Tejas LSP-3 Jettisoned 1200-litre Drop Tank at Chitradurga ATR

Jettison-able drop tanks are carried by a combat aircraft, after completing the mission are required to be dropped from the mother aircraft for a quick get away from the enemy territory and other emergency situations. To ensure safety of flight, clean separation of the tank with adequate clearances from the mother aircraft or neighboring stores need to be established from flight test.

This extremely safety critical flight test requires thorough planning and preparation supported by theoretical analysis and a level of verification of the predictions through ground tests on specialized test rigs set up for this purpose. The theoretical predictions were further verified through what is called 'Pit drop tests' conducted on a test specimen using specially designed test rig with part of the aircraft system and high speed photography system integrated with it. The test cases covered a member of conditions such as empty, partial and full drop tanks as well as different Ejector Release Unit (ERU) settings.

The flight test were planned by the National Flight Test Center (NFTC), ADA at certain representative critical release condition. Considering the safety critical nature of this test, a safety review was conducted at NFTC to ensure all foreseeable safety issues were taken care of before embarking on this important test. To capture the flight data, a dedicated and specialized Airborne Separation Video System (ASVS) is installed on the Test aircraft.

The system comprised of very high speed digital cameras installed in a specially designed camera pod and linked to a Multi System Controller (MSC) installed on-board the aircraft. The MSC gets a pulse from trigger to jettison the tank where upon the cameras are switched on in a pre-determined sequence to capture this critical event.

Mr PS Subramanyam, Programme Director (CA) and Director, ADA told "the 1200 Ltr drop tank jettison trial was conducted on 17 December 2010 at a critical point in the jettison envelope on Tejas LSP-3 aircraft piloted by Gp Capt Suneet Krishna. The trial was conducted over the recently commissioned NFTC Air to ground range at Chitradurga. The trial aircraft was escorted by another Tejas PV-2 which captured the external video picture of the drop tank trajectory after release".

Dr Prahlada, CC-R&D (Ae-SI) -- DRDO opined "with such test experiments made by the team, the aeronautical test range facility at Challakere has paved the smooth way for subsequent trials of different natures. He also said that if this facility were not to be commissioned at Challakere, all such flight tests would have to be carried on either at Hyderabad or Pokran. In view of the close proximity to Challakere to Bangalore it was more comfortable in conducting the test flights by the dedicated team the process of which could be monitored from Bangalore".

The successful trial is the result of orchestrated team effort on the part of different organizations and specialists involved in this prestigious national programme -- yet another feather on the decorated cap of the Team Tejas.

(DRDO Press Release, indiadefense)