Dye makes sense - not in the engines, but what about a small amount of intense dye inside the hull (e.g. floor construction) that would be released if the fuselage breaks apart?

I'm amazed at the fuel dye proponents, for the reasons given so far. There's no reason to dye all fuel when it is needed only for the downed A/C. Dye also isn't a lot better than an oil slick and no good at night, or for an intentional non-disintegrative ditching, so Porlock's florescence or luminescence is a better choice. Dispersal and disappearance over time and via weather also suggests that one 'dose' isn't enough, and that multiple containers that would degrade in water over a sequence of time would be better yet. But by the time you have such a system with its weight installed, a floating locator with a sea anchor begins to make more sense. Back to step one.

mm_flynn, (http://www.pprune.org/rumours-news/5...#post9397831);

In terms of tracking & locating technology, it has existed for some time - we have been using it to follow our aircraft locally and around the world; it works extremely well. It is real-time interrogation using web-based interfaces with user-selected 30" to 10' polling periods. I have no idea why tracking is such an issue; we've been doing it for at least six years now; we know where our aircraft are all the time.

And, for a price, it can do parameter/event monitoring say, for high-acceleration events for example, so that maintenance can meet the aircraft based upon data not crew reports, etc. It isn't an entire DFDR process but it could be sufficient for initial explanations and certainly LKPs.

In terms of retro-fitting for deployable recorders and/or streaming data, I would argue against an industry-wide, regulatory requirement. All recorders in recent over-water accidents have been recovered and read with one exception, the Asiana B744 freighter loss over the Korean Straits.

Acknowledging that, like all human activities, aviation works on risk probabilities (and the management of same!), the design and engineering manufacturer's groups of the industry work on the basis of what an acceptable failure rate of mission-critical elements/components is; the certification standard is, as some here will know already, 10^-9. We can reasonably consider that the loss of MH370 is such an event to which the same standard may be applied, and that the "normal" pattern is the historical one in which in all cases, above exception noted, the recorders have been recovered and accidents understood.

The argument for deployable recorders & datastreaming is essentially an economic one only, and that is a different arena than the case for flight safety. Such standards (for flight safety), are borne by the industry and ICAO member countries when/where accidents occur, and yes, it is expensive, but as you point out, also extremely rare.

I think the case for deployable recorders/data-streaming has not been demonsrated against this accepted standard.

You broach an interesting scenario in your post which needs examination and that is power sources for recorders.

If we are to invest significant funds and the ensuing subsequent certification/regulatory work at all in changing the way aircraft recordings are done, it would be reasonable to focus on power sources for both the data and voice recorders.

Public cries for instant sources of data do not demonstrate the flight safety case for such capability, they demonstrate a willingness to engage in media and political arugments. Ensuring that recorders have uninterruptible sources of power is a flight safety case, and as such is demonstrable, (SR111); they should include as a factor not only electrical system auto-responses to load-shedding and/or damage to wiring through fire or mechanical processes etc., but also losss of electrical power through the intentional use of emergency electrical configuration drills which are intended to remove all power from normal AC & DC busses during smoke of unknown origin emergency drills. (As you observe, we may see loss-of-data here for this very reason, but we don't know yet).

Far to sensible...
 

What is with all this sensible chit-chat about plausible identification mechanisms?

Surely these belong somewhere else, where other sensible ideas are discussed - you know like the Tech Log?

Where are all the rumour-mongers? Come on... I haven't read a good crackpot idea in perhaps 5 days of the thread now! :D

Just Use the ELT
 

These aircraft already have an ELT, and computerized fault detection. The ELT can already be manually switched on, or triggered by impact (searching the net I found two numbers, 5G and 2.3G) What could be done simply and cheaply is list conditions which are always an emergency and trigger the ELT automatically when those occur. For example, the aircraft:
* is inverted
* is descending at 10,000fpm
* has lost pressurization at high altitude
* has lost power

You get the idea. In one of those emergencies the pilots may never get to the last priority in Aviate - Navigate - Investigate - Communicate, but the ELT is just sitting around. Let it handle the communications.

crackpot ideas
 

Garage Years, surely throwing bags of dye on board every flight qualifies?

