Ryanair in 2014

[Flanker2]

Once again you demonstrate zero operational knowledge, flanker!
A p.brake gets its hydraulic brake pressure from an accumulator, and as such brake pressure decays as time goes by, so whereas a p.brake easily holds a plane during a static engine run if it was applied shortly before, it can't be relied upon to even hold a plane static without its engines running after a while, as was demonstrated here once again...
For the rest: I suggest you forward your technical insight to the manufacturers as they clearly don't understand the (ir)relevance of the operational limitations of their own planes. ROTFL.

It's not only Boeing that doesn't know how to design and/or manufacture aircraft: Bombardier also has stupid engineers. But luckily, someone is there to advise them how it must be done:
viewtopic.php?f=14&t=53413

Nice try trying to work on my credibility in a ridiculous attempt to deviate from the big problematic we have exposed here. (Believe it or not, thousands of professionals in the airline industry are asking themselves the same questions regarding the PW GTF, whether you like it or not.)

Let's stick to the topic, the problem is as follows:
We were discussing how a commercial airline pilot proudly waving his employer's flag explains an accident at another airline with extremely flawed knowledge over one of the most basic aircraft systems.

It makes me wonder whether he really is a commercial pilot and if he is, what lead him to base his conclusions on information proven wrong mixed with wild speculation, without having a lick of information about the circumstances of the accident in question, and to add insult to injury, while questioning my correct understanding of this very basic aircraft system.

We don't have enough information to judge about what happened at FR.
But we do have enough information to raise our eyebrows towards this pilot's statements.

At FR apparently even the FA seems to know operating capabilities of the aircraft that pilots at other airlines don't know..and it's not like FA's have training or opportunity to access such information.
I think that we can applaude Sean and indirectly FR, for his/her ability to engage into a technical discussion about aircraft operations that is way beyond what one would expect from an FA.
And I surely am disappointed but not surprised about Tolipanebas, as in his function this is very basic knowledge about something he uses every day (or at least according to his claims). Instead, all we get to read is stuff that anyone can look up on Google. Very disappointed.

[Passenger]

Nice try trying to work on my credibility in a ridiculous attempt to deviate from the big problematic we have exposed here. (Believe it or not, thousands of professionals in the airline industry are asking themselves the same questions regarding the PW GTF, whether you like it or not.)

I didn't say that Bombardier doesn't has a problem with their new engine. I only said that you are not the person to solve them, like you pretend to do in that other forum.

"Your credibility". Let’s remain serious, shall we? Except for the newly luchtzak members, we all know that your information source is internet, and not own practice and/or experience. Agree, you are extremely good in finding stuff on the net. But sometimes, you fail. And when you fail, it is done is such terrible way that your “credibility” is gone with just that one post. May I remind you how you described your visit from Kinshasa airport to downtown as “a drive, just two blocks away”? This is what happened: you asked Google Maps for “Kinshasa airport”, and Google showed that the airport was indeed next to main street. However, it was N’Dolo, not N'djili International. And you then want us to believe that you have been in Kinshasa? Com'on please. Same happens with all your maximum range theories: aircraft manufacturers always give a theoretical max range, and you use that for range calculations. tolipanebas keeps on telling you that it ain’t that in real life (example: aircraft manufacturers don't count fuel for on hold's or deviations), but you insist.

Now, back on topic: fact is that an aircraft not on chocks goes wild. Contrary to what you say, the insurance company of the ground handlers will refuse, unless ground staff would have removed the blocks after the crew left (quid non). So only two possibilities seems to be left: technical failure or crew error. One of these possibilities has been eliminated by professionals ("the failure was predictable"), which narrows the cause to just one. Allow me to copy/paste from another forum: “So the Ryanair crew didn't think to put chocks in themselves. Or don't they carry a set with them?”.

My guess: one Irish manager had calculated how much fuel is saved annually, without this overweight. An expensive miscalculation, isn’t it?

