North Sea query: will splash impact trigger ADS "Park mode"?
 

Hello!

I'm currently in transfer-training as an ATC working an offshore sector @ North Sea.

At the moment we do not accept "PARKED"-signals via ADS from helicopters on deck to indicate a safe landing, because we fear that a ditch in the sea will trigger the "PARKED"-ADS-signal being transferred unintentionally because the "weight on wheels" that can occur during a ditch.

Does anyone have any information on this? Has the system been designed as not to send the PARKED signal in case of a landing on water?

Regards,
Quintilian

Hi Quintilia,

long time since I spend my time over the water
but technically speaking, a weight on wheel switch closes, when there is weight on the wheel - hence landing - and opens, when there is no weight on the wheel.
Evenso there is some air in the wheels - I can´t imagine, that that is enogh buoancy, to trigger the switch, when the bird is swimming on its floats.

Greetings Flying Bull

Flying Bull - good point on the wheels probably not floating,but does ADS send the "parked signal" on the making of the WOW, or after another series of conditions have been met? I'd think that if you hit the drink with the wheels down, the force of impact, regardless of flotation, would probably make the WOW for a few seconds?

Trying to remember if water imersion switches will activate emergeny mode on ADS? Certainly a high rate of decent (ie. Autorotation) triggers emergency mode.

TiP

From recent reading on this, the ADSB signal is line-of-sight at 1Ghz. The ADS Out antenna is mounted on the belly of the aircraft. No matter what the software is telling the aircraft to transmit, I'd be very surprised if any signal were received from an immersed antenna.

wheels
 

The weight on wheel's swt only works when the wheels are down, and you dont have the wheels down when you ditch only if you fall off the deck after an engine failures.

Keys:

What happens if you a) miss the deck... or b) if you have a transmission failure on short finals to the pad?

I agree on the antenna thing though.