HAL Issued Tender on RFI for HLFT 42 Engine

HAL Floated a Tender on RFI for Military Turbofan engine to be integrated on HAL's HLFT-42 supersonic lead in fighter trainer Aircraft, on 17th March 2025, to be valid till 17th April 2025

HAL Issues Request for Information for Turbofan Engine to Power HLFT-42 Supersonic Trainer Aircraft

On December 3, 2024, Hindustan Aeronautics Limited (HAL), India’s premier aerospace and defense company, issued a Request for Information (RFI) to identify potential suppliers for a high-performance turbofan engine. This engine is intended to power the Hindustan Lead-in Fighter Trainer (HLFT-42), a next-generation, single-engine, supersonic trainer aircraft currently in the advanced stages of configuration finalization. The RFI, bearing reference number D/DD-PFS/OP/HLT/005/2024, outlines detailed technical and performance requirements, signaling HAL’s intent to bolster its training capabilities for the Indian Air Force and potentially other customers.

Program Background and Purpose

The HLFT-42 is designed as a twin-cockpit, supersonic, fly-by-wire aircraft aimed at preparing student pilots for advanced jet training. With a focus on reliability, maintainability, and cost-effectiveness, the aircraft is expected to support up to four sorties per day throughout its operational life. HAL’s RFI seeks to gather comprehensive data on aero-engine solutions that can meet the demanding specifications of this trainer platform. The information collected will inform future procurement decisions and possibly lead to a formal Request for Proposals (RFP).

Key Performance and Technical Specifications

The RFI specifies a turbofan engine with a bypass and afterburner configuration, controlled by a Full Authority Digital Electronic Control (FADEC) system, and equipped with a self-contained lubrication system. Key performance requirements include:

• Thrust: A maximum continuous thrust of 21,350–22,500 lbf (95–100 kN) at International Standard Atmosphere Sea Level Static (ISA SLS) conditions.

• Specific Fuel Consumption (SFC): Targeted at less than 70 g/s/kN for fuel efficiency.

• Endurance: Preferably capable of 8 hours of continuous operation.

• Aerobatic Capability: Sustained high-g maneuvers up to 9g, including operation in negative and zero-g conditions.

• Durability: A Time Between Overhaul (TBO) of at least 2,000 flight hours and a Total Technical Life (TTL) exceeding 6,000 hours.

The engine must support an aircraft operating envelope with a maximum Mach number of 1.8, a top speed of 1,400 km/h (750 knots), and a flight altitude of up to 18 km (60,000 feet). It should also enable stable operation at low speeds down to 150 km/h (80 knots) and perform reliably across a temperature range of -57°C to +50°C, including humid tropical and saline seaside environments.

Additional technical requirements include provisions for aircraft accessories such as a starter, alternator, and hydraulic pumps, as well as bleed air extraction from both high-pressure (HP) and low-pressure (LP) compressor stages for cabin pressurization, avionics cooling, and fuel tank pressurization. The engine’s physical constraints are a maximum length of 158 inches (4 meters), a diameter of 36 inches (0.9 meters), and a dry weight not exceeding 2,650 lbs (1,200 kg).

Compliance and Standards

Suppliers are expected to ensure their engines meet rigorous military and aerospace standards, including MIL-STD-810 for environmental testing, MIL-STD-461 for electromagnetic compatibility, and MIL-STD-704D for aircraft electrical power. Compliance with airworthiness certifications such as those from the FAA or EASA is also required. The engine must be compatible with aviation kerosene (Jet A-1, JP-5, JP-8) and potentially biofuels conforming to IS17081-2019 standards, reflecting HAL’s interest in sustainable technologies.

Supplier Expectations

HAL has called on vendors to submit detailed responses, including company overviews, relevant experience in military aerospace engine development, and specifics on manufacturing and quality control processes (e.g., ISO 9001, AS9100 compliance). Suppliers must also outline their global support infrastructure, including spare parts availability and on-site maintenance capabilities. To aid evaluation, vendors are requested to provide a 3D model of the fully dressed engine, installation drawings, and a performance computer program to assess aircraft capability.

Innovations and Future Potential

The RFI encourages suppliers to highlight innovations in fuel efficiency, advanced materials, and performance optimization, as well as future upgrade paths and compatibility with other aircraft platforms. HAL is also keen on environmentally friendly solutions, such as reduced-emission technologies and the use of bio-compatible fuels.

Submission and Next Steps

Responses to the RFI are to be submitted electronically in PDF format to Mr. Gopal K. Yelwanti, Head of Hydraulics and Powerplant Systems at HAL’s Aircraft Research and Design Centre (ARDC), by email at gopal.yelwanti@hal-india.co.in. The deadline for submissions was not specified in the document, but HAL emphasized that this RFI is for informational purposes only and does not commit the organization to procurement at this stage. All submissions will remain confidential and be used solely for evaluation.

Strategic Implications

The HLFT-42 program underscores India’s push toward self-reliance in defense manufacturing under the “Make in India” initiative. By developing an indigenous supersonic trainer aircraft powered by a cutting-edge engine, HAL aims to enhance the Indian Air Force’s training pipeline while potentially positioning the aircraft for export markets. The selection of an engine meeting these stringent requirements will be a critical step in realizing this vision.