Numerous Incidents and Accidents Reported: HAL Upgrades ALH Dhruv's Control Rods to Steel

The absence of stringent quality control measures increases the risk of component failures, thereby highlighting the need for HAL to implement robust quality assurance protocols to ensure the safety of its aircraft.

Numerous Incidents and Accidents Reported: HAL Upgrades ALH Dhruv's Control Rods to Steel

Hindustan Aeronautics Limited, based in Bengaluru, is taking action to improve the fatigue tolerance of the Dhruv Advanced Lightweight Helicopter, a domestically produced helicopter used by the Indian armed forces, following three recent accidents. The company will replace a crucial component of the helicopter, as recommended by a regulatory panel. These crashes occurred on March 8th (Navy), March 26th (Coast Guard), and May 4th (Army). Currently, around 300 of the more than 335 ALH produced are in use by the armed forces.

In light of recent accidents involving the Dhruv advanced light helicopter, including one just last week, a top government regulatory body responsible for certifying the airworthiness of military aircraft, the Centre for Military Airworthiness and Certification (CEMILAC), has suggested that a design review of a "safety-critical system" may be necessary. Officials familiar with the matter have stated that although the India-made helicopter has a stable and mature design, the expert panel's design review is aimed at improving its airworthiness.

The CEMILAC issued the directive to the three services and the coast guard on April 23rd. The ALH has a worrying safety record, having been involved in 12 accidents over the past five years. Following a helicopter crash in Kishtwar, Jammu & Kashmir, on May 4th, which resulted in the death of a soldier and injury to two pilots, the army grounded its ALH fleet to conduct a comprehensive safety check. The helicopter is used by the army, air force, navy, and coast guard.

Following an expert committee's investigation into the March 8th incident in which a navy ALH had to make an emergency landing in the Arabian Sea, CEMILAC, a regulatory body functioning under the Defence Research and Development Organisation (DRDO), has concluded that a design review of the booster control rods is necessary. These rods are critical for controlling the helicopter's movement, and failure can lead to accidents by severely affecting power input to the rotor blades. The recent string of accidents has prompted the comprehensive grounding of most of the military's ALHs for safety checks. Additionally, the Indian Air Force's latest light combat helicopters (LCH), which have several features inherited from the ALH, have also been grounded.

The regulatory body has raised concerns over the significant reduction in the fatigue life of the rods, according to officials. As the Indian armed forces rely on more than 300 multi-role ALHs, developed by Hindustan Aeronautics Limited, a state-run aircraft maker, the design review is crucial. The delivery of these helicopters by HAL commenced in the early 2000s. The expert committee, formed by the CEMILAC chief executive (airworthiness), has determined that a technical failure, specifically an error in the assembly of serrated washers in the booster control rods, was the most probable cause of the navy ALH incident on March 8th, as per one of the officials. The committee has put forward suggestions for improving the safety of the twin-engine ALH, both in the short and long term.

The CEMILAC-formed committee's discovery regarding the malfunction of the booster control rods on the navy ALH is consistent with the failure analyses carried out by Council of Scientific and Industrial Research-National Aerospace Laboratories (CSIR-NAL), Bengaluru, and HAL's Rotary Wing Research & Design Centre (RWR&DC).

Following the March 8 incident, a coast guard and army ALH were also involved in accidents. The coast guard helicopter made an emergency landing in Kochi on March 26, while the army ALH conducted a precautionary landing on May 4 in Kishtwar. ALH operations were suspended by the army for the second time in less than two months after the pilots reported a technical fault to air traffic control on May 4, which led to the incident.

After the navy ALH experienced an inexplicable power loss and ditched into the sea, the three services grounded their ALH fleets for safety inspections. Currently, the navy's helicopters remain grounded, and the Indian Air Force is allowing its ALHs to fly in batches only after conducting mandatory safety checks. The army had resumed its ALH operations a few weeks prior to the May 4 crash landing, but it was grounded again after the incident.

