Air Asia Indonesia Lost Contact from Surabaya to Singapore
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Presumably cockpit sounds and pilot communications are only clearly differentiated if the pilots are wearing headsets. I understand that pilots don't routinely wear headsets all the time in the cruise. Is this right?
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I am new here and reading with great interest.
I have read that there was a write-up on this aircraft and a swap out of ELAC2 and FAC2.... And that uncontrolled rudder trim is now suspected.
I am not a pilot so hope the experts here can perhaps shed more light. Do the past issues with runaway rudder trim on AB have potential importance here?
Many thanks and enjoy this forum!!!
I have read that there was a write-up on this aircraft and a swap out of ELAC2 and FAC2.... And that uncontrolled rudder trim is now suspected.
I am not a pilot so hope the experts here can perhaps shed more light. Do the past issues with runaway rudder trim on AB have potential importance here?
Many thanks and enjoy this forum!!!
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Presumably cockpit sounds and pilot communications are only clearly differentiated if the pilots are wearing headsets. I understand that pilots don't routinely wear headsets all the time in the cruise. Is this right?
I'll defer to the sea lawyers here, but I think the requirement to wear headsets below FL180 on most 'modern' airliners does indeed come from CVR regulations.
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LONE WOLF 50`S QUESTION
"Question on g limitation & flight laws: is 1.75 or 2.5 G (not sure why those numbers are in my head) where the system doesn't let you pull any more G in the A320? With the idea that they got it stalled, and on the way down finally got it un-stalled (which takes some altitude, and might be a challenge if doing it in the goo in very turbulent air) they might end up in a dive but only be able to pull "x" amount of G and not be able to break the rate of descent before impact with surface.
Does that fit the impact being such that the break up spread the major pieces out more?
"
I would have thought unlikely, pancake with the surface would confine debris field. Aggressive external control inputs resulting in possible aerodynamic excessive yaw, resultant from loss of external data. Roll beyond the vertical plane with negative G on horizontal stabilator more likely rather than back pressure on side stick, and in-flight break up of fuselage and empennage.
"Question on g limitation & flight laws: is 1.75 or 2.5 G (not sure why those numbers are in my head) where the system doesn't let you pull any more G in the A320? With the idea that they got it stalled, and on the way down finally got it un-stalled (which takes some altitude, and might be a challenge if doing it in the goo in very turbulent air) they might end up in a dive but only be able to pull "x" amount of G and not be able to break the rate of descent before impact with surface.
Does that fit the impact being such that the break up spread the major pieces out more?
"I would have thought unlikely, pancake with the surface would confine debris field. Aggressive external control inputs resulting in possible aerodynamic excessive yaw, resultant from loss of external data. Roll beyond the vertical plane with negative G on horizontal stabilator more likely rather than back pressure on side stick, and in-flight break up of fuselage and empennage.
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I generally wear a noise cancelling headset while in cruise, especially when flying internationally. Many of my colleagues take off the headset and switch to speaker above FL 180.
I'll defer to the sea lawyers here, but I think the requirement to wear headsets below FL180 on most 'modern' airliners does indeed come from CVR regulations.
I'll defer to the sea lawyers here, but I think the requirement to wear headsets below FL180 on most 'modern' airliners does indeed come from CVR regulations.
CVR's record all conversations with or without headsets.
23.1457 Cockpit voice recorders.
(a) Each cockpit voice recorder required by the operating rules of this chapter must be approved and must be installed so that it will record the following:
(1) Voice communications transmitted from or received in the airplane by radio.
(2) Voice communications of flight crewmembers on the flight deck.
(3) Voice communications of flight crewmembers on the flight deck, using the airplane's interphone system.
(4) Voice or audio signals identifying navigation or approach aids introduced into a headset or speaker.
(5) Voice communications of flight crewmembers using the passenger loudspeaker system, if there is such a system and if the fourth channel is available in accordance with the requirements of paragraph (c)(4)(ii) of this section.
(6) If datalink communication equipment is installed, all datalink communications, using an approved data message set. Datalink messages must be recorded as the output signal from the communications unit that translates the signal into usable data.
