Primarily for general aviation discussion, but other aviation topics are also welcome.
#1719482
I sort of lost interest in the rules about mandatory Mode S when I fitted a Mode S transponder in my last aeroplane, now sold.

I am now possibly looking at buying a replacement aircraft that only has a Mode "C" transponder. It has an 8.33 radio.

I don't have an I/R so I'm not allowed in Class A anyway. As of today, and in practical terms, how would having only a Mode "C" transponder limit me in UK airspace?


Thanks.
#1719484
TMZ needs mode S, or follow any specific procedure that exists, if any, for aircraft which haven't. (Lost track of requirements abroad, didn't the Dutch require a switched off Mode S xpdr somewhere once upon a time?)
#1719485
You normally cannot fly in:
- Class C airspace
- At or above FL100
- Under the Stansted CTA stubs
- The London CTR
- In Class E TMZ areas
unless granted permission by ATC.
#1719489
Irv Lee wrote:TMZ needs mode S, or follow any specific procedure that exists, if any, for aircraft which haven't. (Lost track of requirements abroad, didn't the Dutch require a switched off Mode S xpdr somewhere once upon a time?)


The Dutch required a Mode S transponder, if flying above 1200' ( I kid you not!)
This then swamped the ATC systems at Schiphol, during nice days when everyone was flying.
The Dutch CAA ( forget what they are called) panicked, then mandated that if you then flew beneath the Amsterdam TMA you have to turn your transponder to Standby or Off.

About a week later I was flying beneath the very same TMA and as mandated I turned off my transponder.
" Why have you turned off your transponder?" came the cry from ATC
" Because that's what your CAA have mandated and Notamed" was my reply.
" That load of idiots know absolutely nothing! Turn it on again please"

It seemed to me, that us and the Dutch, may have a lot in common.

Anyway about a month or so later the " turn off the transponder" lark was quietly dropped.

G-JWTP
#1719524
You can also call LARS to transit TMZ without one, just on radio, in the UK you have "controlled airspace" (class A wich you can't acess anyway unless IDs, altitudes, sqwaks are "verified" ) and the rest wich you can acess to some extent with your mode C (or even without tranponder) subject to ATC mood or Letter Of Agreements these may includes Class C, London CTR/CTA...saying "vintage C152" when asking for your next City/Heathrow transit may help :lol:

For Europe, without mode S (or without transponder) it gets tricky or even impossible for any CAS acess, the exception of France where ATC still have a direct say on what they like in their managed airspace but those deep south will often refuse to grant you acess (even may kick you out when transponder fails, so you better off with a shut up on RT as well :shock: )
#1719542
The southwest Stansted TMZ isn't an issue as going around it adds only a couple of minutes to your journey, lets you fly higher above built up areas and keeps one away from Stapleford Tawney.

Been through there several times recently and will jink round next time. Farnboro' North reminding me about airspace above on a very thermic day when each bump equated to a 400'/min climb finally convinced me.