How does the IFE display things like altitude and speed

Boeing757100 · Thu Jun 09, 2022 7:53 am

In the past month, since it is summer vacation, I have been on more flights in just the span of last month than throughout the entirety of 2020-2021. As some of the flights I was on were really long, I got bored and just scrolled through the IFE. Nowadays, I like to keep the page where it shows the current altitude, speed, and other parameters so I can feel almost like a pilot monitoring the instruments (but obviously its different). But I wondered, where does the IF get access to this information? Is it fed directly from the cockpit? If so, how is that done? I actually flew in a Qatar Airways QSuite and I saw that they even had magnetic heading, the exact attitude, and many many other parameters. I know that the information isn't usually up to speed but still, how does the IFE get information from the cockpit so it can be displayed on the IFE?

Thanks for answering, I've wondered this since I was about 10

77west · Thu Jun 09, 2022 10:03 am

Boeing757100 wrote:
In the past month, since it is summer vacation, I have been on more flights in just the span of last month than throughout the entirety of 2020-2021. As some of the flights I was on were really long, I got bored and just scrolled through the IFE. Nowadays, I like to keep the page where it shows the current altitude, speed, and other parameters so I can feel almost like a pilot monitoring the instruments (but obviously its different). But I wondered, where does the IF get access to this information? Is it fed directly from the cockpit? If so, how is that done? I actually flew in a Qatar Airways QSuite and I saw that they even had magnetic heading, the exact attitude, and many many other parameters. I know that the information isn't usually up to speed but still, how does the IFE get information from the cockpit so it can be displayed on the IFE?

Thanks for answering, I've wondered this since I was about 10

On modern airliners there is a one-way feed of this information from the flight management system. It is designed in a way that prevents any communication back to the flight systems from the cabin systems. IE, there is generally no way anything in the cabin could interfere with the flight management computers, but the data is real-time, or almost so.

Starlionblue · Thu Jun 09, 2022 11:38 am

I think the IFE gets GPS information only.

When we fly on standard QNH it will seem a bit off that the IFE altitude is displaying something like 36143 feet. GPS altitude is actual altitude over mean sea level. Flight levels, on the other hand, vary in actual altitude depending on the current pressure.

luv2cattlecall · Thu Jun 09, 2022 12:44 pm

Starlionblue wrote:
I think the IFE gets GPS information only.

When we fly on standard QNH it will seem a bit off that the IFE altitude is displaying something like 36143 feet. GPS altitude is actual altitude over mean sea level. Flight levels, on the other hand, vary in actual altitude depending on the current pressure.

Some systems show head/tailwind information - wouldn't those need to come from the FMS?

N1120A · Thu Jun 09, 2022 2:01 pm

I'd imagine the more involved systems are getting it in a one way feed from the FMS, or even the transponder itself.

Starlionblue wrote:
I think the IFE gets GPS information only.

Some of them are much more involved. As mentioned, they give TAS info.

Boeing757100 · Thu Jun 09, 2022 2:31 pm

N1120A wrote:
I'd imagine the more involved systems are getting it in a one way feed from the FMS, or even the transponder itself.

Starlionblue wrote:
I think the IFE gets GPS information only.

Some of them are much more involved. As mentioned, they give TAS info.

Yes, I believe some airlines even have groundspeed on their IFE, which is interesting as well.

N1120A · Thu Jun 09, 2022 2:56 pm

Boeing757100 wrote:
N1120A wrote:
I'd imagine the more involved systems are getting it in a one way feed from the FMS, or even the transponder itself.

Starlionblue wrote:
I think the IFE gets GPS information only.

Some of them are much more involved. As mentioned, they give TAS info.

Yes, I believe some airlines even have groundspeed on their IFE, which is interesting as well.

Groundspeed is actually easier, as it can just use GPS input.

celestar345 · Sun Jun 12, 2022 3:59 am

The IFE takes in more than just GPS data.

Take the Panasonic eX2 as an example, it would take in information like:
Door (Any doors opened for pre-recorded announcements)
Engine Running (The speakers will be MUCH louder with engine running)
Air/Ground information (inhibites any system servicing)
Oxygen Deploy (Pre-recorded announcements to get people to get back to the seat!)
Position - Lat/Long/Altitude/Heading - For moving map display and WIFI service
Flight Plan destination airport

And VHF audio for those who would like to listen into ATC conversation.

And before anyone ask: The IFE system is incapable of outputting any signal back to the aircraft side (apart from IFE system status report) so the answer is NO - you can't control the aircraft with the onboard WIFI even if you can hack into the IFE system.

77west · Sun Jun 12, 2022 4:34 am

celestar345 wrote:
The IFE takes in more than just GPS data.
And before anyone ask: The IFE system is incapable of outputting any signal back to the aircraft side (apart from IFE system status report) so the answer is NO - you can't control the aircraft with the onboard WIFI even if you can hack into the IFE system.

There was a case of a computer engineer who did manage, apparently, to access more than he should have been able to:

https://www.wired.com/2015/05/feds-say- ... red-plane/

zeke · Sun Jun 12, 2022 9:35 am

Starlionblue wrote:
I think the IFE gets GPS information only.

When we fly on standard QNH it will seem a bit off that the IFE altitude is displaying something like 36143 feet. GPS altitude is actual altitude over mean sea level. Flight levels, on the other hand, vary in actual altitude depending on the current pressure.

It’s height above the WGS84 mathematical geoid, not MSL. The mathematical model closely represents earth.

zeke · Sun Jun 12, 2022 9:38 am

celestar345 wrote:
Take the Panasonic eX2 as an example, it would take in information like:
Door (Any doors opened for pre-recorded announcements)
Engine Running (The speakers will be MUCH louder with engine running)
Air/Ground information (inhibites any system servicing)
Oxygen Deploy (Pre-recorded announcements to get people to get back to the seat!)
Position - Lat/Long/Altitude/Heading - For moving map display and WIFI service
Flight Plan destination airport

Most of that is the same information displayed on the cabin displays for the cabin crew. Our cabin crew have to initialise the mast et IFE control with the flight number and destination.

zeke · Sun Jun 12, 2022 9:42 am

77west wrote:
There was a case of a computer engineer who did manage, apparently, to access more than he should have been able to:

https://www.wired.com/2015/05/feds-say- ... red-plane/

What he claimed he could do on a real aircraft just is not possible. The IFE is an independent network, it gets some data from the aircraft, however that is like a constant serial stream.