(b) The recording requirements of paragraph (a)(2) of this section must be met by installing a cockpit-mounted area microphone, located in the best position for recording voice communications originating at the first and second pilot stations and voice communications of other crewmembers on the flight deck when directed to those stations. The microphone must be so located and, if necessary, the preamplifiers and filters of the recorder must be so adjusted or supplemented, so that the intelligibility of the recorded communications is as high as practicable when recorded under flight cockpit noise conditions and played back. Repeated aural or visual playback of the record may be used in evaluating intelligibility.
(c) Each cockpit voice recorder must be installed so that the part of the communication or audio signals specified in paragraph (a) of this section obtained from each of the following sources is recorded on a separate channel:
(1) For the first channel, from each boom, mask, or handheld microphone, headset, or speaker used at the first pilot station.
(2) For the second channel from each boom, mask, or handheld microphone, headset, or speaker used at the second pilot station.
(3) For the third channel—from the cockpit-mounted area microphone.
(4) For the fourth channel from:
(i) Each boom, mask, or handheld microphone, headset, or speaker used at the station for the third and fourth crewmembers.
(ii) If the stations specified in paragraph (c)(4)(i) of this section are not required or if the signal at such a station is picked up by another channel, each microphone on the flight deck that is used with the passenger loudspeaker system, if its signals are not picked up by another channel.
(5) And that as far as is practicable all sounds received by the microphone listed in paragraphs (c)(1), (2), and (4) of this section must be recorded without interruption irrespective of the position of the interphone-transmitter key switch. The design shall ensure that sidetone for the flight crew is produced only when the interphone, public address system, or radio transmitters are in use.
(a) Each cockpit voice recorder required by the operating rules of this chapter must be approved and must be installed so that it will record the following:
(1) Voice communications transmitted from or received in the airplane by radio.
(2) Voice communications of flight crewmembers on the flight deck.
(3) Voice communications of flight crewmembers on the flight deck, using the airplane's interphone system.
(4) Voice or audio signals identifying navigation or approach aids introduced into a headset or speaker.
(5) Voice communications of flight crewmembers using the passenger loudspeaker system, if there is such a system and if the fourth channel is available in accordance with the requirements of paragraph (c)(4)(ii) of this section.
(6) If datalink communication equipment is installed, all datalink communications, using an approved data message set. Datalink messages must be recorded as the output signal from the communications unit that translates the signal into usable data.
(b) The recording requirements of paragraph (a)(2) of this section must be met by installing a cockpit-mounted area microphone, located in the best position for recording voice communications originating at the first and second pilot stations and voice communications of other crewmembers on the flight deck when directed to those stations. The microphone must be so located and, if necessary, the preamplifiers and filters of the recorder must be so adjusted or supplemented, so that the intelligibility of the recorded communications is as high as practicable when recorded under flight cockpit noise conditions and played back. Repeated aural or visual playback of the record may be used in evaluating intelligibility.
(c) Each cockpit voice recorder must be installed so that the part of the communication or audio signals specified in paragraph (a) of this section obtained from each of the following sources is recorded on a separate channel:
(1) For the first channel, from each boom, mask, or handheld microphone, headset, or speaker used at the first pilot station.
(2) For the second channel from each boom, mask, or handheld microphone, headset, or speaker used at the second pilot station.
(3) For the third channel—from the cockpit-mounted area microphone.
(4) For the fourth channel from:
(i) Each boom, mask, or handheld microphone, headset, or speaker used at the station for the third and fourth crewmembers.
(ii) If the stations specified in paragraph (c)(4)(i) of this section are not required or if the signal at such a station is picked up by another channel, each microphone on the flight deck that is used with the passenger loudspeaker system, if its signals are not picked up by another channel.
(5) And that as far as is practicable all sounds received by the microphone listed in paragraphs (c)(1), (2), and (4) of this section must be recorded without interruption irrespective of the position of the interphone-transmitter key switch. The design shall ensure that sidetone for the flight crew is produced only when the interphone, public address system, or radio transmitters are in use.
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“The warning [alarms] kept on screaming, and in the background, they [the pilot and co-pilot] were trying to recover the plane,” said the crash investigator. “But what they said wasn’t clear,” the investigator said."
