. No. 144, 2008, p. 17
