BA 757 Nose Cones

[df1]

Hi,

I expect this has something to do with radar performance but what exactly is the black band on BA 757 nose cones as shown here (http://www.airliners.net/open.file?id=643007&WxsIERv=Qm9laW5nIDc1Ny0yMzY%3D&WdsYXMg=QnJpdGlzaCBBaXJ3YXlz&QtODMg=U3RvY2tob2xtIC0gQXJsYW5kYSAoQVJOIC8gRVNTQSk%3D&ERDLTkt=U3dlZGVu&ktODMp=QXVndXN0IDksIDIwMDQ%3D&BP=1&WNEb25u=U3RlZmFuIFNq9mdyZW4%3D&xsIERvdWdsY=Ry1CUEVL&MgTUQtODMgKE=TGVhdmluZyB0ZXJtaW5hbCAyIGZvciBkZXBhcnR1cmUgcnV ud2F5IDA4Lg%3D%3D&YXMgTUQtODMgKERD=MTY2&NEb25uZWxs=MjAwNC0wOC0yMg%3D%3D&ODJ9dvCE=&O89Dcjdg=MjU4MDgvNjY1&static=yes&size=L) and if it is indeed due to radar performance why is is not apparent on other airlines 75's or indeed other aircraft?

Thanks.

Edited to show this (http://www.airliners.net/open.file?id=640723&WxsIERv=Qm9laW5nIDc1Ny0yMzY%3D&WdsYXMg=QnJpdGlzaCBBaXJ3YXlz&QtODMg=TG9uZG9uIC0gSGVhdGhyb3cgKExIUiAvIEVHTEwp&ERDLTkt=VUsgLSBFbmdsYW5k&ktODMp=SnVseSAyMywgMjAwNA%3D%3D&BP=0&WNEb25u=U2ltb24gRy4gQm9vdGhyb3lk&xsIERvdWdsY=Ry1CUEVJ&MgTUQtODMgKE=&YXMgTUQtODMgKERD=MjQwMg%3D%3D&NEb25uZWxs=MjAwNC0wOC0xNw%3D%3D&ODJ9dvCE=&O89Dcjdg=&static=yes&size=L) clearer example.

[FLR-PSA]

BA have been trailing a Microwave landing system on some of their 757 fleet. The black 'ring' on the Radome was found to absorb microwaves better than the standard painted radome.

Of course, I'll stand corrected :ok:

[avioniker]

Actually the black ring is a conductive strip for static dissipation. It's on all radomes but BA doesn't paint it over. Its effect is more for radio communication and to some extent lightning dissipation.
Some radomes have it embedded in the structure so it isn't visible.
It was there long before we considered microwave navigation.

[Robert.humphrey]

The BA 757 that had the trial MLS system had a black and white quadrant painted on the nosecone. The MLS system was for recording only, there was no indications or controls in the flight deck.

[AA717driver]

TWA and AA have had the same nose jobs before. I believe I was told they were "loaners" from Boeing.TC