The guys in the lab can take unmolested, digitized factory copies of each standard Airbus alarm voice or sound, make it 180 degrees out of phase (make the positive voltage negative and vice versa) and sum each with each corresponding alarm on the CVR recording, increasing the amplitude until each alarm sound is at zero amplitude. This should leave the remaining sounds, including the pilots voices, easier to hear and understand.
This could take a day or two, then it might take a little while to figure out what it all means, but it should be in plenty of time for use in the preliminary report.
The guys in the lab can take unmolested, digitized factory copies of each standard Airbus alarm voice or sound, make it 180 degrees out of phase (make the positive voltage negative and vice versa) and sum each with each corresponding alarm on the CVR recording, increasing the amplitude until each alarm sound is at zero amplitude. This should leave the remaining sounds, including the pilots voices, easier to hear and understand.
This could take a day or two, then it might take a little while to figure out what it all means, but it should be in plenty of time for use in the preliminary report.
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Joejosh999
What a truckload of garbage. Nothing is suspected. A lot of things and possibilities are discussed.
Early Boeing 737 had issues with stuck rudders and even rudder reversal. That was a long time ago.
What do you mean with uncontrolled runaway rudder trim? Do you know what a rudder is?
I have read that there was a write-up on this aircraft and a swap out of ELAC2 and FAC2.... And that uncontrolled rudder trim is now suspected.
I am not a pilot so hope the experts here can perhaps shed more light. Do the past issues with runaway rudder trim on AB have potential importance here?
I am not a pilot so hope the experts here can perhaps shed more light. Do the past issues with runaway rudder trim on AB have potential importance here?
Early Boeing 737 had issues with stuck rudders and even rudder reversal. That was a long time ago.
What do you mean with uncontrolled runaway rudder trim? Do you know what a rudder is?
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"I'll defer to the sea lawyers here, but I think the requirement to wear headsets below FL180 on most 'modern' airliners does indeed come from CVR regulations."
In my memory it was introduced aeons ago for UK CAA reg'd aircraft as compulsory headsets + boom mics below FL150.
All this following a botched RTO at major UK airport where the DC10 Captain was attempting to communicate using hand-mic whilst trying to do other things requiring his standard issue of 2 hands.
Now the selection of speaker and hand mic, above whatever, seems to be favoured by that group of F/Os who like to appear "cool" whilst reading the paper/Ipad or whatever THEY think is their function in the upper levels.
I think it is a practice to be discouraged, if only to protect what's left of their hearing after a (short) lifetime of personal stereo earpieces and industrial noise-level bars and clubs.
Yes, I'm a grumpy old fart and proud of it!
In my memory it was introduced aeons ago for UK CAA reg'd aircraft as compulsory headsets + boom mics below FL150.
All this following a botched RTO at major UK airport where the DC10 Captain was attempting to communicate using hand-mic whilst trying to do other things requiring his standard issue of 2 hands.
Now the selection of speaker and hand mic, above whatever, seems to be favoured by that group of F/Os who like to appear "cool" whilst reading the paper/Ipad or whatever THEY think is their function in the upper levels.
I think it is a practice to be discouraged, if only to protect what's left of their hearing after a (short) lifetime of personal stereo earpieces and industrial noise-level bars and clubs.
Yes, I'm a grumpy old fart and proud of it!
Crew voices drowned by alarms?
If the headset was active but not being worn then a voice could easily be drowned out by ambient noise.
Where are the alarm speaker(s) located?
Try taking your headset off to see the extent of the effect.
When the speaker switch is activated then the panel mounted mics would become active?
If so where are these mics located?
If the headset was active but not being worn then a voice could easily be drowned out by ambient noise.
Where are the alarm speaker(s) located?
Try taking your headset off to see the extent of the effect.
When the speaker switch is activated then the panel mounted mics would become active?
If so where are these mics located?
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Originally Posted by Coagie
The guys in the lab can take unmolested, digitized factory copies of each standard Airbus alarm voice or sound, make it 180 degrees out of phase (make the positive voltage negative and vice versa) and sum each with each corresponding alarm on the CVR recording, increasing the amplitude until each alarm sound is at zero amplitude. This should leave the remaining sounds, including the pilots voices, easier to hear and understand.
