CAT II & III requirements

[Dmax]

Hi guys,

I'm not Low Visibility trained or qualified and I'd like to have a more clear view of the requirements regarding the manual or automatic landing.
I've taken a look to JAR-OPS1 but the table and descriptions given are not clear.
So, in CAT II can I fly manually? (I know yes, but please confirm :O );
During CAT III A? CAT III B (with and without DH)?

Thanks
Davide

[GlueBall]

Neither is ever a manual approach, except that in CAT-2 [D/H 100'] you have the option, for example, to continue [Fail Operational] and flare manually if no "Flare Green" in Dual. If no "flare green" in triple [A/P] mode, you would continue with autoland. [747]

[Drop The Dunlops]

Neither is ever a manual approach, except that in CAT-2 [D/H 100'] you have the option, for example, to continue [Fail Operational] and flare manually if no "Flare Green" in Dual. If no "flare green" in triple [A/P] mode, you would continue with autoland. [747]

This only applies to Fail Operational a/c with 3 autopilots though, doesn't it?

AFAIK some turboprops fly down to CAT II minima using one autopilot then the pilot takes over and lands.

In most 737's (Fail Passive models) CAT II and CAT IIIa are both autoland approaches, with the option to continue manually if (a) an autopilot fails, and (b) you are visually established. Otherwise it's a manual go-around.

DTD.

[Dmax]

I know that the requirements are not aircraft related but under the JAR-OPS1 law. There is a table in the section E (All weather operations) where it's stated, related to DH and RVR, whether is required a "Rollout / guidance system" or not. My doubt came from this. "rollout / guidance system" means "rollout (autoland + rollout) OR guidance system (autoland without rollout)" or it means "rollout guidance system" as a total equipment?

Thanks
Davide

[Graybeard]

Hi guys,

I'm not Low Visibility trained or qualified and I'd like to have a more clear view of the requirements regarding the manual or automatic landing.
I've taken a look to JAR-OPS1 but the table and descriptions given are not clear.
So, in CAT II can I fly manually? (I know yes, but please confirm :O );
During CAT III A? CAT III B (with and without DH)?
Davide
The Flight Dynamics (now RockwellCollins) HGS, Headup Guidance System, was initially certified in about 1977 on the 727-200 at Alaska Airlines to CAT IIIa, 50' DH and 700' rvr. That's hand flown, of course. It has since then been expanded to many airlines and airframes, even those with autoland guidance.

Autoland doesn't help at all for departures, whereas the HGS provides takeoff guidance, certified to lower minima.

The number of hours an airport is between CAT I and CAT II minima turns out to be pretty small, so many airlines chose not to bother with the additional cost of CAT II.

CAT IIIa can be either fail passive, such as in the MD-80 and 737-3+, or fail active as in the widebodies and newer designs.

CAT IIIa Fail Passive means if there is a failure or deviation difference on the approach, the autopilot disconnects and gives it back to the pilot. The MD-80 series and 737-3+ don't have a Fail Operational rudder control, so cannot be Fail Active.

There are a lot more rules and intricacies of course. Your question regarding rollout guidance is good. The Glideslope and Radio Altimeter inputs are gone at touchdown, leaving only the Localizer, which will continue to provide good data, but now control is largely nosewheel steering. Look at the systems diagrams of your plane; is there a connection between rudder and the nosewheel?

GB

[Dmax]

My question is easier than how it appears:

Not regarding the failure etc.
Example:
I'm going to an airport that is in Low visibility (CAT II or III), and I'd like to know if I can:
1) Fly the landing manually or
2) I need to use the Autoland.

I which category is the autoland compulsory? I mean, the use not the fact that it's installed on the airplane.

Where do I find this? JAR-OPS1, as already mentioned?

Thanks
Davide

[FlapsOne]

I'm not Low Visibility trained or qualified.........

Can't do it without training and recency.

I'll look up a reference for you.

[FlapsOne]

Appendix 1 to JAR OPS 1.450
Low Visibility Operations – Training & Qualifications

The earlier comments about manual landings are valid. You can manually land from a Cat 3B approach IF you are visual at the time a failure hits.

Problem is, if the weather is that bad, you can only make the approach in the first place if you have the appropriate kit and qualifications.

Manual Flight limits you to Cat 1.

[Dmax]

Are you joking? :confused:

I know that I can't do it without training...:ugh:
I was asking for pure curiosity and it was an example...I wrote:

Example:
I'm going to an airport that is in Low visibility (CAT II or III), and I'd like to know if I can:
1) Fly the landing manually or
2) I need to use the Autoland.

I which category is the autoland compulsory? I mean, the use not the fact that it's installed on the airplane.

