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View Full Version : Autoland allowed on ILS CAT II RWY?


geohei
22nd Jan 2012, 09:42
Hi.

There are airports which allow only CAT I or II approaches (for whatever reason). No ILS CAT III approach allowed. An example might be LPPR RWY 17 107 FT RA for ILS CAT II.

While shooting an actual CAT II approach under LVO conditions, is it allowed to autoland on these RWYs, assuming of course that Crew is CAT III qualified and aircraft is CAT III equipped and the landing criteria fulfilled (approach lights/RWY in sight).

I believe that if the airport is CAT II only, that there is a good reason, like e.g. reflections of localizer below minimum.

Regards,

seat 0A
22nd Jan 2012, 09:51
Yes, the vast majority of aircraft will only make auto lands under actual CAT 2 conditions.

wiggy
22nd Jan 2012, 11:44
In many airlines you can Autoland on a runway with only CAT 2 or even CAT 1 limits - provided you have approval from your operator, the weather is above the appropriate minima, you have the appropriate visual references in sight at those minima, and you are aware of, and ready for the possibility of interference with the LOC/GS if Low Vis Procedures are not in use.

geohei
23rd Jan 2012, 20:26
@seat 0A

Yes, but that's not my point. I'd like to know if it is technically speaking allowed to let the airplane autoland below CAT II minima under LVO conditions, keeping in mind potential localizer deflections since RWY is only CAT down to #100 FT, and not to 0 FT (as for CAT III).

@wiggy

Are you talking about a simulated CAT II/I approach?
I was referring to a real LVO situation.-

Thanks,

Longhitter
24th Jan 2012, 08:22
The ability to autoland and the ILS Category are two separate issues.

An aircraft can be certified to autoland (within the certified wind and glideslope angle limits) after an auto-coupled ILS approach, regardless of the standard (CAT I, II or III) the ILS ground equipment is certified to. If a certain ILS system cannot be used for autolands it must be specifically stated in the approach plate for the runway involved.

An aircraft operator's manual and/or operations manual will state down to which visibility and to which DH autolands may be executed from a CAT I, II or III ILS.

Mind you: an ILS can be certified to CAT III standard at all times, only if all other requirements for CAT III operations are satisfied (safeguarding of the ILS critical area etc.) can CAT III ILS approaches to the associated minima actually be carried out.

To answer you initial question: there is no requirement to be CAT III qualified (aircraft, crew and ground equipment) in order to execute an autoland from a CAT I or II approach.

excrab
24th Jan 2012, 09:38
geohei,

I can only refer this to the boeing 737 under UK CAA rules at the two uk operators I have flown them for. For approaches below cat 1 minimums (normally 200ft decision/550 metres RVR) we have to make an auto land, we are not allowed to fly a cat 2 approach to a manual landing.

However, this does not allow a landing below cat 2 minimums in LVOs on a cat 2 runway. at cat 2 decision height we must have sufficient visual reference to land, this means that the approach can be monitored visually to ensure the aircraft is properly positioned in the touch down zone. Don't confuse the autopilot being engaged below decision height with landing below minimums, the first is fairly standard even for a cat 1 approach in very marginal conditions, the second is illegal, foolish and dangerous.

There may be other technical limitations for different aircraft and airworthiness authorities, I believe that the FAA allow manual cat 2 landings for the 737, for example.

Although as longhitter states there is no need to be cat 3 qualified the crew would have to be cat 2 qualified. I suspect that most operators of cat 3 capable aircraft will have low vis ops approval that covers cat 3 and cat 2 also. Some aircraft types can only operate to cat 2, in which case that operators LVO approval will only cover cat 2, not cat 3.

Also, a few cat 1 airfields may specify that autolands cannot be carried out, but that will be stated somewhere in the airfield briefing charts, I can only recall seeing that once and can't remember where it was.

Denti
24th Jan 2012, 13:29
There may be other technical limitations for different aircraft and airworthiness authorities, I believe that the FAA allow manual cat 2 landings for the 737, for example.

The rest of europe does allow that as well. However in my outfit using autoland is strongly recommended and we do not train specifically for manual CAT IIs, although they are allowed.

Tinribs
26th Jan 2012, 15:29
I spent fifteen years flying the 737 and fkr 70/100

The rules for each aircraft are set by the operating authority and the airline

Some aircraft are cleared by the manufactuer for approaches which the operator, airline, does not wish to train for and so those approaches are not allowed

In general the 737 may be allowed, when operated by a uk airline, to manual land in Cat 1 conditions 550mtrs 200ft and must autoland, cat 1 or 2 below this. Manual landing off cat 2 approaches are not allowed

In all cases operating cat 2 or 3 the aircraft must be serviceable for that procedure the airfield must also be certified and serviceable and the crew must be op to date with training

BA suffered a nasty autoland event, they talked a captain into making an auto approach at Heathrow when the fo was out of training. The result was unfortunate and the captain finished up in front of a court. He later killed himself

The fokker 70/100 may autoland off cat 2 or 3 approaches