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Barbara you've delved more deeply into airline saftey than I can possibly imagine. I've always been interested in the topic due to my fear of airliner flight, but I'm no expert. I'm wondering if you can help me with a question I have.

I know that the CVR and FDR on the plane failed when the electrical systems were severed, I also know that having a battery backup for the FDR would be pointless because all the control surfaces wouldn't be able to relay information without power. But I'm wondering would it be feasable to have a battery backup of the CVR so that it wouldn't fail when electrical power is lost, and also was that mentioned anywhere in the CTSB's reccomendations?


"Those Who Don't Learn From The Past Are Doomed To Repeat It."
 
Posts: 180 | Registered: Sun July 09 2006Reply With QuoteReport This Post
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Murray, I'm checking into this for you with IASA.
 
Posts: 2566 | Location: USA | Registered: Sun April 07 2002Reply With QuoteReport This Post
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You are correct in that the TSB did recommend a battery-powered CVR be instituted. They had some other recs as well..... to do with the utility of the Quick Access Recorder and the potentiality of an image recorder. Chairman Jim Hall of the NTSB later strongly supported the concept of image recording as being cheap and readily adaptable for business jets and turboprops.
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1.11.4 Lack of CVR Information
The CVR in the occurrence aircraft had a 30-minute recording capacity; this met the existing regulatory requirements. The requirements were predicated upon the technology available in the early 1960s, and 30 minutes represented the amount of recording tape that could reasonably be crash protected. Current technology easily accommodates increased CVR recording capacity. The majority of newly manufactured, solid-state memory CVRs have a two-hour recording capacity; however, regulations pertaining to HB-IWF at the time of the accident did not require more than the 30-minute CVR recording capacity.
The earliest information on the SR 111 CVR was recorded approximately 17 minutes before the unusual smell was detected by the pilots. Conversations and cockpit sounds prior to the beginning of the CVR recording would have been useful in looking for potential initiating or precursor events that led to the in-flight fire.
Aircraft electrical power to the SR 111 flight recorders was interrupted at about 10 000 feet, which resulted in the FDR and the CVR recording stoppage. The aircraft continued to fly for about 5.5 minutes with no information being recorded.
Modern, maintenance-free, independent power sources and new-technology CVRs make it feasible to provide independent CVR and CAM power for at least several minutes. This would allow the continued recording of the acoustic environment of the cockpit, including cockpit conversations and ambient noises, in the event of the loss of aircraft power sources.
Current battery technology would not provide sufficient independent power to allow for the same option for FDR information. The multiple sensors and wiring that feed information to the DFDAU require aircraft power.
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http://www.tsb.gc.ca/en/reports/air/1998/a98h0003/01rep...ctual/rep1_11_04.asp
 
Posts: 13 | Registered: Sun May 12 2002Reply With QuoteReport This Post
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1.11.5 Quick Access Recorder (STI1-59)
Initiatives undertaken by airlines, such as the development and implementation of increasingly complex flight operational quality assurance programs, require that an increased number of data sets be recorded. Quick access recorders (QAR) were developed because information in FDRs was not easily accessible for routine maintenance and monitoring of aircraft systems. This type of recording has been done on QARs, which are not required by regulation. Most QARs in use routinely record far more data parameters, at higher resolution and sampling rates, than do FDRs.
Unlike FDRs, QARs are not designed to survive in a crash environment. From the numerous pieces of magnetic tape recovered from the aircraft wreckage, 21 individual segments were identified as likely being from the aircraft's QAR. Attempts were made to extract information from the QAR tape; however, it was not possible to extract meaningful information from any of the pieces.
The QAR installed on SR 111 had a tape-based cartridge that recorded approximately 1 400 parameters, which is about six times the number of parameters recorded on the FDR. The additional data recorded on the QAR included numerous inputs that could have been valuable to the investigation. Such information could have assisted in determining the serviceability of aircraft systems prior to, during, and after the initial detection of the unusual smell and subsequent smoke in the cockpit.
Investigative agencies have traditionally promoted the view that additional parameters should be added to those already recorded on FDRs. Typically, the recording capacity of FDRs has not been the limiting factor; rather, these initiatives have been tempered by the high costs of installing the necessary equipment into the aircraft, including the additional data sensors and associated wiring. An additional limiting factor has been the high cost of obtaining certification for the changed mandatory FDR data set.
Modern FDRs, which employ the same solid state memory technologies as modern QARs, make it technically feasible to capture the QAR information within the FDR in a crash-protected environment. However, current regulations do not require that this be done.
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1.11.6 Lack of Image Recording
The SR 111 cockpit was not equipped with an image recording device, nor was this type of device required by regulation.
Recently it has become economically realistic to record cockpit images in a crash-protected memory device. New "immersive" technology provides for economical single-camera systems that can capture a 360-degree panoramic view of the cockpit environment. Special playback software allows investigators to "immerse" themselves in the cockpit and virtually view the entire cockpit.
Such a capability could have been valuable during the SR 111 investigation; the investigation could have been expedited and potential safety action more easily identified.
 
