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underwater beacons on CVRs and DFDRs

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underwater beacons on CVRs and DFDRs

Old 10th Apr 2014, 07:42
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underwater beacons on CVRs and DFDRs

As I am reading the news on MH370's search in the South Indian Ocean, I came to realize that these underwater beacons look like really cheap and outdated devices. Starting with the beeping for only 30 days. As with AF447, 30 days proved to be a ridiculous short time a find anything in the high seas. Surely the cost and weight of a 6 month-life battery is by no means a financial or technical burden on an airline; look at bulletproof cockpit doors for a comparison.

I don't know the very technical data of the underwater pinger, but to quote a line in some online news article:

"The range of the pinger is limited because it uses a relatively high frequency of 37.5 KHz. In water, high-frequency sounds travel shorter distances, meaning the pinger signals can travel only 2,000-3,000 metres."

Damn! This is where we're at, in the 21st century?! For millions of years the ocean floors had depths in excess of 6000 meters in places, what do we expect from a plane going down at sea? To float for 3 months?

Is there today any pinger that does a better job? Like a lower frequency to get a better range underwater, or a CVR/FDR mounted with a battery lasting a year?

What I am talking about here are not technological breakthroughs, but merely upgrades to existing equipment, as it is obvious in this day and age, that we can't find an aircraft in the time available from the pingers batteries to give off their position, let alone the depth at which they could be transmitting from, incompatible with surface detection... time for a change?
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Old 10th Apr 2014, 07:58
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There are moves to go to a longer lasting ULD and at lower frequencies.

Things will change but it is almost vanishingly rare to lose an aircraft.

Isn't it wonderful though that despite losing so much nav and comm's we were still, in all likelihood, able to find the aircraft?

I'm all for increased tracking and recording capability. Passengers need to know flying is not cheap, nor is it inherently safe. They'll need to pay a bit more for the extra safeguards so many seem to be demanding.
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Old 10th Apr 2014, 10:02
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underwater beacons on CVRs and DFDRs

Too bad the comm and data services via Sat are expensive and airlines elect not to use them to save money.
These types of events do not happen often. To change the batteries or beacons would require changes to maintenance programs, storage and maintenance practices, paperwork and procedures.
239 people and 1 aircraft is sadly a loss but not significant to update world fleets. They will boost up current technology available and not used on the ground.
These Frequencies are optimal for submarine operations not to mention low power requirement.
The news are babbling whatever they hear. Sad way to broadcast and educate viewers who depend on the news for information.
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Old 10th Apr 2014, 11:15
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Though I'm not especially technical nor in the industry, I do wonder if a transponder might be better than a simple beacon because...1) less power would be needed while in receive-only mode, so the batteries would last longer; 2) the time taken from the transmission of the interrogate pulse to the receipt of the reply would give a rough distance.
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Old 10th Apr 2014, 12:51
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The rules have already changed, and 90 day life batteriers are compulsory from the end of the decade. Many companies have already incorporated these into their products as they come through for scheuduled servicing...


The drawback to a transponder is the added complexity of the recieve / process / transmit circuitry needed.

Many companies are already looking at ejected CVR / FDR, or even a simple floating transmitter with a GPS locator built in.

There is always a cost/benefit analysis, and ultimately the number of aircraft lost in this way is tiny in the grand scheme of things.
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Old 12th Apr 2014, 23:38
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HR Smith Crash Position Indicator, Deployable Beacon, 503 Series - Hayward & Green Aviation

Standard fit on offshore helicopters
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Old 13th Apr 2014, 06:57
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Thanks for the info Eric, sure looks a step ahead of what we can see on current airliners, although it seems that the battery lasts only a couple of days, sure it must be enough, as it is designed to transmit GPS coordinates to satellites, then any search & rescue operation can be launched right away.

Of course, the cost implications mean we may not see this as standard on airliners before or long time.

