Qatar Airways B77W hit airport approach lights on departure, flight continued

[3WE]

Confirmation bias...(and your other comments)

Indeed and Concur.

They weren't blindly blasting off with no idea if it was ok.

I am saying that the computer procedure lead them to NOT have a value in their head to check against the distance remaining signs nor to check against a chart/diagram showing available takeoff distances.

[elaw]

Fair enough... but are you sure a procedure based on information acquired from paper and/or verbally would not be subject to the same problem? Or different problems of equal or greater magnitude?

I suppose a *very clearly labeled* paper chart would have been helpful, but in my very limited mostly-Internet-based experience have never seen an airport diagram that shows runway lengths from intersections to the end. It's possible charts exist showing the distances between intersections, but you'd have to add them all up to get the overall length and adding numbers can sometimes be problematic when done by carbon-based life forms. Or by really badly programmed computers.

And if the desired type of paper chart *was* available, it could be loaded into and displayed on a computer.

So I guess I'm not willing to say this accident occurred simply because the crew was using a computer and would not have occurred had they not been doing so.

[Evan]

So I guess I'm not willing to say this accident occurred simply because the crew was using a computer and would not have occurred had they not been doing so.

This incident would not have occurred if they had a paper airport diagram. The industry HAS moved on to electronic flight bag versions, but this should be a VERY strong wake-up call that scrolling devices are a potential pitfall and modifications need to be made to make it perfectly clear that the chart is cropped and continues offscreen.

[elaw]

Are you saying the cropped image misled the crew into thinking they were departing from the end of the runway vs. an intersection? I don't buy that... from every indication the crew was fully aware they were departing from an intersection and therefore could not possibly be using the full length of the runway.

If you're saying they perhaps didn't realize how far down the runway they were departing because the image on the computer didn't show the whole runway I'll agree at face value... but the reality is that visual estimation of how far apart things are on a chart is no way to plan a takeoff. I suppose there could be exceptions when there are huge margins like if you were planning to depart that same runway in a 172 but that's not the case here.

BTW paper charts can be cropped too, via a fairly well-known mechanism called "folding".

[Evan]

Are you saying the cropped image misled the crew into thinking they were departing from the end of the runway vs. an intersection?

Did you read the report? DId you see the image of the EFB cropped image? They knew it was an intersection but it appeared to be an intersection near the threshold because of the cropped EFB image. A paper chart would have made it clear that this was not the case. End of incident.

I'm not saying go back to paper charts. That's not going to happen. I'm saying make the EFB safer with respect to cropped views and offscreen image scrolling.

[Gabriel]

Gabriel, an ambiguous hand gesture is TERRIBLE CRM.

That's sort of the same I said, isn't it?

hat is still good CRM, or it would be if made in a clear way to avoid misunderstandings like the ones that happened in this case

Also, They managed to get off the ground at 330K kg in 2,610m + the overrun. I'm guessing that WAS full throttle.

I seriously doubt it. The take-off roll was 2866m. That's an awful lot of a distance. And that's just the unstick point with both engines running. Remember that the take-off distance assumes an engine failing at V1 and takes into account the plane reaching 35ft after that.

More importantly, the groundspeed plot doesn't show anything remotely like the change in slope you would expect from an increase in thrust (that could be explained if the PF ignored the reduced thrust setting and used full thrust since the beginning, which again I doubt).

And if you look at the dotted black line indicating "takeoff roll" on the FDR pitch attitude plot, the angle seems to exceed 10° on the ground. AFAIK, the 773ER has a tailstrike pitch attitude of 10° so the PF seems to be giving it all it's got at that point.

I noted that and wondered about the tailstrike even without knowing which is that angle for the 777ER.
Another things that called my attention:
The rotation was done at a rate of 2 deg/second. I'd like to see what the experts say but that seems to me like a normal rotation pitch rate.
The rotation was started at 190kts!!!!! That seems like a very high Vr. At the same time, the plane settled in the climb at about 210kts. Since the initial climb speed with both engines running typically settles at about V2+10/V2+20, the speed difference between the apparent Vr and the climb speed seems too small.
These two hints make me think that they were not desperately trying to get off the ground. I see no signs of an early rotation or a violent rotation. (Disclimer: this is VERY a preliminary and not solid analysis)

And lest we forget, the failure of the crew to request an immediate ground inspection after nearly plowing down the approach lights must be mentioned here. They were quite aware of the POSSIBILITY of some contact. That should be enough to require this.

I don't see that as a so clear call, but ok. The approach lights were likely not visible to them, they saw the "300m left" light when already in the rotation, the nose-high attitude during lift off makes it difficult to judge altitude... but asking could do no harm.

I also wonder when did the first person realize of the incident, what was done after that, and if they were supposed to note it earlier. I find it surprising that they landed in the destination without knowing of the incident.

[Gabriel]

And Gabriel.

Whats wrong with determining:

1. Our takeoff roll should be 9,285.13 feet at this weight, temperature, wind and power setting...

2. We have 9,185.13 feet available from this intersection as determined.by diagrams and the distance remaining signs.

3. Confirm if value 1 and value 2 work together in the best interest of the approach lights.

But no (and again).were focusing on computers and decision trees to reduce CO emissions.and the Boy Scout CRM handbook and cryptic acronyms, and mundane stuff, while glossing over old fashioned important stuff.