[FlapsOne]

Not joking......you question wasn't that clear to me, or anyone else it seems.

See my other post.

[Dmax]

Sorry for the misunderstood but being a pilot I know that I have to be trained and qualified to perform low visibility.
I've tried to keep the question easy.

So, in CAT II (and III) no manual landing supposing no failures?

Thanks
Davide

[popay]

Dmax, hi mate.
Look CAT II manual landing at any time but not lower than 80 ft above AGL
CAT IIIa and CATIIIb auto land is mandatory however fail passive for CAT IIIa CM1 can land an airplane manually provided CM1 has got sufficient visual reference at DH and the landing can be accomplished safely. CATIIIb is auto land only cause there's just not enough reference to complete the landing manually.
Roll out has got nothing to do with auto land it's simply the ability of the aircraft to track the LOC signal until full stop. That's the reason why the MID RVR can be reduced down to 75 m if auto roll out or 125 if manual. I'll give you one scenario like:
CATIIIa (TDZ RVR 200 MID 75 ) with 50 ft DH.
At 50 ft there's NO FLARE CM 1 action is either to shoot a go around or to complete the landing manually. However the AP is ought to be engaged again after landing in order to complete the roll out.
Cheers.

[FlapsOne]

popay

re: the first part of your answer, that's an Airbus thing I think that says if you plan a Cat 2 approach followed by a manual landing the AP must be disconnected by 80'.

Just to be clear for Dmax - What you cannot do is start an approach in Cat 2 wx conditions without the automatics to do LVOs becasue you cannot manually fly below Cat minima .

How you actually set about physically landing the aircraft depending on what you see or don't see at the bottom, has already been answered I think.

Any time you can see what you need to see, you can land the aircraft manually - irrespective of the approach flown. Some aircraft however (737) can leave you with a big trim problem though as soon as AP is deselceted.

[AHRS]

Succinctly explained Dmax....you are cleared to land...your options!

Whomever NEEDS further explaination, i suggest there are no shortcuts:theory and the regulations governing the topic in question should be studied and comprehended and subsequently expect to have an intelligent discussion over the topic.

Cat1 designed for manual ops,Cat2 for auto with manual back up,Cat3 strictly auto with provision for manual go-arounds.The 3 classes of cat3 require comprehension of their specific limitations.The commander of the plane monitors the approach and if necessary takes over manually.This is in a nut shell in simple english I dare say.

Each category has its restrictions and implications and they shoud be adhered to with no room for error in judgement.If it says by 50 ft if visual and you have a failure be prepared to land manually if not go around.In anycase you should commence the overshoot just prior to acquiring 50ft if not visual to arrest the inertia of sink ,otherwise you might touch down during the go around phase(especially when heavy)- if you are go around minded at 50ft.Please correct me if mistaken in this last statement.
Thank you Dmax


Dmax, hi mate.
Look CAT II manual landing at any time but not lower than 80 ft above AGL
CAT IIIa and CATIIIb auto land is mandatory however fail passive for CAT IIIa CM1 can land an airplane manually provided CM1 has got sufficient visual reference at DH and the landing can be accomplished safely. CATIIIb is auto land only cause there's just not enough reference to complete the landing manually.
Roll out has got nothing to do with auto land it's simply the ability of the aircraft to track the LOC signal until full stop. That's the reason why the MID RVR can be reduced down to 75 m if auto roll out or 125 if manual. I'll give you one scenario like:
CATIIIa (TDZ RVR 200 MID 75 ) with 50 ft DH.
At 50 ft there's NO FLARE CM 1 action is either to shoot a go around or to complete the landing manually. However the AP is ought to be engaged again after landing in order to complete the roll out.
Cheers.

[popay]

a-bas, hi there.
Not quite right though. It's got nothing to do with airbus whatsoever it's solely JAR. if you look up the minima and RVR required for CAT II there's a sheet stipulating 100-120 ft DH with RVR req, of 300 m up to cat. C and 350 for cat D (300 can be used provided auto land is conducted) That's the only exception. The reference to ‘auto-coupled to below DH’ in this table means continued use of the automatic flight control system down to a height which is not greater than 80% of the applicable DH. Thus airworthiness requirements may, through
minimum engagement height for the automatic flight control system, affect the DH to be applied.
Just to be clear 80 % of the lowest DH of 100 ft is 80 ft regardless of the aircraft. NO AUTO LAND is required for CAT II unless RVR to be reduced for cat D down to 300m. The best example is A 320 flight to Ankara with the field elevation of 3300 ft. Max auto land alt for a 320 is 2500 ft nevertheless the CAT II approach can be conducted without restrictions and MUST be continued manually below 80 % of the DH with manual landing and roll out.
Cheers.

