Sorry, Detent, but that dog won't hunt.

I am more familiar with the 330 due to the 447 discussions some years back, but your FBW has a lot more modes and submodes and "shaping" algorithms of control surface movement and rates than so-called "protection" at the edges of the envelope. e.g. bank angle and other limits vary according to which "alternate:" law you are in until "direct".

My diagrams of the instrument panel seem to show a handle and adjacent indicator just above the center pedestal. Clearly marked "up" and "down". So your last minute checks don't involve touching or visually verifying the position and the lights?

I thot HAL knew if gear was down for a landing and the FBW was switching into the "flare" mode at "x" altitude above the ground/runway. So can I perform CFIT by just getting above "x" speed with gear up? Somehow, I thot GPWS/HAL would have said something. "Dave? Sure you wanna try this?" I gotta admit they "greased it on", but maybe that was because they were not in "flare" mode, which seems to be almost pure "direct" law with "heavier" pitch command deflection.

Oh well, back to the Tech Log.....

From the report it seems they hit a maximum of 258kts IAS at 2000ft just before the indicated retraction of L/G. In which case the 260kts overspeed limit should not become an issue, so far as L/G is concerned.

That aside, I am curious about a small difference in the report concerning the landing gear controls.

The report at 7221ft determines that the FDR "indicated action of lowering of the landing gears".

At 1740ft the FDR "shows action of raising of the landing gears" and "the landing gears and speed brakes were retracted".

Does it mean that between 7221ft and 1740ft we cannot tell from the FDR evidence whether the L/G was actually extended, even if there is evidence to show that action was taken to lower it?

Gums, if you go back 20 or 40 pages (:sad:) there is a discussion about the gear up warning. Apparently, above 210 knots, the warning changes from 'Too Low Gear' to the GPWS 'Too Low Terrain' (or words to that affect) based on the assumption that if your going over 210 knots, you're probably not trying to land. Assuming they got the 'Too Low Terrain' warning, it would be somewhat understandable if the pilots dismissed it as a nuisance since they thought they were landing.
I presume similar flight control logic would have come into play (or not come into play) since the gear was up and they were going to fast.

Yeah, TD I finally found an A320 FCOM and am wading thru it. Definitely looks like the "Too Low Terrain" warning should have come on, and I agree that it could be judged a nuisance if you trying to land and already know you are faster than normal.
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Trying to find the excruciating details for the "flare" mode, as I am thinking it was not in effect and normal gear up control laws helped them to grease it on. Might also explain why thrust reversers may not have actually deployed regardless of throttle position/selection/whatever when WoW shows airborne.

Farsouth, it is quite possible that the PIA can in fact be blamed on a non-western mindset while at the same time the Houston accident can be blamed on an excessively western mindset (ie cowboy).

Your point that western aviation mindset isn’t infallible is of course correct.

Another factor I have not seen mentioned is the disconnection of the autopilot early in the approach @ about 9000’. .

A320 gets full speed brake without AP but only half with.

This is consistent with recognition that we are high and we’re going to get down as fast as we can. Further backed up by the 7000{‘ lowering of the gear.

True, though rated pilots might find your re-phrasing a bit coarse around the edges. The gear v.s. HAL was what I was pointing at, meaning to say apart from the F/CTL FWB, the A320 is a totally conventional aircraft. Vilas pointed the rest.

For your Q about verifying lights and levers for the final checks: Yes we do, and other pilots too. Typically challenge-response read from a laminated check-list, confirmed by both pairs of eyes.

Unlike the doomed crew. Come to think of it, once they already raised the L/G thinking they were lowering it, touching the lever would not amount to much. The lights would be showing nothin, with gear up and closed. ... why no "3 greens check"??? Well, easy. Normally the ECAM upper screen displays abbreviated "LDG MEMO" with 5 action lines, that change as you finish the individual items (arm spoilers, LG/DN). Hence we verify (from the paper C/L) "ECAM MEMO? .... (displayed) LANDING: (showing) NO-BLUE" I.e. we look at the ECAM for LANDING memo, that is showing all green text with no blue action items left.

