Woke up in the morning to a sms from an ATR 72 pilot asking about the ability of the ATR 72 to fly a GPS approach to minimums.
The question, and my search through my files got me a bit confused. There was no clarity on the viability of the on board HT 1000 to support GPS approach. So I had to head online.
It was a crazy search, but search I did, nevertheless! I found online an Airworthiness Approval document from the UK CAA, which specifies under limitations:
“The GNSS HT1000 must not be used for GPS approaches.”
This question has clearly caught me off-guard, and I’m now trying to understand what makes a non-WAAS GPS approach feasible. And another thing bothering me is whether this approval is only for the specific aicraft: : G-BXTN.