Let L-410 Turbolet

Development

Development of the L-410 was started during the mid-1960s by the Czechoslovak aircraft manufacturer Let Kunovice. The company had decided to launch the project with awareness that the Soviet airline Aeroflot was actively seeking a turboprop-powered replacement for the Antonov An-2 biplane, which was viewed as a potentially lucrative opportunity for a suitable aircraft. Preliminary studies performed by Let centred around a design referred to as the L-400. In addition to its use as an airliner, equal attention was paid towards its suitability for the role of a cargo aircraft.

Following considerable revision of the original concept, a new version was produced, which the company called the L-410 Turbolet. On 16 April 1969, the first prototype, designated XL-410, performed its maiden flight, piloted by Vladimir Vik and Frantisek Svinka. The prototype was not only used for test flights but also to promote the aircraft to potential customers, appearing at various air shows, including the 1969 Paris Air Show. As a consequence of the delayed development of a suitable Czech engine, the Walter M601, both the prototype and the initial production model were powered by Pratt & Whitney Canada PT6-27 engines and Hartzell HC-B-3TN-3D three-blade propellers, both of which were imported from North America.

Once development of the M601 engine had been completed, it was quickly adopted and coupled with Avia-built V 508 three-blade propellers to replace the PT6 engine on the second production model, designated L-410M.

The most common variant of the type, the L-410 UVP-E, possesses an increased maximum take-off weight of 6400 kg, is equipped with more powerful M601E engines that drive new five-blade propellers designated V 510, and is provisioned for equipping wing tip tanks that increase the aircraft's overall fuel capacity.

The L-410 UVP-E9 and L-410 UVP-E20 are versions which vary from each other only minorly, these were produced to satisfy the differing regulations of various certifying authorities of different regions. Later production L-420s have been outfitted with a newer Walter engine variant, the M601F. Production of the L-410 UVP-E20 was underway in the early twenty-first century, being powered by the latest derivative of the M601 engine, designated GE H80-200, and outfitted new Avia Propeller AV-725 five blade propellers.

Following the end of the Cold War, company officials opted to pursue opportunities for the aircraft in Western markets. On 11 March 1998, the L-410 first received approval for its use in North America by the Federal Aviation Administration (FAA); the improved L-410 UVP-E20 was similarly certified on 30 June 2015. In the mid-2010s, a typical production rate of 15 L-410 UVPs were being completed each year.

On 3 September 2013, the Russian company UGMK (Iskander Machmudov) became the majority owner of LET Kunovice Aircraft Industries. At the time of the acquisition, it was announced that a new production line for the L-410 would be established within Russia within one year. As part of this strategy, the company developed the most substantial variant of the aircraft to date, the L 410 NG, which can be visually distinguished from its predecessors by its considerably longer nose as well its enlarged rear area, the latter change being made to accommodate the carriage of double the luggage. It is also furnished a new wing design and has been fitted with a modernised Garmin G3000 glass cockpit. The propulsion system has also been redesigned, featuring more powerful and quieter GE H85 engines that drive Avia-725 propellers. The L 410 NG can fly for double the range of the original model of the aircraft.

On 7 July 2015, the company displayed the first L 410 NG, which had been manufactured in Russia; it performed its first flight on 29 July 2015. Power grew up to 850 shp instead of the previous 800 shp GE H80-200, speed increased to 223 kn. Maximum take-off weight rose 500 kg to 7000 kg and range to 1350 nmi up from the original 820 nmi. Fuel capacity rose from 1300 to and endurance from five hours to nine hours. FAA, EASA and Russian certification took place in late 2017. Serial production of the L 410 NG commenced in March 2018.

Due to the Russian invasion of Ukraine, which led to sanctions against the Russian Federation by the European Union and other Western countries, Aircraft Industries lost its main customer for its passenger aircraft – Russia. Due to the subsequent financial difficulties, the Kunovice based aircraft factory was acquired by the OMNIPOL Group in 2022.