The memo comes up automatically whenever RA<2500 ft (large A/C passing below you in cruise, you will get it at 35k - like I said, no HAL apart from the F/CTL). The problem for the PIA flight is that the LDG MEMO occupies the same ECAM screen space on the upper display unit (called Engine/Warning Display) as any ABN warning will and those take precedence. Hence in overspeed it shows OVERSPEED in red letters and the applicable limiting speed, and no LDG memo.

There are 3 green triangles showing on the panel above the gear lever, but those we do not really check actively, it's done via the ECAM LDG MEMO. For normal landing, the lower DU shows ECAM "WHEEL page" with another 3+3 green triangles, ... the page automatically comes on with ... you guessed right: selecting the L/G down. Malakia.

Basically, if you attempt to land this aeroplane in flap overspeed and ignore the landing paper check-list (which even lists the 5 action lines in print, in case the screen went T.U.), it is perfectly possible to land gear up unnoticed, unless you notice.

Thanks for the info, Detent.

Quite a bit different with electronic "help" for the procedures and such from what I endured for a few thousand hours.

At which point does a person lose faith in the electronics, assume that all the various warning signals are false, and maybe remark that there must be technical problems?

You can 'grease' it on with Flare Mode btw!!! HAL as you call it is not all doom and gloom...

I'd considered the lack of presentation of this page ought to have been another hint. Maybe the lower ECAM was otherwise occupied for some reason? Admittedly, this would've been a subtle hint, lost in th ocean of bells and whistles going off.

Good point on the LDG MEMO not showing while above Vmax. The more I think about it, the less sense it makes. They had the GPWS going off, airspeed above Vmax and no LDG MEMO on the ECAM. I hope the final report shows us what the screens looked like at 500ft.

Maybe they had no warnings. Maybe the combination of things warnings that had to be presented was way beyond what the engineers had envisioned, and the DMC's and FWC's just gave up and rebooted.

Certainly appears to be mental overload, for whatever reason.

We are not supposed to speculate but........a possible scenario is as follows:

Captain is a very autocratic Captain who had marginal ability and got into the LHS by other means.......and a meek or compliant F/O.

The Cap f****d up the descent, but did not want to lose face to his F/O, so instead of acknowledging his mistake and asking for extra track miles, the Cap kept saying he was comfortable, and barked orders to the F/O and then ignored instructions from ATC. I can imagine Cap saying "He [ATC] is a donkey, what does he know, we are on the ILS and visual....".

The A/P disconnect is consistent with wanting full speed brake to increase rate of descent. Selecting gear down is also consistent with this, although a bit desperate when all you need are some more track miles. But pride probably prevented Cap from asking or agreeing to longer vectors.

Cap almost got it sorted, but then, as he just about regained the profile, (but crazy fast), his "muscle memory" kicked in, and he barked "Gear", while stowing the speed brakes, as you would if you had just recovered a slightly high and a fast approach. Unfortunately, the Gear was already selected down but the F/O had stopped thinking for himself or was too cowed to say anything, so simply moved the lever in response to the shouted order, in this case to UP.

Cap, not realising the Gear reversal, now thought he had made it. He ignored all the warnings that must have been sounding and became focussed on the runway and the landing. He forgot speed, forgot stability and forgot landing checklist, one item of which is to check the gear is down. (As others have said ECAM memo might not have been displayed, nor the Wheels page on the SD. However there are secondary independent conventional gear indicator lights on Airbus FBW - 'three greens').

Cap flies down and flares, but because of ridiculous speed, the sink rate is much less than in a normal flare and he greases it on, lower and lower and..........oh sh*t !!...............TOGA!! They get airborne again but having fatally damaged the engines, the subsequent accident is now sadly inevitable. RIP

All possibly caused by ego, and a person not able to say, "Oooops, sorry, I made a mess of that! [descent]. Can you ask for some more track miles". RIP


I have a simple mantra I use at a few miles out from landing to double-check we can land safely: "Fly......By......Wire".

