PIA A320 Crash Karachi

[Superpilot]

Have seen their names plastered on some local media outlets. Captain and FO.

[tarik123]

you are absolutely right

[siropalomar]

Originally Posted by Milvus Milvus

I have read elsewhere
"A seperate safety valve is also incorporated. This shuts off hydraulic pressure to the actuators when the aircraft exceeds 260kt, and restores pressure only when the gear lever is selected down with the aircraft below 260kt."

This implies that the Gear will come down when "Selected", so if the lever is already down when reducing below 260kt does the lever need to be recycled for the system to detect a "selection"

I fly A330, been flying A320 too. FCOM states literally what you state. Type rating Instructors tell me that during simulator sessions Landing gear will come down when speed falls below 260 kt , no need to recycle Lng Gear lever. In that case, if they landed with gear retracted, it means they simply didn’t select Gear down. Obviously plenty of aural warnings (“too low gear, too low gear”) and ECAM Warning “landing gear not down” up to the moment they struck the runway. That is what we call “tunnel vision”, pilots exclusively centred on getting the plane on the runway, disregarding everything else. Let’s wait for the voice recorders reading, maybe the copilot was yelling “we’re too fast, too high, or please go around” all the way down. It’s happened before.

[retired guy]

Originally Posted by Airbus Unplugged

One way of operating an aircraft safely is to have a briefing at a sensible period of low workload, in which the crew openly and cooperatively discuss the approach, the threats to be faced, the required performance of the aircraft, how the aircraft is to be operated and what modes/level of automation to be used, and a number of points or gates during the approach where the energy can be measured against the planned profile. These gates can then be used as decision points as to whether it is safe and sensible to continue the approach, or whether the configuration of the aircraft should be changed or extra track miles should be requested.

Ultimately, both pilots will ensure that at a bottom line, let's say 1000 agl, that if the aircraft is not on the centre line and prescribed glide path, with the speed stable and close to target and the engines at approach thrust - a go around shall be flown.

Some occupants of some aircraft flight decks may use different methods or no methods at all to achieve different outcomes.

Thanks Airbus, you have the nub of the matter right here. You describe what should happen in a well run airline and on a disciplined flight deck. SOPs are always very clear on gates and there are usually a few of them. Some are mandatory such as the 1000 RA or the 500 RA where if certain conditions are not met (basically the approach must be stable) then a GA must be flown. In a well known LCC the PNH can even instruct the Captain to "Go Around" if at 500 ft the plane is not fully configured for landing, on profile and at the correct speed. The Captain must respond with a GA. There are other gates such as the obvious one at 30 nm out at FL 100 at about 300 kts, which is the harbinger of things to come. If you are too high and fast at this point you need to start doing something and work at it until back in the slot. 10nm at 3000 at 210 kts to thereabouts is another really good one of course, but you do need to know your 3 x table. I have met some pilots who don't - and I am not making that up. So the question arises how did this plane end up the way it did? The CVR and FDR will reveal all, but will it be released in full? This is all very sad since like most crashes it appears to be completely avoidable if best practice we to have been applied. But we don't know yet of course and must await the CVR and FDR. All the best Ret'd Guy.

[siropalomar]

Originally Posted by pineteam

Anyone going on an A320 simulator soon? A friend of mine tried on his flight simulator to lower the gears above 260kt the gears remained up as expected and never came down when he slowed down below 260kt! Would be interesting to try it in a real FFS.

In real Full Flight Simulators, if Lng Gear Down is selected with speed>260 kt, lng gear will remain retracted . Overspeed warning will trigger as long as speed remains above 260 too. When speed drops below 260, landing gear will come down, no need to recycle lng gear lever.

[Flying_Scotsman]

Originally Posted by Black Pudding

Hot, High, Fast.........Could it be someone on the flightdeck was a Maverick or had CRM issues that they selves were simply not aware of. Could it be a simple matter of having a perfectly serviceable aircraft destroyed to human error. Hot, High, Fast ? Distraction caused by being behind the aircraft leading to human error.

When I was wearing 'light blue', and first arriving at a hole in the ground as an investigator, it was very easy to ask "Why on earth did they do this or that?" However, what you have to ask is "With the situation they were in, and the information they had, why did they think what they were doing was correct?"

[Mad (Flt) Scientist]

Originally Posted by siropalomar

In real Full Flight Simulators, if Lng Gear Down is selected with speed>260 kt, lng gear will remain retracted . Overspeed warning will trigger as long as speed remains above 260 too. When speed drops below 260, landing gear will come down, no need to recycle lng gear lever.

I would be very cautious in concluding anything about actual aircraft system behaviour, in an abnormal condition, from behaviour observed in a simulator whose intent is training not engineering investigation. The only way to know for sure what the system would do is to actually do it by test, the next best is a full-up engineering simulation. A FFS is a poor man's version of the latter when it comes to this kind of thing.

