Can we perform autoland with ils cat1 signal?
 

I'd ever heard that cat1 ils signal wasn't approved for autoland.

But in some authorities approved the runway with only ils cat1 for autoland

according to

1 no offset locallizer

2 glide path not steeper than 3.0 degree

3 have at least ils cat1 signal

4 runway slope not more than ....%

5 terrain 300 m before threshold is different from threshold elev not more

than ....ft somethings like that

etc.

so can we perform autoland with ils cat1 signal.

if we can't

how can we practice for currency simulated autoland in cat2/3 and for

aircraft airworthiness for autoland every 30 days eg.

would you please give me and answer?

What is this, 'CAT' 1/2/3 stand for?

An 'Autoland' is not the same thing as a Cat 2/3 approach. The aircrfat doesn't care whether visibility is good or bad, or whether the ILS is a CAT 1 or a CAT 3 installation, if you tell it to do an autoland, it will try and do one to the best of it's ability. It's ability to do so is affected by the exmaples of criteria you mention: G/S angle, no offset LLZ etc.

CAT 2/3 approaches don't use a 'special' kind of ILS system - it's the same bit of kit, just supplemented with runway lighting, back-up power, monitoring, an accurately surveyed approach, ATC LV Ops etc etc.

So as long as the technical requirements for a safe autoland are in place (and you mention a few of them) as defined by your regulator/company, you don't need a 'CAT 2/3' ILS to do one - if you are conducting the approach to CAT 1 minima (as you should be), there ought to be no problem letting the aircraft fly to touchdown, since you will have the necessary visual references to disconnect the autopilot and take control if you don't like what you see (just like when the FO's flying ;)).

Be sure to apply any other relevant procedures, such as performance corrections to LDR or GA WAT limit, which may be associated with autolands, though.

If in doubt, ask a company training captain.

In theory a good autopilot system will fly an autoland on a Cat 1 ILS. However, in practice beware of the quality of the beam – all UK Cat 1s were suitable, but I cannot vouch for any others – ask the flight checking department. Cat 1 ILS are unprotected from external disturbances and do not have failure backup systems. Thus training on ILSs within the constraints you that quote should be OK, but one of the biggest problems is the terrain profile in the undershoot, if this is not suitable, then the rad alt input it can give some very interesting arrivals which detract from the confidence in the system.
I doubt that ground roll-out will work satisfactorily.

With the Lockheed L1011, the only constraints are the following, besides those already listed...

There must be no limitations on the use of the glidepath below a certain height (which is normally printed on the approach chart), if there is, and...

The threshold crossing height must not be lower than 42 feet with the standard body model.

IF the TCH is lower than 42 feet, and an automatic approach/landing is attempted, the MLG to approach light clearance can be severy compromised.

Frangible approach light bits are just that, but you surely don't want to find out, the hard way.:uhoh:

NB.
The rollout function works just fine, in my experience, with the L10.

After all, the L1011 was designed from a clean sheet, with CATIII in mind, with no compromises.
None whatsoever.

A fine aeroplane!

:ugh:


yawn......

Yes you can !

Once the weather minima get worst (below CAT I min.) then it become illegal ! Right ??

Most of it's been said but remember that if you are intending an autoland on a Cat I ILS (or even Cat 2/3 when LVP are NOT in force) that objects such as aircraft and vehicles etc may well be manoeuvring and affecting the integrity of the ILS which may cause an autopilot disconnect at an embarassing time!

I recall doing a practice autoland years ago on the B737-300 on a Cat 3 ILS when LVPs were NOT in force when the autopilot disconnected after the nose up trim had been applied by the automatics at 400 ft and having to do some pretty rapid retrimming and correction of the approach to ensure a safe landing. The oscillation on the localiser had been caused by an aircraft that had departed and overflown the localiser transmitter when we were on short final.

In summmary, by all means autoland off a non-protected ILS but exercise caution!

