If you’ve upgraded to the Futaba T26SZ and noticed that it doesn’t support the original FASST (2.4GHz) protocol, you’re not alone.
I get asked this quite a bit.
The short answer? It’s not a technical limitation — it’s a regulatory one.
Let’s break it down properly so you understand what changed, why it changed, and what it means for you
What Happened to FASST?
Back in the early days of 2.4GHz RC, Futaba’s FASST (Futaba Advanced Spread Spectrum Technology) was rock solid. It was reliable, interference-resistant, and quickly became a gold standard.
However, things changed in Europe on January 1st, 2015.
New regulations under ETSI EN 300 328 v1.8.1 introduced stricter requirements for devices operating in the 2.4GHz ISM band. The big change?
Listen Before Transmit (LBT)
All new radio equipment had to include Listen Before Transmit (LBT) capability.
LBT means the transmitter must check whether the frequency is clear before transmitting. This helps reduce interference in increasingly crowded 2.4GHz environments (Wi-Fi, Bluetooth, RC systems, etc.).
The original FASST protocol was designed before these regulations existed — and it does not support LBT.
As a result, it could no longer be sold in new equipment in Europe after 2015.
What About Existing FASST Gear?
Good news:
If your FASST equipment was already in the EU before January 1st, 2015, it was effectively “grandfathered” in.
That means:
- You can still legally use it.
- You just can’t import or sell new non-LBT compliant FASST systems in Europe.
So if you’ve got older FASST receivers and transmitters — they’re fine to use.
You just won’t see them in new radios anymore.
Futaba’s Response
To remain compliant in Europe, Futaba moved forward with:
- FASSTest
- T-FHSS
- LBT-compliant firmware in newer systems
By the time the T26SZ was developed, supporting legacy non-LBT FASST simply wasn’t viable for European-spec transmitters.
In fact, European Futaba radios are often region locked, meaning they physically cannot enable the old non-compliant FASST mode.
US-spec radios sometimes differ because the regulatory environment is different — but EU radios must comply with ETSI standards
Why the T26SZ Doesn’t Include FASST
So to be clear:
The Futaba T26SZ does not support original FASST because:
- The original protocol does not meet LBT requirements.
- New radios sold in Europe must comply with ETSI EN 300 328 regulations.
- Futaba chose to move forward with compliant, future-proof protocols.
- Regional firmware prevents enabling non-compliant modes.
It’s not that the radio couldn’t technically do it.
It’s that it can’t legally ship that way in Europe.
What This Means for You
If you’re upgrading to a T26SZ:
- You’ll need FASSTest or T-FHSS receivers
- Older pure-FASST receivers won’t bind
- Some third-party “FASST-compatible” receivers (like older FrSky models) may not work due to firmware and compliance changes
This is also why you’ll see compatibility discussions online where US and EU users have different experiences.
Final Thoughts
The move away from original FASST wasn’t Futaba abandoning a great system — it was about keeping pace with changing spectrum regulations and ensuring legal compliance in Europe.
The T26SZ is built for the current regulatory environment, not the 2008 one.
If you’re unsure whether your receivers will work with your setup, feel free to reach out — I’m always happy to help fellow pilots make sense of the compatibility maze.
