PPRuNe Forums

PPRuNe Forums (https://www.pprune.org/)
-   Tech Log (https://www.pprune.org/tech-log-15/)
-   -   A320 can you do auto-land overweight? (https://www.pprune.org/tech-log/588236-a320-can-you-do-auto-land-overweight.html)

Mooneyboy 13th Dec 2016 22:04

A320 can you do auto-land overweight?
 
I know Im not the only one confused by this so was wondering if anyone here can help? I've been looking in the Airbus FCOM and can see in the overweight QRH checklist for a A319 it mentions auto lands have been demonstrated upto 69tons and certified up to MLW. In the A320 overweight landing check it mentions nothing about weight restrictions in relation to autolands.

My question is can you do an autoland in an A320 over MLW or are you essentially a CAT 1 aircraft? I've gone through FCOM and can't find anything definitive.

Many thanks.

dream747 14th Dec 2016 00:49

Under the Limitations section (in my FCOM at least), the autoland is only allowed at or below the MLW.

Mooneyboy 14th Dec 2016 07:32

Thanks dream747.

Had a look again and yes it's there in black and white. Can't believe I missed. So it's FCOM LIM 22-20 automatic approach, landing and roll out.

Still think it would be nice for them to mention it in the overweight landing QRH. Can't understand why they mention it in the QRH for 319 but not the 320.

paradisefound 14th Dec 2016 08:00

The FCOM limitations says that it has been demonstrated at or below maximum landing weight.
Doesn't prohibit.
My company permits overweight autoland in case of an emergency requiring an immediate landing.

Mooneyboy 14th Dec 2016 08:29

Yes I agree it says demonstrated so yes in case of uncontrollable fire/smoke and no other options yes you would go for autoland.

But eng fail(land Asap Amber)/sick pax you would be looking at other cat 1 altn.

Metro man 15th Dec 2016 06:33

Autoland tends to give a "firm" arrival so wouldn't be compatible with the low V/S required on a overweight landing.

johndo 15th Dec 2016 18:29

If you take the Fcom again and select a A319 registration, you see a note saying: The flight crew can decide to perform an autoland up to 69T.
Does not say this on a 320 reg

Mooneyboy 16th Dec 2016 07:13

Yes it mentions it in the overweight landing checklist.

I've also tried putting in overweight and autoland in our landing performance module and it says 'check FCOM the possible combination Autoland+Overweight'. Interestingly it still says this when you select say 67T autoland with the A319.

Meikleour 16th Dec 2016 12:11

Since the A319 model is a lot newer than the A320/A321 models perhaps Airbus included the overweight autolanding scenario during their certification flying testing?

Golden Rivet 18th Dec 2016 03:27

when you couple an overweight landing with a potential hard landing, the airframe inspections get rather unpleasant.

Maxfli 18th Dec 2016 17:39

Do you want to use the aircraft again?
 
It's an interesting question.

Autoland will not and is not designed to to flare and govern a RoD at touchdown of 360' pm, from the QRH.

In the final approach stages:

TARGET SPEED VLS
Reduce the selected speed on the FCU to reach VLS at runway threshold.
Touch down as smoothly as possible (Maximum V/S at touchdown 360 ft/min).

However you might get consider using Autoland in certain circumstances such as pilot incapacitation.

vilas 19th Dec 2016 05:45

If Airbus has not demonstrated then line pilot shouldn't become a test pilot. Rather than doing something non standard by an opinion poll on PP why not your company seeks clarification from the manufacturer?

downunder35 22nd Dec 2016 06:49

What would you consider a normal "good" every day acceptable V/S in ft/min touchdown compared with a Autoland V/S in ft/min in the A320. I imagine the autoland by design is not for comfort but to get the aircraft to be firmly connected with the runway with doing no damage to the aircraft.

roulishollandais 23rd Dec 2016 00:46

@vilas
"why not your company seeks clarification from the manufacturer?"
:}They don't want to do some request they didn't discovered themselves!
I had such a very bad experience after I discovered a wrong N2 (MD83) in our FCOM, to use in case of UAS : missing 13% , Landing configuration, MLW, 3000ft... After two months of correction procedure question, using the appropriate form, without feedback from my company, our engineer sent a fax from his own, and quickly the manufacturer answered with thanks and congratulations. It was a storm for me, accused (!) to contact the manufacturer myself...:mad: At that time more than 60 airlines "used" the wrong figure since 13 years. Happily no plane had such an UAS!
The company is afraid too to explain to the DGAC why they didn't see the mistake :E

vilas 23rd Dec 2016 02:20

That may be an exception but I have personally got many clarifications from them and as a customer they cannot deny their advice. On the present topic what a pilot can do in emergency? Well! virtually anything that he thinks will save his life.