As previously stated the autoland works with any ILS no matter what category. Interference from taxiing aircraft, etc is not protected. One day landing with smoke in cockpit on a B757 I coupled up as an autoland on a Cat 1 just as insurance in case the situation deteriorated during the approach so the plane would land and stop itself. Once we knew it wasn't needed we shut it off. Why not use every tool available in case TTTS.

Hello all,

Teung, Of course the airplane can do it !

The danger comes from the ground : LVPs (Low Visibility Procedures) HAVE to be in effect in order to free the ILS signal from any parasites that may deviate it : for example, the Runway Hold short positions are different when LVPs are in progress (further away from the runway, you've seen those cat II/III stop signs right ?) so that waiting aircrafts don't interfere with your signal in the last 100 feet.

so in case of emergency, if you want to do an autoland make sure the tower knows about it ! (there might be a whole lotta fire trucks and ambulances waiting for you there, well intentionned but DISRUPTING YOUR ILS SIGNAL ! !)

cheers

You can but As long as CAT1 IS NOT display on your FMA.
If CAT1 is display on the FMA you are not allowed to do an autoland. (well at least for airbus).

toung, it all comes down to what aircraft your are flying!
Check your AFM and you might find things such as "AP coupled landing compliance has been demonstrated with CAT II and CAT III performance quality beams only" or similar. It means the manufacturer places a restriction on the ILS beam quality to perform an autoland, disregarding the actual met conditions.
On top, any simulated (actually only the CAT II or III is simulated...) autoland performed ouside LOVIS procedures takes place on unprotected ILS signals and might be subject to disturbance(s).

Hope this helps :cool:

The ILS system is a method of "feeling" your way to the runway - this was shortened to "feline" by the US pilots, and hence "CAT".

But to be honest it is short for CATegory

Unless further restricted by your company documents (FOM/AOM, FHB/AFM), the 747 series (200/300/400 at least) are certified to autoland when coupled to any approved/certified ILS. It makes sense to alert Approach and/or Tower that you will autoland, so they can protect the ILS intrusion zones on the taxiways. If you don't, you may get undesirable excursions.

Generally 2 or 3 functioning and connected autopilots are required for a full autoland, just as they are required for Cat 2 and Cat 3 approaches.

So, to practice a Cat 2 or Cat 3 approach/landing, you can do it in any weather, as long as you meet the requirements and notify Approach/Tower.

Thanks veryyyyyyyyy much for every comments.

I've got many ideas from all of you and my eyes were opened.(cavok:} )

Thanks again.

Boeing 717 autolands quite nicely with CAT 1 (which is all we have in Australia). Right on the money and nicer touchdown than many 717 pilots can manage.

Just make sure the ILS critical area (as we call it here) is protected.

Is this from the A320 Series FCOM any use to you?
''AUTOMATIC LANDING IN CAT I OR BETTER WEATHER CONDITIONS
The automatic landing system's performance has been demonstrated on runways equipped with CAT II or CAT III ILS/MLS approaches. However, automatic landing in CAT I or better weather conditions is possible on CAT I ground installations, or when ILS sensitive areas are not protected, if the following precautions are taken :
The airline has checked that the ILS/MLS beam quality and the effect of terrain profile before the runway have no adverse effect on AP/FD guidance. In particular, the effect of terrain discontinuities within 300 meters before runway threshold must be evaluated.
The crew is aware that LOC or GS beam fluctuations, independent of the aircraft systems, may occur and the PF is prepared to immediately disconnect the AP and take appropriate action, should unsatisfactory guidance occur.
At least CAT2 capability is displayed on the FMA and CAT II/III procedures are used.
Visual references are obtained at an altitude appropriate to the performed CAT I approach, otherwise go–around is initiated.
When the crew does not intend to perform an autoland, they should disconnect the AP at or above 80 feet : this altitude being the minimum to take over and feel comfortable.
Nevertheless, for safety purposes, the AP may be disconnected at anytime.''
Cheers all,
mcdhu

In the UK, if you tell the TWR that you will be doing a practice autoland you are likely to simply be told that the ILS Sensitive Area is not protected. It is usually just not possible or practical to provide the protection that is required to support an actual CATII/III approach for a single aircraft in good wx.

