PIA A-320 crash in Karachi

[Rbass 27]

3 hours ago, HighBypass said:

A question regarding speed brakes/spoilers, especially for those who use them in real aeroplanes. I thought that you get buffet/vibration and extra noise when you deploy them which "should" I say "should", give the game away in addition to any visual indocators in the cockpit. I remember a couple of times as pax on an airliner, one of the pilots warning us about the vibration and noise and what it was. In addition when I deployed them myself in a glider - the airframe was telling me I'd altered the aerodynamics. I was of course still holding on to the lever, but still I think you know what i mean. 😉

Each type is different with regard to noise and vibration, but some are very noisy with a lot of buffeting. Generally speaking, speed brakes are much rougher than modulating spoilers, but at full deflection and especially higher speeds they will be noticeable. A straight wing citation speed brakes feel like a piece of the plane just fell off. The pax will definitely know they’re deployed, I promise you that. ;D

One other thing to add is that full automation can cause a pilot to not realize they’re extended. Usually speed brakes or spoilers can be extended regardless of the auto flight systems, so if you put the brakes out while still using the auto throttles, the A/T’s will simply increase to maintain your set speed, so a distracted pilot won’t see any airspeed change and might forget they’re out. I can say that as advanced as these planes can be, running full automation takes less hands on, but magnitudes more brain on. In a heavy workload situation, and especially one that’s departing from normal ops, things get distracting and overlooked very fast, and the speed brakes can fall into that. Warning horns aren’t heard, confusion sets in, and the pilot is trying to figure out what’s happening. I think these guys were at that point.

[CYXR 257]

France's BEA (Civil Aviation Safety Investigation Authority) tweeted yesterday that it is wrapping-up it's on site investigation and will begin repair and analysis work on the FDR and CVR  on June 2nd.  https://twitter.com/BEA_Aero?ref_src=twsrc^google|twcamp^serp|twgr^author

[HighBypass 2,339]

17 hours ago, Rbass said:

Usually speed brakes or spoilers can be extended regardless of the auto flight systems, so if you put the brakes out while still using the auto throttles, the A/T’s will simply increase to maintain your set speed, so a distracted pilot won’t see any airspeed change and might forget they’re out...

Thanks for the reply. Would this not indicate a possible "need" from manufacturers to deliberately engineer in some buffet and vibration physically so that the airframe is giving the pilot cues as well?

[threexgreen 3,135]

18 hours ago, Chock said:

US Airways Flight 1549 (aka the Miracle on the Hudson) and Air Canada flight 143 (aka the Gimli Glider).

I raise you Air Transat 236. This one often gets overlooked but is one of the best pilot performances in aviation history I'd say. Losing both engines nearly simultaneously over the middle of the Atlantic Ocean is basically as bad as it gets. This one also proves your point because Robert Piché is, in fact, an experienced glider pilot, and did an otherworldly job together with his first officer, Dirk de Jager.

[threexgreen 3,135]

18 hours ago, Chock said:

Yup. The problem with saying that an airliner crew member has 'a lot of hours', is that it is an extremely misleading statistic.

17 hours ago, Rbass said:

Warning horns aren’t heard, confusion sets in, and the pilot is trying to figure out what’s happening. I think these guys were at that point.

One look at the PFD (altitude, airspeed) tells you there is no way you can expect this approach to be successful, whether you have a lot of stick flying time or not. Even if hours don't have to mean much, there is knowledge on one hand which tells you this is not going to work and there are rules (SOPs) on the other hand that dictate to abort an approach like that. Especially if your mental workload is exhausted and you get confused, by all means pull the plug and abort the approach.

Unless the investigation finds a reason why they had to keep going, this one is just extremely hard to swallow considering you have ~ 100 people in the back counting on you to do your job responsibly, as in abort that approach.

 

 

[him225 51]

After due to whatever event they ended up high during decent, could it be they decided out of technical curiosity to see if the plane could land from that situation or what energy state it would end up at the runway, thinking there is nothing unsafe with it - calm weather, vacant skies - that they would just make a go around from over the runway. But ended up in a chaotic non standard state and missed something at the go around.

Or perhaps something related to epidemic was making them impatient, wanted them to get out of the aircraft and their PPE as soon as they can, but it seems less possible.

Edited June 1, 2020 by him225

[Bert Pieke 7,584]

Maybe they were just in a hurry... it happens..

[Chock 17,769]

7 hours ago, Bert Pieke said:

Maybe they were just in a hurry... it happens..

Yup, simplest explanation is usually the correct one. A bit of the old 'get-home-itis'. Not usually a good idea, but probably responsible for more aeroplane accidents than anything else ever.

[Rbass 27]

18 hours ago, threegreen said:

One look at the PFD (altitude, airspeed) tells you there is no way you can expect this approach to be successful, whether you have a lot of stick flying time or not. Even if hours don't have to mean much, there is knowledge on one hand which tells you this is not going to work and there are rules (SOPs) on the other hand that dictate to abort an approach like that. Especially if your mental workload is exhausted and you get confused, by all means pull the plug and abort the approach.

