Standby Attitude Indicator ILS

[FlightDetent]

Sorry, 750 m for a CAT I approach installation without FDs, is it?

AMC5 CAT.OP.MPA.110 Aerodrome operating minima (a) (4) An RVR of less than 750 m as indicated in Table 5 may be used:

(ii) for CAT I operations to runways without RTZL and RCLL when using an approved head-up guidance landing system (HUDLS), or equivalent approved system, or when conducting a coupled approach or flight-director-flown approach to a DH. The ILS should not be published as a restricted facility;

[wondering]

If you read (a)(4)(i) you can use less than 750m if you have a FALS, RTZL and RCLL. No FDs needed. Check table 5.

[FlightDetent]

Correct, that means CAT II approach light set. Wouldn't you just shoot CAT IIIA (or fancier) with RVR 200 and be done with it?

On a standard CAT I installation as already mentioned (twice) FDs are valuable well beyond ILS deviation needles.