• MH370 speculation has become excessive recently. Metabunk is not a forum for creating theories by speculation. It's a forum for examining claims, and seeing if they hold up. Please respect this and keep threads on-topic. There are many other forums where speculation is welcome.

Cockpit Flight Recorder question

Qualiall

Member
I apologize if this was addressed in another thread. I was wondering if after such a long flight, possibly after everyone aboard was dead, and seeing as the cockpit voice recorder only records the last two hours, that recovery of this would not answer any questions, or there would be a way to access overwritten data?

When I was younger, I remember discovering that when recording on cassette tape, if I pressed the record button so it wasn't fully depressed that I could overlay sound upon what was recorded before. (had lots of fun remixing songs that way) . So I would imagine recovering overwritten data on a magnetic tape would be easy.

But with solid state technology, is this possible? From what I understand about solid state is that data is completely overwritten.
 

TWCobra

Senior Member
It is over written every two hours but I believe that with digital processing they may be able to extract some data. The most important data though will be the Flight Data Recorder, which has the last 25 hours of flight time recorded.
 

Svartbjørn

Senior Member
So... just to clarify Cobra.. there's more than one recorder? One's a Flight Data Recording, which records everything the mechanical aspects of the aircraft were doing... button presses, pilot input, altitude, speeds, (vectors?) etc.. and then there's the Voice Recorder, which records all the sounds and conversations etc in the cockpit? Or is that over simplified?
 

WeedWhacker

Senior Member
So... just to clarify Cobra.. there's more than one recorder? One's a Flight Data Recording, which records everything the mechanical aspects of the aircraft were doing... button presses, pilot input, altitude, speeds, (vectors?) etc.. and then there's the Voice Recorder, which records all the sounds and conversations etc in the cockpit? Or is that over simplified?
Yeah, the FDR and CVR are all digital nowadays (compared to 1960s and 70s era, with foil tape and needles scratching into it for the FDR, and a continuous-loop magentic tape-- like an old 8-track cassette -- that had about 30 minutes of recording time).

You're spot on RE: the FDR - And, even more than you mentioned. LOTS of data points can be monitored, and recorded. (You've no doubt already learned of the ACARS transmissions that routinely send "Status Reports", too). Also nowadays, just about every airliner also has a QAR (Quick Access Recorder) which we call a "snitch"...this could also be called an "FDR-lite". Its data is regularly downloaded by the avionics specialists in the Maintenance Department. Then, it is checked for any "gotchas" such as flap limit overspeeds, unstabilized approaches, etc. This info is part of an airline's "Continuing Maintenance Program" (or some similar terminology) and it is designed to lower costs (of course) due to the increased monitoring.

Particularly egregious excursions from SOPs are flagged....usually "de-identified" (but this is per a Collective Bargaining Agreement, and will vary from company to company). This "de-identified" data is often used in annual refresher training ("re-current training") whenever a 'trend' is seen.

Also, SOPs are sometimes altered, due to observed 'trends'. Of course, if a really bad violation has occurred, then in concurrence with the Union, the responsible crew are called in, and either disciplined, and/or given "extra" training. The FAA can also take administrative action.


...and then there's the Voice Recorder, which records all the sounds and conversations etc in the cockpit?
When you get a chance to read an NTSB accident report (for example) and the CVR transcript, you will see acronyms like "CAM"....that is 'Cockpit Area Microphone'. Yes, that is one thing recorded by the CVR....also, all of the audio channels (VHF Comm #1 and #2...and #3 if installed ...HF #1 and #2, etc)....and the Interphone(**)...that's the way to communicate within the jet (Flight Deck to cabin, and within the cabin, F/A to F/A....and we, of course, can monitor that on one of our audio channels....when I was particularly bored, I'd have that in my earpiece, and also to have a hint about what was going on "back there"), and to the ground crew when they have headsets plugged in....and of course, all PAs are recorded too.

(**)BTW, next time you fly, note the chimes in the cabin. The two-tone "Bing-Bong" doorbell sound is the Interphone call. You will also see lights in the ceiling...pink (IIRC) is the Interphone, within the cabin. Blue means the cockpit is calling. A single chime (if not a seatbelt sign turning on or off) is a passenger call from the PSU above their seat...white (unless they're in the Lav....which, of course, is ......yellow! ;)

PPS- The colors might vary between companies, per their preferences. But, yellow never changes! :D
 
Last edited:

MikeC

Closed Account
SOPs - Standard Operating Procedures :) Just another of the myriad TLA's in aviation

(TLA - Three Letter Abbreviation)
 

Svartbjørn

Senior Member
This is probably way off topic... but why the hell are they called black boxes when they're usually yellow or orange? Was that a media thing because black box sounds better than orange box?
 