Posts: 13 | Registered: Sun May 12 2002Reply With QuoteReport This Post
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Why would you make a flight recorder that's not designed to withstand impact? That seems like a waste of money and material to me.

As for image recorders I'm mixed on them, because they would provide valuable information, but at the same time the media would be screaming for their release and that's rather tasteless. (Which is why the media would want it) Also I imagine the families of the pilots wouldn't be too keen on this idea, but maybe I'm wrong. I definatly don't think a cabin cam would be a good thing, but I've never lost someone in a crash so I don't know how families would feel about that. I imagine most of them wouldn't want to see it, but at the same time I'm sure some of them also have a desperate need to know what happened to their loved ones and it may help them find peace.

Either way it is a very difficult subject.

If they ever did so something like this I'd only support it if strict regulations regarding the banning of publication of the images was observed.

As for the power source issue, I seem to remember I saw a show one time where a plane lost all of it's power so the pilots flipped some switch or something and it deployed a fan outside the aircraft that the rushing air spun around and generated electricity. Perhaps something like that could be permanently attached to the tail section of an aircraft and connected to the Flight Recorders as a secondary backup.


"Those Who Don't Learn From The Past Are Doomed To Repeat It."
 
Posts: 180 | Registered: Sun July 09 2006Reply With QuoteReport This Post
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Video would play in the hands of ghouls. But the caveat is, change is often political too. It takes public outrage for the government and corporations to listen, otherwise it can be papered over.

Video is needed in the belly of the planes and to view the tail of jets. Not so much what was going on in the cockpit, as it'll also record the deaths (not a pleasant sight for anyone, and serves absolutely no public purpose).

The fleet needs digital recorders that can compress full flight data for enough time to travel across the Atlantic and Pacific (like 8hrs). With compression software now, it wouldn't take much space, less than what's currently used and still offer more data (including video).
 
Posts: 17 | Registered: Tue July 18 2006Reply With QuoteReport This Post
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Ya, as I said I'm mixed on video. But what I do think desperatly needs to be done is adding a backup power source to the Data and Voice recorders. Compressing the info is a good idea I didn't think of before. I'm pretty sure (I'm no expert so maybe you can shed some light) that the new Recorders are digitalized so if that's the case it shouldn't be too hard to change them to compressed.


"Those Who Don't Learn From The Past Are Doomed To Repeat It."
 
Posts: 180 | Registered: Sun July 09 2006Reply With QuoteReport This Post
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Each format has it's advantages and disadvantages. Quality of digital audio (and video) is superior to taped resources (can scan the recording for those minute structural sounds, for example), and it can hold more data in a smaller box. But digital is more prone to electrical interference and shorts. Tape can last in environs that digital electronics would bust (like 500ft in salt water -- tape can shred and tear and corrode, but the data won't be wiped clean [unlike a EPROM or any other chip is damaged]. It's possible to splice what's left, while with digital it's just gone [unless there's some backup media that it records on]).

Battery backup is a nice redundancy feature and should be required (even a second recorder that runs strictly on battery power would be nice). Chances of both recorders being destroyed is slim. Even another way to save data is using an encrypted channel (UHF or even microwave perhaps) that relays the chatter to a central recording station [it's good for recording the entire dialogue before a crash, and possibly record any sounds that indicate problems too -- seems investigators now are scanning the CVR for tale tale structural damage sounds, which can occur long before a crash, too].
 
Posts: 17 | Registered: Tue July 18 2006Reply With QuoteReport This Post
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