(a) whether the Hindustan Aeronautics Limited (HAL) manufacturing Jaguar Aircraft in the country has made some changes/modifications in its hydraulic and fuel supply system;
(b) if so, the details thereof;
(c) whether Jaguar aircraft upgraded recently by the HAL have been returned by the Indian Air Force;
(d) if so, the reasons therefor; and
(e) the action taken to ensure the use of quality standard of components and material in upgradation of Jaguar aircraft?