Can you raise an A/C category?

[Trash 'n' Navs]

This subject was debated at work and there were enough different interpretations to suggest that it is not a cut and dried issue.

(The reference is in the Australian AIP's but I'm assuming that the ICAO requirement is the same or similar.)

AIP 1.5 para 1.2 states that "an aircraft shall fit in only one category and may not reduce category because of reduced operating weight".

1. Can you legally increase your category?
2. Can a Cat B aircraft fly to the Cat E approach requirements in speed, heights etc?
3. Can a Cat B aircraft use the Cat E circling area for departure planning?

Logic and commonsense says that a lower category aircraft using a higher category circling area is safe (because of the increased obstacle clearance over a larger area) but is it legal?

What's your opinion? Do you know of a reference in the books to back it up?

[fernando]

flying below aircraft-cre-airfield minima will be ilegal. If you stay above it you are on the safe side and I assume it is not ilegal.

[wysiwyg]

Surely the prescribed minima are precisely that. If a commander should choose to make a decision at any higher point or based on a higher rvr then that is just him applying what he sees as common sense.

regards
wizzy

[Tinstaafl]

wysywig,

There's more to it than just raising the MDA.

Operating in a higher category also requires observance of all of the higher category's limitations eg Initial/intermediate/final/holding speeds, circling minima & manoeuvring area.

Oz rules state that an a/c may operate in a higher category but may not operate in a lower category etc etc.

[FL310]

This sounds all very logic but if you follow a higher category approach procedure and use the perhaps different tracks, you should at least inform the controllers as well as they may expect you on a different track.... ;)

[wysiwyg]

yep, that all makes sense.

wizzy

[swh]

One Oz operator uses cat B for their SF340s on two enginess, and cat C for single engine to give the better handeling on single engines.

Overseas it is not uncommon to select a speed cat you want to do, they are not based on the stall speeds in the landing config in all countries.

[Intruder]

From the Pilot/Controller Glossary appended to my copy of the US Aeronautical Information Manual (AIM):

"AIRCRAFT APPROACH CATEGORY A grouping of aircraft based on a speed of 1.3 times the stall speed in the landing configuration at maximum gross landing weight. An aircraft shall fit in only one category. If it is necessary to maneuver at speeds in excess of the upper limit of a speed range for a category, the minimums for the next higher category should be used..."

If you're doing a no-flap approach, you may need to use the next higher category.

BTW, the Glossary is based on ICAO as well as FAA definitions.

[ 02 November 2001: Message edited by: Intruder ]

[Trash 'n' Navs]

Sorry for not returning to my question earlier but I've been away drinking for a few days...

The agreement then, is that there are no problems in doing it because of the greater safety margins. As FL310 mentioned, what about different specified tracks (eg NDB approach) that are based on category? Do you need to advise ATC of which profile you will fly or is that just a courtesy?

The other issue is one of latent approval v. positive exclusion. If the rules say you can do it, great fill your boots. What if the book doesn't specifically mention it? Can you still go and do it or does it need to specifically exclude you from doing so?

The question does delve in to the legal aspects of the documentation by which we conduct our operations. With common sense a key factor (most of the time) in the interpretation of the rules and regulations, where will the line be drawn in an increasingly litigous world?