You can't go any higher than TOGA on a 747-400.

good post by Bula:
Anything can go wrong. Cables, hydraulic actuators or lines, wires and computers. A broken hydraulic line leaves a computer in a bad place trying to actuate whatever surface, just as a jammed jackscrew withstands any physical pulling by its cable or motor. There’s no such thing as an absolutely failsafe system, therefore none seems definitely better than the other.
When you end up in a critical situation close to ground, having very little time to react, the taking manual, pulling up and shoving the levers full forward is the fastest and most instinctive way to get out. It might not be the most elegant, but once safe you regain time and can then sort out how to get back to a more comfortable state. I like the possibility of intervention in this manner.
If the system might not react in such a situation, you have to do the sorting out first and switch off some things, as to be able to get the desired reaction. However, when the surprise is huge, the scare is enormous, I tend to have a slower thinking processor and even with adequate knowledge of the system, I think I am too slow for a precise analysis and switching close to ground.
Having experienced some critical situations in my career, I prefer the earlier solution.

The FBW issue doesn't end with the failure of control runs, there's also the command authority issue.


People spent years arguing over protocols, but this post of mine says a lot about being able to demand that excursion out of the envelope.



http://www.pprune.org/tech-log/14972...ml#post1584468

TripleBravo: The unit cost argument you make leaves a bit to be desired. Those ADIRUs are so expensive in large part because they will be built in quantities over years that Toyota builds a single model in a single plant in a day.

The benefits available via FBW in autos or GA simply haven't justified the disadvantages and economics to this point. FBW made sense very early for large aircraft because of the tremendous advantages it gave designers. You'll note that FADEC is in all recent automobiles, and throttle-by-wire is increasingly popular. Certain luxury cars are nearly 100% brake-by-wire right now, and most cars have ABS and EBD.

Pure mechanical controls will be around in GA long after automobiles shun them, much like antique environmentally indefensible engines burning antique fuel still predominate in GA, despite being outlawed decades ago for new autos in civilized countries.

It is annoying how certain luddites refuse to recognize that good design is good design, and to the end user it really doesn't matter much whether it is mechanical or electronic if someone screwed up and it goes badly. There are many ways in which a simple hydraulic steering boost can go badly, and I've had one lock up on me before. That recently mentioned MD80 accident was all about failing to lubricate a pretty simple, pretty life critical component. Simple doesn't equal safe, and complex doesn't equal dangerous.

I certainly hope the DFDR is healthy enough, and I hope the authorities are successful in swiftly determining what went tragically wrong here.

320 was on its way home
 

The aircraft was not due to land back in france but was heading for Germany then Auckland for an Upgrade. To turn back to france meant it had a problem!

Now THAT make a whole lot more sense........

sorry - I dont know how to use the quote function

c130airman

The aircraft was not due to land back in france but was heading for Germany then Auckland for an Upgrade. To turn back to france meant it had a problem!

According to previously published reports the plane was supposed to land at Perpignan after this flight before departing again for FRA and handover ... do you have some new information that contradicts this ?

c130airman saidAnd you know that because .....

Apart from an early news item in a NZ newspaper, this has never been repeated. Are you saying that the second flight was bound for FRA? Surely this would have come out earlier as flight plans to that effect would have been filed??

It is interesting that the DFDR and CVR are reported as "damaged". Well they would be - it crashed - but to what extent are they damaged? The initial reports of the impact site stated wreckage spread over a wide area. This is normally indicative of a shallow(ish) impact angle as opposed to "spearing in" i.e. very steep impact angle.

By inference, the "damage" to the recorders should be less severe with the former scenario and in any case they are designed to withstand huge impacts. With this being a fairly young Bus they would also be the solid state variety so data recovery should be relatively straight forward compared to tape or wire.

If it subsequently turns out that the data was "not recoverable" then there will ineviatabley be accusations of a cover up.

I'm an experienced Bus pilot and I have to say I'm mystified by this accident.

A4

Well, having flown the A320 from inception in 1989, like a few others, I don't have any concerns at all about the airplane!

Prangs happen! Fact of life! Probably nothing to do with FBW or any thing else you might like to conspire about!

A4, You wrote: "The initial reports of the impact site stated wreckage spread over a wide area. This is normally indicative of a shallow(ish) impact angle as opposed to "spearing in" i.e. very steep impact angle."

