Aeroflot deactivates brakes on nine aircraft, relies solely on reverse thrust • Hacker News Board

Re: Aeroflot deactivates brakes on nine aircraft, relies solely on reverse thrust

#201

Post by stevehawk » Tue, Aug 08, 2023, 2:00 AM UTC

aunty_helen wrote: post #139

ssabev wrote: post #26

This is probably going to be just the tip of the iceberg. There was already articles around cannibalisation of planes so that you can service and repair an ever dwindling number of aircraft. If it keeps going on for another year or two it's not going to be good

This literally happens everyday, everywhere and to every airline. Sometimes even between airlines. I’ve personally been responsible for a part getting pulled off another engine from another airline and swapped for one that got its electrical connector damaged so the engine would ship on time. There is a whole industry of buyers and sellers of 2nd hand aircraft parts.

That doesn't mean this is the same situation. In examples you are likely thinking of, this is happening because of the immediate need for parts or as cost savings, etc. Russia is doing it because they are blocked from primary and secondary markets. For many of their aircraft in the country there are no replacement parts coming except what falls off of the truck in China and gets passed along. So their supply chain is slowly approaching zero until their aircraft have to simply be grounded (or they quit invading neighboring countries and the embargoes are lifted.)

Re: Aeroflot deactivates brakes on nine aircraft, relies solely on reverse thrust

#202

Post by AndrewKemendo » Tue, Aug 08, 2023, 2:02 AM UTC

nvy wrote: post #182

bri3d wrote: post #28

I'm curious the actual mechanics of this operation. The main primary-source I found is a Telegram post of an Aeroflot pilot memo [0], but this only discusses the side-effects of reverser only braking, not the mechanics of "disabling the brakes." There is a possibility the brakes are still available and not worn through, and this is a preemptive measure to leave enough brake material to handle an emergency rejected ta…

So I used to work in aircraft maintenance (never in Russia though) and the policy is to change the brakes when there is $minimum_thickness of brake pad remaining. There's a little wire embedded in the pad and eventually as the pad wears thin the wire completes a circuit with the rotor, and lights up the aerospace version of the Check Engine Light. The brakes on these planes certainly have some remaining life but they…

How does the wire from the removable pad couple electronically with the permanent housing? Is it like a contact plate or is there an actual m-f style plug?

Re: Aeroflot deactivates brakes on nine aircraft, relies solely on reverse thrust

#203

Post by barbazoo » Tue, Aug 08, 2023, 2:04 AM UTC

ars wrote: post #32

barbazoo wrote: post #11

Take off and landing aside, can you properly control the aircraft on the ground without brakes? I'm thinking of stopping at hold short lines, at the gate, etc. How precise, responsive is reverse thrust in those cases? Or will they get picked up by those little cars and pulled right after landing?

I suspect they can still use them in those situations, since there is very little wear just holding still. The planes probably still have brakes, just the pilots are told not to use them when landing - this would make them last much longer, but still be available.

Yes that makes much more sense.

Re: Aeroflot deactivates brakes on nine aircraft, relies solely on reverse thrust

#204

Post by alexey-salmin » Tue, Aug 08, 2023, 2:05 AM UTC

Planes don't stop with the reverse thrust, only slow down to 100-120km/h. If you use it a lower speed there's a real risk of lifting a piece of debris off the runway and sucking it into the engine intake.

This is why we have to bother with pushback for jet aircrafts unlike the convenient powerback we have for props.

Re: Aeroflot deactivates brakes on nine aircraft, relies solely on reverse thrust

#205

Post by mulmen » Tue, Aug 08, 2023, 2:10 AM UTC

vbezhenar wrote: post #162

mulmen wrote: post #29

Earlier quoted context omitted.

I don’t speak russian, would you mind pointing out the relevant part of that article that inverts the claim of disabled brakes?

According to this article, using planes with some of the brakes disabled is OK and generally accepted everywhere, up to 10 days. Of course brakes will be replaced soon, but just the fact that some breaks are not functional does not mean that plane have to be moved to repair immediately. There are some plane defects which are considered acceptable for limited time use and this situation is one of them.

The post I replied to is now flagged so you probably didn’t see the specific claim I was replying to.

