View Full Version : Cat 1 ILS and Safeguarding

U R NumberOne
29th Jan 2002, 13:53
You're making a CAT 1 ILS approach in poor weather, say BKN 200ft with 1400m RVR. On the approach ATC advise the airfield safeguarding measures are not yet completed, therefore Low Visibility Procedures not yet fully active. Do you have to go around and hold or can you still land?

Hew Jampton
29th Jan 2002, 17:13
What do you mean by "airfield safeguarding measures", a fairly generic term covering for example masts and chimneys within a radius of some miles from the ARP? If Cat 1 ILS protection (LOC and G/P Critical Areas etc) is not in place, no, you can't land. If Cat 2 protection, ie LVPs, is not in place, then, depending on your Ops Manual, you can land.

[ 29 January 2002: Message edited by: Hew Jampton ]</p>

29th Jan 2002, 18:02
In the USA, you most certainly CAN land, as CAT I. .ILS approaches may be hand-flown if desired. If pilots cannot (or will not) hand-fly a CAT I ILS approach, they most definately should be sent back for retraining...or terminated. . .It's called...basic airline flying skills.

29th Jan 2002, 18:27
411A,. .glad to see you`re back on your old horse again...

Now, back to the subject on hand,. .If ATC indicates that the protection area is not clear, you can continue to cat 1 limits.. .Reaching cat 1 limits, you can either go around, or, if you have enough visual clues, you can continue for landing.. .Hope this answers your question.

29th Jan 2002, 23:27
Static, you may be interested to know...that for an FAA type rating, the applicant must hand-fly a basic ILS approach to a 100 foot DA, followed by either a landing or go-around, all engines operating. Airlines train for this maneuver with an engine out as well.. .These basic skills must be demonstrated...or no rating. Same for recurrent. If the flight director is not used, slightly higher minimums apply.. .And yes...you are quite correct...LVP not necessary for landings with CAT I minimums.. .And...1400m RVR...rather good weather actually.... <img src="rolleyes.gif" border="0">

30th Jan 2002, 00:07

I'm going from memory here but I beleave the 100 ft DH is a requirement to meet lowwer than standard landing minimums under FAR 121. It is also requirement to have either 2 flight directors up and operating or 1 flight director and an opertive approach coupler on the auto pilot available. These do not need to be shown on a type ride but are required for a PC.

For the type ride (PTS) one approach must be hand flown but you can use the flight director and down to an altitude of 200 feet or a normal CAT1 minima.

If you had two pilots getting a type in the same airplane but one pilot operates the airplane under FAR 91 and the other under FAR 121 the type ride would be very simular except the 121 pilot could have a few maneuvers waived (like a circling approach).

Again, I'm going from memory, with out my referance material, I could be wrong.

30th Jan 2002, 00:31
Okay, well my guess is that all airline pilots can handfly an ils. With or without the FD. And with all engines operating as well with an engine out.

So,to return to the original question.

U R number one :. .As with all airline procedures it's quite simple.. .I will give you one example for "airfield safeguarding measures".. .e.g.. .A real life one could be :. ."ils ground checked only".. .This means that ils is operative and checked ok, however there hasn't been a flight check yet by the authorities.. .In this case it is looked up in the operaters manual(as there are many varieties on the subject one would rather not take this from memory). .And the crew will find that in this example the LOC only minima apply.(so GS should not be used at all). .Easy isn't it ?. .hope it answers the question?


U R NumberOne
30th Jan 2002, 02:59
Thanks for the replies so far. The safeguarding I'm talking about consists of things like certain taxiways being blocked off if they have no stop bars leading on to the runway, ensuring the airfield generators are running in case of a mains power failure, more regular checking of equipment tolerences such as the IRVR system.

To get these protective procedures put in place takes a bit of time, during which the weather may deteriorate further. Our manual states we must inform aircrew when the weather conditions are such that these procedures are required, but are not yet in place - so that brings about my original question - what are your procedures for such an event on a CAT 1 (I appreciate CAT 2 or 3 will be much different) approach? Can you still make the approach or is it a matter of holding for the Low Viz Procedures to be fully activated?

30th Jan 2002, 14:38
As long as you have a published instrument approach procedure, you can start the approach in any weathercondition (some states excepted, like the UK, I believe).. .You can continue the approach past the outer marker if the visibility is above the minimum required for the approach (typically 550 meter for cat 1).. .So in the sketched scenario, with rvr 1400 meter, you can continue the approach past the outer marker. Now, if ATC indicates that LVP`s are not yet in operation, you can only go to cat1 limits (typically 200 ft AGL).. .However I would be perfectly happy to do the approach to cat 1 limits under these conditions.