That is (generally) a "correct" statement for a land impact, but not necessarily so for water. The specifics of wreckage patterns on, and in, water vary of course, based on many factors that are quite different than the factors at play in ground contact scenarios. Having said that, your post also got me thinking about “impact damage” as opposed to “wreckage patterns”.

Actual “impact forces” are based on four (main) criteria regarding the impacting object (aircraft): forward speed, vertical speed, nose angle at impact, bank angle at impact. The fifth main ingredient is the physical nature of the impacted surface. In that regard there is one important aspect of water impact that many people don’t realise, or are possibly just not aware of the physics involved. Without going into unnecessary detail, water is nowhere near as easily displaced as most tend to think, meaning that the impact forces can be quite comparable to a very hard land surface (concrete, for example). One only needs to read this excerpt (for example) from the CTSB report on SwissAir111: “impact forces were in the order of at least 350 g”. (http://tsb.gc.ca/eng/rapports-reports/aviation/1998/a98h0003/01report/01factual/rep1_13_03.asp )

In addition to SW111, there are many other examples of incredibly – almost indescribably – strong impact forces where the CVR and FDR were virtually undamaged or barely damaged. Most “failure to read” scenarios result from fire or heat damage as opposed to impact damage, and there are very few cases of water impact (no matter how severe) wherein the CVR and FDR have been damaged to a point of yielding little or no information. My point (finally . . .) is this: Given the known circumstances of this horrid occurrence, I will be quite surprised (and, I admit, a tad suspicious) if it turns out that either the CVR or the FDR are so damaged as to preclude them providing adequate and accurate information.

Grizz

A4 : Not quite : the "boxes" themselves seem to be physically OK, it is the contents ( at least of the CVR ) which is reported to be not "exploitable" as the BEA says.

This might indeed be the case, the problem is that in France,and surely by coincidence , this kind of things seem to arrive a bit too often, especially when involving AI types. Therefore the suspiscion.

To make matter worse for the BEA , the State prosecutor first declared that the CVR was recovered and readable, and 2 days later said the opposite.

What's the French for déjà vu?

The black box of an Airbus that crashed during an air show in France in 1988 was replaced with another after the accident, a report shows. Pilot Asseline was sentenced to ten months in jail by an appeal's court for manslaughter but he always maintained that the flight data used by investigators and displayed at the trial was a fabrication.

Acting on Mr. Asseline's request, the renowned Institute of Police Forensic Evidence and Criminology (IPSC) of Lausanne (Switzerland) examined documents from the crash and the trials and concluded that the black box of the aircraft had been switched after the accident. Along with its report, the IPSC published photographs of a French Directorate General for Civil Aviation (DGAC) official retrieving the black box from the wreckage of the aircraft. After enlarging, a photograph shows straight white stripes on the side of the black box. The black box presented at Mr. Asseline's trials as the original one had angled white lines on its side.

AirDisaster.Com: Investigations: Air France 296

Modern CVR/FDR (black boxes) units are built to withstand 3600g for 6.5 milliseconds, this roughly equates to an impact velocity of 270 kts. In addition to the penetration resistance, static crush, high/low temperature fires, deep sea pressures, sea water immersion and fluid immersion.

FDRs are usually located in the rear of the aircraft, typically in the tail. In this position, the entire front of the aircraft acts as a "crush zone" to reduce the shock that reaches the recorder. Also, modern FDRs are typically double wrapped, in strong corrosion-resistant stainless steel or titanium, with high-temperature insulation inside.

Judging by the impacts down through the years that black boxes have remained "exploitable" after, serious question will have to be answered if the "un-exploitable" report is true.

ADIRU
 

At the risk of being repetitious, there has been no response to my earlier question. My contacts at Qantas feel that this might be relevant.

forget
 

That article about the Air France A320 crash was written by Chris Kilroy.

His qualifications in the field of accident investigation are summarised below:

"Chris Kilroy is an IFR rated Private Pilot, and has been flying since 1998. He has over 150 hours logged in various types of aircraft. He brings knowledge of aircraft systems, flight rules, and meteorology, along with computer experience..."

Guys, you are getting this all wrong.

