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yyzdub
20th Aug 2007, 17:25
Hi All,

A few questions....

1/ How do you practice a CAT II or CAT III approach in an aircraft (as distinct from a SIM) if the weather isn't CATII or CAT III ?

2/ Can you opt to do a CAT III approach in conditions that only require CAT II ?

3/ On certain routes will you always use a particular landing "technique" irrespective of the landing conditions prevailing at the time ?


Many thanks,

yyzdub

TopBunk
20th Aug 2007, 17:51
1/ Be alert to the fact that because CAT2/3 protections are not in place, there is no signal protection, and that loc/gs signals may not be relied upon - be prepared to take out the autopilot and complete a manual landing. The ILS must be annotated as Autoland suitable.

2/ yes, and indeed it makes sense to operate to the lowest limits available, so that you don't have to go-around unnecessarily if the rvr drops.

3/ I tend to prefer manual landing off non precision approaches, and when outside autoland limits!

fantom
20th Aug 2007, 18:02
"I tend to prefer manual landing off non precision approaches, and when outside autoland limits!"

Exciting; for whom do you fly?

Intruder
20th Aug 2007, 18:17
You can "practice" a Cat II or Cat III approach any time an ILS is available that does not have an aotoland restriction. We do it all the time. However, as TopBunk noted, the pilot is responsible for alerting ATC that he will be attempting the autoland, so they can either protect the ILS critical area on the ground or warn the pilot that the area is not protected.

When "practicing" a Cat II or Cat III approach, you still cannot descend below the MDA for the actual approach in use unless you have visual reference.

RYR-738-JOCKEY
20th Aug 2007, 18:36
In my humble opinion, if you do a practice CatII/III into a CatI field, (especially without experience with that specific ILS) you could find yourself in a situation where you realize excactly why it's only CatI...
I don't know much about the criteria for II/III approval, but I do know the accuracy is vital ;-) As I see it, there's two options in regards to practice approaches; be very prepared to do a go-around, or be very prepared to disconnect and hand-fly.

yyzdub
20th Aug 2007, 18:50
Thanks for that!

yyz

411A
20th Aug 2007, 20:11
1/ Be alert to the fact that because CAT2/3 protections are not in place, there is no signal protection, and that loc/gs signals may not be relied upon - be prepared to take out the autopilot and complete a manual landing. The ILS must be annotated as Autoland suitable.


Be prepared, yes, necessary...generally not, in one particular aeroplane, designed more than thrity five years ago at KBUR, and built to a superb specification at Palmdale, California...by the Lockheed California Company.

It is still the type that is used to compare to all others where automatic approach/land operations are considered.

TriStar.

AirRabbit
20th Aug 2007, 20:31
This is one of those “when-did-you-stop-beating-your-dog” kind of questions. There isn’t really any way to answer it without getting into trouble of some kind.

I am of the opinion that flight training is more than just practicing the manipulation of the flight controls. Of course, low visibility approach training surely IS to practice those flight control manipulations (particularly for CAT II and CAT III situations) – because as we all know, it might be some time between the requirements to do it “for real.” However, the piece that often gets lost is the piece of practicing the ability to see and recognize the cues a pilot must use to provide him or her the information needed to verify where the airplane really “is” on the approach, where it is “going” at any given time on the approach, and to practice the reactions to whatever is seen that leads to the appropriate flight control input (pitch, bank, yaw, power, trim) to safely continue the descent to the runway and land.

As you would probably guess, the traditional way to “simulate” a lower visibility when flying the airplane is an “all-or-nothing” approach (no pun intended). You use some vision restricting device; i.e., a hood or some sort of screen placed on the glare shield in front of the forward window. These methods produce very realistic “zero visibility” (meaning, you can’t see any farther than the hood or screen) until you remove that restriction, where upon you instantly have the visibility provided by mother nature. Of course in a “real” low visibility situation, “breaking out” doesn’t mean getting 12 miles and sunshine.

The aspect of this that I (personally) find a bit awkward is this is perfectly acceptable to the regulators in the US. While the advisory circulars describing the requirements for ground-based and airborne equipment as well as the operational requirements and training necessities, constantly use terms like “preferably in a simulator,” “typically in a simulator,” and “flight training should be accomplished in an appropriately qualified flight simulator,” there is no requirement to do so. Practicing in an airplane is OK.

My hearburn with this is that doing this practice in an airplane is really only ensuring the tick in the correct box. It simply cannot provide the training exposure that can be achieved in a properly qualified flight simulator. In today’s market, it would seem to me that the best method available for training what is actually going to be seen, felt, heard, etc., should be required – and we shouldn’t be accommodating that training using some cobbled-together work-around to fill the square … particularly when almost everyone recognizes the work-around done in the airplane as failing to provide what it really needs to provide!

Sorry, but you asked.

BelArgUSA
20th Aug 2007, 23:08
:eek:
xxx
I fly old 747-200s...
We are operating down to Cat.II minimums.
Once or twice a year, we may have to complete a Cat.II approach/landing.
The planes were Cat.IIIa certified long ago, expensive maintenance.
The 747-200/300s had Cat.IIIb capability, but never were certificated as such.
Not worth the few actual landings requiring that certification.
None of the airports we operate to require us to have that capability.
So, now Cat.II only is all we need...
xxx
So yes, we "practice" all that in simulators, once every 6 month...
We play Cat.IIIa, or even Zero/Zero Cat.IIIc autoland... for fun...
It is all about moving switches ON/OFF and push buttons anyway...
Planes do it fine if ever needed...
As simple as that.
:)
Happy contrails.

GlueBall
21st Aug 2007, 04:39
It's really an autoland [A/L] training maneuver in VMC conditions, so it doesn't necessarily have to be to a full CAT-II/III standard at a CAT-II/III airport.
A/L can be performed at CAT-I airports. But be aware that the ILS signal is less precise; the radar altitude may not conform to CAT-II/III terrain standards; the airplane may not touch down on centerline, and there is no assured rollout guidance.
You're checking to see if the airplane can still land itself somewhere on the pavement in Dual or Triple mode [2 or 3 A/Ps]

8846
21st Aug 2007, 20:16
Just to offer up how we do it in a fairly major european shorthaul carrier:

We practice Cat 2/3 Autolands on a Cat 1 Promulgated ILS to Cat 1 minimums.

The only big differences between a Cat 1 and Cat 3 ILS are:

A guaranteed instant back up should the transmitter fail at a critical moment.

and

As many have already said, the course structure is guaranteed because of the critical areas being free of vehicles and a/c on the ground close to the localiser and g/p aerials.

That means the decision to land/go around is made at 190 feet, but the a/p can stay in all the way to the roll out at 60 knots.

Obviously we check ALN, FLR and RET and all that good stuff as you would in a proper Cat 2/3 a/land.

Makes sense really - if any deviations occur between 190' and 60 knots you just disconnect and take over manually.

It's only a little Fokker so it's not as sophisticated or involved as a big transport like an L1011.

:ok:

Intruder
21st Aug 2007, 22:29
We are operating down to Cat.II minimums.
Once or twice a year, we may have to complete a Cat.II approach/landing.
The planes were Cat.IIIa certified long ago, expensive maintenance.
The 747-200/300s had Cat.IIIb capability, but never were certificated as such.
Not worth the few actual landings requiring that certification.
In the US, anyhow, the airplanes need to log periodic Autolands (every 15 days in our case) to maintain Cat II certification.