StrIA 24th Dec 2016 09:50

QRH 80.07A

macdo 31st Dec 2016 10:24

I recently asked a senior trainer about this, in the scenario of having very low fuel. I was told that the autoland over mlw was the way to go if the weather was marginal. At the end of the day, a slightly bent aeroplane is better than a hole in the ground.
Slightly unrelated, but I also had a demo of autoland at max demonstrated (manual) cross wind limits in the sim. Worked well.

sonicbum 31st Dec 2016 15:39

Hi macdo,

Can't really see how you would end up above MLW with very low fuel on an A320. You would only attempt an auto land above MLW if you have weather below CAT II and a very time limiting situation (aka undetermined fire, smoke). Typical example could be takeoff close to MRTOW in LVTO and you're lucky enough on that day to have heavy smoke shortly after takeoff.

KayPam 31st Dec 2016 22:41

Well yes, it would be very odd being low fuel and still above MLW.
Except if you were planning on ditching some passengers before landing.

macdo 1st Jan 2017 01:03

The serious fuel leak immediately after t/o (punctured tank from tyre burst and losing fuel rapidly) was the scenario discussed. Admittedly a freak occurrence but it lead to the thought of doing an autoland if the weather at the departure airfield was marginal and the a/c was still above mlw. I should think serious smoke on the flight deck would be another good reason.
The point was really that the a/c was capable of doing more than just what the FCOM indicates in an extreme situation.

macdo 2nd Jan 2017 13:19

Just some additional info. I was just reading some official Airbus Instructor notes and it has the statement " Autoland has been demonstrated up to MTOW".

No Fly Zone 6th Jan 2017 09:12

Until there is weight on wheels/squat switch compressed, HOW does airplane KNOW that it is landing above MLW? As far as I know, only the attentive pilot knows this; the airplane does not unless you tell it so. And, once there is weight on wheels, you're down anyway - all that matters is stopping w/o burning up the brakes. Am I missing something?

Mooneyboy 12th Apr 2018 19:12

Hello all,

Since I started this thread there has been a relatively big overhaul in the FCOM.

I'm basically asking the same question. Where does it say in the FCOM what the MLW for a A320 autoland?

I've checked FCOM LIM and there is now no mention. The QRH overweight checklist for both 319 and 320 now mention nothing about autoland overweight. In the FCTM PR-AEP-MISC overweight landing for the 319 it mentions autoland certified to MLW demonstrated to MTOW. For the 320 again autoland isn't mentioned.

Anyone any ideas?

Many thanks,

Mooneyboy

Roj approved 12th Apr 2018 21:22

If I recall it correctly, there was an improvement in Yaw damper and rudder travel limiters on the later aircraft that then allowed auto land OEI up to MTOW, I believe they have retro fitted it to some of the earlier ones too

Mooneyboy 13th Apr 2018 21:25

Hopefully that's the case for the 319 and 320 as it would certainly be handy to have the option to autoland up to MTOW. As I read it that's the case for the 319 but no written mention in FCOM for the 320.

Escape Path 14th Apr 2018 19:11

My A319 FCOM says this:


Originally Posted by LIM-AFS-20
Depending on the situation (e.g. emergency or other) and provided that the runway is approved for automatic landing, the flight crew can decide to perform an autoland up to 69 t (152 118 lb).

No such note on the A320's.

Mooneyboy 14th Apr 2018 21:01

I'm sure before the FCOM overhaul FCTM mentioned autoland 320 upto MLW but I find there is now no mention.

I would have thought if that previous restriction was lifted for the 320 then in my company at least a NTC would have been generated.

Lantirn 1st May 2018 12:39

I saw some time ago that it is missing from the LIM and asked the technical pilot about it. After he got a clarification from Airbus he told me that since airbus has made a lot of changes to make all manuals from all types to be common, they forgot to mention.

Funny but true. Expect in the next revision to be back there

Mooneyboy 1st May 2018 16:08

Thanks.