But it is permanently attached to the aircraft. So for a water landing, there may not be much time between the impact and fuselage (and ELT) submerging. Once under even a small depth of water, radio transmissions are useless.

Deployable ELTs are feasible, technically (already used in some military aircraft). But the commercial transport certification issues differ and make this a rather expensive technology. Particularly considering the number of crashes where a deployable ELT would make a difference in recovery efforts*. The news isn't all in on this incident, but it appears that the aircraft and recorders may be located in a relatively timely manner. A deployable ELT might have only saved a few days of search effort.

*AF447 is one example of where a deployable ELT may have been of great value. MH370 is another.

I think the priorities are being mixed up. The ELT will find the a/c, or rather the ELT. The FDR & CVR data will help the crash detectives discover the reason. The old thinking was that the ELT will find the FDR & CVR. Plus, both boxes would be readable. Neither are correct. We've seen, via documentary reconstruction, that the boxes can be very difficult to find and recover, even after the wreckage has been traced. 2ndly it has been the case where one or both boxes had be corrupted and important data was missing.
What we are discussing is 1. finding the wreckage, 2. deciphering the data. The two need not be necessarily be related. The FDR & CVR data can be transmitted live and downloaded at operations and saved for 2 hour periods. It should not be necessary to find 'the boxes' to decipher the data.
That is the debate. Finding the wreckage should be for other reasons, but not the data.
Watching the media telling stories about searching for the Black boxes, then eventually, after humungous efforts finding them, (aka AF447), is like watching an Indian Jones film about 'search for the Holy Grail.' It is so old tech compared with today's aviation space technology. It is as archaic as HF ATC communications. That is a debate been on-going for decades and achieved squat. Let's not fall into the "that's the way it we've been doing for a long time with no problems" cosiness. What will it take to shake the apple cart and catch up with reality? Years ago GPS/TomTom was the work of the devil. Now it is used by mariners, aviators, bikers, hikers. surveyors. runners, GA pilots, etc. etc. The new technology has been embraced. The top of the food chain still has some prehistoric components. Some XXA's are amongst them.

Rat_5;

I don't think any aviation folks would disagree with your vision. The above was about, "What do we do on Monday?"

I would love nothing more than to write the rules, for example, that require all aircraft over say, 12,500lbs, to have a minimum of 200 parameters. I've worked with some types that have two parameters (again for example), for the engines...prop speed & torque and which do not have fuel, weight or lat/long parameters. It's legal but essentially useless for serious work.

Here, as has been suggested as a possibility, if the crew used the emergency electrical configuration drill & checklist the recorders stop working and the last few minutes become guess work which can make kicking tin necessary.

In any case, the industry will go where it will go and progress at its own speed which as we know is a conservative but glacial pace.

"Aircraft to aircraft exchange of data packages has always seemed logical to me."

Loose Rivets: You are describing an implementation of "mesh networks". The technology I am familiar with has been maturing at a workable level for about 10-15 years or so, and is usually proposed for swarms of robots/UAVs. It is probably the best proposal I have seen on this forum for reliably propagating small amounts of critical data in sparse regions.

MS804 - press release from CNES (French Space Agency)
 

3 June 2016: https://presse.cnes.fr/fr/disparitio...u-commandement

* data of 20 May 2016 received by Cospas-Sarsat https://en.wikipedia.org/wiki/Intern...rsat_Programme
* analysis by the French Space Agency (CNES) + Joint Space Command (CIE)
* drift models by Meteo-France
* guidance to the Navy, allowing to pick up signals emitted by the black boxes

PJ2
And of course MH370 which you mention later

You fail to mention cost.

