Potential Disaster, 5G and Aircraft 6

[TugboatEng]

Interesting, it looks like the FAA is concerned about 5g interfering with altimeters on many commerical aircraft.

https://www.faa.gov/newsroom/faa-statement-5g

The current restrictions would prevent the use of auto-land as well as landing in low visibility conditions.

 

[Alistair_Heaton]

Phones are on in the back and in the front = ?

Back = Cabin ie cabin crew and pax

Front = Flight deck aka pilots.

Punter is UK English slang for paying customer. I think it comes from betting on horses and having a punt ie a bet on a horse.

Yes your right I am getting to that point in life I need reading glasses and don't always have them when posting on my phone.

Yes crew have to pay for wifi internet if they use it.

If they connect to the mobile tech for calls in flight they have to pay for it as well for personal use. Every airline is different with these data and call technology. But I don't know any crew that get it for free. In fact there have been quiet a few sacked for taking a pax's internet connection voucher and using it.

The ipad issue is an IT issue with certificates and networks, Apple have a feature with unsecure networks apparently which prevents them going online and doing certain things. Per say its not a general issue its more an installation setup issue. We don't seem to have an issue with it at work but friends at other airlines it creates a lot of problems. But then again we are not internet connected its only internal cabin sales. Don't really know much about it.

 

[Alistair_Heaton]

John he is correct. Some situations its down right dangerous to do a "greaser"

The plane won't sometimes go into ground mode and get the lift dump out which may then not trigger the auto brakes and release the reverser buckets.

The tyres can skiff water and that generates steam which blisters the rubber which then peels off 10-20 landings worth of rubber in 1 go.

 

[Alistair_Heaton]

the faraday cage reference is linked to the lightning protection the skin is a cage so apart from the windows which point out the side there is earthed metal between the phones in the cabin and the antennas. The Rad alts will be on the bottom of the aircraft so there is no line of sight between the phones internally and the receiver. The antenna can only "see" the base stations on the ground.

 

[dik]

Ditto...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[Strong]

Related Articles "advertised" on this forum:

https://www.engineering.com/story/h...ze-industrial-control?utm_source=relart-etips

https://www.engineering.com/story/future-networks-5g-in-action?utm_source=relart-etips

Walt

 

[Eufalconimorph]

> the faraday cage reference is linked to the lightning protection the skin is a cage so apart from the windows which point out the side there is earthed metal between the phones in the cabin and the antennas. The Rad alts will be on the bottom of the aircraft so there is no line of sight between the phones internally and the receiver. The antenna can only "see" the base stations on the ground.


That doesn't form a Faraday cage for any wavelength shorter than 4x the smallest dimension of the window. For 4.4GHz (in the rad alt band) that's 68mm. For 3.8GHz it's 79mm. Plane windows are bigger than that, it's not an effective shield. There's some attenuation due to the body of the aircraft, but it's not a Faraday cage. A phone not in airplane mode will try to seek a nearby tower when it loses signal, in doing so it turns the gain on its amplifiers up. So a plane attempting to land with a non-airplane-mode phone will be going from out of range of the towers to in range, thus landing will be the most likely time to have phones transmitting at their maximum power. Phones are also much closer to the rad alt than cell towers, so the relative power seen by the rad alt isn't straightforward to calculate (not just straightforward inverse square law, neither is a perfect isotropic radiator).

 

[Alistair_Heaton]

Below the window there is metal skin between the cabin and receiver and composite hulls have a metal mesh in them.

They produce charts with the signal propagation through the windows. But thats getting into certification which I have no clue about.

We are told that cabin radio noise is shielded and the antennas on the hull are shielded on the roof and on the belly.

I know mobile phones won't work in the hold because we sometimes have to go and get the baggage charge hand because they can't get him on his mobile because he is in there sorting out lashing cargo down.

This has very little to do with 5G itself. This is purely the band that's been sold for its use in the USA. In Europe we have 5G and its been in use for over a year and we don't have any problems or restrictions.

 

[dik]

at a reduced frequency?