889091 · Sun Jun 12, 2022 10:59 am

zeke wrote:
77west wrote:
There was a case of a computer engineer who did manage, apparently, to access more than he should have been able to:

https://www.wired.com/2015/05/feds-say- ... red-plane/

What he claimed he could do on a real aircraft just is not possible. The IFE is an independent network, it gets some data from the aircraft, however that is like a constant serial stream.

After removing the cover to the SEB by "wiggling and Squeezing the box," Roberts told agents he attached a Cat6 ethernet cable, with a modified connector, to the box and to his laptop and then used default IDs and passwords to gain access to the inflight entertainment system. Once on that network, he was able to gain access to other systems on the planes.

He'd have had to crawl under the seat to remove the cover and attach the RJ45 Cat 6 connector. Didn't anyone notice this?

I mean, Richard Reid tried to set something alight and pax/crew were all over him in an instant....

kalvado · Sun Jun 12, 2022 11:40 am

889091 wrote:
zeke wrote:
77west wrote:
There was a case of a computer engineer who did manage, apparently, to access more than he should have been able to:

https://www.wired.com/2015/05/feds-say- ... red-plane/

What he claimed he could do on a real aircraft just is not possible. The IFE is an independent network, it gets some data from the aircraft, however that is like a constant serial stream.

After removing the cover to the SEB by "wiggling and Squeezing the box," Roberts told agents he attached a Cat6 ethernet cable, with a modified connector, to the box and to his laptop and then used default IDs and passwords to gain access to the inflight entertainment system. Once on that network, he was able to gain access to other systems on the planes.

He'd have had to crawl under the seat to remove the cover and attach the RJ45 Cat 6 connector. Didn't anyone notice this? I mean, Richard Reid tried to set something alight and pax/crew were all over him in an instant....

Excuse me, I dropped my phone under the seat..

889091 · Sun Jun 12, 2022 11:51 am

kalvado wrote:
889091 wrote:
zeke wrote:

What he claimed he could do on a real aircraft just is not possible. The IFE is an independent network, it gets some data from the aircraft, however that is like a constant serial stream.

After removing the cover to the SEB by "wiggling and Squeezing the box," Roberts told agents he attached a Cat6 ethernet cable, with a modified connector, to the box and to his laptop and then used default IDs and passwords to gain access to the inflight entertainment system. Once on that network, he was able to gain access to other systems on the planes.

He'd have had to crawl under the seat to remove the cover and attach the RJ45 Cat 6 connector. Didn't anyone notice this? I mean, Richard Reid tried to set something alight and pax/crew were all over him in an instant....

Excuse me, I dropped my phone under the seat..

...whilst emerging few minutes later with said phone and a Cat6 cable..... Presumably he would have had to also 'drop' his phone a few times....

Dalmd88 · Sun Jun 12, 2022 3:56 pm

889091 wrote:
zeke wrote:
77west wrote:
There was a case of a computer engineer who did manage, apparently, to access more than he should have been able to:

https://www.wired.com/2015/05/feds-say- ... red-plane/

What he claimed he could do on a real aircraft just is not possible. The IFE is an independent network, it gets some data from the aircraft, however that is like a constant serial stream.

After removing the cover to the SEB by "wiggling and Squeezing the box," Roberts told agents he attached a Cat6 ethernet cable, with a modified connector, to the box and to his laptop and then used default IDs and passwords to gain access to the inflight entertainment system. Once on that network, he was able to gain access to other systems on the planes.

He'd have had to crawl under the seat to remove the cover and attach the RJ45 Cat 6 connector. Didn't anyone notice this? I mean, Richard Reid tried to set something alight and pax/crew were all over him in an instant....

He would have to be very nimble and pretty much have to have the row to himself to get to the box. I know I have to have everything clear to get to those connections. Plus I don't think most of those boxes have RJ45 connections. All the ones I've worked with have various military standard D plugs.

celestar345 · Mon Jun 13, 2022 9:04 am

zeke wrote:
Most of that is the same information displayed on the cabin displays for the cabin crew. Our cabin crew have to initialise the mast et IFE control with the flight number and destination.

I was recalling my memory on that very same screen when writing. And on some setup if the flight crew entered the flight plan the IFE system will automatically pick that up and start the entertainment system for that route.

889091 wrote:
He'd have had to crawl under the seat to remove the cover and attach the RJ45 Cat 6 connector. Didn't anyone notice this? I mean, Richard Reid tried to set something alight and pax/crew were all over him in an instant....

Dalmd88 wrote:
He would have to be very nimble and pretty much have to have the row to himself to get to the box. I know I have to have everything clear to get to those connections. Plus I don't think most of those boxes have RJ45 connections. All the ones I've worked with have various military standard D plugs.

In the article it did mention he used a 'modified plug for the network' so it's not a standard RJ45 connection. It's a pretty standard commercial connector off the shelf but you will need information on the pinout to successfully make any physical connection. But yeh ripping out your seat and start tempering with the seat and no one notices? That doesn't sound right.... Also with the economy seats so cramped together just trying to access under the seat with people around it's nearly mission impossible....

kalvado · Mon Jun 13, 2022 2:00 pm

celestar345 wrote:
zeke wrote:
Most of that is the same information displayed on the cabin displays for the cabin crew. Our cabin crew have to initialise the mast et IFE control with the flight number and destination.

I was recalling my memory on that very same screen when writing. And on some setup if the flight crew entered the flight plan the IFE system will automatically pick that up and start the entertainment system for that route.

889091 wrote:
He'd have had to crawl under the seat to remove the cover and attach the RJ45 Cat 6 connector. Didn't anyone notice this? I mean, Richard Reid tried to set something alight and pax/crew were all over him in an instant....

Dalmd88 wrote:
He would have to be very nimble and pretty much have to have the row to himself to get to the box. I know I have to have everything clear to get to those connections. Plus I don't think most of those boxes have RJ45 connections. All the ones I've worked with have various military standard D plugs.

