CAT lll operation on 737 or in general
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CAT lll operation on 737 or in general
I the POM, it lists the name of equipment needed for CAT lll and ll approach and does not mention number required for roll out capability on B737 MAX. Going through standard callout, If no roll out below minimum or AH, response call outs from captain as well, except no flare FMA. So, does this mean that we can continue without roll out(crosslined rolleout mode on FMA) and touch down then disengage autopilot and maintain directional control ?
Secondly, in pom it states rhat HYD A or B fails, after AH, AUTOLAND and rollout may continue. Can we continue even though POM states I need two APs for CAT3b ?
Secondly, in pom it states rhat HYD A or B fails, after AH, AUTOLAND and rollout may continue. Can we continue even though POM states I need two APs for CAT3b ?
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It's been a very long time since I flew the 737, and even then it was the 3/4/500 series with no roll out capability, so this is a general observation rather than type specific.
Cat 2 & Cat 3A require a 'fail passive' auto-land system which, as you probably know, in the event of a a single system failure would require manual intervention but the aircraft will be in trim and present no handling difficulties.
Cat 3B requires a 'fail operational' auto-land system which, in the event of a a single system failure would complete the landing and roll out automatically. The manufacturer will have risk assessed the impact of a single failure below alert height, in which event it is acceptable to continue. This doesn't mean that you can't go around, indeed it may be wise to for some failures.
The A320 QRH draws clear distinctions between the equipment required for Cat 2, Cat 3A & Cat 3B approaches. I would have thought that Boeing would have done something similar.
Cat 2 & Cat 3A require a 'fail passive' auto-land system which, as you probably know, in the event of a a single system failure would require manual intervention but the aircraft will be in trim and present no handling difficulties.
Cat 3B requires a 'fail operational' auto-land system which, in the event of a a single system failure would complete the landing and roll out automatically. The manufacturer will have risk assessed the impact of a single failure below alert height, in which event it is acceptable to continue. This doesn't mean that you can't go around, indeed it may be wise to for some failures.
The A320 QRH draws clear distinctions between the equipment required for Cat 2, Cat 3A & Cat 3B approaches. I would have thought that Boeing would have done something similar.
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There is a big difference between required equipment to commence a Cat IIIb approach and to continue such approach below AH. FCTM gives good guidance on this in the Low Visibility Approach section.
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No idea about the MAX, have only flown the classic and NG (fail operational). According to the FCOM for the NG the 737 is capable of continuing for any single failure below AH (200ft). That includes engine failure, hydraulic failure and so on. The only thing mentioned for the rollout phase was a flashing red A/P disengage warning or VOR/LOC and or G/S and A/P yellow indication, FCOM recommended action is "execute manual rollout".
There is an increased warning inhibition below AH, for example NO LAND 3 or LAND 2 as well as NO AUTOLAND are inhibited and have no consequence, the plane continues to land and rollout just fine. The required equipment table for CAT IIIb mentions that one needs 3 IRS instead of 2 (ISFD acts as third IRS and may be inoperative for CAT IIIB with a DH), that 2 engines are required to start the approach and that antiskid has to be operational. Those things would not be required for a CAT IIIa approach including manual rollout, although automatic rollout on one engine actually works perfectly fine.
There is an increased warning inhibition below AH, for example NO LAND 3 or LAND 2 as well as NO AUTOLAND are inhibited and have no consequence, the plane continues to land and rollout just fine. The required equipment table for CAT IIIb mentions that one needs 3 IRS instead of 2 (ISFD acts as third IRS and may be inoperative for CAT IIIB with a DH), that 2 engines are required to start the approach and that antiskid has to be operational. Those things would not be required for a CAT IIIa approach including manual rollout, although automatic rollout on one engine actually works perfectly fine.