Re: Aeroflot deactivates brakes on nine aircraft, relies solely on reverse thrust

#206

Post by hatsunearu » Tue, Aug 08, 2023, 2:15 AM UTC

AndrewKemendo wrote: post #202

nvy wrote: post #182

Earlier quoted context omitted.

So I used to work in aircraft maintenance (never in Russia though) and the policy is to change the brakes when there is $minimum_thickness of brake pad remaining. There's a little wire embedded in the pad and eventually as the pad wears thin the wire completes a circuit with the rotor, and lights up the aerospace version of the Check Engine Light. The brakes on these planes certainly have some remaining life but they…

How does the wire from the removable pad couple electronically with the permanent housing? Is it like a contact plate or is there an actual m-f style plug?

some cars have this system and yes, there's a connector dangling out the back of a brake pad (more like the side, but you get the point)

Re: Aeroflot deactivates brakes on nine aircraft, relies solely on reverse thrust

#207

Post by sokoloff » Tue, Aug 08, 2023, 2:19 AM UTC

AndrewKemendo wrote: post #202

nvy wrote: post #182

Earlier quoted context omitted.

So I used to work in aircraft maintenance (never in Russia though) and the policy is to change the brakes when there is $minimum_thickness of brake pad remaining. There's a little wire embedded in the pad and eventually as the pad wears thin the wire completes a circuit with the rotor, and lights up the aerospace version of the Check Engine Light. The brakes on these planes certainly have some remaining life but they…

How does the wire from the removable pad couple electronically with the permanent housing? Is it like a contact plate or is there an actual m-f style plug?

On cars with the equivalent system, there’s a plug (single pin on most) and the wearing though of the sensor grounds that pin.

On this page, the black cylinder is the sensor and white body is the connector: https://www.autozone.com/brakes-and-traction-control/brake-p...

Re: Aeroflot deactivates brakes on nine aircraft, relies solely on reverse thrust

#208

Post by flangola7 » Tue, Aug 08, 2023, 2:22 AM UTC

Dalewyn wrote: post #175

Waterluvian wrote: post #172

Earlier quoted context omitted.

This feels like “it’s not as bad as it seems. Only three rooms are currently on fire, not twelve.” …They’re disabling brakes?

I think the moral here is there is an unhealthy dash of sensationalism and propaganda that must be sifted away, if we actually want to take any worthwhile information out of this. As the saying goes, the first casualty in war is truth.

But there's no sensationalism or propaganda here.

Re: Aeroflot deactivates brakes on nine aircraft, relies solely on reverse thrust

#209

Post by dylan604 » Tue, Aug 08, 2023, 2:31 AM UTC

nvy wrote: post #182

bri3d wrote: post #28

I'm curious the actual mechanics of this operation. The main primary-source I found is a Telegram post of an Aeroflot pilot memo [0], but this only discusses the side-effects of reverser only braking, not the mechanics of "disabling the brakes." There is a possibility the brakes are still available and not worn through, and this is a preemptive measure to leave enough brake material to handle an emergency rejected ta…

So I used to work in aircraft maintenance (never in Russia though) and the policy is to change the brakes when there is $minimum_thickness of brake pad remaining. There's a little wire embedded in the pad and eventually as the pad wears thin the wire completes a circuit with the rotor, and lights up the aerospace version of the Check Engine Light. The brakes on these planes certainly have some remaining life but they…

>the aerospace version of the Check Engine Light.

why does it use such a vague light. are they afraid one more specific light for "brake pad warning" lamp will just make the cockpit untenable?

Re: Aeroflot deactivates brakes on nine aircraft, relies solely on reverse thrust

#210

Post by jdietrich » Tue, Aug 08, 2023, 2:32 AM UTC

closewith wrote: post #47

blibble wrote: post #38

Earlier quoted context omitted.

> but they are certainly not falling out of the skies they will be shortly and you won't hear about it unless you're on it

Hard to hide an airliner crash in this day and age. Certainly over land, anyway.

It's hard to hide a crash, but it's easy to downplay one. Threaten a few witnesses, pay off a few bereaved families and you can turn a catastrophe into a minor incident.

Russian warships in the Black Sea have been "catching fire" at a suspiciously high rate since February 2022. Same for petroleum facilities and ammo dumps near the Ukrainian border. We all know what really happened, but the Kremlin can spin a line and nobody who saw what actually happened is brave or foolish enough to contradict that line.