In the article it did mention he used a 'modified plug for the network' so it's not a standard RJ45 connection. It's a pretty standard commercial connector off the shelf but you will need information on the pinout to successfully make any physical connection. But yeh ripping out your seat and start tempering with the seat and no one notices? That doesn't sound right.... Also with the economy seats so cramped together just trying to access under the seat with people around it's nearly mission impossible....

There are flights with very few passengers. I was on 737 and md80 flights with a single digit number of passengers. For a frequent flyer figuring out one of these flights should be fairly simple.
I was also on a flight with a packed regular Y, but no free upgrades to virtually empty Y+, to help with getting to the box.

celestar345 · Tue Jun 14, 2022 1:55 am

kalvado wrote:
There are flights with very few passengers. I was on 737 and md80 flights with a single digit number of passengers. For a frequent flyer figuring out one of these flights should be fairly simple.
I was also on a flight with a packed regular Y, but no free upgrades to virtually empty Y+, to help with getting to the box.

True...

Last time I was talking to an IFE vendor engineer, and he was saying that the interface unit with the aircraft is physically incapable of outputting any signal to the aircraft side so this should not be a problem. In the article he did it in a simulated environment maybe this is the difference.

dunkelfalke · Tue Jun 14, 2022 5:36 am

celestar345 wrote:
Last time I was talking to an IFE vendor engineer, and he was saying that the interface unit with the aircraft is physically incapable of outputting any signal to the aircraft side so this should not be a problem.

This is easy to achieve by the way. My previous job was telematics for tanker trucks and I used this kind of connectors to make sure I cannot send anything to the internal truck CAN bus:
https://copperhilltech.com/cancrocodile ... us-reader/

Not this particular one, though. They are essentially reading the signal from the electromagnetic interference created by the wiring.

kalvado · Tue Jun 14, 2022 11:24 am

dunkelfalke wrote:
celestar345 wrote:
Last time I was talking to an IFE vendor engineer, and he was saying that the interface unit with the aircraft is physically incapable of outputting any signal to the aircraft side so this should not be a problem.

This is easy to achieve by the way. My previous job was telematics for tanker trucks and I used this kind of connectors to make sure I cannot send anything to the internal truck CAN bus:
https://copperhilltech.com/cancrocodile ... us-reader/

Not this particular one, though. They are essentially reading the signal from the electromagnetic interference created by the wiring.

It is definitely possible to achieve one-way airgap. no question about that. Was it properly achieved, though?
Interface you show would definitely work that way. Can it be used on the aircraft? Can it be certified for in-flight use? Would the cost of such certification for the single point of use be justifiable?

Aviation industry seem to be much more focused on safety certification and regulation compliance than actual safety. There is a lot of proprietary and confidential stuff leading to compliance through obscurity. Actual safety seems a second thought, sometimes pretty remote one.
On the other hand, IT security seems to be very agile and used to doing pretty unorthodox things.

Starlionblue · Tue Jun 14, 2022 12:09 pm

kalvado wrote:
dunkelfalke wrote:
celestar345 wrote:
Last time I was talking to an IFE vendor engineer, and he was saying that the interface unit with the aircraft is physically incapable of outputting any signal to the aircraft side so this should not be a problem.

This is easy to achieve by the way. My previous job was telematics for tanker trucks and I used this kind of connectors to make sure I cannot send anything to the internal truck CAN bus:
https://copperhilltech.com/cancrocodile ... us-reader/

Not this particular one, though. They are essentially reading the signal from the electromagnetic interference created by the wiring.

It is definitely possible to achieve one-way airgap. no question about that. Was it properly achieved, though?
Interface you show would definitely work that way. Can it be used on the aircraft? Can it be certified for in-flight use? Would the cost of such certification for the single point of use be justifiable?

Aviation industry seem to be much more focused on safety certification and regulation compliance than actual safety. There is a lot of proprietary and confidential stuff leading to compliance through obscurity. Actual safety seems a second thought, sometimes pretty remote one.
On the other hand, IT security seems to be very agile and used to doing pretty unorthodox things.

Do you have any specific examples of "compliance through obscurity"?

kalvado · Tue Jun 14, 2022 1:42 pm

Starlionblue wrote:
kalvado wrote:
dunkelfalke wrote:

This is easy to achieve by the way. My previous job was telematics for tanker trucks and I used this kind of connectors to make sure I cannot send anything to the internal truck CAN bus:
https://copperhilltech.com/cancrocodile ... us-reader/

Not this particular one, though. They are essentially reading the signal from the electromagnetic interference created by the wiring.

It is definitely possible to achieve one-way airgap. no question about that. Was it properly achieved, though?
Interface you show would definitely work that way. Can it be used on the aircraft? Can it be certified for in-flight use? Would the cost of such certification for the single point of use be justifiable?

Aviation industry seem to be much more focused on safety certification and regulation compliance than actual safety. There is a lot of proprietary and confidential stuff leading to compliance through obscurity. Actual safety seems a second thought, sometimes pretty remote one.
On the other hand, IT security seems to be very agile and used to doing pretty unorthodox things.

Do you have any specific examples of "compliance through obscurity"?

MCAS

Starlionblue · Wed Jun 15, 2022 12:20 am

kalvado wrote:
Starlionblue wrote:
kalvado wrote:
It is definitely possible to achieve one-way airgap. no question about that. Was it properly achieved, though?
Interface you show would definitely work that way. Can it be used on the aircraft? Can it be certified for in-flight use? Would the cost of such certification for the single point of use be justifiable?

Aviation industry seem to be much more focused on safety certification and regulation compliance than actual safety. There is a lot of proprietary and confidential stuff leading to compliance through obscurity. Actual safety seems a second thought, sometimes pretty remote one.
On the other hand, IT security seems to be very agile and used to doing pretty unorthodox things.

Do you have any specific examples of "compliance through obscurity"?

MCAS

I knew you'd say that.

And that's fair.

However, I see MCAS as an outlier. Any other examples? Honestly curious.

dunkelfalke · Wed Jun 15, 2022 7:25 am

kalvado wrote:
Aviation industry seem to be much more focused on safety certification and regulation compliance than actual safety. There is a lot of proprietary and confidential stuff leading to compliance through obscurity. Actual safety seems a second thought, sometimes pretty remote one.

