Flying through the Netherlands without mode-S is still possible, but becomes a fairly difficult bit of flight planning. You need to stay out of the TMZs and stay fairly low (1200' or below) in other areas.
Start with the AIP, available here:
AIS Netherlands Check out GEN 1.5, para 4.1 and ENR 1.6, para 2.
There are two AICs relevant as well:
Aeronautical Information Circular Series NETHERLANDS A 07/08
Aeronautical Information Circular Series NETHERLANDS 01/09
And yes, if it looks like the AICs and the AIP contradict each other on some minor points, that seems to be right and I don't know why, and which document takes priority.
Furthermore, currently in force (introduced by NOTAM a while ago) are the SRZ Schiphol, SRZ Lelystad and SRZ Hilversum, where you must put your transponder on standby. This to avoid radar clutter and spurious TCAS RAs. This situation is supposed to be temporary but nobody knows when this will end.
http://www.lvnl-ohd.nl/maps/BVG/Schi...SUP0509_V3.pdf
Okay, that's the official rules covered. Practically speaking, what I would do is call the Operation Helpdesk of the LVNL (the Dutch NATS), tell them your route and see what they think.
Homepage - OPS help desk LVNL.
Furthermore, during the flight stay in touch with Amsterdam info 124.3 or Dutch Mil info 132.35. If you do anything wrong, transponder-wise, they will inform you.
The other item you might want to check out is whether for your intended flight an ELT or PLB is required.
As for A'dam, I'm pretty sure BackPacker and/or VanHorck will be along any second....
Finding the proper links took a while...
