ILS 200ft cloud - elect to do an autoland?
 

OK firstly, I'm a mere PPL(IMC) so apoligies if any of this sounds daft.
Assume (IR) pilot is current, aircraft is capable and airfield is suitably equipped, you can descend to 200ft DH on an ILS , if you are not visual at that point you have to fly a go around.
Now with something like a 747 for example, if the METAR at your destination is showing that the cloud base is 200ft, would you still manually attempt an ILS approach and land if visible by 200ft or go around if not. To save going around though if the cloud base was slightly below 200ft, is it normal practice to set up the aircraft for an autoland if the cloud base is say 300-400 ft to give you a bit of a buffer and avoid the potential of a go around?
I ask this as obviosuly the details in the METAR could change by the time you actually get over the threshold.

Thanks in advance.

Interesting question.. I fly the A320 at the moment, and can see your point, but there are a few considerations. If the forecast conditions at the field are acceptable to make a CAT I approach (a normal ILS which is hand flown, or with autopilot down to no later than 80') we may make the approach down to minimums for that CAT I approach, i.e. not lower than 200'.

If low vis procedures are not in force, the ILS is not protected, which means backup power supplies for it and the runway lights etc are not online. Also the CAT II/III holding points will not be used, so the ILS radiating area is also not protected from other aircraft or vehicles that may be taxiing/moving near the runway.

If, before we get to the FAF the weather report given by ATIS or by the tower (or from other aircraft) is good enough, we'll carry on with the CAT I approach. If the weather deteriorates after we have passed the FAF, we can legally continue down to minimums, and land if we become visual. If not, we'd go around, hold if necessary, then either make a CAT II/III approach (which takes time for the airport to sort out), maybe needing to divert. Had to do this last week, ended up going elsewhere as the ILS was off the air.

high-flyer

In principle, you are correct, in so far as that you would 'go around' if not visual at 200ft. However, in my company, the reported ceiling is not the controlling factor. The reported visibility or RVR are the controlling factors for any type of ILS approach, so you would not be wrong to descend to 200 feet and then go around if not visual.

Experience, and good airmanship though, would suggest, as you do, that you prepare at least for a CatII approach in those circumstances. Saves all the extra fuel and ASR's from going around.

At our airfield (& I assume, at most other CATII/III capable airfields) our instructions are that we commence the procedures for activating LVPs PRIOR to the conditions deteriorating that far, in order to try to avoid exactly the situation described - ie. get to 200ft and can't continue for an autoland because the airfield isn't yet in LVPs. Thus, if the conditions are approaching CAT I minima and forecast to deteriorate further, we instigate LVPs, giving you the option of setting up for an autoland even if the RVR / cloud are still marginally above CAT I minima.
RC

Thanks for the replies.

Hmmm, from a couple of the posts, it would appear that more modern types get far too 'twitchy' during an automatic approach/land (autoland) maneuver, without LVP procedures in place, during CAT I.

An older type, with far superior performance, has no such restriction.
TriStar.

In my opinion 200ft base is not a problem at all if you are making an approach into an airfield with CATII lighting. For such a cloud base the approach lights will be visible well before minima. The problem is an airfield with only CAT I lighting. Our company operates frequently in VV001 RVR1000 weather with no problems when CATII lighting is available (we don't have CATII approval), but the A/P is used to minimum cert. height. Today I hand flew all approaches and the bases were around 400ft.

Depends on the operators' SOP's, but the simple answer is yes!