Well, I have used these kinds of interfaces specifically because it was much easier to certify hardware that doesn't actually connect to the truck internals and I assume that the same considerations are just as valid in aviation, but I don't know for sure. But I do know an engineer who used to work for Airbus before she got laid off after the first wave of covid, so I'll ask her, she might know more.

kalvado · Wed Jun 15, 2022 11:48 am

Starlionblue wrote:
kalvado wrote:
Starlionblue wrote:

Do you have any specific examples of "compliance through obscurity"?

MCAS

I knew you'd say that. And that's fair.

However, I see MCAS as an outlier. Any other examples? Honestly curious.

That is a good tough question.
Of course, I have no rock solid answer for you - such things are generally not becoming public until there is gross problem, like it happened with MCAS.
However, my strong impression is that certification system, like any system designed to impose a set of fixed requirements to meet, would focus on meeting formal requirements rather than underlying conditions. Withholding information which would hurt my case? Well, I only did that on a much smaller scale. In most cases there are no gross consequences, so things go unnoticed. MCAS would still be a small footnote in manuals if the code was written a little better - which would still be a non-compliant thing presented to look OK. Redundancy requirement, which caused a huge delay for MAX, wouldn't be met - but things would still fly (pun intended)
If you want a big ticket example outside of aviation industry, think VolksWagen diesel cars. Everyone pretended surprized - while MCAS seemed to be more of a business as usual going wrong.
If you want a small scale thing within industry, moving gate check bags to the cabin to reduce estimated weight is on the same page of meeting formal metric regardless of underlying assumptions, obscuring the real situation.

There are tons of laws which govern industries - but only of them two never change: Murphy's law and the Law of unintended consequences.
A very contrary example is non-punitive ways of reporting things, specifically popular in aviation. Removing negative effects allows people to share experience much more freely. It is difficult to remove consequences when an assumingly unsafe design - rather than a single mistake - is the problem.

zeke · Wed Jun 15, 2022 1:26 pm

kalvado wrote:
That is a good tough question.
Of course, I have no rock solid answer for you - such things are generally not becoming public until there is gross problem, like it happened with MCAS.
However, my strong impression is that certification system, like any system designed to impose a set of fixed requirements to meet, would focus on meeting formal requirements rather than underlying conditions. Withholding information which would hurt my case? Well, I only did that on a much smaller scale. In most cases there are no gross consequences, so things go unnoticed. MCAS would still be a small footnote in manuals if the code was written a little better - which would still be a non-compliant thing presented to look OK. Redundancy requirement, which caused a huge delay for MAX, wouldn't be met - but things would still fly (pun intended)
If you want a big ticket example outside of aviation industry, think VolksWagen diesel cars. Everyone pretended surprized - while MCAS seemed to be more of a business as usual going wrong.
If you want a small scale thing within industry, moving gate check bags to the cabin to reduce estimated weight is on the same page of meeting formal metric regardless of underlying assumptions, obscuring the real situation.

There are tons of laws which govern industries - but only of them two never change: Murphy's law and the Law of unintended consequences.
A very contrary example is non-punitive ways of reporting things, specifically popular in aviation. Removing negative effects allows people to share experience much more freely. It is difficult to remove consequences when an assumingly unsafe design - rather than a single mistake - is the problem.

You need to calm down an objectivity look at what this person claimed he could do before claiming conspiracy theories regarding certification.

The 737 has as many computer networks in it as a 1960s tractor or car does. As a thought experiment what is being claimed is like a 1960s Cadillac someone installed an android 10 car entertainment system in, with additional seat back screens. And this guy gets in the back seat of the car, plugs a cable into the screen and then claims he can lock and unlock doors, turn the wipers, and increase the accelerator.

Basically all he could do is corrupt the IFE in the worst case, and cause property damage to the seats. He should not be allowed to ever fly again.

The 737 does not have a thrust management computer and it does not have EICAS. No aircraft has a direct interface from IFE into the cockpit, they all go via some other data/signal concentrator. If you also look at the items seized from him, there were no cables to connect to the aircraft when he was arrested after landing.

To me it’s all B/S, just seeking attention from those who don’t know any better. And there is obviously gullible people who believe the fantasy.

kalvado · Wed Jun 15, 2022 3:31 pm

zeke wrote:
kalvado wrote:
That is a good tough question.
Of course, I have no rock solid answer for you - such things are generally not becoming public until there is gross problem, like it happened with MCAS.
However, my strong impression is that certification system, like any system designed to impose a set of fixed requirements to meet, would focus on meeting formal requirements rather than underlying conditions. Withholding information which would hurt my case? Well, I only did that on a much smaller scale. In most cases there are no gross consequences, so things go unnoticed. MCAS would still be a small footnote in manuals if the code was written a little better - which would still be a non-compliant thing presented to look OK. Redundancy requirement, which caused a huge delay for MAX, wouldn't be met - but things would still fly (pun intended)
If you want a big ticket example outside of aviation industry, think VolksWagen diesel cars. Everyone pretended surprized - while MCAS seemed to be more of a business as usual going wrong.
If you want a small scale thing within industry, moving gate check bags to the cabin to reduce estimated weight is on the same page of meeting formal metric regardless of underlying assumptions, obscuring the real situation.

There are tons of laws which govern industries - but only of them two never change: Murphy's law and the Law of unintended consequences.
A very contrary example is non-punitive ways of reporting things, specifically popular in aviation. Removing negative effects allows people to share experience much more freely. It is difficult to remove consequences when an assumingly unsafe design - rather than a single mistake - is the problem.

You need to calm down an objectivity look at what this person claimed he could do before claiming conspiracy theories regarding certification.

The 737 has as many computer networks in it as a 1960s tractor or car does. As a thought experiment what is being claimed is like a 1960s Cadillac someone installed an android 10 car entertainment system in, with additional seat back screens. And this guy gets in the back seat of the car, plugs a cable into the screen and then claims he can lock and unlock doors, turn the wipers, and increase the accelerator.

Basically all he could do is corrupt the IFE in the worst case, and cause property damage to the seats. He should not be allowed to ever fly again.

The 737 does not have a thrust management computer and it does not have EICAS. No aircraft has a direct interface from IFE into the cockpit, they all go via some other data/signal concentrator. If you also look at the items seized from him, there were no cables to connect to the aircraft when he was arrested after landing.

To me it’s all B/S, just seeking attention from those who don’t know any better. And there is obviously gullible people who believe the fantasy.