This could take a day or two
This could take a day or two
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since it was discussed so many times here...
on this forum, thought this might be of interest.
NTSB Calls for Better Ways to Find Aircraft Accident Sites and Retrieve Critical Flight Data
January 22, 2015
WASHINGTON - The National Transportation Safety Board today issued a series of safety recommendations to the Federal Aviation Administration calling for improvements in locating downed aircraft and ways to obtain critical flight data faster and without the need for immediate underwater retrieval. The Board also re-emphasized the need for cockpit image recorders on commercial airplanes.
Recent accidents have pointed to the need for improved technologies to locate aircraft wreckage and flight recorders lost in remote locations or over water. In the 2009 crash of Air France Flight 447, it took almost two years and $40 million to find the recorders. Investigators are still searching for Malaysian Airlines Flight 370. So far the search has involved 26 countries using 84 vessels and numerous aircraft.
“Technology has reached a point where we shouldn’t have to search hundreds of miles of ocean floor in a frantic race to find these valuable boxes,’’ said NTSB Acting Chairman Christopher A. Hart. “In this day and age, lost aircraft should be a thing of the past.”
Last October, the NTSB held a forum, Emerging Flight Data and Locator Technology, which explored these issues in detail.
Among the recommendations to the FAA are to equip commercial airplanes with a tamper-resistant method to broadcast to a ground station sufficient information to establish the location where an aircraft terminates flight as a result of an accident within six nautical miles of the point of impact.
The NTSB also called for the FAA to coordinate with other regulatory authorities and the International Civil Aviation Organization to harmonize implementation of several of these recommendations.
The NTSB also repeated recommendations for a crash-protected image recording system that would record the cockpit environment during the last two hours of a flight.
A link to the recommendation letter can be found here: go.usa.gov/Jsaz
A link to the recorder forum page is here: go.usa.gov/JsCW
NTSB Calls for Better Ways to Find Aircraft Accident Sites and Retrieve Critical Flight Data
January 22, 2015
WASHINGTON - The National Transportation Safety Board today issued a series of safety recommendations to the Federal Aviation Administration calling for improvements in locating downed aircraft and ways to obtain critical flight data faster and without the need for immediate underwater retrieval. The Board also re-emphasized the need for cockpit image recorders on commercial airplanes.
Recent accidents have pointed to the need for improved technologies to locate aircraft wreckage and flight recorders lost in remote locations or over water. In the 2009 crash of Air France Flight 447, it took almost two years and $40 million to find the recorders. Investigators are still searching for Malaysian Airlines Flight 370. So far the search has involved 26 countries using 84 vessels and numerous aircraft.
“Technology has reached a point where we shouldn’t have to search hundreds of miles of ocean floor in a frantic race to find these valuable boxes,’’ said NTSB Acting Chairman Christopher A. Hart. “In this day and age, lost aircraft should be a thing of the past.”
Last October, the NTSB held a forum, Emerging Flight Data and Locator Technology, which explored these issues in detail.
Among the recommendations to the FAA are to equip commercial airplanes with a tamper-resistant method to broadcast to a ground station sufficient information to establish the location where an aircraft terminates flight as a result of an accident within six nautical miles of the point of impact.
The NTSB also called for the FAA to coordinate with other regulatory authorities and the International Civil Aviation Organization to harmonize implementation of several of these recommendations.
The NTSB also repeated recommendations for a crash-protected image recording system that would record the cockpit environment during the last two hours of a flight.
A link to the recommendation letter can be found here: go.usa.gov/Jsaz
A link to the recorder forum page is here: go.usa.gov/JsCW
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Fortunately there is already ready-made sophisticated audio spectral editing software for this, e.g, Izotope RX4. It easily allows a skilled forensic analyst to null out specific spectral patterns such as alarms which obscure speech.
I didn't mean to insinuate this is a new idea. I just wanted to give some understanding how the lab goes about it. In fact, they may use a purpose built CVR sound editing program, where they just select "Boeing" or "Airbus", so it knows which alarms to filter.
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Mr. Snuggles offered:
I know what a jackscrew is, and I'm wondering about this aircraft's jackscrew. After all, many have said in this space that this rapid climb is not something a pro pilot would do on purpose.
