After seeing the live footage of the WTC crashes, as well as the aftermath of the Pentagon and PA crashes, how likely is it that the airplanes black boxes would have survived intact enough to glean the details of the onboard events of these flights?
Also, has any info been released as to what downed the flight that crashed outside of PA? I’m interested in knowing if it was a)shot down, b)brought down during a struggle inside, c)something else.
Finally, how many planes were involved? I know there were:
2 at the WTC
1 at the Pentagon
1 outside of Philly
but I thought there was another one- I just can’t seem to find anything on it.
Thanks in advance
-j
They are specifically designed to survive crashes and jet fuel fires. Here is an article from Scientific American on black boxes. These things are tested to 1100 degrees C (about 2000 degrees F). Temperatures in the WTC fires were estimated at 1500 degrees F, according to one of the broadcast networks last night.
The likelihood that they survived seems pretty good but the likelihood they would be found in the rubble is probably slim (IMHO).
Bet your butt the boxes survived and they will be found.
The accidents were horrific air crashes, but there have been ones with greater impacts, at greater velocities, in terribly remote areas…and ther boxes were found.
The extra plane everyone is referring to is becoming sort of a legend. One plane was briefly unaccounted for, but as an f-16 flew alongside the last plane landing in Denver, all planes were accounted for. (Four planes were involved, three hit targets, one crashed after u-turning over wester PA and heading thru PA to DC.)
The hijackers knew how to cut off communications with the towers, so it’s possible that they turned off all recordings.
ABC had someone last night (can’t remember who, sorry. I’m in information overload right now) that surmised it would be at least one to two days before the black boxes can be recovered for PA, even longer for the other three planes. Just so much goddamn rubble and debris to go through.
I have the utmost confidence that they will be recovered eventually, though.
So, in addition to the new question on black box accessibility raised by Philster’s remarks, I’m also interested in the possible targets of the PA flight.
I had heard, fairly early on that it was assumed that the White House was a planned target. This makes sense. But I’m confused as to which plane was heading for it. I have heard several reports claiming that the plane that hit the Pentagon was actually meant for the White House. Of course, knowing about the PA crash, it can be assumed that the White House was a separate target, which would have created a sort of symmetry to the attacks (2 in NY, 2 in DC).
However, I’ve also heard that the Sears tower was another presumed target. Or am I confusing that with the destination that people thought the (non-existent) fifth hijacked plane might have taken?
Wasn’t there another plane detected off the east coast? I know that people were told to seek cover at the Pentagon later in the day.
Sorry for the incoherence, and please forgive the questions that I know raise speculation and not hard facts. I’m just trying to make sure that I’m not missing any smaller bits of info after watching everyting unfold on TV and on the Web over the past two days.
The black box is not going to give any useful info re the 4th flight. We already know everthing it will reveal: the speed of the plane, the path, etc. It does not disclose any conversations on board, which is crucial. Only the voice box can disclose that, and it won’t disclose anything if the transponder was turned off, which it assuredly was by the terrorists.
I’ve read from several sources that the 4th plane was headed for Camp David.
It appears that we did not shoot that plane down, but somehow the crew managed to down it themselves. Something the other crew members would have done, if they knew the ultimate destination of their planes.
I don’t know that it is possible to turn off either the Cockpit Voice Recorder (CVR) or the Flight Data Recorder (FDR). What would be the point if these things could be turned on and off? Every hijacker inthe world with a clue would be demanding that the thing be shut off which is something investigators definitely don’t want to see happen. I think if the plane is ‘on’ (or running) the CVR and FDR are automatically running as well.
Federal law strongly regulates the release of CVR tapes and transcripts so the pilots can generally feel free to speak their mind without worrying that their latest tale of sexual conquest won’t get back to their spouse (or some such thing).
As for the survival of the Black Boxes (which are actually orange) I’m not so certain. Certainly they’ll get the one in Pittsburgh and prbably the one at the Pentagon. However, as tough as those boxes are, not much could survive the weight of a building falling on them. I have no doubt they will be eventually recovered but I worry about their ability to give up information after the business they’ve just been put through.