If my memory serves me right, flight control story was about 757 or 767. At least the story I have in mind was about a newer generation one. Not new enough to be designed with paranoiac data security thoughts, but new enough to have significant computing on board.
"no direct link" may be a rephrase of "it's a one way link" - that is what is usually said. And next thing you'll learn is something along the lines that return signal is disabled via "flight/service" switch on the box. It's not too much to ask to have the switch in a proper position, right? Oh, it can be accessed from the cabin without authorization?.... Physical isolation stuff may also depend on things like differences between ARINC 429 and 629 - which seem to be similar to RS422 and 485 in civilian world, with different architecture and ability to physically isolate a datasource.

If you look at original 737 story, the example was fake "pax oxygen on" message. Pax O2 flow should include cabin wiring to every seat, and probably action on a single unit O2 deployment is the same as for an all-cabin deployment. To make things more feasible, is it possible that IFE uses same interface to cockpit electronics as cabin safety signalling - assuming there is indeed a middle man unit? Or signal is routed through IFE?

There are way too many fairly credible reports that someone could do something. e.g. https://www.aviationtoday.com/2017/11/0 ... -dhs-says/
So, total isolation may be more of a wishful thinking, and we're talking about what are the implementation issues.

Although I agree that FBI are generally not as qualified as they show in Hollywood movies, so FBI arrest doesn't prove much.

zeke · Wed Jun 15, 2022 11:20 pm

kalvado wrote:
If my memory serves me right, flight control story was about 757 or 767. At least the story I have in mind was about a newer generation one. Not new enough to be designed with paranoiac data security thoughts, but new enough to have significant computing on board.
"no direct link" may be a rephrase of "it's a one way link" - that is what is usually said. And next thing you'll learn is something along the lines that return signal is disabled via "flight/service" switch on the box.

He was arrested after landing as a passenger on a 737 claiming he would set off EICAS messages. No cables to connect to the aircraft, and the 737 does not have EICAS.

756/767 do not have computing networks, they have data busses, and they go between individual LRUs.

The whole story is utter rubbish.

kalvado · Thu Jun 16, 2022 12:14 am

zeke wrote:
kalvado wrote:
If my memory serves me right, flight control story was about 757 or 767. At least the story I have in mind was about a newer generation one. Not new enough to be designed with paranoiac data security thoughts, but new enough to have significant computing on board.
"no direct link" may be a rephrase of "it's a one way link" - that is what is usually said. And next thing you'll learn is something along the lines that return signal is disabled via "flight/service" switch on the box.

He was arrested after landing as a passenger on a 737 claiming he would set off EICAS messages. No cables to connect to the aircraft, and the 737 does not have EICAS.

756/767 do not have computing networks, they have data busses, and they go between individual LRUs.

The whole story is utter rubbish.

So you arguments boil down to this guy uses incorrect terminology hence cannot be right.
Let's try to get more technical.
737 cockpit has 2 items related to pax O2 - manual deploy switch and a single indicator light.
Are those signals using dedicated wires in a bundle or a databus? If on-off wire, Is it a separate per-box wire or many boxes are connected in parallel? If it is a databus, does each row unit have a separate address? Did that change between 737-100 and max?

zeke · Thu Jun 16, 2022 12:39 am

kalvado wrote:
So you arguments boil down to this guy uses incorrect terminology hence cannot be right.

No, because he was caught lying red handed. He tweeted in flight he was on an aircraft and was going to set off the passenger oxygen EICAS. After the United 737 landed, he was arrested, they seized and listed all the tech gear he had including devices, cables, thumb drives. There was no cat 6 cable. The 737 is also the only Boeing without EICAS, the issue behind the 787-10 not being certified.

Most aircraft I am familiar with will have the elevation and also a switch/relay to the cabin pressure controller, that cabin pressure controller will deploy masks automatically in the event of excessive cabin altitude (eg Helios) or by the pilots pressing a switch. The landing elevation and cruise altitude is fed in to control the cabin altitude.

Older aircraft were typically built around one box does one job, and connected within the avionics bay via a ARINC 429 data bus.

The A380 was the first large airliner to use computer networks, and it was a ADFX network. They also changed the idea of one box one job and started doing jobs within software on an industrial blade server, for example aircraft environmental surveillance system (AESS) is a software application on the A380 that does transponder, ADS-B, TCAS, GPWS and weather radar.

kalvado · Thu Jun 16, 2022 1:22 am

zeke wrote:
kalvado wrote:
So you arguments boil down to this guy uses incorrect terminology hence cannot be right.

No, because he was caught lying red handed. He tweeted in flight he was on an aircraft and was going to set off the passenger oxygen EICAS. After the United 737 landed, he was arrested, they seized and listed all the tech gear he had including devices, cables, thumb drives. There was no cat 6 cable. The 737 is also the only Boeing without EICAS, the issue behind the 787-10 not being certified.

Most aircraft I am familiar with will have the elevation and also a switch/relay to the cabin pressure controller, that cabin pressure controller will deploy masks automatically in the event of excessive cabin altitude (eg Helios) or by the pilots pressing a switch. The landing elevation and cruise altitude is fed in to control the cabin altitude.

Older aircraft were typically built around one box does one job, and connected within the avionics bay via a ARINC 429 data bus.

The A380 was the first large airliner to use computer networks, and it was a ADFX network. They also changed the idea of one box one job and started doing jobs within software on an industrial blade server, for example aircraft environmental surveillance system (AESS) is a software application on the A380 that does transponder, ADS-B, TCAS, GPWS and weather radar.

Ok, so you are not familiar with specifics of NG mask deployment system?

Starlionblue · Thu Jun 16, 2022 3:08 am

kalvado wrote:
zeke wrote:
kalvado wrote:
So you arguments boil down to this guy uses incorrect terminology hence cannot be right.

No, because he was caught lying red handed. He tweeted in flight he was on an aircraft and was going to set off the passenger oxygen EICAS. After the United 737 landed, he was arrested, they seized and listed all the tech gear he had including devices, cables, thumb drives. There was no cat 6 cable. The 737 is also the only Boeing without EICAS, the issue behind the 787-10 not being certified.