Design

The Let L-410 Turbolet is an unpressurized all-metal high-wing commuter aircraft. It is characterised by its relatively low maintenance and operating costs, as well as its adaptable design, which includes special interchangeable configurations. All models are equipped with a retractable undercarriage. The L-410 UVP-E features two hydraulic circuits, one being the primary and the other intended for emergencies; the main electrical system operates with 28V DC. The de-icing system is leading edge pneumatic deicers and electrical heating of propellers, cockpit windshields and pitot-static system heads. The maximum take-off weight of the L-410 UVP-E is 6400 kg with the possibility of an increase to 6600 kg for the E9 and E20 variants, possessing a maximum seating capacity of between 17 and 19 passengers. The L-410 UVP-E is equipped with Avia V 510 five-blade propellers.

The L 410 UVP-E20 is certified on the basis of FAR 23 either Amendment 34 or Amendment 41. It is certified by the European Union, the Russian Federation, the United States, Brazil, Argentina, Chile, Peru, Venezuela, Cuba, India, Nepal, Philippines, Korea, Indonesia, Republic of South Africa, Algeria, Australia, Taiwan, Turkey, and many other countries accepting some of the previous certificates. The aircraft has also been approved for operation in a number of other countries, such as Kenya, Tanzania, Uganda, Tunisia, Colombia, Venezuela, South Korea and others. The airplane is certified for IFR operation, CAT I ILS approaches, and flights in icing conditions.

Variants

• L-410: Prototype, three units built.
• L-410A: First series with Pratt & Whitney PT6A-27 turboprop engines and three-blade Hartzell HC-B3TN-3D propellers. 25 built.
  • L-410AB: Version with four-blade Hartzell HC-B4TN-3 propellers.
  • L-410AF: Aerial photography and cartography version with glazed nose and fixed nose wheel. One built.
  • L-410AS: Ten examples for the Soviet market, with upgraded navigation and communication equipment
• L-410M: Second series with Walter M601A engines and three-blade Avia V508 propellers.
  • L-410MA: Version with M601Bs and Avia V508B propellers, also known as L-410MU.
• L-410UVP: (Ukorochennaya vzlot-posadka, "short take-off and landing") Third series, fundamentally modified. The principal changes are a trunk, an extended wingspan by 0.80 m, M601Bs (M601Ds after 1983) with Avia V508B (V508D after 1983) propellers, and a higher horizontal stabilizer. The UVP variants possesses STOL characteristics. Passenger capacity fell to 15 due to increased weight.
  • L-410FG: Identical to L-410AF, but based on the L-410UVP
  • L-410T: Transport variant of UVP with larger loading hatch (1.25 x), can transport 6 stretchers as a medical airplane with a medic, or 12 parachutists. It can also carry 1000 kg of cargo containers.
  • L-410UVP-S: VIP variant of UVP with upward-hinged cabin door.
  • L-410UVP-V: (Vstavka, "insert") 1986 stretched version for 22 passengers; remained a prototype.
• L-410UVP-E: (ekonomicheskiy, "economic") Fourth series, improved L-410UVP with M601E or E-21 engines, five-bladed Avia V510 propellers and optional tip-tanks. The rear baggage compartment was also redesigned, increasing capacity back to 19.
  • L-410UVP-E1: Two examples for Bulgaria, reportedly in a photography/transport role
  • L-410UVP-E2: Modified version for the Polish Maritime Office
  • L-410UVP-E3: Version for skydive operations
  • L-410UVP-E4:
  • L-410UVP-E6: Navaid calibration version
  • L-410UVP-E8:
• L-410UVP-E9: Identical to L-410UVP-E, but with increased MTOM and MLM.
  • L-410UVP-E9A: Version for Swedish market with Bendix/King avionics
  • L-410UVP-E9D: One example modified with a Bendix/King EFIS cockpit system
  • L-410UVP-E13:
  • L-410UVP-E14: Version with Bendix/King avionics for transporting military dignitaries
  • L-410UVP-E15:
  • L-410UVP-E16:
  • L-410UVP-E17: Version for Polish market
  • L-410UVP-E19:
• L-410UVP-E20: Westernized version to US FAR-23 standards; certified as the L-420E
  • L-410UVP-E20C: Version for South Africa
  • L-410UVP-E20D: VIP version for government use
  • L-410UVP-E20G: Version for the Tunisian Armed Forces
  • L-410UVP-E27: Four examples for high altitude operations in India
• L-410UVP-EPT: A L-410UVP-E9 converted to PT6A-42 engines and Avia AV-725 five-blade propellers. One built.
• L-420: upgraded L-410 UVP-E - new M601Fs, certified variant of the L-410UVP-E20
• L 410 NG: Substantially redesigned and expanded version, powered by new GE H85 engines and a glass cockpit. Capable carrying twice as much cargo as well as roughly double the endurance of the original model.

