744 CAT 3B

[SRS]

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 captain’s option. Am I missing some other possible events? Will the NO AUTOLAND come on ?

Thanks for all inputs.

[bigduke6]

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.

[BalusKaptan]

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!

[PEI_3721]

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'.

[BalusKaptan]

'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.

[Stanley Eevil]

'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.

[FlightDetent]

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.

[BalusKaptan]

3B DH is 0'.

[Stanley Eevil]

3B DH is 0'.
In EASA, not always!

[FlightDetent]

ICAO 3B: Less than 50' RA or no DH.

[Stanley Eevil]

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.

https://cimg5.ibsrv.net/gimg/pprune.org-vbulletin/1280x720/cat_iii_minima_cb4417538c116f7191cb8b21cdc53c7bc23287fd.gif

[deltahotel]

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

[FlightDetent]

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.

[Stanley Eevil]

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..

[FlightDetent]

A320 NEO - PW engines:
https://cimg9.ibsrv.net/gimg/pprune.org-vbulletin/501x147/nodh_neo_pw_519c393a980c65ded0803ab3dc462f57ccee3a30.png

A320 CEO - IAE with and without sharklets:
https://cimg8.ibsrv.net/gimg/pprune.org-vbulletin/495x363/somedh_iae_3d8f4debf24fc5e42b8c01f8db16691877b493b1.png

[PEI_3721]

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.

[FlightDetent]

(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.

[SRS]

thanks to all of you. a great source of information.
✈

[PEI_3721]

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.

[FlightDetent]

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.

Training 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.

[Uplinker]

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 would say the DH is the (final) point at which you elect to continue the autoland, or go-around, and even with a DH of 0 ft there is still the rollout tracking and stopping part of the autoland left to go. If the aircraft landed way off to one side of the runway (or even the grass) instead of on the runway centreline, you might elect to go-around, even though you had "landed".

[deltahotel]

Cat 3B. The DH is either a positive number (and there aren’t many around anymore) or it’s no DH, not DH 0’. On my ac where we set 0’ because it doesn’t go any lower there are no auto calls of ‘approaching DH or minimums’ and 0’ actually means NO DH. So providing everything keeps working (ASA doesn’t say MANLAND, Flare annunciates) it will land with no requirement for any visual reference.

[wiggy]

I would say the DH is the (final) point at which you elect to continue the autoland, or go-around, and even with a DH of 0 ft there is still the rollout tracking and stopping part of the autoland left to go. If the aircraft landed way off to one side of the runway (or even the grass) instead of on the runway centreline, you might elect to go-around, even though you had "landed".

TBH the odd occasion I've done a CAT III B No DH landing as captain ( and I've done it on the 744 and the 777) my attention has been glued to the PFD ( especially the raw G/S and especially the raw Loc )right down until probably 60 knots or less.. I was sure as heck not looking up at "zero" or immediately thereafter for lights or grass if all the other annunciations were normal.

[PEI_3721]

Thanks FD; its good to hear that some aircraft systems are being used with matching certification and operational approval. Also, that common sense is not yet flattened by 'training for the sake of training'.

What was the other aircraft type.

Uplink, 'off the runway'; a highly improbable scenario given system integrity requirements, and instrument displays and alerts, e.g. LOC deviation.
Operational thinking from 'the early days' has evolved with increasing experience and knowledge. Low DHs relating to visual cues became 'confirm a runway', which was more for the pilots peace of mind than operational practicability.
Also changes in procedure with more knowledge of realistic minimum visibilities, 50-70m RVR could be 00 met vis; personal experience lowest was 90-110m RVR (ATC / fire rescue may limit operations to 50/75 m)

GA from the runway might be muddled operational regulatory thinking about a mixed integrity auto-land and rollout systems; fail-op land, fail-passive rollout.
Not a lot of common sense in some operational regulation.

dh, wiggy; ok.
Why not look outside and enjoy the view; there is a lot to see, and many differences day/night, different runway surfaces/lighting.

LOC deviation on the runway - unlikely; yet in VMC practice it was quite a surprise when ATC switched runways and ILS while ground-roll was still engaged. (I think that LOC display remained centred, but the aircraft didn't).

[Stanley Eevil]

I would say the DH is the (final) point at which you elect to continue the autoland, or go-around, and even with a DH of 0 ft there is still the rollout tracking and stopping part of the autoland left to go. If the aircraft landed way off to one side of the runway (or even the grass) instead of on the runway centreline, you might elect to go-around, even though you had "landed".

If on a CAT3B fail operational approach and autoland, with no adverse annunciations, there still exists, for your ac type/autopilot technology, a `risk` from historical data of not landing on the centreline, then the pilot needs to be given a `casting vote` in the form of a DH>0. Even if its just 12 ft, which I believe was used by the Trident ac on occasions?

[deltahotel]

PEI. I love a good view as much as anyone, but with 75R my concentration is elsewhere.

SE. Absolutely if there is a DH, otherwise the casting vote is based on cockpit indications alone(GS, LOC, ASA, FMAs etc). Today’s lockdown challenge is to find approaches with a 3B DH. My starter for ten is Brescia (30/100) as the only one on our list of lo vis airfields. Good luck !

[8che]

Interesting that some don’t want to look out of the window on 3b no DH. The basis of AWOPS training is one pilot heads out (normally PF) and one firmly heads down in (normally PM depending on operator SOP). Are you saying you see no value to seeking visual cues on a no DH approach ? A good unexpected visual cue forms another great resource if you’re lucky. Fog patches, midpoint significantly greater than 75m ? Perhaps you join the group of guys with newspapers In the windows to block out the sun or cockpit storm/ override light on in the dark because you’re IFR so there’s no need to look out.

Another lockdown question teeser. Why 75m for 3B no DH ?

[atakacs]

A320, fail-operational. Certified NO DH (min RVR 75m).

Only lurking in this thread but what does RVR 75 mean if there is no DH ? In effect does it still mean that if you don't see the runway at 75m you should go around ?

[FlightDetent]

Only lurking in this thread but what does RVR 75 mean if there is no DH ? In effect does it still mean that if you don't see the runway at 75m you should go around ?
Definitely no, as you suspected.

For no DH operations unless there is a failure the pilot takes no decisions and actions apart from operating non-automated stuff like the reversers.

The min value of RVR = 75 is an arbitrary limit to enable vacating the runway and taxing. In the sense you'd at least will be able to repot where you are after getting lost.

There are two other values of similar nature:

​​​​​​125 m is the min requirement for manual roll-out.
300 m for manual landing (IIRC used to be 350, happy to be corrected on this one).

A proposed fully autonomous landing under nil/0 conditions exists on paper for quite some time, search the interweb for ICAO CAT IIIC. The technology does not exist yet.