Let L-410 Turbolet

L-410 Turbolet
Role	Regional airliner, cargo aircraft
Manufacturer	Let Kunovice
First flight	16 April 1969
Introduction	1970
Status	In service
Produced	1971–present
Number built	1,200[1]
Unit cost	L-410UVP-E20: $6.3 Million (2016)[2]

The Let L-410 Turbolet is a twin-engine short-range transport aircraft, manufactured by the Czech aircraft manufacturer Let Kunovice (named Aircraft Industries since 2005), often used as an airliner. The aircraft is capable of landing on short and unpaved runways and operating under extreme conditions from +50 °C (122 °F) to −50 °C (−58 °F). In 2016, 1,200 L-410 have been built and over 350 are in service in more than 50 countries.^[1]

Development

Walter M601 engine installation

Commuter cabin

Development of the L-410 was started in the 1960s by the Czechoslovak aircraft manufacturer Let Kunovice. The Soviet airline Aeroflot was looking for a turboprop-powered replacement for the Antonov An-2 aircraft, initiating the design development by Let. After preliminary studies of an aircraft called the L-400, a new version was introduced called the L-410 Turbolet. The first prototype, designated XL-410, flew on April 16, 1969. Because of delays in the development of a suitable Czech engine (Walter M601), the prototype and first production version were powered by Pratt & Whitney Canada PT6-27 engines.

After M601 development was completed, the PT6 engine was replaced by M601 engines coupled with Avia V508 three-blade propellers and the next variant was introduced, the L-410M.

A further version for Aeroflot was the L-410 UVP. This has improved performance in take-off and landing due to increased wing and tail area - STOL. However, due to an increased empty weight and a shift in the center of gravity, the aircraft had a decreased seating capacity: 15 passengers.

The L-410UVP-E (the most common variant of the L-410) has increased maximum take-off weight to 6400 kg, M601E engines with increased power, new five-blade propellers designated V 510 and the provision for wing tip tanks to increase fuel quantity. First flight was made in 1984, and production started in 1986.

The L-410UVP-E9 and UVP-E20 are versions which vary from each other only by minor changes arising from various certification regulations. The last L-410 family member is the L-420 which uses the new Walter engine variant, the M601F. Currently produced L 410 UVP-E20's are powered by next derivative of M601 engine designated as GE H80-200 and new Avia Propeller AV-725 five blade propellers.

The L-420 was first approved by the US FAA on March 11, 1998, then the L-410 UVP-E20 on June 30, 2015.^[3] The L-410 UVP-E20 was EASA certified on 4 February 2005 on the other variants on 28 March 2007.^[4]

On 3 September 2013 the Russian company UGMK (Iskander Machmudov) became the wholesale owner of LET Kunovice Aircraft Industries. They announced that they would produce the L-410 also in Russia within the year.^[5] On 7 July 2015 UGMK represented first L-410NG aircraft manufactured in Russia.^[6]

Design

Landing on snow

The L-410 UVP-E is an unpressurized all-metal high-wing commuter aircraft, with Avia V 510 five-blade propellers. It is equipped with a retractable undercarriage. The aircraft uses two hydraulic circuits: main and emergency. 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. 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, seating capacity 17 to 19. Cruise speed is 170 KIAS, maximum range about 770 nautical miles (1,430 km). The airplane is certified for IFR operation, CAT I ILS approach, and flights in icing conditions.

The L 410 UVP-E20 is certified on the basis of FAR 23 either Amendment 34 or Amendment 41. It is certified by the EU, the Russian Federation, the US, 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.^[7] 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.