BTW: They are designed to withstand 1100 degC for 30 minutes. I don’t know the temperatures inside the WTC but they were obviously hot enough to weaken the steel supporting beams and the fires burned for more than 30 minutes (45 minutes?) before the tower(s) collapsed.
Whack-a-mole: see, that’s what I thought- it doesn’t make sense to me that something as potentially important as the black/voice boxes could just be turned to the “off” position- that would just undermine their function.
evilhanz: Thanks for the link, but I suspect you need to get some more exercise, as you are huffing away at the keyboard.
Just because he’s a pilot doesn’t mean he’s right.
A transponder does not carry voice information - it carries a signal to secondary radar with data about the plane registration, altitude, and possibly other information (there have been several types over the last 5 decades)
A cockpit voice recorder, IIRC, is hooked up to three voice mikes in the cockpit. One for each pilot and one to pick up background noises.
There is no way to turn these on or off from inside the plane.
What kind of pilot was he? Airline, private, hangglider?
It does not make logical sense to have the CVR connected to the transponder.
The transponder is simply a secondary radar device as described by Broomstick. It sends primarily altitude data to the ground based radars. In order for the radar operators to discern between diferent aircraft, each aircraft is assigned a 4 digit code which is manually set on the transponder and appears as a tag on the appropriate contact on the radar screen.
The CVR and FDR are specifically wired to NOT allow them to be disconnected by the crew, otherwise, the crew knowing they’d made a monumental cockup could turn it off.
A crew in the process of having a bad day and contributing to their crash may never have turned the transponder on, or may have inadvertantly turned it off.
There is no reason for the CVR to be connected to the transponder, they are unrelated pieces of equipment.
I’m a pilot too, does that make me more or less right than the guy on the radio?
So where do the voice and flight recorders get their power? Do they have battery backups inside? If not, is it possible that they share the power source with the transponders, which are vital for flight safety and are required to be on all the time?
It would make more sense to either give the CVR and FDR their own battery, or simply harwire them into the aircraft power, when the plane is powered the recorders are powered.
I don’t know for sure though, have been trying to find some info on them on the net but just get the general stuff about what they do.
The CVR and FDR are far more important than the transponder. What would happen if a crash was caused in part by a non functioning transponder?
Gosh, you folks ask a lot of questions. I may be a pilot but CVRs and FDRs aren’t my forte since I fly the little planes.
The CVR and FDR are probably hooked into the main power, but with battery back-ups that come on line in the event of a power failure.
About those transponders - this will probably shock a few folks, but they are only required if you fly into certain types of controlled airspace. There is a lot of airspace in this country where they are not required, but if you don’t have one you must remain in those areas which are away from major cities and air routes.
If you have a transponder you aren’t required to have it on unless you are flying in airspace that requires it, or are on an instrument flight plan. On the other hand, most people leave it on because it certainly doesn’t hurt and it makes you more identifiable on radar, which helps air traffic route traffic.
Once, I had a malfunctioning transponder on my Cessna 150 (it was giving my altitude as 35,000 feet) and ATC told me to actually turn it off because it was too distracting.
I can’t imagine how a crash could be caused by a malfunctioning transponder except in the most tangental manner. If a transponder quits in flight (and it does happen) ATC tells you they aren’t picking you up and you usually wind up making regular altitude and position reports. If it’s particularly busy airspace they may divert you.
I realise it would be very unlikely for a transponder fault to cause an accident, it could be a contributing cause if a radar controller gave incorrect instructions assuming an aircraft was at a particular altitude when it’s not.
What I meant by posing the question, is that it would be irresponsible to link the CVR to the transponder because that would mean that a transponder failure would also mean a CVR failure, which would also mean no CVR crash data if an accident occured coincidentally with a transponder failure. Therefore I find it highly unlikely that the CVR would be linked to the transponder or any other piece of equipment on the flight deck.
The CVR and the FDR are two completely separate boxes. Neither one has anything to do with the other. The FDR is hooked to the transponder but even if that failed the FDR will still gather whatever data is showing on cockpit instruments that it is programed to gather.
The CVR, on the other hand, isn’t much more than a fancy and robust tape recorder. Short of digging the microphones out of the cockpit or some complete failure of power (including battery backups) the CVR will continue to work till the crash.