AI want to sell aircraft and things are moving a bit slow at the moment, so other measures have to be implemented, if this situation is not exacerbated.

Lets see, there was the TU 144 crash a LBG, the A320 into the trees as previously mentioned and now possibly this.

If the damned thing had to crash, it is a shame it had to be on French soil.

Phil - as I am sure you know, each operator has different specs, and different ADIRUs may be installed on different types of similar aircraft, let alone different types in different fleets (google Honeywell ADIRU, and you can see that it might be on anything from 737s to A340s). While I am sure that someone would know exactly what is installed, in the interests of minimising speculation, I am not sure that anyone will be revealing here as to which ADIRU ANZ and Qantas ordered respectively for their fleets.

If you contacts at Qantas are in engineering or involved in the investigations on the A330, they will almost certainly know what was installed on each. If not, it is futile to speculate, as even if they are the same (it is certainly possible), then individual coding, version (if manufactured in a different year), updates etc could mean that the same base computer is operating in a very different way.

I cannot see how this information would be useful other than for uninformed speculation. There is no obligation on anyone to reply to all questions on a bulletin board!

A320 Crash
 

The Airbus was on a post maintenance test flight. Had been leased, and was about to be delivered back to its owner. Latest news 7POB, none survived.
Any news on the most probable cause??

Cheers.

Am I to believe that no other agency, such as the NTSB from the US, will be allowed to try and examine the 'black boxes' from this accident?

TOGA vs firewall
 

I fly 330's. Toga is throttles full forward, with max thrust still controlled by fadec's, and is not above max "rated" thrust.

In DC10 and 737's that I flew previosly, Go Around thrust was a setting slightly below throttles full forward, and at a position appropriate for max "rated" thrust. If I pushed the throttles all the way forward, i.e. firewall (which used to be a proper SOP term in some airlines), I would use max available thrust, which would possibly be above max rated thrust. This could lead to a complete failure of the engine/s if unlucky, and most surely would lead to some damage or life-time degradation, but could be used in a situation where the only other alternative was ground impact.

Is this not the case in B747-400? What about B777?

As a side-note, it's still possible to use "firewall thrust" in an airbus, but selecting N1 mode and set the levers to the Toga position regardless of outside atmospheric conditions. It'll just take a few seconds longer than on a classic steam driven airplane.

Regarding the black box being "too damaged to yield useful results" (assumning there is any substance to this): does anyone remember a similar case (impact into water, no fire, relatively quick recovery of the FDR/CVR) with such an outcome, especially with solid state based recorders ?

I muss say that I am very perplexed by this report.

"Damaged black box will give answers"
 

"A senior accident investigator in France has dismissed claims one of the black boxes recovered from the wreck of the Air New Zealand Airbus A320 which came down in the Mediterranean last week is too damaged to yield useful results.

A member of the multi-national investigation team has told the NZ Herald that black boxes are tested at such length and extremes it is rare to find absolutely no data.

The source, a senior accident investigator with decades of experience, said he knew of only one or two incidents when the memory cartridges had been compromised.

The black box equipment will be sent to manufacturer Honeywell in North America to determine what data can be extracted."

can anybody shed some light please why they haven't found the bodies of the other 5 guys, yet.

(does it mean the fuselage was obviously completely destroyed, broken into pieces and everything from inside plunged into the open sea?
Picking up the CVR and the DFDR, any information obtainable if the divers saw anything from the rest of the fuselage e.g. seperated in pieces or still intact ?

If you'd ever seen the effect of a relatively steep impact on an aircraft, or on the human body, you wouldn't ask such a macabre question....

CJ

Is it possible that when one says that "...no useful information could be extracted...", that it's in the context of an easy 'plug- in- cannon plug or USB and play' was impossible, but that Honeywell will crack the case and retrieve full data? I'm suggesting that perhaps the comments regarding the CVR and FDR were not well expressed, or not in their entire context, but in fact, we'll see the data extracted successfully by the manufacturer(?)...

I am not a pilot. I am, however, a retired electrical engineer who long worked for a semiconductor manufacturer in design, reliability, and manufacturing data analysis jobs.

