Mode "S" Transponders

[tregonissy]

Hi,

I am in the process of formulating an avionics package for the aircraft I am building and have noticed a few comments about the Mode "S" transponder - apparently all GA aircraft will need one in the next couple of years so I would prefer to fit one now instead of changing the standard unit I was considering at a later date.

Your Comments would be most welcome.

[owenlars]

Basically if you fly IFR in CAS you will need it by March next year (2005) For VFR flight you will need it by March 2008. The following very abbreviated comments may help.


General Air Traffic of below MTOM 5,700Kgs and 250 KTAS flying IFR/GAT in en-route and major TMA airspace will NOT require Enhanced Mode S at any stage but WILL require Elementary Mode S from 31 March 2005 in UK, France and Germany – but from 31 March 2003 in Belgium, Netherlands and Switzerland.
Note –a. The Enhanced Surveillance requirements agreed between France, Germany and the UK are captured in a Common Regulatory Framework that you will find on the Eurocontrol web site.
b. Elementary will also be accepted in Enhanced Surveillance airspace where the aircraft cannot support technical Enhanced.

In addition - For aircraft flying VFR, latest dates for the carriage and operation of Mode S Elementary in designated airspace are as follows:
New production aircraft to be compliant by 31 March 2005
Completion of retrofits by 31 March 2008, subject to individual State agreements.

BUT in Belgium the Netherlands and Switzerland the following are eligible for exemption - VFR flights by aircraft:

(a) first registered in an ECAC member State or elsewhere prior to 31 March 2005 and already equipped with non Mode S transponders having Mode A 4096 capability and Mode C altitude reporting or

(b) when the carriage of a transponder is impracticable or

(c) when an exception to the requirement is authorised.

NB. In Switzerland exemptions for VFR is only to 31 March 2008

Comment from the CAA (regarding the position in the UK):
“Airspace in which Enhanced is mandated will require elementary in those aircraft which require access but either cannot support enhanced or are outside of the discriminates. However, they will be able to apply for exemptions on a case by case basis during the transition period.

Elementary is required in this airspace to support the delivery of the benefits from a safety and RF environment perspective. However, the exemption arrangements will mirror the implementation arrangements and exemptions will therefore be granted for access to that airspace where Mode S Enhanced has yet to be implemented.

All details are contained in the draft exemption arrangements which will be circulated with the next stage of the RIA. (Note –Regulatory Impact Assessment).

[S-Works]

When reffering to CAS are you refering Class A and airways only or Class D?

i.e will for example the IMC flyer require a Mode S to do an IFR flight non-airways from Coventry to East Midlands for example?

[A and C]

If you are puting the package together now you would be unwise not to fit a mode "S" unit as the instalation cost is a big part of the total cost of getting mode "S".

Some King units just a "box change" from a mode A/C transponder but these will also require a bit of programing if you fit a replacment unit as if you do not have the new rack fitted you cant have the E-prom that carries the aircrafts individual data.

Narco tell me that they are looking into a mode "S" unit that will fit into the AT50/AT150/AT155 rack but they have no in service date yet for this unit.

[LowNSlow]

Why is it that Belgium, the Netherlands and Switzerland have managed to negotiate an exception for VFR flights where "the carriage of a transponder is impractical" and the UK hasn't yet? Is this the nanny state supporting euro control by default rather than determining if Mode S is REALLY a requirement in UK airspace?

tregonissy, as your aircraft is a PFA type (I assume) and is therefore VFR only why go to the expense (and Mode S is currently VERY expensive) when there is a possiblity that a) an exemption may yet be negotiated and b) you will probably be fitting it yourself thus negating the future costs mentioned by A & C ? If you fit a relatively cheap Mode A (or preferably a Mode C) now, at least you will have the panel space ready for a Mode S if you have to fit one in the future when costs will hopefully have reduced to a sensible level.