High performance take off
 

1.150m for an A320, not bad.....
Arabia A320 at Sharjah on Sep 18th 2018

Especially when any tailwind component is taken into account..... :ugh:

Yikes. Not the first time that it has been done... DC10F at PANC... but at least Air Arabia has been clean living and survived the whoops. Wonder at what point the crew picked up the hints that they were going in the wrong direction. The Airlines response may seem excessive, but it gets rid of the easy but gross error that occurred here.

Not quite a parallel (npi), as unlike the Air Arabia the KAL at Anchorage didn't even make it as far as the intended runway, but mistakenly used one oriented at 80° to it.

Ironically, the light aircraft with which it collided had taxied all the way to the end of the latter 10,000' runway rather than electing to depart from an intersection.

This flight (L9-111) departs about 1630 local – daytime – surely at least one of the pilots must have looked out of the window at lineup and said, or thought, "that looks a bit short"? Or is everything "heads-down" these days?

Although of course I've no evidence, I do wonder if there was bit of non-CRM taking place, rather like Tenerife but without the disaster. Junior co-pilot: "Aren't we headng the wrong way?" Captain with press-on-itis: "No, no, let's get out of here."

I am still trying to work out how this could possibly happen. This is a single runway airport in (I assume) good visibility. We are not talking Chicago O'Hare or Detroit Metro in the fog at night! Not only that but this airline is actually based there. Absolutely remarkable.

I wonder what the Aerodrome Controller was looking at?

While there aren't enough data points on the FR24 plot to determine exactly where the A320 became airborne, the last point shown with WoW is around 300 meters short of the upwind piano keys with a groundspeed of 67 kts (subject to usual FR24 caveats).

Years ago I (nearly) took part in one of these at HRE. A (then) TAP 707 taxied out and turned left instead of right at the intersection. That left about 2500ft available of the 15000ft runway. Initially I thought he was backtracking, but lots of jet blast was very obvious and lead to a quick radio call and a reset (and I presume some embarrassment on the Flight Deck.)

Hard to believe for those who know HRE, but it happened.

Very good example of a knee jerk reaction.

But having made that error, how can they have got it into the air? Presumably the take off run was calculated for 3 times the distance that was actually available. I am sure I have read on here that you chaps don't thrash the thing unnecessarily but derate appropriately. So they realized early on, did some rapid mental arithmetic and decided to floor it ?!

No problem.(sarcasm alert)
One time we only used about 3000' to lift off in a 777-200 full of pax with 10 hours of fuel. :}

Well if Viet airlines can do a max takeoff. .. :D

Sure, but when deration happens it doesn't always mean you will use the full runway. Also, there are a lot of safety margins. Probably they just got lucky and cleared it just in time.

Not much different than individual companies banning LAHSO (which most do) or a verbal confirmation/callout of compass/runway alignment on line-up after the ComAir 5191 accident in Kentucky back in 2006. Procedures are constantly being adjusted/amended after screw-ups that result in incidents/accidents/threats to safety and it has always been so in aviation. In fact, oversight authorities investigating them will demand it if a company's procedures or safety culture are found lacking. The "knee jerk" reaction is a blanket procedural change designed to prevent a recurrence with immediate effect, and sometimes it's entirely appropriate because it works and many spread industry-wide.

Obviously, the long-recommended, verbal confirmation/callout by the crew that a runway one is cleared to line-up on/cleared to T/O from coincides with the compass heading of the aircraft before applying power to help prevent taking off from the wrong runway either wasn't incorporated into this Company's procedures or adhered-to by the crew if it was. The simple procedure of having both pilots verbally confirm Rwy clearance vs compass heading before closing a line-up checklist is a final backstop, prevention measure against this sort of thing when SA has broken down. This recommendation was already written in passenger and crew blood, and it doesn't really matter if one calls it "knee-jerk" or not.

Sterile cockpit, approaching assigned altitude callouts, no circling approaches unless in VFR conditions, no side-stepping below 1,000' AGL, etc etc etc could all be said to have have roots in "knee jerk" reactions to incidents/accidents. It doesn't automatically mean they're the wrong answer.