Operators

Main article: List of Let L-410 Turbolet operators

Large numbers of L-410s were delivered to the Soviet Union; by 1985, 500 aircraft had reportedly been obtained by various operators within the USSR alone. Accordingly, the type has been heavily operated by various ex-Soviet states, in particular Russia. Furthermore, numerous L-410s have been sold to airlines across Asia, Africa, Central America, and South America. Forty aircraft are in use throughout Europe for commercial operations, including skydiving.

Civilian

In July 2015, 178 Let L-410 were in airline service: 73 in Africa, 58 in Europe, 41 in Americas and 6 in Asia Pacific and the Middle East; its airline operators with four or more aircraft were:

• 25: Air-Tec Global
• 8: Orenburzhie Air Company
• 7: Searca
• 5: Kin Avia, Air Express Algeria and Petropavlovsk-Kamchatsky Air Enterprise
• 4: Eagle Air, Solenta Aviation, 2nd Arkhangelsk United Aviation Division, Van Air Europe, Komiaviatrans, KrasAvia, Air Guyane Express and Comeravia

Accidents and incidents

Main article: List of accidents and incidents involving the Let L-410 Turbolet

According to statistics, the L-410 has had 118 accidents.

Specifications (L-410 UVP-E20)

|prime units? =met General characteristics

|max takeoff weight kg= 6,600 |max takeoff weight note= Powerplant

Performance

|never exceed speed kmh= |never exceed speed note= |minimum control speed kmh= |minimum control speed note= |wing loading kg/m2= |fuel consumption kg/km= |power/mass=

• Fuel consumption: 240 kg/h
• Take-off run: 510 m (ISA, SL, MTOW)
• Landing run: 500 m (ISA, SL, MTOW)

References

Citations

Bibliography

References

1. Jane’s 1980, p. 725.
2. Polek, Gregory. (15 July 2015). "Updated L-410 Turboprop Rolls Out in Czech Republic". AIN Online.
3. Stoffels, Felix. (11 September 2019). "The L-610 shall rise from the dead".
4. Cross, Lee. (16 April 2023). "4/16/1969: Maiden Flight of the Let L-410". airwaysmag.com.
5. Cecrdle 2023, p. 267.
6. (7 November 2017). "L 410 / L 420 Short-Range Aircraft". Aerospace Technology.
7. Cecrdle 2023, pp. 267-268.
8. (24 June 2016). "Type Certificate data sheet No. A42CE". [[Federal Aviation Administration]].
9. (14 August 2017). "Type Certificate data sheet A.026 Issue 22". [[European Union Aviation Safety Agency]].
10. Steenhuis and Eriksson 2015, p. 327.
11. (25 July 2013). "Новости NEWSru.com :: Чешский самолет L 410 окончательно станет российским". newsru.com.
12. "ВЗГЛЯД / УГМК представила новый российский самолет L-410 NG". vz.ru.
13. (October 2015). "Let L-410NG". Airliner World.
14. (29 July 2015). "Czech Mates: Once Bound for Siberia, this Airborne Duo Keeps Climbing Higher". [[General Electric]].
15. (31 May 2016). "ILA: Aircraft Industries targets 2016 sales for new L 410 turboprop". Flight International.
16. E. Howard, Courtney. (8 March 2018). "Aircraft Industries launches New Generation aircraft".
17. "About Us - Omnipol".
18. "L 410". let.cz.
19. "Certificates L-410". LET.
20. (1985). "Indian Trade Journal". Department of Commercial Intelligence and Statistics.
21. (August 2015). "World Airliner Census". Flight Global.
22. Ranter, Harro. "Aviation Safety Network > ASN Aviation Safety Database > Aircraft type index > Let L 410 > Let L-410 Statistics".
23. Smith, Oliver. (19 June 2013). "'Least safe' aircraft models revealed". The Telegraph.
24. (2016). "L 410 UVP-E20 brochure". LET.
25. "The Incomplete Guide to Airfoil Usage".