Unless the investigation finds a reason why they had to keep going, this one is just extremely hard to swallow considering you have ~ 100 people in the back counting on you to do your job responsibly, as in abort that approach.

 

 

You would think, right? Unfortunately there are way too many accidents where the crews don't realize whats happening and put their planes into very bad situations,  just like these guys did. Boggles the mind, but keeps on happening.

Since you mentioned the number of pax, whether zero or hundreds of people behind them makes no difference.  If they don't realize they're jeopardizing their own safety, the thought that they're putting pax at risk will never enter their minds.

Edited June 1, 2020 by Rbass

[Rbass 27]

19 hours ago, HighBypass said:

Thanks for the reply. Would this not indicate a possible "need" from manufacturers to deliberately engineer in some buffet and vibration physically so that the airframe is giving the pilot cues as well?

No. They're plenty noisy and rough enough as is. 😉 I should've added that many or most do have some sort of auto retract system, such as the brakes will retract if the throttles are pushed up past a certain point, or if the airplane is approaching a stall.

Edited June 1, 2020 by Rbass

[jon b 2,041]

20 hours ago, HighBypass said:

Thanks for the reply. Would this not indicate a possible "need" from manufacturers to deliberately engineer in some buffet and vibration physically so that the airframe is giving the pilot cues as well?

What I normally do , and I believe it’s written somewhere, probably FCTM, is when ever you have the speed brake lever out you physically keep your hand on it on only take your hand off once the speed brake lever is stowed again, that way you won’t forget its out.

That works for Boeings, I’m not sure about Airbus as they have those little levers and things.

There was the case a few years back involving an American 757 I believe ,performing a terrain escape manoeuvre in South America somewhere. Unfortunately they hit the ridge, they would have made it over the top but sadly they had speedbrake out and forgot about them in the confusion, very easily done in those sorts of scenarios.

 

[Chock 17,769]

That's exactly why I do a scan of the control levers from time to time.

I had an instructor years ago (this was in tandem cockpits, with him sat behind me) who would sometimes sneakily unlatch the spoilers and extend them when I was in the circuit for a landing concentrating on other stuff. You'd think that the sound over the wings would give that away, but when you are concentrating on your position and altitude, it's easy to miss that kind of thing, then you'd wonder why even though you'd flown a perfect circuit, it'd look like you were going to undershoot the landing for some mysterious reason. He'd just say: 'check the controls' or some such, to which, when I spotted what he'd done, my reply would usually be: 'aaah, you sneaky b*st*rd!'

That sort of thing is the sign of a good instructor. Especially at the point where you are getting good at things and starting to feel a bit cocky about your abilities, because those things stay with you and make you a better pilot, so I appreciated him doing that kind of sneaky stuff to me. It's very easy to miss something which, with hindsight, seems unbelievable.

In the case of PK8303 with regard to missing the obvious, there is of course the good old adage of: 'there's two kinds of pilots; those who have made a wheels up landing, and those who are going to.'

Edited June 1, 2020 by Chock

[threexgreen 3,135]

5 hours ago, Rbass said:

You would think, right? Unfortunately there are way too many accidents where the crews don't realize whats happening and put their planes into very bad situations,  just like these guys did. Boggles the mind, but keeps on happening.

Since you mentioned the number of pax, whether zero or hundreds of people behind them makes no difference.  If they don't realize they're jeopardizing their own safety, the thought that they're putting pax at risk will never enter their minds.

What I just can't wrap my head around is that there are so many things which (should) make you aware of an unstable approach. Assuming they didn't realize they were starting to put the aircraft into an approach which wouldn't work, you often have altitude constraints you have to verify making your way down the runway along the STAR. There are checklists to verify the configuration including the landing gear. You check speed and altitude at the FAF. You put out flaps and the flap overspeed warning goes off. Fixing your eyes on the runway, you're so much faster than usual you should just see it. You actually respond to ATC that you're at 3500 ft at 5 miles. ATC queries you about the approach and offers a vector, but you turn it down and say you're comfortable on the ILS. When the instruments show you (provided you're using them as backup on the visual, which you should) you're nowhere near the glide slope. Etc.

The explanation is probably as simple as saying humans work in mysterious ways. But to think none of these things ever made them aware of the situation or decide to abort the approach is just bizarre.

[Rbass 27]

1 hour ago, threegreen said:

The explanation is probably as simple as saying humans work in mysterious ways. But to think none of these things ever made them aware of the situation or decide to abort the approach is just bizarre.

That’s one reason we can’t make conclusions until a full investigation has been done. They will look at everything, including the the crews days leading up to the accident. Without knowing the entire scenario, we are just wagging it.

Edited June 1, 2020 by Rbass

[threexgreen 3,135]

17 hours ago, Rbass said:

That’s one reason we can’t make conclusions until a full investigation has been done. They will look at everything, including the the crews days leading up to the accident. Without knowing the entire scenario, we are just wagging it.

Yep. The BEA is beginning work on the FDR and CVR today btw.