Most aircraft I am familiar with will have the elevation and also a switch/relay to the cabin pressure controller, that cabin pressure controller will deploy masks automatically in the event of excessive cabin altitude (eg Helios) or by the pilots pressing a switch. The landing elevation and cruise altitude is fed in to control the cabin altitude.

Older aircraft were typically built around one box does one job, and connected within the avionics bay via a ARINC 429 data bus.

The A380 was the first large airliner to use computer networks, and it was a ADFX network. They also changed the idea of one box one job and started doing jobs within software on an industrial blade server, for example aircraft environmental surveillance system (AESS) is a software application on the A380 that does transponder, ADS-B, TCAS, GPWS and weather radar.

Ok, so you are not familiar with specifics of NG mask deployment system?

Ad hominem fallacy. You're not refuting the actual point.

Regardless of how mask deployment works on the NG, the guy in question was lying. There is no way to do what he claimed.

kalvado · Thu Jun 16, 2022 7:32 am

Starlionblue wrote:
kalvado wrote:
zeke wrote:

No, because he was caught lying red handed. He tweeted in flight he was on an aircraft and was going to set off the passenger oxygen EICAS. After the United 737 landed, he was arrested, they seized and listed all the tech gear he had including devices, cables, thumb drives. There was no cat 6 cable. The 737 is also the only Boeing without EICAS, the issue behind the 787-10 not being certified.

Most aircraft I am familiar with will have the elevation and also a switch/relay to the cabin pressure controller, that cabin pressure controller will deploy masks automatically in the event of excessive cabin altitude (eg Helios) or by the pilots pressing a switch. The landing elevation and cruise altitude is fed in to control the cabin altitude.

Older aircraft were typically built around one box does one job, and connected within the avionics bay via a ARINC 429 data bus.

The A380 was the first large airliner to use computer networks, and it was a ADFX network. They also changed the idea of one box one job and started doing jobs within software on an industrial blade server, for example aircraft environmental surveillance system (AESS) is a software application on the A380 that does transponder, ADS-B, TCAS, GPWS and weather radar.

Ok, so you are not familiar with specifics of NG mask deployment system?

Ad hominem fallacy. You're not refuting the actual point.

Regardless of how mask deployment works on the NG, the guy in question was lying. There is no way to do what he claimed.

That's what many IT guys said. Next thing they learn is it would take $1M to a Bitcoin account to get things back to normal.

Thinking about it, and assuming 737 being a Ruby Goldberg machine with WWII style architecture, IFE being a total afterthought, how messing up things is possible.

See, both IFE and cockpit have to receive mask drop signal - IFE for a prerecorded cabin announcement. Assuming 737 uses a single voltage line for that- and that's the way WWII design would do it, and IFE simply reading that line with a 8255 style buffer - actually a 3-state pin ...
It would take a pretty deep knowledge of system interfacing to explain why that is not possible. Certainly way beyond plainly believing Boeing.

Starlionblue · Thu Jun 16, 2022 8:20 am

kalvado wrote:
Starlionblue wrote:
kalvado wrote:
Ok, so you are not familiar with specifics of NG mask deployment system?

Ad hominem fallacy. You're not refuting the actual point.

Regardless of how mask deployment works on the NG, the guy in question was lying. There is no way to do what he claimed.

That's what many IT guys said. Next thing they learn is it would take $1M to a Bitcoin account to get things back to normal.

Thinking about it, and assuming 737 being a Ruby Goldberg machine with WWII style architecture, IFE being a total afterthought, how messing up things is possible.

See, both IFE and cockpit have to receive mask drop signal - IFE for a prerecorded cabin announcement. Assuming 737 uses a single voltage line for that- and that's the way WWII design would do it, and IFE simply reading that line with a 8255 style buffer - actually a 3-state pin ...
It would take a pretty deep knowledge of system interfacing to explain why that is not possible. Certainly way beyond plainly believing Boeing.

Burden of proof fallacy...

kalvado · Thu Jun 16, 2022 11:42 am

Starlionblue wrote:
kalvado wrote:
Starlionblue wrote:

Ad hominem fallacy. You're not refuting the actual point.

Regardless of how mask deployment works on the NG, the guy in question was lying. There is no way to do what he claimed.

That's what many IT guys said. Next thing they learn is it would take $1M to a Bitcoin account to get things back to normal.

Thinking about it, and assuming 737 being a Ruby Goldberg machine with WWII style archite тоcture, IFE being a total afterthought, how messing up things is possible.

See, both IFE and cockpit have to receive mask drop signal - IFE for a prerecorded cabin announcement. Assuming 737 uses a single voltage line for that- and that's the way WWII design would do it, and IFE simply reading that line with a 8255 style buffer - actually a 3-state pin ...
It would take a pretty deep knowledge of system interfacing to explain why that is not possible. Certainly way beyond plainly believing Boeing.

Burden of proof fallacy...

And of course finding all the relevant information requires IFE system manual and full 737 wiring diagram. But it is usual "through obscurity" thing

I have a better and more interesting question for you, though.
Why flight data is available to IFE at all? Apparently, when 737 systems were designed, IFE wasn't a real thing. Boeing providing information by redesigning whatever their computing units are called - certified, extremely important units - just to please the pax is totally unlikely. So why the data is available at all?

If I answered that question correctly, there could be another serious vulnerability in many planes....

Starlionblue · Fri Jun 17, 2022 2:43 am

kalvado wrote:
Starlionblue wrote:
kalvado wrote:
That's what many IT guys said. Next thing they learn is it would take $1M to a Bitcoin account to get things back to normal.

Thinking about it, and assuming 737 being a Ruby Goldberg machine with WWII style archite тоcture, IFE being a total afterthought, how messing up things is possible.

See, both IFE and cockpit have to receive mask drop signal - IFE for a prerecorded cabin announcement. Assuming 737 uses a single voltage line for that- and that's the way WWII design would do it, and IFE simply reading that line with a 8255 style buffer - actually a 3-state pin ...
It would take a pretty deep knowledge of system interfacing to explain why that is not possible. Certainly way beyond plainly believing Boeing.

Burden of proof fallacy...

And of course finding all the relevant information requires IFE system manual and full 737 wiring diagram. But it is usual "through obscurity" thing

I have a better and more interesting question for you, though.
Why flight data is available to IFE at all? Apparently, when 737 systems were designed, IFE wasn't a real thing. Boeing providing information by redesigning whatever their computing units are called - certified, extremely important units - just to please the pax is totally unlikely. So why the data is available at all?