De-rating assumes they get to V1 with enough runway left to abort the takeoff and stop so they're not going to need all of it to get airborne (as it wasn't an A340). If their numbers had suggested that 10000ft was required for a V1 abort then they probably wouldn't have done an intersection departure in the first place.

Had they lost an engine then it would have gotten rather messy. It's possible that the approach of the end of the runway encouraged forward movement of the throttles to make sure.

Taking off from the wrong runway at home base am i missing something

Well yes.

He took off from the intended runway. But after turning on to it in the wrong direction.

If this had been a BA 747 taking a wrong turn at Joburg all the " there for the grace of God go I " types would be swarming all over this.

No aircraft on the approach or short final? My word were they lucky :eek:

Totally different circumstances.
The BA Johannesburg accident happened on a moonless dark night, taxiing straight ahead with the crucial taxiway lights indicating the turn they missed not lit due to a lack of ground maintenance.
It was an accident waiting to happen, compounded by being loaded at an unusual stand and thus sent onto a taxiway which is never used from BA's usual stand.
The world ganged up on them. JNB at night is blacker than a coal cellar with no visual references other than the missing lights.

Imagine yourself in the same circumstances, a few taxiway lights out, more ahead on and visible. What would you have done .

The SACAA enquiry was scathing about the management of the airfield and sympathetic to the crew.

at 67kts GS, ~300mtrs to the end of TORA, the guys need to be accelerating at better than 0.35g to get to Vmu. However, they have another 1000' of runway beyond the displaced threshold, and a further 400' of clearway that is better than sand at least to run your wheels over.

Getting to 67Kts GS in around 1200' from the entry into the runway from the rolling on speed of say 15kts is a gentle acceleration, around 0.15g average, with a peak of only 0.2g. At some point the guys need to be adding some noise in order to not leave sand tracks, otherwise they don't get to Vmu on the concrete. If they are light, and add full thrust at the 1000' TR to the displaced threshold, then they can get to about Vmu with at the displaced threshold, and the aircraft has around 1400' of hard surface ahead. We would be hearing about the damage on the plane in that case, so that didn't occur. Rotating at around 110-115 kts instead would occur about 500' past the displaced threshold, and the wheels come off the ground around the beginning of the chevrons of the clearway, just east of the displaced threshold arrows.

That is the rough go case, and it needs adding of thrust promptly by the crew to make it work as it did.

The stop case is at 67GS 1000' TR, which gives 2400' to the sandpit, is stoppable. A couple of seconds later, it is not going to work, but the plane is going to be hitting frangible structures mainly, however, the aircraft on a soft surface will be impacting the structures at a lower height than they may have been designed for. Other than the frangible objects issue, that particular runway is about as good an outcome as you can expect outside of Edwards.

The acceleration curve is highly non linear, being roughly a 6th order polynomial on a normal takeoff from commencement of thrust addition or brakes off, through to maintaining V2 + XX kts. The curve from achieving thrust setting through to rotate is more or less a simple second order function, as drag from the airframe and the rolling friction act as a increasing force, with the thrust either being stable or slowly decaying (dependent on the engine characteristics, bypass, etc). Adding a thrust increase in the middle of that gives another 3 inflexion points... gets busy but can still be approximated, and doesn't need that anyway, it is recorded by the DFDR, and the QAR as well, so the info will arise eventually as to where the wheels were relative to the sand.

Takeaway is just having the right amount of runway in front of you when you set the thrust is a highly preferred state. Anything the system can do to increase the reliability of that simple situation is not a bad thing. The airlines "knee jerk" response is a good start to reinforce safety. Intersection departures increase operational risk through the potential of misidentification of the intersection used, miscalculation or no calculation of the performance change (long runway, light aircraft, no problem, don't bother checking), and potential for a loss of S.A./brain freeze leading to a wrong direction on the runway.

Beating up the crew in this instance doesn't stop the problem, they are now probably the least likely crew out there to mess up TO performance. They were also lucky, if ATC had cleared another aircraft onto the runway at full length (assuming that there was no WIP precluding that) then the obstacle would have been impossible to avoid in a go case, and the stop case would only occur if the crew recognised the problem early enough to react effectively. Would another aircraft follow ATC clearance to line up behind, and always note that the other aircraft is pointing in the wrong direction? maybe...