I have been wondering for a while now, but why to British Airways B757's have a black ring around their nose? Seams a bit strange when the rest of the fleet haven't. Lol.
Sorry for the late reply.
I take it you mean a black ring like this? (Also on their 737s)
Picture by Nathan Zalcman, from www.airliners.net
I believe its part of the static-discharge system that protects the aircraft. All Boeing jets have it, some choose to paint over it with an static dissipating paint, but for some reason, it was left on the 757 Airbus have them hidden from view I think.
I believe also that they were designed to be apart of the MLS (Microwave Landing System) which were supposed to replace the ILS before 2000. The MLS was deemed more advantageous as it allowed pilots to fly curved precision approaches (when terrain was a problem). Pilots just have to fly non-precision approaches for the unconventional approaches. The idea was scraped - I don't know why.
I hope that helps.
Superb reply 99jolegg. Your mind is a hive of information.
That makes total sence.
In my Radio Navigation class we were discussing about the MLS. My teacher said that the MLS will replace the ILS in the future.
"The FAA suspended the MLS program in 1994 in favor of the GPS (Wide Area Augmentation System WAAS) that may supplement or replace existing MLS systems. Many countries in Europe (particularly those known for low visibility conditions) have embraced the MLS system as a replacement to ILS. Phasing down of MLS systems in the U.S. is planned to begin in 2010. However, it is unclear whether all the systems will be replaced or taken out of service, but (like LORAN-C) it is reasonable to speculate that if funding becomes unfeasible, they will be."