CONF 3 Take off @ AMS

[Jack1985]

Hi Guys, I have limited experience with the Technical side of aircraft (currently working as a ground handler at Cork) but have a small question about a flight I've just taken.

My Aer Lingus flight tonight EI845 (EI84X) operated with an A320-214 (EI-DEN) departed around 20:50 local from AMS tonight taking off from RWY 06 which measures 11,429ft. Those familiar with AMS and particularly of RWY 06 should understand my next point we immediately began rolling after turning onto RWY06, I spotted an aircraft on final and it became apparent the crew were accelerating from the taxiway onto the runway to get airborne as quickly as possible, I also noticed the flap setting was extended from CONF 2 to CONF 3 and the take-off roll was significantly shorter. I'm wondering is this standard practice? aren't the V1, V2, V3 speeds calculated from a selected Take-off Config?

Thanks for any info :)

[mcdhu]

it's unusual to take off from RW06 at AMS (don't think I ever have), but it is not one of the landing only RWs.
Short notice intersection take-off S1 or S2 maybe?
I guess we'll never know!

Cheers
mcdhu

[ATCast]

Your flight took of from RWY 24, the opposite direction of RWY 06 at 20:41. At the same time a helicopter was turning inbound to RWY 22 for landing which might look like an aircraft being on final for RWY 24.

Replay available here (http://inzicht.bezoekbas.nl/)

Cheers ATCast

[Jack1985]

Thanks ATCast this makes complete sense now :). But my question remains is there any significant change to the aircrafts performance other then a faster climb rate by changing the take-off config from CONF2 to CONF3? And would the imputed V1, V2, V3 speeds then become irrelevant? Or am I just reading into nothing? Thanks again!

[Lord Spandex Masher]

You'll actually get a lower climb rate with more flap but a shorter takeoff run and yes, the V speeds would have changed.

[HPbleed]

When looking at the performance they may well have planned on full length, or at least a longer intersection departure using conf 2 and certain V speeds, but also looked up figures for a shorter intersection with flap 3 and written those numbers down . Once they have been checked by both pilots if you do get the shorter intersection it doesn't take long to change the performance page in the MCDU and select the correct flap.

[Jack1985]

You'll actually get a lower climb rate with more flap but a shorter takeoff run

Yes I did notice the flaps were retracted from CONF 3 to CONF 2 when the gear had gone up presumably to increase the climb and speed.

When looking at the performance they may well have planned on full length, or at least a longer intersection departure using conf 2 and certain V speeds, but also looked up figures for a shorter intersection with flap 3 and written those numbers down . Once they have been checked by both pilots if you do get the shorter intersection it doesn't take long to change the performance page in the MCDU and select the correct flap.

I see, this does make complete sense now. Thanks for clearing this question up mcdhu, ATCast, Lord Spandex Masher and HPbleed really appreciate it :).

[Sky Wave]

Yes I did notice the flaps were retracted from CONF 3 to CONF 2 when the gear had gone up presumably to increase the climb and speed.


This would seem a very strange way of operating the A320 and I'm struggling to believe it.

We've already discovered that you were mistaken about which runway was in use and you were also mistaken about where the other aircraft was. Could you have been mistaken about which config the aircraft was in and when they retracted the flaps?

I fly the thing and I also sit at the hold point behind many A320's on a daily basis and I'd struggle to tell you what config they are in just by looking.

What I do know is that simply changing the flap setting will not change the V1 and VR speeds that you have programmed into the MCDU and will therefore not get you airborne any faster. One explanation would be that they'd planned a Config 3 take off but incorrectly set Config 1+F. They realised this late and then reset config 3 whilst going through the checklist. The problem is that I can't imagine any operator using anything other than config 1+F on a 3500m runway unless it was contaminated. Perhaps they did it as a training exercise?

As for retracting the flaps when the gear went up, once again this would be strange. Schiphol is very noise sensitive and aircraft adopt noise abatement procedures which will normally involve maintaining V2+10 and the take off flap setting up to 3000ft. Retracting flap at gear up is not a procedure that I'm familiar with and it's not an Airbus procedure. I wouldn't know if it's a procedure that Air Lingus use.

SW

[NOLAND3]

Let's forget that fact that he said they retracted the flaps to Config 2 at gear retraction, he has already stated he doesn't know much about operating the A320.

I don't see any reason for using config 3 out of EHAM unless as others have stated they were given an intersection and did a last minute recalculation for performance reasons.

[Jack1985]

Sky Wave, don't know if you've ever been in AMS but there's lots of Runways. The aircraft that was on approach if you seen it it looked like it was headed for landing on Runway 24 as has been pointed out it was indeed landing on Runway 22 but it looked like to me it was headed for Runway 24.

I fly the thing and I also sit at the hold point behind many A320's on a daily basis and I'd struggle to tell you what config they are in just by looking.

To me its pretty easy CONF 1+F is very distinctive and there's also noticeable difference from CONF 2 to CONF 3.

I said after the gear was fully retracted the flaps were retracted from CONF 3 to CONF 2 before maybe a few minutes and a right turn later being fully retracted. I wouldn't know if it was a trainee F/O I'm just saying what I saw and I could bet my house on it being CONF 3, flaps were extended to CONF 2 after we pushed back from the D Gates and before entering Runway 24 to CONF 3.

[i_like_tea]

I said after the gear was fully retracted the flaps were retracted from CONF 3 to CONF 2 before maybe a few minutes and a right turn later being fully retracted. I wouldn't know if it was a trainee F/O I'm just saying what I saw and I could bet my house on it being CONF 3, flaps were extended to CONF 2 after we pushed back from the D Gates and before entering Runway 24 to CONF 3.

Maybe it was CONF2...

As what you say isn't how Airbus do things.
After a take off it would have gone from CONF 3 (or2) straight to CONF 1, the flaps would then be retracted fully.

It is quite possible flaps were extended before entering the runway though, maybe someone set the wrong stage of flap, which was picked up by the BEFORE TAKE OFF checks, at which stage the correct flap setting would have been set.
Sometimes these checks are run all the way through (above and below the line) on line up if time is short, hence why the flaps could have been set to the ACTUAL position they were meant to be just before entering the runway.


I fly the airbus and I commute home in the back of the plane every weekend, and unless I count the number of deployments (on approach due to the noise) I couldn't tell you what config we are in (other than pitch attitude I suppose), I just don't think it is that easy to see!


So, what everyone seems to have forgotten above, it IS possible that flaps were extended just before departure... but not due to a re-calucation. Just due to some forgetting. And let's all admit it, it is easy to do the same thing you do every single day by accident, Day 5, 20th sector?
That's why we have two people, warnings and checklists.