Originally Posted by
Thruster763
Lightning protection is ever evolving and as said earlier new construction techniques like carbon composite are a challenge. Electronic devices (inside equipment) are also using smaller geometries and lower voltages potentially making them more vulnerable. Even existing standards are subject to review and change.
The acceptable lightning voltage transients that must be accounted for (and tested) are different for carbon composite - the 787 had to meet (IIRC) 2/3rd higher induced voltage transients than for a conventional aluminum airframe. The size or type of electronic device is immaterial - it needs to be tested and demonstrate it can withstand the appropriate lightning transients - this applies to every critical and essential system on the aircraft. Otherwise it shouldn't be on the aircraft.
So my original point stands - If a lightning strike caused multiple systems to fail, making the aircraft dangerously difficult to fly and land, it's critically important that we know why. Because it either means the requirements are wrong, the testing was wrong, or the implementation was wrong. If was the implementation, it points to a problem with Sukhoi and the Superjet. If it was the way it was tested, we need to refine the testing standards (and make sure they are complied with). If it's the requirements, we have a big problem that could potentially impact thousands of aircraft and the industry as a whole.
Honest question, does the Superjet use significant carbon composite structure? I thought it was fairly conventional aluminum construction.