Early Boeing 737 had issues with stuck rudders and even rudder reversal. That was a long time ago.
What do you mean with uncontrolled runaway rudder trim? Do you know what a rudder is?
What do you mean with uncontrolled runaway rudder trim? Do you know what a rudder is?
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Quote... The NTSB also repeated recommendations for a crash-protected image recording system that would record the cockpit environment during the last two hours of a flight.
They will not have to call it a 'Cockpit Video Recorder'.....
They will not have to call it a 'Cockpit Video Recorder'.....
CVR Details
Where are the alarm speaker(s) located?
When the speaker switch is activated then the panel mounted mics would become active?
If so where are these mics located?
When the speaker switch is activated then the panel mounted mics would become active?
If so where are these mics located?
There are no "panel mounted mics" that activate when the speaker switch is selected. There is a single "area mic" mounted in the CVR panel itself that is continuously active and recorded on a separate track on the CVR.
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'boofhead' I believe you..
Back on 12 Jan 14:54 boofhead said the old radars were ok. I second the motion. My background is 25 years of military flying, back in the 60ties and 70ties. Even though I always had the luxury of a good navigator, between the two of them it got me through quite a few squall lines. No I did not penetrate any cells, I was vectored around them.[with that old radar].
The reason for my post is actually to express my surprise, how readily commercial pilots request max altitude for their aircraft, not knowing if it will put them 'on top'. Having flown the B-47 I am well aware of the coffin corner and how sloppy the controls feel up there. I would not penetrate any wx up there. Maybe more commercial pilots should find out how their ac will feel manually at max altitude. We also queried opposite traffic as to wx en route. Later when I flew the C-130 and encountered turbulence, I would kick off the autopilot and fly it manually. This way I could tell what forces were exerted on my aircraft. But then, I guess, I am ancient...
The reason for my post is actually to express my surprise, how readily commercial pilots request max altitude for their aircraft, not knowing if it will put them 'on top'. Having flown the B-47 I am well aware of the coffin corner and how sloppy the controls feel up there. I would not penetrate any wx up there. Maybe more commercial pilots should find out how their ac will feel manually at max altitude. We also queried opposite traffic as to wx en route. Later when I flew the C-130 and encountered turbulence, I would kick off the autopilot and fly it manually. This way I could tell what forces were exerted on my aircraft. But then, I guess, I am ancient...
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Someone said that would be nice to overlay the weather over the trajectory plot before crash.
See in link below an approximate, the time is 23:00 UTC and the flight path is the small yellow curve
http://www.mediafire.com/view/xxaocp...5e/weather.jpg
See in link below an approximate, the time is 23:00 UTC and the flight path is the small yellow curve
http://www.mediafire.com/view/xxaocp...5e/weather.jpg
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phoeniks...
you are not ancient...you are good.
about 25 years ago I started seeing people fly at max altitude close to T storms...I knew we were close on the margins you are talking about.
when I became captain I always flew lower (other things considered too)> In fact I routinely flew 4000' lower than the canned flight plans...fuel burn came out the same and I had a bit better margin for the unexpected turbulence.
I asked my friends about their take on G load margins and they were all flying at the max...why I asked ...they didn't even know what the G margins meant.
I respect you and your candor...I just hope the new guys start to think and get some perspective from our posts!
you are not ancient...you are good.
about 25 years ago I started seeing people fly at max altitude close to T storms...I knew we were close on the margins you are talking about.
when I became captain I always flew lower (other things considered too)> In fact I routinely flew 4000' lower than the canned flight plans...fuel burn came out the same and I had a bit better margin for the unexpected turbulence.
I asked my friends about their take on G load margins and they were all flying at the max...why I asked ...they didn't even know what the G margins meant.
I respect you and your candor...I just hope the new guys start to think and get some perspective from our posts!
Phoeniks...B-47 eh? Respect. 
Glendale...add me to the list of non-believers in the max altitude cruise near CBs or the upper shear zone of a jetstream. Or most places, really.
Glendale...add me to the list of non-believers in the max altitude cruise near CBs or the upper shear zone of a jetstream. Or most places, really.