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744 CAT 3B

Old 14th May 2020, 05:58
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SRS
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744 CAT 3B

My understanding is that below Alert Height ( we use 100 ft ) only a NO FLARE will require a missed approach. We have recently changed a NO ROLL OUT as a captainís option. Am I missing some other possible events? Will the NO AUTOLAND come on ?

Thanks for all inputs.
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Old 15th May 2020, 07:59
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If it passed the autoland self test at 1500 and had no message regarding it prior to the 100 RA, I actually doubt the NO AUTOLAND can display below 100 RA.

My somewhat simplified system manual does not show a NO ROLLOUT message. I don't think that while it is only in armed mode (above 5 RA ) that ROLLOUT can display with an amber line though it, indicating degraded function. So it would have to change from armed to active at/below 5 ft to then show you degradation. We train in the sim that the PM will give a "no rollout" callout and then a "steer left/steer right" call using the LOC for centerline if ROLLOUT does not become active or is degraded with a line through it. But not to go-around as you will most likely be the TO/GA dead zone by the time that you realize the failure and try and do anything about it.


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Old 15th May 2020, 21:29
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Summarised from the FCOM (B744/-8).
AFDS needs to annunciate LAND 3 for 3B.
AFDS will not change annunciation from LAND 3 to LAND 2 below Alert Height (200’ RA).
Autopilots protected
At or Below A.H.; -
Captain should not interfere unless obviously required or ‘NO AUTOLAND’ annunciated.
NO AUTOLAND annunciated on the AFDS requires a CAT 1 minima to be used.

Unrelated Caution messages are inhibited Therefore any Master Caution Light or Aural Signal is critical and requires visual landing or go-around.
At low RAs, excessive deviation from LOC or G/S causes associated scale and pointer to flash.
Above Alert Height: If a/c correcting may continue.
Below Alert Height: Go-around or visual landing.Autopilot inadvertently disconnected below Alert Height: Go-around or manual visual landing.
If going around, must press TOGA sws otherwise FDs remain in Approach mode

Autoland - Additional Callouts
At 40’ if “FLARE” not annunciated. PM: ‘No Flare’ PF: Takes corrective action.
At 25’ if “IDLE” not annunciated. PM: ‘Retard’ PF: Takes corrective action.
On Rwy if ROLLOUT not annunciated. PM: ‘No Rollout’ PF: Takes corrective action.

Hope this helps
P.S. One time an F/O gets to call the Captain a Retard and doesn't have to buy the Crew drinks!
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Old 16th May 2020, 07:04
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Balus, a helpful response.

Thoughts for comment from non type rated, but Cat 3 qual pilot many years ago.

NO FLARE annunciation; presumably from an automatic detection and alerting system which can be generated prior too and at flare commence.

The monitoring pilot's 'No Flare' callout presumably relates to an assessment of either the lack of Flare annunciation ( if applicable in that aircraft type ), or that the aircraft does not flare at the expected height by judgement of the expected aircraft motion after that height.
The latter condition might be difficult to assess if the auto-land system uses a variable flare height ( small adjustments made for wind / ground speed correction ), and / or dependent on the foibles of human judgement - can be mistaken, a late call, or 'what if' called too high …

Re options to continue visually; what recommendations are made re reported visibility, e.g if Fail Op (Cat 3B) presumably the approach visibility is very reduced, limiting the ability to see the runway or sufficient cues for flaring, thus what is expected from 'a manual visual landing'.

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Old 16th May 2020, 21:21
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'No Flare' call is solely based on the annunciator. In a 74 at 3B minima you have no chance of assessing the point to flare visually.
Minimas for 3B are; -
ceiling 0'
RVR 100/100/100
Visual reference Not Required.
Approach lighting Not required
Runway lighting One centreline light