The huge and extreme cost of just recent searches for DFDR/CVR say back 5 years, is immense. But it is not set even against the aviation industry as a whole - it is borne by the taxpayers of sometimes quite poor countries. Certainly, for a short search some claim could be made that it is good training for the personnel and assets that may be in existence already, but after a few days of continuous search burning through the active life of parts and maintenance schedules, and the contracting of specialized equipment this is no longer true. I am happy to accept your argument if your airline (or more correctly your airline's insurers) as part of their operating license accept that they will fund the entire expense incurred by the responsible country(ies), of any search for DFDR/CVR that may be necessary after a crash of one of their aircraft.

At the moment the aircraft operators are freeloading on the international community to pick up the pieces and even to organize the inquiry and tell those operators where they fell short of operating correctly. I do not think that this is acceptable given that relatively cheap simple technological fixes could reduce these costs to the international community substantially.

The numbers may look big but in reality the Search and Rescue costs are around the same as the replacement value of a single widebody aircraft.
In the vast majority of cases the recorders are recovered so there is little perceived benefit in imposing a much more expensive equipment upgrade on the global fleet.

But you could equally argue that the international community and the industry as a whole, not just the operator of the aircraft in question, stands to benefit from the recovery, investigation and any resulting findings and safety recommendations.

Current Patents.


Underwater Echoes
Filed August 21, 2012, by The Boeing Company.
Canadian patent not yet granted.


Aircraft "Buddy" System
Filed March 21, 2011, by Thales.
U.S. patent granted March 4, 2014.


The Floating Black Box
Filed August 26, 2010, by Lockheed Martin.
U.S. patent granted March 11, 2014.

As for "dye bags" or rather "Sea Marker Packet Inflatable Survival Equipment" are in/have been in wide-spread use for many years, but have not been adapted for Commercial Aviation. The question would be, "where would you put said item so that it could be maintained and deployed if ever required.

Further reading available at....

Patent 2843612 Summary - Canadian Patents Database

Patent US8666650 - Method and device for assisting in the locating of aircraft - Google Patents

Patent US8670879 - Automatically ejecting flight data recorder - Google Patents

Ian W;

I accept the cost argument as both reasonable and necessary - I mentioned it but didn't/don't emphasize it.. I also accept that, for some, it could be too much to argue that such enormous expense is the cost of engaging in the "long line" side of commercial aviation. After all, the billions spent otherwise, (generally by rich country's governments, I acknowledge), on R&D, regulatory processes and achieving that 10^-9 engineering standard isn't viewed in the same way as the "necessary" response (and enormous immediate/unplanned costs), of finding lost information and knowing what happened. Yet this is the model of progress in aviation safety, and clearly it has worked given the enviable and outstanding record for safety the industry achieves.

This will sound like hedging to those focussed on the realities of fiscal responsibility alone, but it is not intended as such. I truly don't intend that things should continue as they are - things will unfold as they will. But I don't see industry specialists clamouring for such a solution (deployable/streaming), as a priority, and I think that tells us something.

My "What do we do Monday?" remark conveys the need for action now that can have material benefits, but the case for the deployables or streaming and other, more elegant solutions may still be made on a flight safety basis. These two notions require careful examination on their merits alone and should not be accepted out-of-hand as a "logical" solution to an "obvious" problem.

The risk management matrix for making this decision assesses severity and likelihood. Those sitting in on this kind of decision are from where? What is being hedged against? The risk of a crash, or the cost of what happens after one? Where would you argue that a dollar be spent if you are:

so there is little perceived benefit in imposing a much more expensive equipment upgrade on the global fleet.

Has it ever been costed?
Has the idea ever been discussed?

If AF447 could be sending back live data about its pitot tubes and air con packs, and the QA 380 could be doing similar things with its engine parameters, surely it is not beyond the wit of man to start fitting FDR/CVR transmitters to all a/c being manufactured from 2018.
Remember the debate about cargo fire detectors and extinguishers after the Valuejet cargo fire? The FAA did a risk/cost analysis about retro-fit of all similar type a/c. It was considered too expensive. The category of cargo hold was designed to survive a fire as it burnt itself out. There had not been a precedent to Valuejet, and it was deemed that had root cause in human error. Notice, now, that all B737 NG and AB's, with the same category of cargo holds, now have fire detection AND extinguishers. They were designed in and cost absorbed. When was the last time they were used? How many times in past 20 years? Yet they are there. How many times would FDR/CVR dreaming have been invaluable in the same time frame? And in the future which is more likely to be needed the most; cargo fire or FDR/CVR data?