Variants

Cockpit

L-410NG at the ILA 2016

• L-410: Prototype, three units built.
• L-410A: First series with Pratt & Whitney PT6A-27 turbo-prop engines. Twelve built.
  • L-410AB: Version with four-bladed propellers.
  • L-410AF: Aerial photo version supplied to Hungary.
  • L-410AG: With modified equipment. Never built.
  • L-410AS: Test aircraft, supplied to the USSR. Five airplanes built
• L-410FG: Aerial photography version based on L-410UVP
• L-410M: Second series with Walter M601A engines.
  • L-410AM: Version with improved M601Bs, also known as L-410MA or L-410MU.
• L-410UVP: (Ukorochennaya vzlot-posadka, "short take-off and landing") Third series, fundamentally modified. Main changes are a trunk, an extended wingspan by 0.80 m (2.6 ft), M601Bs, a higher horizontal stabilizer. The UVP variants possesses STOL characteristics.
  • L-410UVP-S: Salon variant of the UVP with upward hinged entrance hatch.
  • L-410UVP-E: Re-equipped with M601Es, five-bladed Avia V510 propellers, additional fuel tanks at the wing ends.
  • L-410T: Transport variant of the UVP with larger loading hatch (1.25 m × 1.46 m (4.1 ft × 4.8 ft)), can transport 6 stretchers as a medical airplane with a medic, or 12 parachutists. It can also carry 1,000 kg of cargo containers.
• L-420: upgraded L-410UVP-E - new M601Fs, certified variant of the L 410 UVP-E20
• L-410NG: New version featuring new GE H85 engines, a longer nose and a larger rear area to contain more luggage, new wings and a new glass cockpit. The fuselage will be the same of the classic L-410 but it will be made of newer materials. Following the roll out of the prototype it made its maiden flight on 29 July 2015. Type certification is expected in 2016 with production planned to start in 2017.^[8] Power will grow to 850 shp instead of the previous 800 shp GE H80-200, speed increases to 223kt (412 km/h). Maximum take-off weight rises 500 kg to 7,000 kg and range to 1,350 nm up from the current 820 nm (1,520 km). Fuel capacity rises from 1,300 kg to 2,450 kg and endurance from 5h to 9h. FAA, EASA and Russian certification due in late 2017.^[9]

Operators

Skydiving

Many L-410 were delivered to the former Soviet Union and ex-Soviet states and stayed there and in Russia, but some have been also sold to airlines in Asia, Africa, Central America, and South America. Forty aircraft are in use throughout Europe for commercial operation or skydiving.

Notable accidents

The L-410 has experienced 116 accidents with 426 fatalities.^[11] With at least 20 fatal crashes from 2003 to 2013, it is one of the most accident-prone aircraft.^[12] However, the operator’s safety rating and operations procedures are more important than the aircraft design, and the L-410 operate where most aircraft cannot, in rugged mountainous and jungles, often onto grass or gravel runways; the latest LET410 UVP-E20 and L420 produced since 1990 have an excellent safety record.^[13]

Specifications (L 410 UVP-E20)

Below

Data from LET^[1]

General characteristics

• Capacity: 19 passengers
• Payload: 1,800 kg (3,968 lb)
• Length: 14.42 m (47.30 ft)
• Wingspan: 19.98 m (65.55 ft)
• Height: 5.97 m (19.55 ft)
• Wing area: 34.86 m² (375.2 ft²)
• Empty weight: 4,200 kg (10,582 lb)
• Loaded weight: 6,000 kg (13,228 lb)
• Max. takeoff weight: 6,600 kg (14,550 lb)
• Fuel capacity: 1,300 kg (2,866 lb)
• Powerplant: 2 × General Electric H80-200 turboprop engines, 597 kW (800 hp) each
• Propellers: Avia 5-blade AV 725
  • Propeller diameter: 2.30 m (7.50 ft)

Performance

• Cruise speed: 405 km/h (219 ktas) max cruise
• Range: 510 km (275 nmi) 1,800 kg payload, ISA, FL140, 45 min reserve
• Ferry range: 1,500 km (810 nmi)
• Endurance: 5.1h
• Service ceiling: 8,382 m (27,500 ft) single engine: 4,755 m (15,600 ft)
• Rate of climb: 8.50 m/s (1,673 ft/min) single engine: 1.8 m/s (354 ft/min)
• Fuel consumption: 240 kg/h (77 gal/h)
• Take-off (ISA, SL, MTOW): 510 m (1,673 ft)
• Landing (ISA, SL, MLW: 500 m (1,640 ft)

See also

On ramp

Aircraft of comparable role, configuration and era

• Antonov An-28/PZL M28 Skytruck
• Beriev Be-30
• Britten-Norman Trislander
• CASA C-212 Aviocar
• de Havilland Canada DHC-6 Twin Otter
• Dornier Do 228
• Embraer EMB 110 Bandeirante
• Evektor EV-55 Outback
• Harbin Y-12
• IAI Arava
• Shorts SC.7 Skyvan

References

External links

Wikimedia Commons has media related to Let L-410.

• Official website
• L410.cz (in Czech)
• Fred George (Jun 17, 2013). "Pilot Report: L410 UVP Turbolet". Aviation Week Network.
• L-410 UVP-E Turbolet X-Plane Module