The revenue made on oil rigs seems to dictate the use of this nice equipment; passenger revenue on airliners seems to be the contrary... oil worth more than lives
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Old 13th Apr 2014, 15:33
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I begin by saying that I have no answers, only questions.
I am appalled just like you that a large piece of heavy metal can disappear into nothingness so many days long.
I made a great deal of research on all aircraft disappearance at sea since 1937.
But it is so long that I'm saving you the details.
I would just tell you:
1948-1949 8 aircraft disappeared
1950-1959 16 aircraft Missing
1960-1969 19 aircraft Missing
1970-1979 19 aircraft Missing
1980-1989 10 aircraft Missing
1990-1999 7 aircraft Missing
2000-2009 6 aircraft Missing
2009-2014 3 aircraft Missing
It 's clear that from 1950 to 1979 the number increases with the increasing traffic.
Then there is a reversal trend probably caused by the introduction of more and more sophisticated means of locating the wreckage.
But just one plane ditching (cause of the reduced location time, the greater chance to recover some survivor, less pain of relatives, the satisfaction of hunger for knowledge of the causes thanks to the early discovery of the black boxes) would justify the following remarks.
We all know the pros and cons of " ELT " " PLB " " EPIRB " but it seems that under a few feet of water they bcompletely lose their effectiveness.
I was wondering: Is there a way to get them out quickly in the event of ditching?
After I puzzled to conceive a system that did emerge and float, I found that it already existed:

Google EPIRB

Don't you think that even if we are crushed by the pain caused by the MH370 event, we have to do something because such a device is adapted for commercial aviation, certified and installed as soon as possible at least on the aircraft traveling long distances over Oceans, Poles, desert areas?
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Old 14th Apr 2014, 12:43
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Did your search indicate how many aircraft successfully ditched without destroying themselves?
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Old 14th Apr 2014, 15:30
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It's NOT Rocket Science

As someone here pointed out, aviation is not inherently safe and it is necessary to take precautions. As we go higher, faster, and over inhospitable terrain, we must increase those precautions. The basic business model of commercial airlines is flawed in that it really isn't economically feasible to fly masses of people at ridiculously low prices. That's why so many airlines merge and/or fail. If you must fly high and fast over vast ocean areas, it is going to cost lots of money to do so safely.

The 37.5 KHz frequency was chosen because of the lack of competition from natural oceanic noises. While that is rational, increases in electronic technology have made multiple-frequency pingers and transponders possible. The same goes for increased battery life. Rocket science has given us wonderful advances in capabilities but what was rocket science even 25 years ago is no longer rocket science. It's routine technology which we all use in daily life.

With the apparent state of airline pilot training we will see more and more disasters like AF447 and Asiana and hence the need for an increased safety measures. We now know what happened to those but unless the current search is successful we will not know what happened and how to prevent a repeat.

We should all be infuriated that the managers who listen exclusively to the bean counters are playing fast and loose with our safety. If you want to fly safely you need to pay for it.
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Old 14th Apr 2014, 18:16
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FLEXPWR

I doubt cost is an issue here. The offshore boys can afford one on aircraft carrying as few as 10 pax then if an airline cant afford one then they shouldn't be in business.
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Old 17th Apr 2014, 04:51
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eric, I agree. The question is then: what is the issue? If the technology is there, why not use it?

Many air carrier are installing WiFi for passengers, this sure costs more than an extra battery for a pinger?
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Old 17th Apr 2014, 11:58
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Originally Posted by FLEXPWR
Many air carrier are installing WiFi for passengers, this sure costs more than an extra battery for a pinger?
Ah, but wifi makes more money. Few passengers will pay extra to travel with a carrier because they've got a better pinger than everyone else.

With that said, an upgrade to the pinger can't really be done alone. In MH370's case, we got almost ridiculously lucky that (a) Inmarsat was still getting data even though the plane wasn't signed up for that, and (b) someone at Inmarsat realised that they could use the tiny amount of available data to locate the plane. If not for that, we'd still be searching north of Vietnam, and no pinger upgrade is going to help there. Some device to say where the plane went down - be it an ejectable GPS beacon or something else - is really necessary to get search vessels into an area where the pinger might be useful.
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Old 17th Apr 2014, 20:34
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Dukane Seacom Locator Beacons

The new underwater beacons will run for 90 days
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