I find it difficult to believe that the reduction in Maintenance costs alone couldn't offset the cost of real time fault data transmission. I suppose the question is that how can the maintenance data be optimized. In automotive terms we're still at the 'OnStar level' but we really need the F1 level of telemetry to reap the best cost benefit.

Why not send the data to satellite only when the aircraft is flying over water? This would remove a large percentage of aircraft from reporting anything.

Taking this idea seriously for a moment, since the topic is "what to do with these losses that occur over deep water when nobody is in contact ..."

You'll want a buffer zone for coastal cities/airports that have approach paths over water. (12 miles, 10 miles, 20 miles?)

Or, consider a dual parameter trigger such as

Over water**
AND
Above FL 180

** How do you define "water" that fits this model?

An ocean?
A Sea?
A great lake?
Water deeper than 100 fathoms?

What nav system calculates this figure?

How does this system figure into the MEL for a launch?
How much of your fleet has to have it?
What is the operational impact if this system is down? Abort depending upon route?

Why not send the data to satellite only when the aircraft is flying over water?

Remember how many occasions the FDR has been damaged, severely, and taken huge skill and advanced technology to decipher; once it had been found in deep mountain jungle. The data was not 100% available. The same with CVR; often very little recoverable. I would suggest that more a/c crash & burn not over water. True, trawling the depths are expensive and difficult, but high in the mountains is not easy either.
The cost saving to limiting to certain routes would be peanuts.

There's one elegant solution addressing Lonewolf's and RAT's concerns: data offload could be triggered by TAWS.

Again taking this seriously as if it would enhance safety...

You could have certain types of faults and abnormal conditions trigger 'immediate mode' which would immediately upload the last minute or two of FDR data. It is what happened just before the abnormal condition that is important.

The problem with any approach is that by definition such a reporting system would be nonessential. How much power do you want to use from a dying battery to send a message back to base, when modern aircraft do not stay in the air without some sort of electrical power? It is very hard to engineer something that can't in some rare case either cause a problem or make an existing problem worse. The safety of living passengers far outweighs the curiosity of the rest of us.

Interesting idea you have there on the FDR buffer.
Looks like a t-shirt idea in the making.

I haven't yet seen it stated, so I will now, that the the technological capacity to stream live DFDR/CVR data simply did not exist at the time that recording devices were introduced so on-board storage was the only answer.

Technology has moved on in several leaps and bounds since that time. It is now completely feasible to stream live data at relatively low cost.

Surely the answer is that new build transport aircraft should have live streaming designed in (in addition to existing on-board storage) and a later decision can be made, as the existing fleet is retired, whether a live streaming solution ultimately replaces on-board storage.

Is this not making best use of current technology without casting all eggs in one barrel at probably uneconomic cost.

GXER: thank you. You seemed to have answered the question I was posing; i.e. it is perfectly feasible and should not be expensive.
Next question: why is it not happening? The latest most modern a/c are B787 & A350. Was this idea ever considered by the design team? Or were they waiting for FAA/EASA to mandate it? In the technologies of fuel saving and reliability, maintenance and ease to fly with back-up systems & automatics, the manufacturers give it their all. That's what makes them competitive in a jungle marketplace. The idea of FDR/CVR streaming is not going to turn the heads of the buyers, because they ain't going to crash - are they? It would have to be a mandated thing.
Does anyone know, for fact, what caused the B737 category of a/c to have cargo fire detection & suppression systems fitted? As explained it happened after Valuejet. Was it FAA or the initiative of the manufacturers?
Might one steal a lead on the other with this new toy, or wait for the headmaster to decide?

Actually, the answer needs be to the correct question.

Most of the solutions assume A - that robust SatCom links are cheap, B - that CVR/FDR information is the overwhelmingly best source of useful accident investigation, C - that search costs are high relative to recovery costs, D - that with the CVR/FDR data in hand, it would be rare that the cost of rescue/recovery would need to be spent.

I am pretty sure all 4 assumptions are not actually true.

In this accident, I am pretty sure the FDR will tell us nothing new, other than the reason data and responses stopped being sent back was because the crew turned the power off; and the CVR will confirm to us the crew new there was smoke in the cockpit and indications of fire.

However, when they find the ULB they will have a good fix on a junk of the wreck and can start searching for where they avionics bay came to rest so that investigators can work out what went wrong and what changes are needed to prevent it happening again.

let me have a goat answering your objections, that are all well made.

(A) acknowledged but there may be solutions or partial solutions that do not rely on satellite. How is ACARS transmitted?

(B) probably not but it is almost always a necessary element.

(C) I agree bit it should be easy to establish whether or not streaming costs spread across the global fleet would be less than occasional recovery costs. Has the calculation been made? I don't know but it surely ought to be made.

(D) possibly true but if the DFDR/CVR is available, there is possibility of a partial answer rather than no answer.

Keep in mind that live streaming is also going to help in determining the aircraft's eventual location, assuming that the transmission includes GPS coordinates. That should make a search easier and faster.

Another note regarding dye bags. As long as the dye used is non-corrosive and non-poisonous, then maintenance will be minimal. Worst case a bag leaks and someone has to clean it up. Positioning probably isn't all that important - an in-flight breakup or a crash sufficient to tear the plane apart is going to spill the dye, while if the pilot pulls off a successful ditching, then the ELT beacons on the rafts will locate the aircraft.

Live streaming of FDR data may have its merits. But the CVR is a different issue, with airlines and industry being held accountable for privacy issues of broadcasting private conversations of professionals not involved in any incident.

I can well see a huge exodus of experienced pilots from an already overstretched industry group, if live streaming of CVR data was mandated.

The strikes this may create would probably kill the whole industry!

It is worth context 'not very expensive'

I would gues we want something like a 150 kbit stream (4-6 good quality audio tracks, 200 parameters recorded every second)
I think that adds up to 1 MB per minute at say $1.50/MB that is $100/hr on a commercial fleet that does 50 million hours a year. So $5bn per year in data costs, plus all of the hardware, storage, management, repair:maintenance and testing.

I suspect I have underestimated both the cost of mobile data from aircraft and the bandwidth requirement

And this aircraft Actual HAD live streaming of GPS data and that stream was received. Also, through luck the elt appears to have gone off on crashing so we already have those two facts.

I am not saying, 'everything is perfect today', but if there is a proposal to change, make sure it is actually solving a real problem.

There clearly is a challenge to track where the fragments of an aircraft go after it looses control, breaks up in the air, or breaks up on contact with the surface. Also, a general challenge in tracking an aircraft that is not SatCom capable at low altitude,in remote locations, or trying to hide.

I keep seeing reference to dye bags. I don't think those will be of much use. Back in my P-3 days, we had Fluorescein dye in the sonobuoys. They were visible, but not that great, and they dispersed. I suspect the oil slick is more visible - especially to radar because it changes the surface reflectivity by dampening shorter wavelength surface waves and ripples. Also, you have to reliably disperse the dye, and yet keep it from leaking out with the aircraft traveling 100's of knots through heavy precipitation.

If it's really necessary to disperse something, how about a lot of little, very light floating radar reflectors - essentially aluminum foil that springs into a 3D shape in water? They could be tuned to common search radar wavelengths - all this requires is that the little antennae be the right length. Military search radar, like on the P-3 or P-8 should have no trouble finding this, day or night. Done right, they could also show up on orbiting SAR (radar) satellite imagery.

