Helicopter with no navigation lights

Information is publicly available:
https://www.aviation.govt.nz/rules/rule-part/show/91/3

91.233 - Aircraft lights
(a) A pilot of an aircraft must not—

(1) operate an aircraft at night unless it has lighted position lights; or

(2) moor or move an aircraft at night on a water aerodrome unless the aircraft complies with the lighting requirement of the International Regulations for Preventing Collisions at Sea; or

(3) operate an aircraft at night that is required by Subpart F to be equipped with an anti-collision light system unless the anti-collision light system is operating.

(b) A person must not park or move an aircraft at night on a manoeuvring area of an aerodrome ....

(c) Notwithstanding paragraph (a)(3), a pilot of an aircraft is not required to operate the anti-collision light system if the pilot determines that, because of operating conditions, it is in the best interest of safety to turn the system off.

So there is allowance to turn off Anti-collision light (the blinking one) but not the position lights (the steady lights).

I was lucky enough to do a night training flight on NVG equipped helicopter in Auckland as a "victim" for winch training. The crew were turning off all the external lights because the reflections off the rotor blades, landing gear and mist/clouds etc reflected back and interfered/dazzled the night vision (same reason I would assume the police are turning off their lights).

We were operating in closed airspace so there should have been no risk to other aircraft, however a light aircraft ignoring or ignorant to the closure did trying to fly through and straight at us. The helicopter crew were watching out for this, and paused the training mission, went off of the NVG and turned the nav lights back on. The offending aircraft kept approaching us for another 4 or 5 seconds, then (presumably) saw us and did a hard U-turn (busted!!??). We were fairly low, but the helicopter crew were getting ready to descend (further) to increase the (vertical) distance between the aircraft to ensure no collision occurred.

One would assume that the police helicopter has a special and conditional dispensation to operate with no lights. I'd expect that the police helicopter assumes all responsibility to avoid collisions. Also don't forget that electronics safety systems such as TCAS are increasing popular (and increasingly mandatory ?)

GV27

tripper1000

mdooher