DO the pilots even have the 9,285.13 feet information in point 1 to begin with? I don't think so.
Rather, the info they have probably is "use this runway from this point, use this flap setting and this take-off-thrust, this is your V1, Vr and V2. Have a nice flight".

Cuold they have the required take-off distance? Oh yes, and it would be good. But to enable this opportunity is not within the scope of the "airmanship".

[Gabriel]

The computer never explicitly said "you have enough runway to take off from your current position". Nor did it ever say "you do not have enough runway to take off from your current position".

Well, it did say "No intersections take-off allowed" in plain English.

[Gabriel]

Are you saying the cropped image misled the crew into thinking they were departing from the end of the runway vs. an intersection?

Nope, they KNEW they were taking off from an instersection. They even REQUESTED TO THE ATC the take-off from the intersection. What the cropped image clearly hid was the fact that the intersection was 3000ft down the runway. They thought they had "almost" full length available which helped "confirm" their believe that it was Ok to take off from there (together with other facts like the 09#T1 output and the plane landing just in front of T1).

[Evan]

I seriously doubt it. The take-off roll was 2866m. That's an awful lot of a distance. And that's just the unstick point with both engines running. Remember that the take-off distance assumes an engine failing at V1 and takes into account the plane reaching 35ft after that.

More importantly, the groundspeed plot doesn't show anything remotely like the change in slope you would expect from an increase in thrust (that could be explained if the PF ignored the reduced thrust setting and used full thrust since the beginning, which again I doubt).

Maybe you have different information, but what I know about the 777-300ER tells me that needed about 3000m for a safe takeoff run (not runway distance). I assume that is based on full TOGA thrust. They were very close to MTOW. If the system spits out a performance calc for that TOW with a thrust setting from the threshold (full runway), I'm pretty sure they would have ended up in the parking lot. To get off as they did I really think they were at TOGA to begin with.

[Evan]

Well, it did say "No intersections take-off allowed" in plain English.

Wait... where did you get that? There was perhaps a NOTAM to that effect but the report makes no mention of it that I can see.
The report says:

The printed information contained no reference to the fact intersection departures were not permissible from this runway (Figure 3 ), and contained the message ‘No NOTAM data found ’.

AFAIK, they never got the NOTAM.

[Evan]

I don't see that as a so clear call, but ok. The approach lights were likely not visible to them, they saw the "300m left" light when already in the rotation, the nose-high attitude during lift off makes it difficult to judge altitude... but asking could do no harm.

I also wonder when did the first person realize of the incident, what was done after that, and if they were supposed to note it earlier. I find it surprising that they landed in the destination without knowing of the incident.

I think it was an incident-level, sphinterizing situation to any safety-minded crew (unexpected red centerline lights before rotation). A simple request to have someone go take a look at the extended centerline structures would be the responsible thing to do before climbing to pressure altitude. After this incident it DEFINITELY should be required.

I think the reason it took so long to notice the damage was that the airport (or runway) closed for the night shortly after this departure (might be wrong about that).

[3WE]

Fair enough...

...blah blah blah...

...I'm not willing to say this accident occurred simply because the crew was using a computer and would not have occurred had they not been doing so.

"simply" and "would definitely not happened"...I understand what you say- but still support the big picture of mind-numbed actions without really remembering what's really going on and that it may bite us, albeit indirectly, from time to time.

Also, I wonder why we spend money on the distance-remaining signs on runways if they aren't that critical?

And indeed- Humans screw up 1 in a thousand, Computers and software 1 in a million, and negative unintended human-computer interaction screw ups, one in a zillion, so therefore, all of us parlour talkers need to shut the heck up, and accept the fact that we're a ton more safer than Greyhound and should put our total trust in our pilots and not second guess them from arm chairs and keyboards on the internet.

[Evan]

I noted that and wondered about the tailstrike even without knowing which is that angle for the 777ER.
Another things that called my attention:
The rotation was done at a rate of 2 deg/second. I'd like to see what the experts say but that seems to me like a normal rotation pitch rate.
The rotation was started at 190kts!!!!! That seems like a very high Vr. At the same time, the plane settled in the climb at about 210kts. Since the initial climb speed with both engines running typically settles at about V2+10/V2+20, the speed difference between the apparent Vr and the climb speed seems too small.
These two hints make me think that they were not desperately trying to get off the ground. I see no signs of an early rotation or a violent rotation. (Disclimer: this is VERY a preliminary and not solid analysis)

Boeing recommends 2°-3° (2.5°)/sec rotation rate and a max 7-9° pitch before 35'. I see nothing on that plot that would suggest the tailstrike protection kicked in so I think they didn't panic or anything on rotation. Also, the speed at liftoff seems a bit high but remember that this is a 755,000lb TOW. A B744 at 800,000 would normally be around 190kts. But again, I think getting to 190kts in 2800m would not happen with derated thrust.

You might be right about them not realizing how close they came however. I would expect a pilot fully-aware of the situation to apply a 3° rotation rate or even rely on the tailstrike protection to get the max pitch on rotation. A difference of 1° in rotation rate can mean an extra 700' to the 35' threshold!

[Gabriel]

Wait... where did you get that? There was perhaps a NOTAM to that effect but the report makes no mention of it that I can see.

Page 2 paragraph 3:

The OPT also displayed the information that intersection departures were not permissible for this runway.

That information was displayed in the screen but was missing in the printout, though.