If I answered that question correctly, there could be another serious vulnerability in many planes....

Hasty generalisation fallacy.

The data is generated in the first place because it has to be output to the displays in the cockpit, the transponder, ADS-B, the DFDR, and so on. Using the data for IFE does not require redesigning the computing units that actually generate the data. It just requires receiving the data stream. Processing to make it into a nifty map view and so on can be done in the IFE system.

zeke · Fri Jun 17, 2022 3:00 am

kalvado wrote:
Why flight data is available to IFE at all? Apparently, when 737 systems were designed, IFE wasn't a real thing. Boeing providing information by redesigning whatever their computing units are called - certified, extremely important units - just to please the pax is totally unlikely. So why the data is available at all?

Airliners generally are not certified with a cabin, they are certified as empty shells. The monuments, seats, IFE that is installed is fixed cargo that has no impact on the operation and control of the aircraft. I have done literally hundreds of flights during covid with the IFE turned off, there is absolutely no cockpit indications of this.

Boeing have not redesigned anything, they have not amended the type certificate to allow IFE to interface with the aircraft. IFE does not directly connect with the aircraft systems at all, they are isolated. There is something between the IFE and the aircraft that does the interface, and the data just goes one way.

kalvado · Fri Jun 17, 2022 5:29 am

Starlionblue wrote:
kalvado wrote:
Starlionblue wrote:

Burden of proof fallacy...

And of course finding all the relevant information requires IFE system manual and full 737 wiring diagram. But it is usual "through obscurity" thing

I have a better and more interesting question for you, though.
Why flight data is available to IFE at all? Apparently, when 737 systems were designed, IFE wasn't a real thing. Boeing providing information by redesigning whatever their computing units are called - certified, extremely important units - just to please the pax is totally unlikely. So why the data is available at all?

If I answered that question correctly, there could be another serious vulnerability in many planes....

Hasty generalisation fallacy.

The data is generated in the first place because it has to be output to the displays in the cockpit, the transponder, ADS-B, the DFDR, and so on. Using the data for IFE does not require redesigning the computing units that actually generate the data. It just requires receiving the data stream. Processing to make it into a nifty map view and so on can be done in the IFE system.

Ivory castle naivety.

Data may exist somewhere, but getting it out to the required location in the proper format may be expensive.
An IFE system must have minimum modification requirements for flight control part. If it took a single extra line of code to access the data, it would never happen until that is an essential requirement - which moving map is certainly not.
If you remember, UA used to have a unique feature called "channel 9" many moons ago. The way it was implemented, certainly, is a good example of a design with minimal interference to critical cockpit systems

kalvado · Fri Jun 17, 2022 5:32 am

zeke wrote:
kalvado wrote:
Why flight data is available to IFE at all? Apparently, when 737 systems were designed, IFE wasn't a real thing. Boeing providing information by redesigning whatever their computing units are called - certified, extremely important units - just to please the pax is totally unlikely. So why the data is available at all?

Airliners generally are not certified with a cabin, they are certified as empty shells. The monuments, seats, IFE that is installed is fixed cargo that has no impact on the operation and control of the aircraft. I have done literally hundreds of flights during covid with the IFE turned off, there is absolutely no cockpit indications of this.

Boeing have not redesigned anything, they have not amended the type certificate to allow IFE to interface with the aircraft. IFE does not directly connect with the aircraft systems at all, they are isolated. There is something between the IFE and the aircraft that does the interface, and the data just goes one way.

There was nothing between them, not even a thinnest condom.
You cannot get data without some connection.

Starlionblue · Fri Jun 17, 2022 5:51 am

kalvado wrote:
Starlionblue wrote:
kalvado wrote:
And of course finding all the relevant information requires IFE system manual and full 737 wiring diagram. But it is usual "through obscurity" thing

I have a better and more interesting question for you, though.
Why flight data is available to IFE at all? Apparently, when 737 systems were designed, IFE wasn't a real thing. Boeing providing information by redesigning whatever their computing units are called - certified, extremely important units - just to please the pax is totally unlikely. So why the data is available at all?

If I answered that question correctly, there could be another serious vulnerability in many planes....

Hasty generalisation fallacy.

The data is generated in the first place because it has to be output to the displays in the cockpit, the transponder, ADS-B, the DFDR, and so on. Using the data for IFE does not require redesigning the computing units that actually generate the data. It just requires receiving the data stream. Processing to make it into a nifty map view and so on can be done in the IFE system.

Ivory castle naivety.

Data may exist somewhere, but getting it out to the required location in the proper format may be expensive.
An IFE system must have minimum modification requirements for flight control part. If it took a single extra line of code to access the data, it would never happen until that is an essential requirement - which moving map is certainly not.
If you remember, UA used to have a unique feature called "channel 9" many moons ago. The way it was implemented, certainly, is a good example of a design with minimal interference to critical cockpit systems

Why would you need any extra code to access the data? The data is already being output to multiple systems, one-way only. This is just one extra system that gets the same data.

kalvado · Fri Jun 17, 2022 6:14 am

Starlionblue wrote:
kalvado wrote:
Starlionblue wrote:

Hasty generalisation fallacy.

The data is generated in the first place because it has to be output to the displays in the cockpit, the transponder, ADS-B, the DFDR, and so on. Using the data for IFE does not require redesigning the computing units that actually generate the data. It just requires receiving the data stream. Processing to make it into a nifty map view and so on can be done in the IFE system.

Ivory castle naivety.

Data may exist somewhere, but getting it out to the required location in the proper format may be expensive.
An IFE system must have minimum modification requirements for flight control part. If it took a single extra line of code to access the data, it would never happen until that is an essential requirement - which moving map is certainly not.
If you remember, UA used to have a unique feature called "channel 9" many moons ago. The way it was implemented, certainly, is a good example of a design with minimal interference to critical cockpit systems

Why would you need any extra code to access the data? The data is already being output to multiple systems, one-way only. This is just one extra system that gets the same data.

