Sir - I read with interest Capt Mark Zucal's letter "Electromagnetic hazards" (Flight International, 18-24 June, P68). These are now known as "PEDs" (personal electronic devices).
I am involved in this, not with compact-disc (CD) players, but, more importantly, with medical equipment and work along with operators, manufacturers and both the UK Civil Aviation Authority and the US Federal Aviation Administration.
While airframe and systems manufacturers work hard to "harden" their equipment against the effects of induced interference, the easiest and most effective cure is prevention of emissions from equipment - be it another aircraft system, a CD player, or medical equipment. I believe that the aviation industry is doing its part. If the manufacturers of PEDs want their equipment to be usable in an aviation environment, then they should get their houses in order.
The requirements of the RTCA/DO-160C, Section 21 (Emission of Radio Frequency Energy) make interesting reading, and can be recommended to anyone wishing to supply equipment for use in an aircraft.
Richard Dawnay
Snaefell Aviation Design
Isle of Wight, UK
Source: Flight International