The ALH has faced operational disruptions in the past, with grounding in 2006 due to tail rotor issues and later in 2014 following a fatal crash. The latter incident, which occurred near Sitapur in Uttar Pradesh, resulted in the deaths of the chopper’s entire seven-man crew. The aircraft had only flown for two hours after being serviced in Bareilly. Another incident occurred in the Poonch sector in October 2019 when Lieutenant General Ranbir Singh, a former Northern Army commander, and eight others were injured in a crash.

The current grounding of ALH operations comes at a time when Hindustan Aeronautics Limited is seeking to tap into the helicopter's export potential. HAL is currently discussing a potential order with the Philippines. However, the termination of a contract by Ecuador in 2015 after four out of seven ALHs it purchased were involved in crashes highlights the importance of addressing the safety issues.

Air Marshal Anil Chopra (retd), director general of the Centre for Air Power Studies, emphasizes the critical need to address flaws in the ALH, given the operational and flight safety implications. The helicopter plays a significant operational role, and India operates a large fleet of ALHs. Furthermore, potential foreign customers are closely monitoring the situation.

Steel control rods are preferred over aluminum control rods for helicopters due to several reasons. Firstly, steel possesses superior strength compared to aluminum, making it less prone to bending or breaking under the stress experienced during flight. This characteristic is crucial for maintaining reliable and safe helicopter control.

Moreover, steel exhibits greater resistance to corrosion than aluminum, making it particularly suitable for helicopters operating in harsh environments. The ability to withstand corrosion ensures the longevity and reliability of control rods, reducing the need for frequent replacements and maintenance.

Another advantage of steel is its high recyclability, contributing to environmental sustainability. The recyclability of steel makes it a more eco-friendly option compared to aluminum, which is important in promoting responsible material usage.

While aluminum does offer the advantage of being lighter than steel, resulting in reduced weight for the helicopter, the enhanced strength and durability of steel outweigh the weight advantage in most helicopter applications. The robustness of steel control rods ensures their ability to withstand the demanding forces experienced during flight, enhancing overall safety and performance.

It is plausible that HAL may not have possessed the necessary experience or expertise to utilize steel control rods during the design and construction of the ALH Dhruv helicopter. Working with steel is more challenging than working with aluminum and demands specialized manufacturing techniques.

Regardless of the reasons, opting for aluminum control rods in the ALH Dhruv turned out to be an unfortunate choice. The aluminum control rods were susceptible to fatigue and failure, leading to numerous accidents and incidents. Consequently, HAL has taken the initiative to replace the aluminum control rods in the ALH Dhruv with steel ones.

HAL's productivity and delivery timelines are hindered by the lackadaisical approach exhibited by its unionized employees. This has a detrimental impact on the organization's overall efficiency and effectiveness.

Poor production-engineering standards within HAL contribute to maintenance challenges and prevent standardization across its fleet. This poses difficulties for the effective management of aircraft, making it critical for HAL to improve its production processes.

The absence of stringent quality control measures increases the risk of component failures, thereby highlighting the need for HAL to implement robust quality assurance protocols to ensure the safety of its aircraft.

HAL's product support is often unresponsive, leaving its customers without adequate assistance when facing issues or requiring timely support. This must be addressed to reinforce HAL's position as a reliable and efficient player in the aerospace industry.

HAL must prioritize the above concerns and foster a culture of accountability to address the productivity and delivery timelines impacted by employee behavior. HAL should also improve its production-engineering standards to alleviate maintenance challenges and standardize its fleet. The implementation of robust quality control measures is essential to ensure the safety of its aircraft. Additionally, HAL must provide responsive product support to instill confidence in its customers and reinforce its position as a reliable player in the aerospace industry.

About The Author

Girish Linganna is a Defence & Aerospace analyst, and is the Director of ADD Engineering Components (India) Private Limited which is a Subsidiary of ADD Engineering GmbH, Germany with manufacturing units in Russia.

(Views expressed are the author's own & do not reflect the editorial stance of Mission Victory India)

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