I'm a 744 driver and curently my outfit let us make the initial approach using RNAV - Clearance to do Final Approach is forthcoming. I'm sure RAIM will be covered then.
Uping the stakes:---
If your approach navigation is solely by GPS - I am not surprised that a RAIM outage prevents an approach
If your navigation kit is Dual FMS with DME / DME & IRS updating does that give the redundancy to compensate for RAIM being unavailable?
I know folks are / have been doing these approaches down at LGW - what is actually happening on the day when you are due to make an approach during a forecast RAIM outage?
T'bug