[asdf1234]

Originally Posted by Flying_Scotsman

When I was wearing 'light blue', and first arriving at a hole in the ground as an investigator, it was very easy to ask "Why on earth did they do this or that?" However, what you have to ask is "With the situation they were in, and the information they had, why did they think what they were doing was correct?"

Well said. Safety is about advising others on how not to get into the pickle others did.

[Airbubba]

Originally Posted by Mad (Flt) Scientist

I would be very cautious in concluding anything about actual aircraft system behaviour, in an abnormal condition, from behaviour observed in a simulator whose intent is training not engineering investigation.

Amen to that one. Years ago there was a departure out of EWR with a conditional waypoint that somehow cancelled the speed limit below 10,000 feet. We were getting line checked and I mentioned in the pre-takeoff brief that we might have to manually intervene. The check airman said that we must be using the automation incorrectly. It was a Boeing and we left it in LNAV and VNAV for the departure and as soon as we hit the waypoint the speed bug went to the barber pole. 'It sure doesn't do that in the simulator!' was the check airman's comment.

[Schnowzer]

The A380 and I believe the 320 has an airspeed input into the LGCIU that prevents extension at high speed. In the 380 it’s 280kts, can’t remember the 320.

As to what they were thinking. Nothing. They had pressonitis which then overloaded their cognitive functions. The big question is why the PM didn’t intervene earlier in the error chain. With the time of year and the airlines culture, I think we know the answer to that one.

[DaveReidUK]

Originally Posted by Mad (Flt) Scientist

I would be very cautious in concluding anything about actual aircraft system behaviour, in an abnormal condition, from behaviour observed in a simulator whose intent is training not engineering investigation. The only way to know for sure what the system would do is to actually do it by test, the next best is a full-up engineering simulation. A FFS is a poor man's version of the latter when it comes to this kind of thing.

Is there not a presumption that, regardless of how a FFS might behave, the real aircraft will act as described in the FCOM ? The latter makes it clear that, with the gear selected down, the only thing that prevents hydraulic pressure extending the gear is IAS of 260 kts or more.

[42go]

Sorted it for you, Dave:

The latter makes it clear that, with the gear selected down, the only thing that prevents hydraulic pressure extending the gear is an electronic input of IAS of 260 kts or more.

With computers, that could be relevant!

[Georg1na]

Now I have to admit at this stage that I have never flown an airliner.

But I would like to know if you had touched down on your engine pods - and realised it quickly - would going to reverse thrust have stopped the beast?

[DaveReidUK]

Originally Posted by 42go

The latter makes it clear that, with the gear selected down, the only thing that prevents hydraulic pressure extending the gear is an electronic input of IAS of 260 kts or more.

Well yes, it's generally understood that the inputs to an AND logic gate are electronic.

I suppose we ought to add the possibility that the IAS inputs (from both ADR1 and ADR3) were corrupted to the list of progressively less likely, though theoretically possible, reasons why they landed with the gear up.

Now where did that Occam's Razor go ?

[James7]

Likely scenario. The PNF also a captain called go around and started to configure the aircraft, i.e gear up. The PNF (Captain) not quite in the loop, fixated on landing, and eventually pulled up, most likely after a lot of shouting. Unfortunately too late and contact made. Will be interesting to hear the CVR.

[siropalomar]

Good point, I fully agree. In a couple of months we’ll get a preliminary report with info about CVR and FDR readings.

[Capt Scribble]

Gorgina, if you touch down on the engine pods, the grating of metal on tarmac will bring you to a stop pretty quickly and no need to waste fuel on the reverse thrust. The money saved can go towards a new plane.

[ORAC]

But I would like to know if you had touched down on your engine pods - and realised it quickly - would going to reverse thrust have stopped the beast?

With the pods being on the ground I think the reverse thrust would have difficulty deploying - but the drag would more than compensate.

[Georg1na]

Thank you for that - so the best course of action would have been to chop the engines and hold on tight?

[Airbubba]

Ian at FlightRadar24 has harvested some indicated airspeed data from the extended Mode-S data fields:

Additional Extended Mode S data decoded

Flightradar24 has now retrieved and processed extended Mode S data from individual receivers in the area. Unlike ADS-B data, which always contains the same known data points, Extended Mode S may contain data from a variety of fields like aircraft identification, meteorological data, heading, speed, and others. The data sent varies based on the fields requested by the Secondary Surveillance Radar ground stations used by air traffic control.

The data sent via Extended Mode S does not include the Binary Data Selector (BDS) identifying the type of data. Flightradar24 interprets this data using advanced scripts and historical comparative data, but there may be errors in individual frames due to misinterpreted data fields. Overall trends in the data are correct as reported. We have included the raw data, downloadable below.

Included in much of the Extended Mode S data sent by PK8303 were data on Indicated airspeed. The below graph shows the aircraft’s calibrated altitude and Indicated airspeed from 10,000 feet to the final data received.

This altitude plot agrees nicely with the ones previously posted in this thread.



https://www.flightradar24.com/blog/p...-near-karachi/