Mode S and the FCU

[cornwallis]

Does the mode s information broadcast from an aircraft include what has been set in the flight Control unit?

[Denti]

Depends on the level of Mode S installation you have. With Mode S Enhanced Surveillance one of the things transmitted is Altitude Target, which would be your dialed in altitude in the mode control panel or whatever it is called on your type.

As far as i know mode s enhanced surveillance is mandatory in germany, france and the UK for commercial IFR operation.

More info can be found at EUROCONTROL - Mode S Homepage (http://www.eurocontrol.int/msa/public/standard_page/nv_modes_homepage.html)

[cornwallis]

Thank you for the info.I was looking for info on what indicated speed it broadcasts,actual speed or target speed in the fcu?The bus old and new flies around a speed band in the descent to stay on its profile and sometimes it can be at least 10kts slow/fast on its target speed.

[FE Hoppy]

- Magnetic heading
– Indicated airspeed
– Mach number
– Vertical rate
– Roll angle
– Track angle rate
– True track angle
– Ground speed
– True airspeed
– FCC/MCP selected altitude
– FMS selected altitude
– Barometric pressure setting

enhanced bits from collins.

http://www.eurocontrol.int/msa/gallery/content/public/images/table_operational_overview-2%20copy.jpg

[cornwallis]

Perhaps an atco can comment on the following?When we are told to fly a speed in the descent "exactly" what are the tolerances on this?My old bus has problems doing this and only level change can really be relied upon for speed control.This however is to the detriment of the path you are trying to follow.:sad: