EgyptAir 804 disappears from radar Paris-Cairo

[Lonewolf_50]

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?

[RAT 5]

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.

[Psyborg]

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

[Water pilot]

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.

[Lonewolf_50]

Interesting idea you have there on the FDR buffer.

Originally Posted by Water pilot

The safety of living passengers far outweighs the curiosity of the rest of us.

Looks like a t-shirt idea in the making.

[GXER]

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.

[RAT 5]

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?

[mm_flynn]

Originally Posted by GXER

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.

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.

[GXER]

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.

[jugofpropwash]

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.

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.

[goeasy]

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!

[mm_flynn]

Originally Posted by RAT 5

GXER: thank you. You seemed to have answered the question I was posing; i.e. it is perfectly feasible and should not be expensive.

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

[mm_flynn]

Originally Posted by jugofpropwash

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.

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.

[Mesoman]

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.

[underfire]

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

[Intruder]

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?

[takata]

@underfire

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

"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.

[Mesoman]

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.

[takata]

@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:

Communiqué : Airbus Paris Le Caire, le CNES mobilisé
L'actualité du CNES - 3 Juin, 2016 - 18:43
Dans le cadre des opérations de recherche de l’Airbus Paris Le Caire disparu en mer le 19 mai 2016, le CNES et le Commandement Interarmées de l’Espace de l’Etat-major des armées ont coopéré sur des travaux qui ont conduit à préciser la zone de recherche de l’appareil dans laquelle ont été captés des signaux des boites noires.

Vidéo : Cospas-Sarsat, des satellites pour sauver des vies
L'actualité du CNES - 3 Juin, 2016 - 17:53
Le programme international Cospas-Sarsat permet de sauver chaque année 1500 vies à travers le monde grâce à ses balises de détresse. Cette année, c'est la France qui préside l'organisation.

[vapilot2004]

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.