In that case, be alert for excursions, and go manual if something unusual happens. Not a big deal in VMC!

Not that l am condoning the use of autoland off a CAT 1 ILS, however if you are on the 777 most LLZ interferances are "ironed out" by the autopilot using the GPS signal as a back up.

As such it will do a good job in almost all situations. Probably even better than the geriatric L1011. :}

halas

having read all the previous comments, here comes the question of a non-professional: what is the senes of doing an autoland under catI conditions? do u guys don´t like doing it yourself?

You will have a requirement to do a certain number of them, between each sim check, as part of maintaining your personal All Weather Operation qualification.

Now, if the weather isn't crap enough often enough, you may well have to do a few 'practice' autolands in good weather.

pb

Also, the FAA requires the airplane to actually perform an autoland periodically (every 15 days in our case) to maintain Cat 2/3 certification.

And sometimes it's simply for the fun of it!

Reasons?
- demonstrate the reliability to the authorities
- check the system
- train LOVIS approach procedures
- used when tired :hmm:
- makes marvellous landings at lower flaps setting :\

A couple of questions if you don't mind.
When is that the FMA displays "CAT 1" ? Is that pre-programmed in the MDCU/FMS ? Is autolanding still selectable in "CAT 1" on the Airbus even if it shouldn't ? Does the FMA it ever display "CAT 2" ?
Last one, after landing, is the APPR mode and related light supposed to disarm automatically ?

Why do automatic approach/lands (autolands) in CAT I (or better) conditions?

Oh dear, quite simple really, with regard to the aeroplane that positively does 'em best...the good 'ole Lockheed TriStar.

Simply put, to watch PFM* at work.

NB.
*PFM....pure friggin' magic.:D :D

Only when aircraft systems are degraded. Under normal circumstances it always displays CATIII dual (fail-operational autoland and roll-out). With engine out, the capability is still CATIII. Typicial reason to degrade would be unavailability of back-up systems such as loss of one ILS receiver.
Technically no, because there is no such selector. Keeping AP on below 150 (?) feet with CAT I memo is outside limitations for AP use.
Yes, but again only as a result of failed onboard equipment. For instance both autothrust channels, one radio altimeter or one Flight Mode Announciator display itself.
No, it remains on to provide automatic rollout.
Cheers,
FD (the un-real)

hi there, interesting subject. Well despite the fact that auto land doesn't have anything to do with weather it very much depends on the quality of the ILS signals and accuracy. A little background information of two ILS facilities ILS CAT I does have two waves 150 and 90 Hz both on LOC and GS whereas CAT II-III ILS has got additionally a carrier wave which enhances the accuracy significantly. Here are the parameter of both ILS certifications
CAT I max deviation LOC +/- 10m TDZ; GS +/-3m TDZ
CAT II/III max deviation LOC +/- 5m TDZ, MID, ROLL OUT, GS +/- 1,2m TDZ
As one can see there's quite significant difference in accuracy and area of application ergo the recommendation. Theoretically one shouldn't ever experience a LOC shift on CAT III ILS ground facility.
Auto land is not CAT 3. An automatic landing system is only an equipment providing automatic control of the aircraft during the approach and landing and is not related to particular weather conditions. This system is mandatory for all CAT 3 operations. However, it is a common practice to perform automatic landing in good visibility but in that case, the ILS performance must be sufficient and ILS signals protected.

Therefore some operators may restrict autoland operations to CAT III equipped runways only where the signal geometry is guaranteed. What is the difference between CATI and CAT III on such a runway? Basically, the area on ground is not protected as much as CATIII operations require and back up electricity system may not be available in no-break mode (for CAT III the backup generator must be up and running and on-line). Other operators leave this to commanders responsibility.