For an approach using LVP you always plan and brief the best available, so, if Cat 3B available that is what you use. This gives the ability to possibly continue if there is a degradation of equipment etc using 3A , Cat 2 etc prior to alert height and subject to the weather.
The option for a visual landing is because not all approaches remain IMC to the minima and should a failure occur at such a point it still allows you to legally land.
Over 25 years of LVO never once online have I had such a failure but certainly done my fair share in the sim.
For all intents and purposes, if you are doing a 3B approach and providing the wind remains within limits and equipment performs, then you are landing.
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Old 17th May 2020, 18:08
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Originally Posted by BalusKaptan View Post
'No Flare' call is solely based on the annunciator. In a 74 at 3B minima you have no chance of assessing the point to flare visually.
Minimas for 3B are; -
ceiling 0'
RVR 100/100/100
Visual reference Not Required.
Approach lighting Not required
Runway lighting One centreline light

For an approach using LVP you always plan and brief the best available, so, if Cat 3B available that is what you use. This gives the ability to possibly continue if there is a degradation of equipment etc using 3A , Cat 2 etc prior to alert height and subject to the weather.
The option for a visual landing is because not all approaches remain IMC to the minima and should a failure occur at such a point it still allows you to legally land.
Over 25 years of LVO never once online have I had such a failure but certainly done my fair share in the sim.
For all intents and purposes, if you are doing a 3B approach and providing the wind remains within limits and equipment performs, then you are landing.
Presumably you require a DH (e.g. 20R) for your B74 CAT3B fail operational approaches then, given the requirement to see 1 RW centreline light? Does your operator prohibit a `No DH` approach where no references whatsoever are needed?
Not an expert, just curious.
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Old 17th May 2020, 18:56
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Muddy waters. Our A319 came with AFM that stated Cat IIIB with DH = 0, and as well CAT IIIB no DH in the next paragraph.

Going to France at that time, it actually made a difference.
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Old 17th May 2020, 19:22
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3B DH is 0'.
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Old 17th May 2020, 21:02
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Originally Posted by BalusKaptan View Post
3B DH is 0'.
In EASA, not always!
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Old 17th May 2020, 21:28
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ICAO 3B: Less than 50' RA or no DH.
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Old 18th May 2020, 07:36
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Originally Posted by FlightDetent View Post
ICAO 3B: Less than 50' RA or no DH.
Agreed, assuming `fail operational`. EASA visual reference criteria as follows:

CAT IIIB operations conducted either with fail-operational flight control systems or with a fail-operational hybrid landing system using a DH: at DH, at least one centreline light is attained and can be maintained by the pilot.
CAT IIIB operations with no DH: there is no requirement for visual reference with the runway prior to touchdown.


If a DH is required (eg. 20R) then there HAS to be a requirement to achieve a defined visual reference, in order to actually be able to make a decision at all.
If no DH is required, then obviously no visual references need to be defined.

Question for `BalusKaptan`: I fail to understand how you can actually have a `DH of 0 ft`, perhaps I`ve got the wrong end of the stick. You would be on the runway (hopefully!) at this point anyway. What now forms the basis of your `decision`. Would it , for example, be based on a `roll out status` consideration?

EASA `Table 5` minima included just for interest`s sake.

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Old 18th May 2020, 09:50
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3B can (and usually does) have no DH and no requirement for a visual reference. A lot of French airports used to have DH15, but no longer. The only one I can find from our regulars is Brescia which is 30/100. No, I don’t know why! All the others have no DH.

On our 767s and older 757s we set -20 Radio. On our newer 757s it doesn’t go below zero, so that’s what we set.

HtH

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Old 18th May 2020, 10:13
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I fail to understand how you can actually have a `DH of 0 ft`, [...] You would be on the runway (hopefully!) at this point anyway. What now forms the basis of your `decision`. [...]?
I think it's a legal/mental exercise. Completely unnecessary but some operations were not allowed to use CATIIIB with NO DH. Certifying the aircraft for DH = 0 underscored the stupidity of such administrative restriction.

Thing of the past hopefully now, IIRC Belgium used to be similar.
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Old 18th May 2020, 12:34
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Originally Posted by FlightDetent View Post
I think it's a legal/mental exercise. Completely unnecessary but some operations were not allowed to use CATIIIB with NO DH. Certifying the aircraft for DH = 0 underscored the stupidity of such administrative restriction.

Thing of the past hopefully now, IIRC Belgium used to be similar.
That does actually make sense. Thanks for the reply..
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Old 18th May 2020, 13:04
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A320 NEO - PW engines:


A320 CEO - IAE with and without sharklets:




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Old 20th May 2020, 21:12
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BK, thanks for the reply #5.

