Lockheed Martin has dispatched a C-130J Hercules 2 to Argentina for natural icing tests, the last major hurdle before civil certification of the military transport. The US company plans to begin delayed deliveries of the upgraded Hercules "in the third quarter", but says the exact timing will depend on the availability of suitable icing conditions.
Icing emerged as an issue late in the already delayed certification programme when it was discovered that ice formation on the vertical tail of the C-130J differs from that on the basic Hercules. This is because of a change in airflow over the tail resulting from the new six-blade propellers.
After extensive flight testing with simulated ice shapes, the company believes it has developed a solution to the problem. Anti-icing and de-icing has been added to the leading edge of the vertical tail, in the form of bleed-air anti-icing at the base and pneumatic boot de-icing at the tip.
Flight testing of the C-130J's handling characteristics in natural icing is required for US Federal Aviation Administration certification of the aircraft. Because it is now winter in the southern hemisphere, Lockheed Martin has deployed an aircraft - the first Royal Air Force C-130J-30 - to Argentina for the tests, which will be paced by weather conditions.
Previous delays in the programme were caused by integration problems with the new digital avionics, and unacceptable stall characteristics caused by airflow changes over the wing resulting from the new propellers and overcome by adding a stick pusher.
Source: Flight International