To which systems? How?
In simplest terms, ife package includes a cable labelled "to cockpit data source" and there is a corresponding connector in the cockpit. 787 and 350 may have a connector "IFE" somewhere, I heavily doubt NG does.
However there is such connection, obviously. How is it labelled and why it was installed?

zeke · Fri Jun 17, 2022 9:30 am

kalvado wrote:
There was nothing between them, not even a thinnest condom.
You cannot get data without some connection.

You are reading my posts on this forum without a direct connection to the device I am posting from, you cannot tell what I am reading, what I am doing, or control my device by reading a post. There is something between.

As I clearly stated there is something between the IFE and the aircraft, and that something outputs a transmit only bus to the IFE, typically a single cable pair with ARINC 429 protocol. It is transmit only.

The majority of data busses on older designs like the 737 are one way. The role of those busses is to get data from around the aircraft into the avionics bay.

kalvado · Fri Jun 17, 2022 10:51 am

zeke wrote:
kalvado wrote:
There was nothing between them, not even a thinnest condom.
You cannot get data without some connection.

You are reading my posts on this forum without a direct connection to the device I am posting from, you cannot tell what I am reading, what I am doing, or control my device by reading a post. There is something between.

As I clearly stated there is something between the IFE and the aircraft, and that something outputs a transmit only bus to the IFE, typically a single cable pair with ARINC 429 protocol. It is transmit only.

The majority of data busses on older designs like the 737 are one way. The role of those busses is to get data from around the aircraft into the avionics bay.

These are the words of end user who never looked under the hood. You can certainly deal with asynchronous data flow from gauges. You certainly cannot organize that as a bus since transmissions from multiple devices will start interfering. You will loose ability to use anything but basic stuff - no mode switching, no diagnostic information requested from device. You basically go back to a separate wire to each dumb endpoint approach.
There is probably a single situation in a plane besides IFE where one way connection is not only justified, but is a must.

zeke · Fri Jun 17, 2022 12:44 pm

You could only interfere with gauges if you able to access the cable running between the engines for example and the piece of avionics that drives the gauges. To do that you need to be not in the aircraft cabin. These data busses are not new tech, they are very old reliable tech that only allows something like 20 pieces of equipment on the bus. So what they do is run different busses for different equipment. One bus cannot see the data on another bus.

At the end of the day you simply cannot believe the simple truth that the person was lying. He had no cable to connect to the aircraft. It was attention seeking, and got the attention of the FBI.

kalvado · Fri Jun 17, 2022 1:51 pm

zeke wrote:
You could only interfere with gauges if you able to access the cable running between the engines for example and the piece of avionics that drives the gauges. To do that you need to be not in the aircraft cabin. These data busses are not new tech, they are very old reliable tech that only allows something like 20 pieces of equipment on the bus. So what they do is run different busses for different equipment. One bus cannot see the data on another bus.

At the end of the day you simply cannot believe the simple truth that the person was lying. He had no cable to connect to the aircraft. It was attention seeking, and got the attention of the FBI.

Did you ever run a troubleshooting on a bus? I spent quite a bit of time with oscilloscope trying to fix communication problems. Latest one was when it took 1 bit set incorrectly to turn "very old reliable tech" into a glitchy mess. And yes, I've seen specs.

kalvado wrote:
.... Physical isolation stuff may also depend on things like differences between ARINC 429 and 629 - which seem to be similar to RS422 and 485 in civilian world, with different architecture and ability to physically isolate a datasource.

As far as I understand, 737 has 3 duplicate 429 buses, left/right/backup. Not sure if they run low or high speed, though.

zeke · Sat Jun 18, 2022 5:09 am

kalvado wrote:
zeke wrote:
You could only interfere with gauges if you able to access the cable running between the engines for example and the piece of avionics that drives the gauges. To do that you need to be not in the aircraft cabin. These data busses are not new tech, they are very old reliable tech that only allows something like 20 pieces of equipment on the bus. So what they do is run different busses for different equipment. One bus cannot see the data on another bus.

At the end of the day you simply cannot believe the simple truth that the person was lying. He had no cable to connect to the aircraft. It was attention seeking, and got the attention of the FBI.

Did you ever run a troubleshooting on a bus? I spent quite a bit of time with oscilloscope trying to fix communication problems. Latest one was when it took 1 bit set incorrectly to turn "very old reliable tech" into a glitchy mess. And yes, I've seen specs.
kalvado wrote:
.... Physical isolation stuff may also depend on things like differences between ARINC 429 and 629 - which seem to be similar to RS422 and 485 in civilian world, with different architecture and ability to physically isolate a datasource.

As far as I understand, 737 has 3 duplicate 429 buses, left/right/backup. Not sure if they run low or high speed, though.

This is just more obscuration of the real technical details, how many times do I need to tell you the guy was lying, he had no cables, he physically had no access to the aircraft bus.

No one cares about your troubleshooting experience it is totally irrelevant. If you had the experience you claimed you would know you would need direct physical access to the bus. It has been explained to you when he was arrested getting off the aircraft he had no such cable.

There is more than 3 busses on a typical airliner, the 3 you you mentioned would be for just the base airframe. The cabin and IFE independent.

planecane · Mon Jun 20, 2022 4:32 pm

Southwest's BYOD IFE flight map seems to have gotten an upgrade or the upgrade is rolling out. On a 737-700 flight a couple of days ago, there was a new cockpit view that made it look like you were looking out through a HUD. It had speed (not specified but I think ground speed) on the left with a "speed tape" and then a similar graphic on the right with altitude. The sale on both would move up or down depending on what the aircraft was doing.

There is an attitude indicator but it didn't seem to work. I don't know if attitude is output to the IFE on a 737NG.

gloom · Mon Jun 20, 2022 6:34 pm

planecane wrote:
Southwest's BYOD IFE flight map seems to have gotten an upgrade or the upgrade is rolling out.

Similar to this one?

Airbus, 2016. Nothing new in this world...

Cheers,
Adam

planecane · Mon Jun 20, 2022 6:54 pm

gloom wrote:
planecane wrote:
Southwest's BYOD IFE flight map seems to have gotten an upgrade or the upgrade is rolling out.

Similar to this one?

Airbus, 2016. Nothing new in this world...

Cheers,
Adam

Very similar. I forgot about the compass being on it as well. It does seem like the attitude indication is correct in your picture where I'm pretty sure the Southwest one didn't do anything.

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