(edited -> typo error)

[tolipanebas]

Again, flanker, you demonstrate you simply do not understand what you find online: whether it is a simple payload range chart or a technical description and limitation of a hydraulic brake accu, you really do have problems understanding the correct meaning of operational information and guidance, do you?

Airbus -or in fact any other manufacturer- does NOT guarantee a plane will remain stationary on p.brake alone for 8 or 12 hours like you seem to have understood from the FCOM, they simply say there will be residual brake pressure measurable within that timeframe on a fully functional accumulator system and that as such the p.brake may be considered to be correctly set.

Now, read the above again a few times and note the subtle yet very important difference, boy!

Whether or not a p.brake is in itself sufficient to hold an aircraft from moving due to external factors like wind gusts, apron slope or an accidental push is obviously depending on all of those external conditions as well as the residual pressure in the accu itself, hence the manufacturers aren't saying the p.brake alone is a sufficient tool to secure a parked plane from moving at all, contrary to what you want people to wrongly believe here.

As was demonstrated ample times in the past already and once again only very recently in Rome in the case being discussed here, manufacturers have a very good reason to be extremely careful in how they phrase the exact capability of this particular system, but all of this is obviously too much of a textual subtlety which went completely unnoticed to you, just as they always do when you let your light shine on a certain issue.

As I have told you before, the manufacturer's SOPs require a plane to be chocked when left unattended, period. The technical reason is in the subtlety explained above. Normally your handler will take care of this, but in the absence of such (say a strike or a diversion) most airlines I know of have their own chocks at hands, either in their offices, or in the plane's holds. Let me guess: at Ryanair, they don't because it constitutes additional operating costs, right?

[RTM]

Don't be smuck...
I know you think you know it all... Like a true master of all knowledge... But we all know you don't.

Why don't you just say which one it is?

This one:

You don't deplete your accumulators overnight in normal operations with minimal leaks on the valve and sufficient pressure is applied to it, unless you start toying with the brakes. That's the same on Airbus, Boeing and Avro RJ.

Have to admit I was wrong though... It's not 6 minutes, but a good 17% more than that... 7 minutes. All according the AMM... Did google tell you that? Does that mean the pressure is down to 0 psi...? No, I never said that. But if the pressure drops to the low press indication level in 7 minutes, the remaining pressure is sure not going to last the rest of the day.

[sn26567]

Ryanair seeks answers in 737 ground collision

Ireland-based low-cost carrier Ryanair is seeking an explanation from an Italian ground handling company as to why one of its aircraft was left without chocks at Rome Ciampino Airport and rolled into a building, damaging its port stabilizer.

The Boeing 737-800, EI-DLI, was standing empty when the incident occurred last Wednesday—a day that ground handlers at Ciampino staged a strike. Ryanair said Monday that one of their aircraft had been left unchocked. It rolled backwards until it hit a small apron building used by the airport fire service.

A picture of the aircraft taken after the accident had occurred showed extensive damage to the starboard stabilizer. A Ryanair spokesman said the damaged components had been replaced and the aircraft was expected to fly again “in the next couple of days.”

Source: ATW online

[Flanker2]

Don't be smuck...
I know you think you know it all... Like a true master of all knowledge... But we all know you don't.

Why don't you just say which one it is?

This one:

You don't deplete your accumulators overnight in normal operations with minimal leaks on the valve and sufficient pressure is applied to it, unless you start toying with the brakes. That's the same on Airbus, Boeing and Avro RJ.

Have to admit I was wrong though... It's not 6 minutes, but a good 17% more than that... 7 minutes. All according the AMM... Did google tell you that? Does that mean the pressure is down to 0 psi...? No, I never said that. But if the pressure drops to the low press indication level in 7 minutes, the remaining pressure is sure not going to last the rest of the day.