F = Flaps. Are they set for landing?
B = Brakes. Is there any residual pressure and has auto-brake been selected?
W = Wheels. Is the gear down?

As I say each item quietly to myself, I visually check the appropriate indicators in front of me :ok:

Has it ever been made clear if any form of FDM operated prior to the crash?
If it did or didn’t, then hopefully it will be part of the AAIB investigation.

The EASA suspension letter gives some insight as to the short term relationship with PIA.

The LEVEL ONE item ~ SMS shortcomings. That speaks volumes.....

Quick question from a non-pilot. Any guesses as to what would or could have happened if the landing gear was down, all else being equal? Is it possible they performed similar unstabilized approaches before and got away with it? Thanks.

Best educated guess is that the landing would be pretty much the same (they did manage it after all), only around 60 mph slower. Vacate the runway with hottish brakes (500 deg), engage the cooling fans and 15 minutes later a forensic examiner wound not find a single atom misplaced.

My personal opinion (based on nothing but gut feeling how pilot psyche works) is they were no strangers to wild approaches, but this one was still a league steeper than experienced occasionally before. The sensory overload and unexpected behaviour debilitated the crew, rendering them incapable to put 1+1 together (read the landing C/L and discover the true gear state) nor break the error chain by going around while it still made sense.

Possibly have run off the far end, which would have displaced a few atoms, but likely no deaths.

I guess it depends on where they put it down. Assuming they recognised it at 500ft (which is the last data point we have), from 220kt, I'm also in the camp that they'd wind up going off the far end of the runway.

Too fast
 

See - I told you we'd make it....

Let's not forget the brakes are oversize, designed to stop a rejected TKOF from somewhere well past the runway half-point.

Karachi landing distance available is 3400 m. Performance data show only 1950 m is required at approach speed + 50 knots (QRH numbers).

Back of the fag packet: 220 IAS = (nearly) 220 G/S = 1100 fpm = (nearly) 30 seconds to touchdown from 500 ft. The deceleration rate with landing flap and L/G down is at least 20 kt / 10 sec (yellow speed-trend arrow), ie. reduction from 220 to 160 is possible.

Assuming the original Vapp at 140 kt, 160 is Vapp+20. QRH strikes again: for Vapp+25 LDA is 1500 m. No one would have known, they had double the length required. And the touchdown was well done distnace-wise, given the lack of gear-legs.

In your scenario, there would be a delay before the gear unfolds and comes down, which I conveniently omitted. Still some room to spare, AFAIK.
o my defence, AviatorAtHeart did ask about the effect of L/G down from where they flicked the lever, at 1700 ft / 5 NM.

Come to think of it, with 220 at 5NM and everything hanging down as it should, the approach might have been stable by 500. (Vapp+15 max). Somebody mentioned going 250 to the marker for skills development, didn't they? :E

AviatorAtHeart: Google for Normalization of deviance, someone mentioned already in the thread. It's a common organizational trait, everyone is susceptible. It is that natural and so dangerous, the industry mandated a computerized monitoring of flight parameters long time ago. Called FDM, it is the cornerstone of FOQA / SMS. Without SMS in place the legal requirements to run an airline, or even a small 2 aircraft operation are not satisfied. EASA just banned PIA from EU airspace, citing lack of SMS and their inability to rectify the situation for extended periods of time, in spite of the warnings the've been given.

Touché. Assuming I make it to my next recurrent sim session, I'll give it a shot (is there a way to silence the CRC in the sim?).

We did 250 to the marker with some regularity in the RJ. The most I've done in the 320 was 250 to 10nm, with a pretty good headwind, if I remember. We got the flaps to full at 1020 ft, and were stable at 550ft. If I'm doing that on the line, I'd prefer trying it a few times in the sim first.