Questions About Flight Door, How Do I Debunk a Debunker! Options

[REDSHIFT]

Hi I just joined, as you can see. (IMG:style_emoticons/default/rolleyes.gif) I got hooked on your forum in the middle of the night, while reading about the FDR and Flight 77 Flight Deck Doors not being open. I understand the part about this FDR not being for the actual flight. I got a few knit-picker debunkers, that have me going around in circles about stuff. I asked them to read your whole thread first, before commenting. This one has me stumped. You know more about it than I do, can anyone here explain it to me, so that I can give the poster a snappy comeback? (IMG:style_emoticons/default/handsdown.gif)
http://pilotsfor911truth.org/forum/index.php?showtopic=18405

Quote:
Yes, the FLT DECK DOOR value was CLOSED for the entire flight. You got me. Oh wait, the same parameter is the same for ALL recorded 12 flights. The pilots never got anything to eat or left the flight deck to go to the bathroom, not even on the long LA - DC flights. As a matter of fact, the door is NEVER recorded OPEN for any point ever when the FDR is recording. Very strange. The pilots must have worn those astronaut diapers.

Thoughts and advice: There are 42 HOURS of flight data in Warren RO. It is wise to check your observations for the last minutes or flight against the other 41 hours of recorded data. I don't know why the value is CLOSED for the entire 42 hours (that is one for the pilot folks to hash out), but if the parameter never changes and reason dictates that it should at some point, then I can conclude one of two things. The parameter was not being recorded and a default value was being stored, or the parameter being recorded is not what some think it is.

and after my reply, I got this:

The Flight Deck door parameter is also listed as "Not Working or Unconfirmed" on page 13 of the FDR report:

http://www.911myths.com/AAL77_fdr.pdf

I'll see if I can track down the file 911files was working from.

The poster pulled it from another site, and only posted a thread link, instead of where this information really came from. I questioned their motive. I am a truth seeker. NOT A DEBUNKER or a TROLL. I just have to deal with them.
Lots of the other members, found this forum very interesting, and thanked me.
If you want to check out the thread, so that I can prove my honest intentions, read it here.
http://www.freedomcrowsnest.org/forum/view...asc&start=0
We're all on the same side.

[solequinox]

So help me understand how this sensor works. I have looked at the diagrams but my understanding of electrical mechanisms is very limited.

My understanding is that there is a constant electrical connection when the door is closed and it can measure that every few seconds so that it knows the door is closed. If the connection is broken, by the door opening or by it being broken in some way, then it is assumed that the door is open because that electrical connection is no longer there?

Is it possible that the wire/fuse/relay or something from the sensor to the FDAU or FDR was grounded which made the device think that there was a constant connection and therefore the door was closed the entire time, or that the sensor was not installed and the FDR was recording a default value?

or

Can we prove that N644AA had the sensor installed? It's obvious that the FDR was capable of recording this input and that the aircraft had been upgraded in general for these capabilities, but I can't find anything specific about the sensor, just the FDR and data frame layout.


Just for some background, this is what I've researched so far:

I have looked at the FAA Registry but I can't find anything specific about the airplane being upgraded.

I've seen the FDR Law that made the airplanes upgrade their FDR systems, but I can't find anything specific about necessitating the sensor, just the FDR system.

I've looked at the Federal Code of Regulations for FDRs which lists the 91 data parameters which are required to be recorded, but I can't find anything that specifically points to FLT_DECK_DOOR. Does anyone have any insight on this?

I've also looked at the FAA Regulations for FDRs just out of curiosity. It says that for each FDR the manufactorer has to submit detailed wiring, installation, and equipment guidelines, limitations, and schematics to the FAA. I wonder if this stuff would be useful and if it is available through FOIA?

[Guest_Turbofan_*]

My understanding is that there is a constant electrical connection when the door is closed

It depends on which part of the diagram you are viewing. The proximity switch actually breaks the circuit when
the door is closed, and energizes a relay which supplies power to the lock solenoid.

and it can measure that every few seconds so that it knows the door is closed.

The FDAU polls the EICAS port 41 to read the value every 4 seconds; the signal voltage is present constantly whether the door is open,
or closed (1 = open, 0 = closed).

If the connection is broken, by the door opening or by it being broken in some way, then it is assumed that the door is open because that electrical connection is no longer there?

If the door is open, the proximity switch grounds the relay which supplies power to the lock solenoid and lighting systems. It also illuminates
the pilots' overhead indiactors. There are several circuits connected to the multi-pin relay.

Is it possible that the wire/fuse/relay or something from the sensor to the FDAU or FDR was grounded which made the device think that
there was a constant connection and therefore the door was closed the entire time, or that the sensor was not installed and the FDR was recording
a default value?

No, a broken switch or loss of power to the circuit causes the indicator lights to illuminate showing a "DOOR OPEN" condition. The FDAU also
receives a logic 1 (OPEN) state.

This is why it doesn't matter if the door is kicked, or the switch fails.

Can we prove that N644AA had the sensor installed? It's obvious that the FDR was capable of recording this input and that the aircraft had been upgraded in general for these capabilities, but I can't find anything specific about the sensor, just the FDR and data frame layout.

We are currently tracking down proprietary documentation to document this fact.

All evidence points to the switch being installed as already covered in the main thread, "Hijacking Impossible" which is within the LATEST NEWS
forum. Have a look there for more info.

[rob balsamo]

No, a broken switch or loss of power to the circuit causes the indicator lights to illuminate showing a "DOOR OPEN" condition. The FDAU also
receives a logic 1 (OPEN) state.

Thank you Tino.

So for those laymen out there. The Door fails to the OPEN indication.

Meaning any failure of the switch will record an OPEN position.

This is logical with all indications I've ever seen on aircraft. They fail to the LEAST likely state alerting the pilots, mechanics, etc, to look at it.

In other words, you get a door open indication. You look at the door, its closed. You know readily, for a fact, the switch failed. Engineering 101.