[Dmax]

Well:

CAT II = automatic flight down to 80% of DH, then I could disconnect and go manually (provided I got the visual references).
-------------------------------------------------------------------------------------------------------
CAT IIIa = autoland but, in case of failure, I can decide whether to land manually or to go-around. Rollout not required.
-------------------------------------------------------------------------------------------------------
CAT IIIb = autoland. Rollout required.
- Fail passive is enough down to RVR 125 m and DH < 50 ft.
- Fail operational required down to RVR 75 m and DH < 50 ft or No DH.


This is what I've got from JAR-OPS1 and your advices.
Is it correct?

Davide

[wheresthecoffee]

The reference to ‘auto-coupled to below DH’ in this table means continued use of the automatic flight control system down to a height which is not greater than 80% of the applicable DH.

What the hell does that mean?

Not greater......................surely not less than!!
:confused: :confused:

[Clandestino]

Manual Flight limits you to Cat 1.
Ermmmmm... you're talking type specifics here but that's what manual/auto approach and autoland during lov vis ops is about.
For example ATR is certified for CATII manual approach. Aeroplanes with approved HGS (like some Q400, CRJs, Falcon 2000 etc.) are certified for CATIIIa manual approaches.
So answer is: it's type, certifying authority and even airline specific. Relevant requirements and procedures can be found in respective operations manual.
Look at the systems diagrams of your plane; is there a connection between rudder and the nosewheel?

If by 'rudder' you mean 'rudder pedals' or 'rudder control circuit' the answer is 'yes' on almost everything, except ATR.

[FlapsOne]

Hi Clandestino

Wasn't aware of that 'cos it's not in Jar Ops 1 Subpart E. Well I can't find it anyway.

Manual 3a sounds like a bit of sport to me!!

[Dmax]

FlapsOne,

you can find it just right in JAR-OPS1, subpart E, under the table of CAT II minimas. It's a note.

DAvide

[FlapsOne]

I found that - not convinced I understand what it's saying though. Need to read it a couple more times. Tend to agree with wtcoffee that it should be less not greater but more examination required.

The bit I was referring to that's not convered in Jar Ops is the manual Cat 3 stuff using HGS. Not a mention.

Maybe it's covered by the phrase

"....Other forms of guidance systems or displays may be certificated and approved."

[Dmax]

Maybe it's covered by the phrase

"....Other forms of guidance systems or displays may be certificated and approved."

I think too.

Davide

[Drop The Dunlops]

The Flight Dynamics (now RockwellCollins) HGS, Headup Guidance System, was initially certified in about 1977 on the 727-200 at Alaska Airlines to CAT IIIa, 50' DH and 700' rvr. That's hand flown, of course. It has since then been expanded to many airlines and airframes, even those with autoland guidance.

Holy Schmoly, I didn't realise they had been around that long!!!

I thought my Company was progressive when it had them fitted to some 737's in 1998!!!

[ICT_SLB]

Holy Schmoly, I didn't realise they had been around that long!!!
I thought my Company was progressive when it had them fitted to some 737's in 1998!!!
You're not really that far out. The original 727 cert was, in reality, a one off. After the authorities took a long hard look at everything, it was back to square one for the next cert - I know because I was part of the team that got hit by the "Proof of Concept" 100 landings to certify the CRJ to CAT IIIa.
One of the biggest things was not the actual approach but how to show TCAS advisories & to have all the data that's crept onto the PFD over the years - so-called "ALL Phases" (sorry didn't mean to shout but it looks too like the AII approach mode otherwise). The Manually-flown HUD approaches have to meet the JAA (EASA?) HUD-3XX requirements IIRC.
BTW I don't have JAR AWO with me but I understood CAT IIIa was for DH less than 100 feet but not less than 50. The real limit is the Minimum Break-off Height - 50% above the min altitude at which you just touch the wheels in a go-around - a hairy thing to fly - I was in the back & it was easy thanks to our project pilot, "Latch". You can fly manually to CAT II w/o HUD guidance in both Canada & the US (if the manufacturer has already certified it) but not JAA-land.

[wheresthecoffee]

The reference to ‘auto-coupled to below DH’ in this table (jar ops) means continued use of the automatic flight control system down to a height which is not greater than 80% of the applicable DH.

Would still really appreciate someone explaining that to me clearly.

It seems to my little brain that 'not greater' should really be 'not less'.

[GlueBall]

It has to do with autoland go-around parameters, which means that the autopilot [or the pilot executing a manual go-around] will actually "dip" below the D/H during the maneuver.