Svartbjørn

Senior Member
Ahhhh okok, Ive read all taht before but I wasnt sure how much of it was urban legend and how much of it was factual.. thanks Mike.... and deirdre
 
Thread starter Related Articles Forum Replies Date
TheoryQED Cube videotaped from the cockpit of commercial airline Skydentify - What is that Thing in the Sky? 1
Mick West Hoax: AirAsia QZ8501 Black Box Voice Recorder [Alleged Adam Air 574 in 2007] General Discussion 0
Agent K Serpentine flight pattern over Los Angeles Skydentify - What is that Thing in the Sky? 18
Leifer USS Ford : leaked footage of UFO seen on flight deck [CGI] UFOs, Aliens, Monsters, and the Paranormal 4
Priyadi Antipodal Flight Flat Earth 18
Mick West Explained: Jet Chasing UFO: X-45A and F/A-18B Formation Flight Skydentify - What is that Thing in the Sky? 6
Mick West Ethiopian Airlines Flight 302 and 9/11's United Flight 93 9/11 6
Mendel Debunked: Air Map of the World 1945 is a flat Earth map Flat Earth 0
G Flight data for Flights 11 and 175 9/11 4
Mick West Inexperienced Pilot Recreating 9/11 Flight 77's Descending Turn into the Pentagon 9/11 30
inkwell American Airlines Flight 77 Missing from Bureau of Transportation Departure Report 9/11 12
inkwell American Airlines Flight 77 Aircraft Accident Package lists no. of Passengers/Fatalies as "Unknown" Conspiracy Theories 3
Mick West Explaining the 9/11 Murray St Engine from Flight 175 (N612UA) that hit WTC2 9/11 14
Mick West Halifax, NS: Regularly Spaced Gaps in Contrails [Ethiopian Flight 501] Skydentify - What is that Thing in the Sky? 47
Whitebeard 'Strange' Flight Path on FR24 Skydentify - What is that Thing in the Sky? 10
Mick West A Plane Flying Across the Face of the Sun, with Contrails [Virgin Flight 353] Skydentify - What is that Thing in the Sky? 7
V Flight 93 Crash Physics - Fragmented Plane Buried in the Ground 9/11 10
TEEJ Contrails filmed from commercial flight over the Irish Sea - 6th May 2017 Skydentify - What is that Thing in the Sky? 2
Clouds Givemethewillies UK Flight Reporting 115,000 feet Skydentify - What is that Thing in the Sky? 5
psilyguy Flight Tracking Over Oceans and Emergency Landings Flat Earth 27
Trailblazer Jet Airways intercept video "UFO" (airliner, flight LH998 or LH66?) Skydentify - What is that Thing in the Sky? 14
Trailblazer Identified: linear clouds seen from Virgin Australia flight ['morning glory'] Skydentify - What is that Thing in the Sky? 7
Marin B Flight Radar 24 glitch? Skydentify - What is that Thing in the Sky? 4
Mick West Explained: Chilean Navy "UFO" video - Aerodynamic Contrails, Flight IB6830 Skydentify - What is that Thing in the Sky? 186
TWCobra A Flight over the Antarctic Sea Ice From Chile to Australia (QF28) Flat Earth 23
Mick West Relative Humidity at Flight Altitudes. Resources and Contrail prediction. Contrails and Chemtrails 11
steve holmes I'd appreciate help IDing this very odd contrail flight Contrails and Chemtrails 12
steve holmes I'm trying to ID the flight for this old photo of mine, Feb 19, 2014 5:25 pm Contrails and Chemtrails 5
steve holmes I can't ID this flight of Oct 5th [Alaska 577] Skydentify - What is that Thing in the Sky? 6
Whitebeard EgyptAir flight MS804 Current Events 52
skephu Horizon Air Dash 8 making many circles from Seattle Skydentify - What is that Thing in the Sky? 3
c.eileen Help to ID a plane? [N90 - FAA Flight Inspection Aircraft] Skydentify - What is that Thing in the Sky? 30
Trailblazer Unusual flight paths over SW England Skydentify - What is that Thing in the Sky? 12
JFDee New fuel dump "chemtrail" video [Munich, Thai Airways Flight 925] Contrails and Chemtrails 33
Mick West Flat Earth Theory Debunked by Short Flights (QF27 & QF28) From Australia to South America Flat Earth 276
TEEJ Belfast Observer Skywatch claiming that airliners do not appear on Flight Radar 24 - 10th March 2015 Skydentify - What is that Thing in the Sky? 0
Trailspotter Omega loop contrail over Toronto: Veni Vidi Volavi?.. [Likely Bombardier Test Flight from Montreal] Skydentify - What is that Thing in the Sky? 27
TEEJ Gary Cameron Clydebank, Scotland Video, 1st May 2015- Claim of aircraft not being on Flight Radar 24 Skydentify - What is that Thing in the Sky? 11
Mick West HAL47 and HAL9981 Two Hawaiian Flights Diverted to Oakland Skydentify - What is that Thing in the Sky? 2
Efftup Issue with Flight Radar 24? General Discussion 10
Igrokush1 Plane with Yellow Tail over Redding, CA [Polar Air Cargo Flight] Skydentify - What is that Thing in the Sky? 119
Mick West Flight BOE1 Skydentify - What is that Thing in the Sky? 7
Mick West Hoax: Fuel Dump video on Facebook [Flight BA244 from Buenos Aires to London] Skydentify - What is that Thing in the Sky? 181
WeedWhacker Build your own ADS-B Ground Station! For free premium FlightAware or FlightRadar service General Discussion 12
Mick West Solved: Portsmouth UK, "Alien Flight Path" UFO Contrail [Private Jet + Perspective] Skydentify - What is that Thing in the Sky? 11
Mick West N22387 Zig-Zig flight path near Sacramento [LIDAR data collection] Skydentify - What is that Thing in the Sky? 3
C 9/11 P4T FDR analysis of flight 77 9/11 26
Qualiall Air Algerie Flight AH5017 carrying 116 disappears from radar General Discussion 10
Mick West MH17: Video of flight activity before and after the crash Flight MH17 32
Mick West Flight MH17 News Flight MH17 79
Related Articles


















































Related Articles

Top