Hi,I'm spent almost as much time admiring the visual model of the 737NG as I have in (trying) to fly the aircraft. Last night, I was doing yet another walk around(as part of Timothy Metzinger's excellent tutorial), and noticed two vertical lines on the radome, one above the nose tip(between cockpit and nose) the other below the nose tip(between nose and gear). I think I noticed them because, at first, I thought it was a gap or fault in the way the front of the aircraft was assembled(please forgive my entertaining such thoughts :-)). On closer inspection, the lines seem to be incised on the radome, so I'm sure they must be a feature?. If it's not too anorak a question, are they meant to be there and, if so, what are they?BR,Frank

Frank,I can't tell what they are exactly, but they are supposed to be there. See this picture:http://www.airliners.net/open.file/498905/L/CheersThomas

I believe you're referring to the lightning diverter strips? The glassfiber radome is, like any other part of the aircraft, susceptible to lightning strikes. To protect the radome, metal (not sure if they are copper or aluminium) strips are screwed to the surface of the radome in a radial pattern. The strips are bonded to the metal part of the fuselage (via internal metal clips) to allow the current to flow from the strips to the skin of the aircraft and safely back out into the air. The bonding also helps keep the electric potential of the fuselage and the radome the same, so that sparks are not generated between the two surfaces, interfering with radio and navigation systems.It's important that the radome be kept in good condition (painted), otherwise water may penetrate the glassfiber. If water gets in, two things can happen..1. Lightning hitting the water-impregnated area will make the water boil and the glassfiber explode.2. The water will interfere with the radar system signals.Hope this helps.Cheers.Ian.

Yes, Ian, exactly what I wanted to say.:-hah CheersThomas

Yes, they're indeed the lightning diverter metal strips. They have also the function of continuing the "Faraday cage effect" in the nose too. In some aircraft (don't know if it's the case on the 737) the strips may also have some aerodynamic effect to properly curve the airflow in the vicinity of Pitot or static or combined tubes.

Yes, thought so, Thomas!Nice photo, too!Thank you,Frank

It certainly does, Ian!Very interesting information(can't get enough of it!).This forum sure is a great resource.BR,Frank

Thanks, Enrico!Must save/print all this info. :-)BR,Frank