I've also asked within my company and at the moment too treat as before the update so no autoland above MLW. Hopefully they'll put some mention back in again.

Bergerie1 2nd May 2018 08:14

The first thing to be said is that rules are there for the guidance of wise men and the obedience of fools - to some extent the same applies to SOPs and aircraft limitations. Most limitations which appear in the Flight Manual are 'set back' a little from what has been demonstrated during the test flying (cross wind limits for example) and most structural limits have fairly substantial margins. Thus, under extreme conditions, it is usually safe to exceed them. But NOT in normal operations and some - not at all. This is where you need to know your aircraft.

For example, at max altitude in coffin corner. In totally calm conditions it is possible to fly exactly at the point where the high speed buffet meets the low speed buffet (I have done it on a test flight). BUT you need to know the stall characteristics of your aircraft and its controllability at high Mach numbers. I would NEVER recommend doing this on the line.

However, if you have an emergency and it is necessary to land above the cross wind limit, it is possible provided you consider the effects of the failure that has caused the emergency and the effect it might have on the controllability of your aicraft. Equally, if it is absolutely necessary to land overweight and the only option is an autoland, then do it. This is what airmanship and command is all about. As a previous poster has written it is better to have a slightly bent aircraft than a hole in the ground.

My second point, any company that objects to pilots seeking more information about their aircraft, either from the manufacturer or the relevant CAA, needs its collective head examined. The need for accuracy and truth is paramount.

vilas 2nd May 2018 13:52

Airbus safety first magazine issue12 July 2011 had an article Automatic landings in Daily Operations.
The relevant portion for our topic was as below:
2. Operational Advantages of Autoland Low Visibility Operations (LVO) is the most commonly used (and known) reason for the performance of an automatic landing. But there are many other situations where the use of Autoland provides operational advantages, and where the decision to perform an Autoland is a smart flight crew decision. Although Autoland is commonly associated with bad-weather (Low Visibility Operations – LVO), there is a wider range of benefits applicable to the performance of automatic landings, even in good weather. This article will illustrate cases where Autoland provides such safety advantages, and will indicate the prerequisites required to ensure that the procedure is safely conducted.
Here are some examples of the cases for which an Autoland can prove beneficial: q Flight crew fatigue (e.g. an early-morning landing after a long and tiring night flight). q Unfavorable operational conditions (e.g. Overweight landings. Autoland has been demonstrated with weights much above “Max Landing Weight”, as specified in the FCOM). q Poor visual conditions (e.g. even if the reported weather conditions are VMC, a landing that faces a low-rising or a setting sun, aligned on the runway axis, can seriously affect and reduce the flight crew’s vision). q Crew Incapacitation (e.g. the unaffected pilot could decide to exercise their emergency authority and use the Autoland function in order to benefit from the potential assistance and relief).

Down Three Greens 2nd May 2018 14:51

Airbus’ Stance
 
As mentioned there is a distinct difference in limitations across the Airbus types. In particular between the narrow body and wide body fleets.

To summarise

Airbus is not in a position to recommend autoland on A320 or A321 in Overweight.


In order to understand the Airbus position regarding the difference between A320, A321 and other types such as the A330.

The A330 Overweight Landing procedure in FCOM PRO-ABN-80 starts with the following information:

"Automatic landing is certified up to the Maximum Landing Weight (MLW). Autoland flight tests have, however, been successful up to 229 t (504 853 lb). Depending on the situation (e.g. emergency or other) and provided that the runway is approved for automatic landing, the flight crew can decide to perform an autoland up to 229 t (504 853 lb)."

The A320 and A321 Overweight Landing procedure does not provide similar information because no flight tests were performed to support this information.

The purpose of this information is to ease decision making in case of overweight landing. In general, autoland is beneficial in order to reduce the flight crew workload.

Starting with A319 certification, Airbus took the opportunity of autoland certification campaign to fly some additional autoland up to the MTOW.

However, the reduced quantity of tests does not enable Airbus to publish certified data. Without these flight tests, Airbus is not in a position to recommend autoland on A320 in overweight.

The use of autoland will be a decision of the flight crew, depending on the weather conditions, of an emergency situation, and of the flight crew workload.

Hope that helps explain the FCOM wording.


All times are GMT. The time now is 17:53.


Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.