Arrested recovery landing next big test for NLCA
Bengaluru: With the ongoing pre-Monsoon trials for the naval version of Light Combat Aircraft (LCA) entering its last lap, the designers would now shift their focus towards the maiden arrested recovery landing missions (post-Monsoon), at INS Hansa in Goa.
While the current campaign is scheduled to end next week, sources confirm to Mathrubhumi that the prototypes would be now readied for arrester hook landing trials from the Shore Based Test Facility (SBTF), on their return to Bengaluru.
“Extensive data has been gathered so far and these would be analysed by various system groups. We would assess whether any changes need to be incorporated on the prototypes. Later, arrester hook will be installed on NP2. We have already carried out the Ground Vibration Test (GVT) and Structural Coupling Test (SCT),” an official said.
At Bengaluru, based on the flight test data, scientists have already conducted wind tunnel tests for different combinations of LEVCON (Leading Edge Vortex Controller) and Slats to obtain optimum configuration.
“Structural Test Specimen (STS) tests have already been carried out on the specially- built Main Airframe Static Test (MAST) created at Hindustan Aeronautics Ltd (HAL). The limit loads for high sink rate and full arrester hook loads have been successfully tested.
This is an important precursor for the taxi-in engagement at the SBTF,” says the official.
Ski-jump launches no more a major challenge
The engineers associated with the current campaign say that ski-jump launch is not considered to be a major challenge any more and further launches are to explore the limits that the aircraft can be taken to.
“Normal launch in the aircraft carrier is from around 200 meter, where the Restraining Gear System (RGS) is located. First launch in December 2014 was from a distance of around 300m to establish a safe launch for the first time with a lot of conservatism as this was the first time. The first launch was when there was a tail wind of 8 knots.
Normally on the carrier, there is at least 15 to 20 knots headwind. During the latest set of launches, winds have been both from ahead, cross and tail,” says the official.
NLCA launches done with R-73 missiles
In the current campaign at SBTF, a total of five launches were carried out, including two night launches and in addition to eight already done last month so far by both NP-1 and NP-2.
“Due to the confidence we gained, we have already carried out launches adding two R- 73 Close Combat Missiles. We would further fine tune Control Law to enhance launch capability that would enhance further take-off mass capability. So far, the loads on landing gear system are as per predictions,” says the official.
He said a series of test pre-requisites to actual arrested recovery have been conducted to evaluate the handling qualities (HQ) of the aircraft.
“Towards HQ evaluation, preliminary approaches (about 10) were done during the December 2014 campaign and it was established that the Control Law needed updates.
In the current campaign, over 100 approaches have been done from both NP1 and NP2 to gather data to enable further fine tuning of Control Law,” the official added.
(The writer is an author, blogger and seasoned defence journalist in India. His just- launched book ‘Precious Souls’ captures inspiring stories of special children and their families. He is currently a Content Consultant with Mathrubhumi (English Online) and tweets @writetake.)