The procedure you're describing seems irrelevant to me as the BRK ACC LO PRESS comes on when the accumulator's pressure decreases under a certain reading (2500 psi according to Google Aircraft Manuals ). That annunciator is designed to warn about the pressure available inside the accumulators, not the actual pressure on the brakes.

The relevant hydraulic pressure that tells you whether brakes are effective is the pressure between the pedals and the actual brakes, that's the one indicated in the cockpit. As long as the internal leaks beyond the pedals are minimal, even if the accumulator is for instance empty, the brakes will continue to work as they are already applied. Remember that the parking brake is effectively a single long application of the brakes without release.

Remember that the accumulator pressure is a measure of how many brake applications you have, not how long they stay effective at each application.

The 7 minute test of the accumulators is probably meant to check for small external or large internal leaks of the brakes and/or the relief valve, as I suspect that such leaks would probably manifest themselves as a larger, faster drop in accumulator pressure. If there is a leak, things can go fast and in less than 7 minutes indeed, the accumulator can be emtpy and the aircraft rolling towards a Ciampino hangar.

IMO, as the accumulator loses its charge faster than the brakes themselves, when you charge the accumulators when the brake pressure is low, the brake pressure doesn't start rising immediately as the accumulator has to catch up. I'm sure you have noticed this.
IMO, the test is not meant to test the endurance of the parking brake application itself, so no, it's not meant to cover the time that you have to place the chocks as you've been told, but for leak detection.

Even if there is a drop from 3000+ psi to 2400psi overnight, that's quite normal.
And you'll notice that from there it tends to decrease less fast as there will be less pressure to lose.

So remember:
-accumulator pressure = Available (reserve) pressure
-brake pressure = Pressure applied and > or = to accumulator pressure


RTM, after all this, tell me, how often do you notice the yellow brake pressure at zero or close to zero after parking an Avro RJ overnight? I guess that that's what we're discussing here and you would realise that all your arguments were unnecessary if the final outcome is still that they last longer than overnight parking, whci hyou and Tolipanebas seem to dispute.

Please don't embarass yourself trying to cover Tolipanebas' embarassing misconceptions. I don't say that I know it all but come on, this is parking brakes 101... first day at school, the big basics, student pilot level. Even FA's like Sean know this nowadays.
Maybe it's time for a switch: FA's in the cockpit and the hangar, pilots and mechanics in the cabin.

Maybe this discussion exposes a bigger problem in the aircraft industry than FR's empty aircraft sleep-walking on the ramp... It makes me wonder which one is worse.

[RTM]

I, am embarassing myself...?

Lets make it short... I do not use google aircraft manuals, never heard of, but the actual, up to date manufacturers AMM. The one you use, by the looks of it, are not very accurate. The data you provide for the RJ in this case is incorrect anyway.

Never heard of parkingbrake 101... Have you got any idea how many different systems there are troughout the industry? I guess not, if you think it is possible to cover them by a simple principle.

The 7 minutes is not a test, but a service limit. There is a test to check if it passes or fails the limit. Most of the AVRO's fall in the 7 to 15 minutes band for activation of the low press light.

How many I see completely depleted after an overnight...? Virtually all of them.


Anyway... Back on topic...

A Ryanair spokesman said the damaged components had been replaced and the aircraft was expected to fly again “in the next couple of days.”

Sounds to me like they lucked out, and only damaged the elevator, and not the stabilizer. Close call though, if you look at the pictures...

[Inquirer]

A Ryanair spokesman said the damaged components had been replaced and the aircraft was expected to fly again “in the next couple of days.”

And with this, maybe it's time to conclude the discussion above in which a certain controversial forum member is eagerly trying to prove several aviation professionals don't know what they talk about.
Allow me to say that I find this quest of his which runs through this forum very offputting.

