pandyan wrote:http://tarmak007.blogspot.com/2011/12/e ... [quote]HAL says it had communicated officially to the IAF the need for providing shelters....“The UV rays will have faster aging and hardening effect on the rubber and other non-metallic parts, which can lead to more premature failure, in the longer run. The canvass can only protect the aircraft from UV rays, but not the heat, which can harm avionics parts,” sources said.
http://tarmak007.blogspot.com/2011/12/e ... [quote]HAL officials are amused as to why the IAF didn't bother to provide shelters to the fighters' biggest bases at Pune and Barelley....Air Marshal (Retd) T.S. Randhawa, an expert with Sukhoi platforms, said that the IAF is already in the process of getting shelters. “We understand that there can be an effect due to exposing the fighter to sun. The weather varies – like hot, cold, dust, breeze and over a longer period of time, YES, there could be an impact.
But, these fighters are serviced as per the IAF SOPs,” he said.[/quote][/quote]The reporting is factually not correct, and is more of an attempt by HAL to deflect attention from quality and other issues.
As an example, an aircraft carrier hanger cannot accomodate full complement of aircraft onboard the ship. As a result, half the aircraft complement are parked on deck, exposed not just to sunlight but to corrosive sea spray as well. IAC being built has a hangar capacity of 17 and the remaining 13 that make up its full complement of 30 will be parked on deck. US Navy carrier hanger too can accomodate only 50 odd planes and the remaining 30 odd planes are parked on deck.
Yet US Navy and IN planes dont fall off the sky on their air test after overhaul. Seahawks flew around three decades 60's, 70's & 80's.
And as per available indicators, the present crash was not caused by any rubber or canopy or fuel tank deformation failure. It was under HAL shelter before it took flight.
Most HAS are to protect the aircraft from enemy attack rather than sunlight.
Optronics and radars on ships are exposed to sun all their lives. Yet they dont fail like avionics like HAL states.
http://3.bp.blogspot.com/-HUTDk79tdgE/T ... tpura5.jpg
Sources said that even lightning strike didn't spare a Sukhoi in 2009 causing serious emergency. “The aircraft suffered structural damages, which is unheard of in modern times. All these are definitely pointing towards quality and design issues. If we don't address them now and take corrective steps, it will be a bad publicity for the IAF, HAL, and to both friendly nations of India and Russia. At what cost are we losing them?” a veteran pilot, who were among the first to fly the Sukhois, said.
Lightning strike protection is a design and build issue, rather than parked-under-sun issue.
I'm sure HAL would have done some research, and there might be some correlation between sunlight and flight safety, but from my understanding, it isnt significant, as long as maintenance procedures are adhered to.
Refer
http://www.bharat-rakshak.com/IAF/Image ... a.jpg.html &
http://www.bharat-rakshak.com/IAF/Image ... d.jpg.html all engine inlets above and below wings are covered against sand ingestion, as is IRST, and canopy.