Cat III Approach Climb Limit weigts

[Bearcat]

Any of you guys out there subject to restricted max landing weights on the 73 when the destination is cat III.The outfit I work for has the max landing weight right down due to the restrictive nature of the clb limit weight. Any of you guys like to comment re your own port of employment?

[mabrodb]

Bearcat-

My carrier has a special "low min" landing wt chart for use when the vis is below 3/4sm or 4000 rvr. Accounts for a pssbl longer touchdown pnt.

[CaptainSandL]

We too have very restrictive lo-vis climb limiting landing weights. esp for the –500 series, 300 & 400 not usually a problem. We also get stiffed a further 3000Kg (approx) for “residual ice” which also doesn’t help.

Mabrodb – The JAR reason for the restrictive weight is that the Cat 2/3 go-arund climb gradient must be calculated on the actual go-around speed which is quite draggy and gives a poor climb. Whereas the rules for Cat 1 (or better) are that the go-around climb gradient can be calculated at any speed, so the manufacturer uses a more favourable speed when producing the graphs/tables to exploit this loophole and help the operator.

S & L

[m&v]

My understanding,via JAA rules,is that the 'norm' Go-around climb gradient is 2.1%.
Whereas the G/A climb gradient for a Cat3
Is 2.5%(lower missed approach point??)
ref: A320 Fcom:3.05.35

[CaptainSandL]

m&v

You are correct, it is a combination of both our points.

The Cat 1 missed approach climb gradient is based on a manufacturer's selected speed (max 1.5 Vs) to produce a 2.1% gradient. The Low visibility is separate rule, which requires 2.5% gradient at the 'real' speed, therefore much lower weights.

S & L

[Scallywag]

From Jarops "Minimum steady gradient one engine inoperative required by the regulations is 2.1% at a speed not exceeding 1.4 Vs. In the case of a Category II approach a climb fradient of 2.5% is to be maintained. NB!!! Except for aircraft operated under UK regulation, where for single engine Category II approach a minimum gradient of 3.0% is required!!!! "

Not a lot of people know that (last bit) :)Scally

[quid]

mabrodb-

Could those restrictions exist to be in compliance with OPS Specs. C054 b (2) (a)?

It requires 15% additional runway length if the RVR is less than 4000. If the low vis weights are the same as the "wet" weights, then it's probably the reason.

scally and sandl-

I'm not on a CAT III a/c, so the higher gradient requirement is new to me. Is that also required in the US? If so, I would guess that it's a dispatch/takeoff requirement. I doubt that many would care about that if they actually were planning a single engine CAT III.