FWIW flanker2, these days, technical descriptions and guaranteed product capabilities are being written by lawyers in my sector too, so IMHO tolipanabas nailed it when he questioned your understandable but in hindsight wrong deduction that "having brake pressure" means "guaranteed not moving".
In my sector for instance, we guarantee vacuum tight food packaging for X days, but we do not guarantee the food is still going to be good when used within that timeframe. It may all sound the same at first, but it means we legally move any liability over the content to the end user, the reason being there may very well be external factors beyond our control which affect our packaging beyond it's intended capabilities, so let me tell you it's indeed wrong to extend capabilities of a product beyond the literal wording provided by the manufacturer like you have done here.

[Lysexpat]

FR highest rated airline wordlwide according Standard & Poor's and Fitch!

http://news.airwise.com/story/view/1402447095.html

[sn26567]

FR highest rated airline wordlwide according Standard & Poor's and Fitch!

Highest rated by the banks, not necessarily by the passengers

[sean1982]

LMFAO .... Not

Most of the bad ratings are be people who have never flown FR(a bit like people on this forum actually). Very rarely I have to deal with disgruntled passengers

[RTM]

Very rarely I have to deal with disgruntled passengers

Fair enough,... but that doesn't mean that these same pax will give FR the highest rating above all airlines...

I flew FR, I was polite to the staff, but chose not to fly them again...

[Flanker2]

I, am embarassing myself...?

Lets make it short... I do not use google aircraft manuals, never heard of, but the actual, up to date manufacturers AMM. The one you use, by the looks of it, are not very accurate. The data you provide for the RJ in this case is incorrect anyway.

Never heard of parkingbrake 101... Have you got any idea how many different systems there are troughout the industry? I guess not, if you think it is possible to cover them by a simple principle.

The 7 minutes is not a test, but a service limit. There is a test to check if it passes or fails the limit. Most of the AVRO's fall in the 7 to 15 minutes band for activation of the low press light.

How many I see completely depleted after an overnight...? Virtually all of them.


Anyway... Back on topic...

A Ryanair spokesman said the damaged components had been replaced and the aircraft was expected to fly again “in the next couple of days.”

Sounds to me like they lucked out, and only damaged the elevator, and not the stabilizer. Close call though, if you look at the pictures...

I'm sorry but yes you are embarassing yourself.
First of all, you don't understand irony. Google Aircraft Documents can be reached by going on Google Maps and entering the following coordinates: Dumb degrees North, Ass degrees West.

You don't understand what "...... 101" means? Then I can't help you.

So you're saying that all your aircraft don't have any yellow brake pressure left in the morning?

@Inquirer. Aviation is a conservative industry. Technical writers won't put any conflicting or confusing information and they will never put a specification that an aircraft can't meet, as it's part of certification standards. Lawyers only review and amend the texts, they don't actually write it because they don't have the technical knowledge to do that. There is no aviation engineering law school.
When Airbus says that an A320 will hold accumulator pressure for a minimum of 12 hours, that means that it will hold 12 hours in normal operations.

Reality on the field is that they will hold several days, including the Avro RJ's.
Remember that even when the accumulator is depleted, there could still be pressure left in the brakes if parking brakes remain set.
All it takes to keep an aircraft stopped in normal conditions is a little friction, you don't need massive brake power.

[Lysexpat]

FR highest rated airline wordlwide according Standard & Poor's and Fitch!

Highest rated by the banks, not necessarily by the passengers

Don't tell me you took Mr Fitch, Standard and Poor for passengers who wrote a review on trip advisor.

[Lysexpat]

FWIW flanker2, these days, technical descriptions and guaranteed product capabilities are being written by lawyers in my sector too, so IMHO tolipanabas nailed it when he questioned your understandable but in hindsight wrong deduction that "having brake pressure" means "guaranteed not moving".

The Airbus FCOM is very clear: The accumulator maintains the parking pressure for at least 12 h.
So Flanker was indeed correct (this time).

[RTM]

You don't understand what "...... 101" means? Then I can't help you.

