[MilCom] ICAO Advice to Military Authorities (Military aircraft with ADS-B)

[John Nash via MilCom]

I found this interesting.  Does anyone know the current policies of US Government?  Will Mode S transmissions by military ever be mandated for FAA Next Gen systems?

John Nash
Eastern North Carolina
uctodc at aol.com

See below:

Military aircraft with ADS-B

ADS-B data sharing does not influence the decision by Defence Authorities to equip or not equip
with ADS-B. The equippage decision is usually based upon a large number of factors including :
- the regulations and policies of the State
- the age, capability and cost of equippage of particular aircraft type fleets
- the operational benefits of using ADS-B in the civilian air traffic environment
(and in military ATC environments with ADS-B). These benefits include safety,
efficency, and search and rescue.
- the military advantages and disadvantaes of transmitting ADS-B data

Note that many modern Mode S transponders and Mode 5 transponders support ADS-B.
Some military transponders may support ADS-B based “station keeping” using encrypted DF19
ADS-B messages, but this data is not normally decoded or used at all by civil systems.


Military aircraft will not transmit ADS-B if they wish to be un-observed.

In most cases today, tactical military aircraft are not ADS-B equipped or can choose to disable
transmissions. In future, increasing numbers of military aircraft will be ADS-B capable and will
include the ability to disable the transmisisons.

Military authorities will enable or disable ADS-B data transmission from concerned aircraft taking
into account whether they wish operations to be observed by any ADS-B receiver.

Because low cost ADS-B receivers are available to the general public , ADS-B data sharing is only
making available to the adjacent authority data that is already available to members of the public
(ie: 1 those members of the public that have ADS-B receivers).

Military aircraft that do transmit ADS-B data must always assume they are visible because any

ADS-B receiver (on the ground or in the air) can receive and process the transmitted data.
Military needs can be satisfied

ADS-B on the other hand simply only conveys information from co-operative aircraft that have
chosen to equip and broadcast ADS-B messages.

Further, if required, it is possible for States to instal ADS-B filters which will prevent data about
sensitive flights being shared. These filters can be based on a number of criteria and typically use
geographical filtering to only provide ADS-B data to the other party if aircraft are within 150-200
NM on their side of the boundary.

Appropriate firewalls and data security measures can also be implemented.

The decision to share ADS-B data or not, will have no impact on whether aircraft transmit ADS-B
messages. ICAO standards already allow these transmissions and some states such as Australia have
published regulations which mandate that ADS-B shall be transmitted by airliners.
                                                            
1
 Low cost ADS-B receivers can be purchased on the internet