V22 and Nav Lights
Last night two V22s passed my house some 10 minutes apart. It was about 2200, pitch dark with no significant moon. They were flying at an estimated 500 - 1000ft.
Neither appeared to be showing Nav lights though. The first had a dim, very dim white light perhaps at the rear as I could see it as the aircraft flew away but nothing else, the other had the same but the rotors were illuminated in a ghostly green, much stronger at the tips so it looked like a big green-outlined horizontal figure of 8 flying along, again with a dim white light near the aft end. (If it was nav light illuminating the back side of the rotors I'd have seen one green, one red right? I didn't, both were green) Really quite spectacular.
Low flying at night with no nav lights seems a somewhat hazardous thing to do - so what's the reason? Does NVG training require nav lights off? They were 10 mins apart so not formation flying.
What caused the green glow on the second one? It wasn't there on the first - and deffo no nav lights. Electrostatics? That strange piezo effect in dust that Chinooks have demonstrated - tho it wasn't notably dusty in E Anglia last night?