The question was to explore the extent of independent creation of SOP and logical association with the operation.
Whilst others quibble about limits and wording, there are few examples of what actually happens.

3B no DH, land after AH. "For all intents and purposes; land."

3B with DH; what is the decision. Sufficient visual cues - for what, …

* auto-land; an arbitrary regulatory requirement, i.e. confirm that you are landing on 'concrete' (somewhat illogical for fail op systems). Or a 'real' decision involving the possibility of GA from on the runway (if 0ft) - why do this, relative risks, likely hood of failure, etc.

* manual rollout if dual RO system fails; this would be a 'real' decision based on the visual cues, and assessment of not having rollout control / guidance. How is the system assessment made, who calls, what. In all likely hood the aircraft will have touched down before the situation is understood, then relative risks, etc.


We tend to complicate operations where events are extremely remote, generating additional memory procedures, calls, training (how and when to make 'word perfect' calls).

C'est la vie.



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Old 20th May 2020, 22:15
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(non B744)

1) AUTOLAND red light below AH: trained - G/A
2) NO FLARE: not trained, see 1) (*)
3) NO ROLLOUT: not trained, see 1)

CAT IIIB with DH: no longer trained. Previously trained with a single landing (4 NM re-pos) in the SIM with DH set to 20. No failures for this f(r)oggy exercise). Make the PIC say "continue", tick the box so you can go to CDG and BRU.

(*) Hypothetically, you will hit the ground with about 2 g without touching a thing. Should that ever happen in real life, the impact assures the PIC is awake and takes over, staying on the ground. Yanking the yoke at 20 feet is bound to cause only more physical harm.
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Old 21st May 2020, 21:22
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SRS
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thanks to all of you. a great source of information.
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Old 22nd May 2020, 10:44
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General questions for interest.

Which aircraft (Cat3) have a 'No Flare' alert / warning.

If an alert (amber caution); what triggers the annunciation, i.e. how does the system know if the aircraft will not flare, and when.

If a warning (red), either at flare initiation or later, what triggers the annunciation.

Will either an alert or warning trigger a 'No Autoland' warning and/or disengage the autoflight system (op question #1).

What is the recommended procedure for a 'No Flare' warning, i.e. at or below flare height. Whats the purpose of 'No Flare'.


Influencing thoughts; if an aircraft has sufficient redundancy to operate with an alert height, - carry on and land with any failure, then how can a system with 'no flare' failure qualify as having sufficient redundancy.

Alternatively, if the Cat3B capability is provided by a hybrid autopilot / HUD flight director - if autos fail use HUD, then the system would not qualify to use an alert height because of pilot intervention, and thus requires a decision height.
How might a HUD provide flare guidance when the autopilot cannot - considering symbology vice sensor based computation.
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Old 22nd May 2020, 12:58
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A320, fail-operational. Certified NO DH (min RVR 75m).
Alert height 100', a separate autoland red light is on both stations.approx 10 inches from pilot's eyes. Complex logic what triggers it, but "no flare" itself is not monitored - if simulator behaviour is to be trusted.

For the question "Is it even possible to have a no-flare develop on you without triggering the Autoland RED warning in the first place?" - FCOM does not provide enough clues.

On the previous type, fail-safe CAT IIIA (min RVR 200m), there was no autoland big warning. Loss of RA / G/S signal could have created a no-flare situation. It was the PM's responsibility to discover and announce. With MBH about 17 feet, training was
-> you can land it if the required formal visual reference had been attained and you dare to try.
-> if you go around below 17 ft, there will be ground contact and it is alright.


On A320 later, my operator copied the understanding. The guidance changed to:
-> please make a G/A regardless, since you cannot see enough anyway and the risk of tailstrike (think A321) or runway excursion is too great.
AND LATER, this was ditched altogether.

T
raining for a "no flare" in a fail-operational A/C with a proven record was agreed to make no sense, moreover, relevant technical basis to do so (failure mode) could not be identified. Came to agree that is was not only a waste of precious SIM time, but also negative training as the previously provided guidance was a very dubious lesser of two evils that could land a whole aircraft in very hot water due to the 2nd approach dilemma.
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