As part of a process to acquire certification from the European Aviation Safety Agency (EASA) for Advance Light Helicopter-Dhruv, HAL carried out noise measurement flight trials at Mysuru airport recently in compliance with the International Civil Aviation Organisation (ICAO).

The EASA representatives witnessed the entire flight test and preliminary analysis of the recorded noise data, weather parameters and the aircraft parameters shows that the noise levels are within the acceptable limits specified by ICAO for ALH”, said Mr. T. Suvarna Raju, CMD, HAL.

The trials involved advance acoustic programming and compensation of atmospheric variables against measured noise levels.  A Spanish company Anotec Consulting was contracted to provide hardware, software and technical support for the programme.

The objective of this process is to measure the external aircraft noise levels in three flight conditions: take-off, approach and flyover. The noise measurement test programme starts with the identification of low acoustic profile test site and meeting the geometrical size of runway and cross runway distances.

Earlier, a survey was conducted by HAL in coordination with EASA and the Spanish firm for assessment of test sites at Kolar, Hosur and Mysuru. The EASA finally approved Mysuru airfield as the test site suitable for noise measurement which met the ICAO requirements.

During noise measurement flight testing, eight flights constituting of 96 noise runs were carried out as part of practice and certification runs. Validity of the runs was considered based on satisfactory weather and flight parameters during the run.

HAL produced ALH Dhruv helicopter has a proven track record in both military and civil operations. It is designed to meet the requirement of both military and civil operators. Dhruv has also been exported to Ecuador, Mauritius and Maldives. Dhruv is particularly useful in meeting the arduous tasks in difficult terrains.

Dhruv is being operated by Indian Air Force, Indian Army, Indian Navy, Coast Guard, BSF and State governments since 2002.  More than 140 Dhruv helicopters are in operation logging close to 1, 30,000 flight hours.

Dhruv helicopters played a key role in search and rescue operations during the  recent Nepal earthquake, the 2004 tsunami, the 2010 flash floods at Leh, the 2011 earthquake in Sikkim, the biggest ever rescue operation by helicopters undertaken by IAF in flood and rain-hit areas of Uttarakhand in June-2013 and Jammu & Kashmir  flood relief operation in September 2014.  Dhruv is a multi-role, multi-mission new generation helicopter in 5.5 tonne weight class and meets Federal Aviation Regulations (FAR) specifications. It has demonstrated its capability in long distance flights, vertical climb and manoeuvring. Dhruv is an all-weather helicopter which can carry 10-16 people at heights of 10,000 feet.