Some aerodromes (speaking CDG) even have procedure for practice autolands in cat I conditions when ATC would clear the ground area and increase separation in order not to block the singnal during landing (e.g. by departing aircraft temporarily shielding the LOC antenna).


FD
(the un-real)

I love this discussion
 

Just a few quick points before I hit the sack, somewhat tired on a fatal overrun investigation at the moment...

1. The beam needs to be good enough. There is no way that you have sufficient information in the cockpit to determine this. There is no legal requirement to publish the information about the "straightness" of the beams for a CAT I ILS.

2. Some very large airports to not protect the ILS GP anything like enough in visual conditions. If a 744 taxies in front of the GP, then in certain conditions, it can deflect the beam to 1 degree, which would make your approach fun. Hence some of the reasons for LVPs at airports.

3. The wrong holding points will be in use, hence potential interference.

4. Some idiot at the airport will have decided not to protect the instrument runway strip and have work going on there as the runway landings are visual. Australia especially bad at this. If you fall off, you could be in trouble.

5. Beam deflection from the aircraft ahead on approach (had a GP drop out with this, but very unusual) but LOC can go all over the place, as well as the deviation swing of LOC from the overflight.

6. The terrain may upset your radalt based calls. Hence, if you look in the UK Integrated AIP, you will find a special note about Manchester and CAT II operations onto Runway 06L, as an example. (too late for me to remember if it is an AIC or an AIS) but applies to C/D categories of approach speed but not A/B

7. The terrain may upset the automatics, it can be fun to watch them on autoland trials with downhill runways, having had an uphill approach, float, float, float ooops spool up go-around.

8. Do you have a safety management system agreement with the airport operator and air navigation service provider at this point for your own legal protection. (Not at the last 50 airports I check audited, you don't.) So, if you kill someone when you fall off, expect to go to jail for manslaughter.

9. how long to you need to be stable for, ATC vectoring may well be too tight for the system to cope with. You guys are always calling "established" when you aren't locked on, tracking and happy. Just because something changes colour in the cockpit, does not mean that you are, it might mean that the machine is now in the mode where it is trying to!

10. power supply requirements are quite different and can lead to transient changes in the signal generated, as well as the lights going out!

11. Some ILS LOC signals allow for roll out guidance, but can be very wonky in the 100 foot area, expect a disconnect at any point. When was the last time that you practiced an autopilot disconnect in autoland configuration below DA? Try it at 70 feet in an aircraft with underslung engines and all that nice trim in. Yep, the 737-200 would be fun. Can you get a landing out of it, or are you going to go around at this point? Answers to your Head of Flight Training on a postcard please (OK, some airlines do it, but a few that I know do not!)

So, if you want to do it and not end up in jail, or without a job, then make sure that your planning department has done their work on the Airport PATC (if they even publish it, which they do not for CAT I facilities...) in AIP GEN AD2, they have seen the flight check (which will not go down that far if they have only been paid for a CAT I flight check, in some countries) and it is acceptable, if your insurance company approves it (if your flight operations department even thinks of that one), that the airport has been audit by your men under JAR OPS 1.220 and that the full infrastructure is available (does any airline actually did the full audit anymore, other than counting the fire engines, although I have done a few for a couple of nameless airlines), that ATC and the airport operator have integrated their safety management systems (if they are different organisations) and that your SMS is integrated with theirs (plus operational procedures etc) and so on. Once you have done all of that, and got permission from the airport and ATC insurance companies blah blah, then please, go ahead.

Actually, lots of airports in the US have this ability, but they have the FAA to think about it and approve it. Same in UK. Netherlands publishes some non-standard information about their ILS beams so residents can do it.

If you have any doubts about any element of the list above, which is not complete, and you do not have a specific company instruction listing the runways you may use and any other operational considerations, then I would suggest that you might like to land manually, for your own legal protection.