NPO Saturn AL-55

Not to be confused with Saturn AL-51.
NPO Saturn AL-55
The Jet engine AL-55 (The international aerospace salon MAKS-2011)
Type Turbofan
National origin Russia
Manufacturer NPO Saturn and serial production by Ufa Engine Industrial Association JSC
Major applications Originally designed for HAL HJT-36 Sitara

The NPO Saturn AL-55 is a high performance turbofan engine manufactured by NPO Saturn Russia, for powering advanced trainers, unmanned aerial vehicles (UAV) and light attack aircraft. A variant of the AL-55I powers the HAL HJT-36 Yashas Indian jet trainer.

Development

India's Hindustan Aeronautics Limited, from 1999, was developing HAL HJT-36 Sitara, a subsonic intermediate jet trainer aircraft for the Indian Air Force to replace the ageing HAL HJT-16 Kiran.

This section is an excerpt from HAL HJT-36 Yashas § Propulsion.[edit]

The prototype aircraft was initially powered by a SNECMA Turbomeca Larzac 04-H-20 non-afterburning turbofan developing 14.12 kN of thrust.[1] However, as stipulated by the 2005 Air Staff Qualitative Requirements (ASQRs) from the Air Force there was a requirement of higher thrust engines.[2]

In April 2005, the Larzac engine was to be replaced by NPO Saturn AL-55I (16.9 kN) to meet training requirements. The AL-55I engine would be a Joint Venture of HAL and NPO Saturn and the deal for the development of the same was signed with Rosoboronexport in August. A funding of ₹159 crore (equivalent to ₹540 crore or US$62 million in 2023) by the Indian Ministry of Defence was released for the higher thrust engine development.[3][4]

As per a CAG report on IJT, in February 2014, the engine developed (AL-55I) had a Total Technical Life (TTL) of only 300 hours against the required 3600 hours provided in the ASQR. However, by 2013, it was told that the contract for engine development was fulfilled and the JV intended to increase the TTL to 600 hours though IAF insisted a TTL of 1,200 hours. The increase of TTL was important as ASQR projected a "utilisation rate" of 30 hrs/month per aircraft which meant the engines needed to be replaced every 10 months.[4][1]

On 14 July 2021, it was reported that the United Engine Corporation had deliver two units of AL-55I engines to HAL for the HJT-36 programme. The life cycle of the improved engines were increased to 1,200 hours . Earlier, 16 engines had been supplied to HAL for the prototypes and limited series production (LSP) aircraft. The engines were reportedly ready for licensed production in India.[5][6][7] The new engines also had an improved thrust of 17.27 kN and also featured a reduction of over 50 kg weight.[1]

By February 2025, UEC supplied 18 AL-55I engines to HAL for the project. The engines will undergo type certification followed by start of licensed production of the engines by HAL in India.[8][9]

Design

The design comprises five main features. It has a three-stage low pressure compressor, five stage high pressure chamber, an annular combustion chamber and a single stage high and low pressure turbines.

Variants

AL-55
AL-55/I: A variant designed for licensed production in India.

Applications

Specifications

Data from UEC Saturn.[11]

General characteristics

  • Type: Double spool (two shaft) turbofan
  • Length: 1,950 mm (76.77 in)
  • Diameter: 590 mm (23.23 in)
  • Dry weight: 315 kg

Components

  • Compressor: two-spool, with 3-stage low-pressure (LP) and 5-stage high-pressure (HP) and one annular compressor
  • Turbine: 1 LP stage and 1 HP stage

Performance

See also

References

Wikimedia Commons has media related to Saturn AL-55.
  1. ^ a b c "HJT-36 Flight Test Resumption Renews Hope for AL-55 Engine | AIN".
  2. ^ "HAL HJT-36 | Aviation Week Network".
  3. ^ "Long Road Ahead For HAL's HJT-36 Sitara Intermediate Jet Trainer". Mobility Outlook. Retrieved 2025-01-09.
  4. ^ a b "CHAPTER II: MINISTRY OF DEFENCE" (PDF). cag.gov.in/en. Archived (PDF) from the original on 2 August 2024. Retrieved 2025-01-10.
  5. ^ "TRAINING: India Gets Two AL-55I Engines for Combat Trainers | Times Aerospace". www.timesaerospace.aero. Retrieved 2025-01-10.
  6. ^ "India Gets Two AL-55I Engines For Combat Trainers". Retrieved 2025-01-10.
  7. ^ "Russia supplies India with 2 turbojet engines for HJT-36 training plane - Rostec". UNI India. 2021-07-14. Retrieved 2025-01-10.
  8. ^ "Russian company supplied 18 engines to India's HAL". TASS. Retrieved 2025-02-15.
  9. ^ "Russia's UEC Supplied 18 Engines to India's HJT-36 Trainer Aircraft Project". Defense Mirror. Retrieved 2025-02-15.
  10. ^ MiG-AT aircraft Archived 2012-05-05 at the Wayback Machine
  11. ^ "Engines for military aircraft and UAS AL-55".
  12. ^ a b http://www.russia-algeria.ru/3/Saturn_english_2010.pdf [bare URL PDF]
  13. ^ a b "United Engine Corporation". Uk-odk.ru. Archived from the original on 2014-02-16. Retrieved 2014-04-06.
  14. ^ a b Соколов Константин. "NPO "SATURN" > AL-55". Npo-saturn.ru. Retrieved 2014-04-06.
  15. ^ "AL-55E engine".