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[IRstuff]

you have to 'stick' the landings for them to be considered good

If he was a carrier pilot, the comment has to be in the context of snagging an arresting cable, and the pilots get rated on which one of the 4 they routinely snag.

Phones are also much closer to the rad alt than cell towers, so the relative power seen by the rad alt isn't straightforward to calculate (not just straightforward inverse square law, neither is a perfect isotropic radiator).

Nevertheless, the phones are inside the plane, and are therefore on the opposite side of the antenna aperture, while the 5G antennas' side lobes would be pointing directly into the altimeters. Even at max power, a cell phone's output power is still puny, even compared to a side lobe. As context, I wound up buying another satellite for my mesh router because the signal couldn't get through 4 normal wood frame walls.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

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[JohnRBaker]

My Navy pilot friend (he was actually a co-worker) didn't fly carrier-based planes. He flew Orion P-3's, anti-submarine patrol aircraft, during his service as a Navy reserve pilot.

John R. Baker, P.E. (ret)
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without

 

[dik]

IRS... interesting. I could use my Nighthawk router at the bus stop 200 yds away, through 3 walls, one of which was stucco and brick.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[Alistair_Heaton]

You only see a bump on the outside of the aircraft but there is a bloody great big armoured box on the inside of the rad alt.

Europe our band is up to 3.8 and that's it.

I think 3.8 until 4.6 is for now reserved. Maybe at a later date they will release some of it.

The WiFi seems to be very dependant on the material the wall is made out of. Wood and brick don't do much. Re bar concrete you have no chance even with the router on one side and the receiver 20 cm away on the other.

This is just personal experience of getting a signal in my barn which is 50cm of wooden wall on the house 10 meters of air then 20cm of wood. Cellar nothing at all with 15cm of concrete 5 meters straight line.

 

[Alistair_Heaton]

Japan had similar issues.

https://www.theregister.com/2022/01/19/5g_airliners_solved_by_japan/

 

[davefitz]

My guess is that the telecoms will attempt to meet the 2 mile rule but will not budge on the frequency range. Some planes will crash due to the interference but it will reliably be blamed on pilot error. The real driving purpose for the 5G ( and likely the "vaccines") will never be made public,and likely is related to improved surveilance capabilities , and we just are required to accept the story they put out in the media.

"...when logic, and proportion, have fallen, sloppy dead..." Grace Slick

 

[bacon4life]

What does skiff mean in this context? Is it Reverted Rubber Hydroplaning?

 

[dik]

Great link...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[Alistair_Heaton]

It's when you just kiss the water but don't break through it to the runway surface.

Some countries put grooves in the surface to aid drainage which prevents it happening.

 

[Alistair_Heaton]

This is different to hydroplaning.

Commercial aircraft the braks have a protective system so you can't land with them on and flat spot blow out.

You would need to be landing on a 100% flooded runway and very fast for hydroplane I am not saying it will never happen as there are 5-6 over runs per year due to it.

This is something different. And not as dangerous as the link cases.

Those two the weight of the aircraft is on the tyre this situation there is no or very little load due to the plane still flying.

 

[TugboatEng]

I don't understand how steam blisters the rubber. How hot is this steam?

Not trying to be snarky here. Serious question. We're used to low temp steam that is the result of cavitation. This won't damage rubber. I am aware that rubbers can be more sensitive to damage from steam based on type and hydrolysis. However, the pressures must be very high during hydroplaning so the steam must also be very hot. It seems this would cause charring or burning before blistering, maybe?

 

[Alistair_Heaton]

Don't have a clue we think it's steam but could be something else it has multiple rings that look like skin blister on your feet have burst and the skin has come off leaving a 0,5mm depression. Then over the next couple of lands it peels as skin does on your feet.

The rubber hydroplane cracks the carcass down the thread and leaves rolls of rubber.

The a220 has a very fancy breaking control setup which protects the tyres and gives derogation protection of the nose gear so we don't slam it down.

Q400 I used to see damage alot. This machine hardly ever.