Not so funny when you are flying back from MIA with no RVSM. You are firmly excluded from RVSM airspace which means no higher than 28,000'. Rather than expand the area of protection around affected aeroplanes, they are excluded from flying in that airspace and possibly from getting to their destinations.
That would depend if your transponder was U/S or just your TCAS.
If your transponder was U/S, then you
might be accepted for the flight provided this was co-ordinated and agreed by the ATC agencies whose airspace you would fly through. Note that this is not solely RVSM related, it is applicable to airspace within which the carraige of a transponder is mandated. You would of course lose RVSM capability as a result since it is a requirement.
Neither the European Region, nor the North Atlantic Region, require TCAS as mandatory for flight within their RVSM airspace. However, the European Region may catch you anyway by its separate requirement for TCAS in ALL ECAC airspace if your aircraft is above 15000Kgs and carries more than 30 passengers. (From 1 January 2005, the criteria is above 5700Kgs or more than 19 passengers). Having said that, there is a 10 day alleviation for U/S TCAS equipment, provided you still have a serviceable transponder with altitude reporting.
The RVSM MEL should read:
1. Two independent altitude measurement systems each equipped with:
cross coupled static/source system with ice protection if located in an area subject to ice accretion,
display of the computed pressure altitude to the flight crew,
digital encoding of the displayed altitude,
signals referenced to a pilot selected altitude for automatic altitude control and alerting,
and static source error correcting.
2. One SSR transponder with an altitude reporting system in use for altitude keeping.
3. An altitude alerting system.
4. An automatic altitude control system.
If your airline has TCAS on its MEL for RVSM operations, then they are plain wrong. Point them at JAA TGL No 6 which details the above as the Minimum Aircraft Systems Performance Specification (MASPS) required.
JAA TGL 6
In short - No Transponder, no RVSM - No TCAS, no restriction.