Not very long after our first flash memory chips went in to one of the earlier solid state memory recorders, my reliability lab colleagues had quite a fire drill in assisting data recovery. It seems that in that case the recorder manufacturer's suspension had failed to provided a low-enough shock environment to at least one of the chips, and there was mechanical damage to the extent (if I recall correctly) of fractured wire bonds (yes--this was so long ago that chips were still connected to their pins by wire bonds). Anyway, the lab guys fiddled up an arrangement, the chip was read out, the accident investigation proceeded, and the reputation of solid state recorders was protected.

I suspect the housing/suspension was not very well done in that case. The old specs for bond wire integrity involved momentary accelerations in excess of 10,000 g, if memory serves me correctly.

They are not invulnerable. Actually as a crash survival medium, I'm pretty sure solid state memory of any kind is mechanically inferior to the old aluminum tape with scratchings, and probably also inferior to magnetic tape. But the survival has a lot to do with how well the recorder designer did his job, not just the medium. If it is going back to Honeywell, you only need to trust their greed to expect they will try really hard to get the data out. Their business and reputation have a stake in that outcome.

Holodek7,
I think you probably got it in one.
Getting data from a solid-state FDR or CVR can be as simple as hooking it up and reading it, or as complicated as having to remove every single memory pack from a smashed-up mess, reading it individually and reconstituting the data.
The problems in the wire and tape days were different, but of the same calibre....

archae86,
Nice one.
I know what you're saying.
Let's hope this time they don't actually need to get into the chip packs.

CJ

Yes. French manufactured aircraft, leased to German company by New Zealand company with German and NZ nationals on board crashed in France. Why would the NTSB have to be involved?

You obviously do what you must to keep from "spoiling your whole day", but you'd have to be VERY unlucky to break an engine in the minute or two "max available thrust" is used. I've seen engines abused per above that required nothing more than a special inspection, or perhaps some shroud/air seal replacement to restore performance, but no distress beyond that.

But use your good judgement. :ok:

What's your issue?
Some of the odds and sods on the aircraft are American, so the NTSB might be able to contribute something. Seems the FDR is Honeywell, so there you go.

CJ

I'm pretty sure that the NTSB won't get involved just to watch the french BEA because some folks think they ought.

The NTSB would likely ring up their BEA counterparts if there was a need for a thorough investigation of a US manufactured or designed part (I have not heard of any yet).

If the NTSB happen to have some black box readout experience that the BEA doesn't then the labs may get involved.

The long and short of it is that cross involvement under ICAO is mostly for technical reasons and not political reasons

A one-push GA only gives a 2000fpm climb at the required speed. A two push GA gives you full THR REF.

If you have Rolls Royce engines, selecting ALTernate EEC's could give you a lot more than you bargained for (That's why there are warnings in the manuals about selected ALTernate EEC's at full thrust). Definitely more than TOGA.

Rgds.
NSEU.

Press release to day from BEA :
Protected boxes (CVR and DFDR) have resisted and seem intact, but it was not possible to extract any data. Additional work will be becessary, without being possible today to predict their result.

If would say the result isn't too hard to predict.... :ugh:

BEA press release
 

I think this puts to bed the suggestion that they were returning to land as a result of a problem. A touch-and-go or simple overshoot was intended:

"L'avion était en approche sur Perpignan pour une remise de gaz et un départ sur Francfort"

Airbus Crash in France + recorder data missing....

haven't I heard that before..... :mad:


by the way, the CFM-56 on the 37NG I fly may be 'firewalled' as long as you have the EEC protections - it will produce slightly higher than max. rated thrust and Boeing even encourages you to do so during low level windshear or terrain avoidance.

Why Would NTSB Be Involved?
 

Simply because, depending on the final results, certification of the aircraft to be flown by U.S. carriers might be affected.

NSEU - true, but in reality are you going to start reaching for alternate EECs in a scenario where you need maximum thrust immediately? By the time you've identified the switches (taking care not to accidentally turn off the hydraulics) it'll all be over. So in all practical terms you won't get anything more than TOGA from the 744.

Quote:
Why would the NTSB have to be involved?
There is no reason for the NTSB to be involved unless one of the parties (France, Germany or New Zealand) request their assistance for some reason.

The investigative process is none of their business and they have no remit.

The report that eventually will be circulated will be taken on board by the myriad certification authorities around the world (in the USA the FAA, NOT the NTSB) and each will decide on how it will act - most likely in concert with the others.