Of coarse I do, but if you think it applies, that's your problem. There is a little bit more to it then pull a lever, and the aircraft wil stand still in all eternity.

So you're saying that all your aircraft don't have any yellow brake pressure left in the morning?

Indeed! Please prove my observations wrong.

When Airbus says that an A320 will hold accumulator pressure for a minimum of 12 hours, that means that it will hold 12 hours in normal operations.

When BAe Systems says that an RJ will hold accumulator pressure to the lo pressuere indication threshold for a minimum of 7 minutes, that means that it will hold 7 minutes in normal operations

Reality on the field is that they will hold several days, including the Avro RJ's.

No, they don't. And that is field reality.

Remember that even when the accumulator is depleted, there could still be pressure left in the brakes if parking brakes remain set.

Depends on the type of system, in this case... No.

All it takes to keep an aircraft stopped in normal conditions is a little friction, you don't need massive brake power.

All it takes to move an aircraft with depleted brakes is a little wind and/or an incline on the ramp...

[Passenger]

FWIW flanker2, these days, technical descriptions and guaranteed product capabilities are being written by lawyers in my sector too, so IMHO tolipanabas nailed it when he questioned your understandable but in hindsight wrong deduction that "having brake pressure" means "guaranteed not moving".

The Airbus FCOM is very clear: The accumulator maintains the parking pressure for at least 12 h.
So Flanker was indeed correct (this time).

Amazing stuff, internet:

http://theflyingengineer.com/projects/a ... ding-gear/

Q48. How long will the accumulator maintain adequate parking break pressure?
A48. The accumulator maintains the parking pressure for at least 12 h.

[sean1982]

Last time I checked FR doesn't fly avro's nor airbus

Passenger, lysexpat is a professional pilot, so contrary to yourself he knows what he is talking about

[Inquirer]

When Airbus says that an A320 will hold accumulator pressure for a minimum of 12 hours, that means that it will hold 12 hours in normal operations.

Why are we talking Airbus and Avros here, when the plane involved in this accident was a 737?

Whether such an accumulator holds its pressure for 7 minutes, or 12 hours, the key point is: is it allowed to rely on the plane's brakes alone to secure it when left overnight?

Would be interesting to hear from lysexpat or any other Boeing pilot if indeed Boeing allows you to leave the plane behind without chocks in their handbooks? If they don't explicitly do, or worse even, insist on chocks being used, then you are in uncovered territory and have to face the consequences if you decide not to follow what's in their handbook.

Finally, a question raised already: rather than try to be smart and look stupid like they did now, why not just take the easy option and put the company's own chocks in? Would have been quicker and ultimately also less costly than calling technicians, debating with them and ultimately taking the wrong decision to assume the plane would be just fine like this, wouldn't it?

[tolipanebas]

Would be interesting to hear from lysexpat or any other Boeing pilot if indeed Boeing allows you to leave the plane behind without chocks in their handbooks?

As an ex-737 pilot, let me answer that question for you unambiguously: NO.

1- From the Normal Procedures - Amplified Procedures in the Boeing FCOM:
"Note: Do not assume that the parking brake will prevent
airplane movement. Accumulator pressure can be
insufficient."

2- From the supplementary procedures in the Boeing FCOM:
If the airplane will not be attended, or if staying overnight at off-line
stations or at airports where normal support is not available, the flight
crew must arrange for or verify that the following steps are done:
Pressurization mode selector .............................MAN AC F/O
Outflow valve ...............................................CLOSE F/O
Wheel chocks ...............................................Verify in place C or F/O

Not much room for pilot interpretation, is there?

Just because the parking brake system "should" "normally" be able to keep the plane static "for long enough" not to see it move on a "relatively flat apron" in "fairly calm weather" if the accumulator is working "without leaks", doesn't make it an approved method, which is why Boeing explictly warns against it in their FCOM even.

But what do they know, right?
Better call absolute experts like Flanker2 iso looking at the FCOM in case of doubt.