The track and speed of the Burullus doesnt give too much hope at this point.

How about a number of cheap, floating, water-activated radio beacons stowed relatively INsecurely in various places in the airplane, so that at least a few of them would survive and be released on impact & breakup?

@underfire
"doesn't give too much hope" for what?

a) The crash site was already located within a small circle of less than 2 km following onboard ELT signal picked up by multiple MEOSAR satellites (GPS + Galileo) at crash time.

b) H/V Laplace, once arrived on the spot, quickly picked up an ULB signal ; she is still working the area since a week.

c) deep sea recovery equipment is on its way onboard R/V John Lethbridge ; She is actually off the Southern coast of Sicilia, heading to Alexandria where she supposedly will arrive on Thursday (June 9th, but it's not clear yet if she is really sailing to Alexandria instead of the crash site).

Hopefully, by the end of this week, we'll get news of retrival operation starting, but it does look to me quite good so far.

Yet no other signal has been detected from the seabed, possibly because only one ULB was still working after the crash. Nonetheless, it should not be extremely difficult to find out and recover rapidly some wreckage, considering what those ships, crew and equipment can do in addition to a limited area to explore.

Per NASA, ELT's are picked up by GEOSAR and LEOSAR. I have not heard of GNSS satellites able to do this. Only LEOSAR can give a location unless the ELT transmitted location data.

@Mesoman
On June 3rd, CNES (Centre National d'Études Spatiales) - which is the French Space Agency in Toulouse - and CIS (Space Military Joint Command) issued a communiqué about how their teams located the crash site of MS 804 (with some help from Météofrance), using Galileo and GPS data analysis from MEOSAR constellation, which is not fully operational yet.

They had 5 satellites picking up ELT signal and it was relayed to ground stations in Toulouse (CNES) and 3 others in Europe. Using CNES algorithms, they were able to define a crash zone within 1.5 km or so.

As far as I understand, they can derive positioning from doppler effect when three or more satellites are picking up the same signal even if there is no location data transmited (and it's unlikely in this case).

Here is a paper about MEOSAR, published in Sept/Dec 2014 issue of insidegnss
http://takata1940.free.fr/novdec14-WP_0.pdf
and the link:
MEOSAR: New GNSS Role in Search & Rescue | Inside GNSS

For some reason, the link to CNES site is not working anymore (or the whole site) but I still have an header for it:

Long post - bring a sandwich.
 

Recently schooled by a Hughes SATCOM guru, I learned 'streaming' DFDR and CVR data over satellite link may sound easy, but in fact is not. There are several reasons for this, but two principal issues are bandwidth and available connections.

Cost - directly connected to bandwidth usage and number of stations. Most providers bill by the amount of data and the number of stations or links, ie aircraft. Current SATCOM internet and communication links are subsidized by passenger payments.

In contrast, access to VHF & HF networks, outside of minimal user fees and taxes, is virtually free. Data forwarding is where most of the operating cost for ACARS connectivity comes in using ground-based communication networks and this cost is a single-digit percentage of a comparable SATCOM data rate.

Availability - Spanning several factors, one of which by design allows only a limited number of transponders per satellite. A common satellite band used in North America currently runs at around 75% capacity. Those limited channels and bandwidth would quickly overload should the world's major airlines suddenly start uplinking data from a pool of the 100,000 odd EDIT: commercial flights that typically ply the skies each day.

Build more birds? The cost of a typical Comms Satellite is around $500 million US and obtaining a Geosynchronous parking slot for just one bird typically takes several years of waiting in a queue.

Someone would need to pay for not only the bandwidth once available but also the expansion of existing systems to accommodate. Without subsidization support of passengers or governments, it is doubtful many airlines would be willing to cut into their already tight budgets for this.

You might ask the question, "Wouldn't passengers be willing to pay for the unseen and unfelt benefit of a DFDR/CVR 'streaming' mandate?" Unfortunately, it has been several decades since safety was a marketable commodity in commercial aviation, so I would say, no.