BA A318 Lands at LCY with partial speedbrake deployment

[hiss srq]

I watched a video a spotter in London took of the BA A318 arriving at LCY from JFK earlier... The video was quite fuzzy as it went out of focus untill touchdown but I was certain that it appeared that the "speed brakes" were in the position of partial deployment as it approached... From Airbus manuals I was always of the beleif that it is reccomended against having any form of speedbrake deployment when below 1000 AGL or when the aircraft is configured to landing config (Flaps 4 and gear down).. Sure enough after looking at a passenger view of an arrival they do indeed approach LCY with the boards slightly popped.... After thinking about it and looking at an LCY chart the only conclusion I have been able to make is that it is part of the approved Airbus procedures for LCY and it is done so due to the much steeper than normal approach profile that is present at LCY....

Without furthur ado... Enjoy the two videos
Exterior Video

http://www.youtube.com/watch?v=owwLgi90FOA&feature=related

Second video

http://www.youtube.com/watch?v=R_5uoyTz06M&feature=related

[Matt Molnar]

You are correct, sir.

A few years ago Airbus actually developed a steep approach mod for A318s specifically for LCY ops involving an extra button in the cockpit and some software edits. The crew pushes the button at the top of the descent, which will cause the outer spoilers to deploy to 30 degrees automatically at idle thrust so as to prevent acceleration during the steep descent. At 80ft the spoilers slowly retract so that they reach 8 degrees at touchdown. In the event of a go around they retract completely, or they deploy completely when wheels hit the ground. I believe BA's baby buses are the only ones fitted with this option so far.

More details here: http://www.flightglobal.com/articles/2006/05/23/206788/a318-makes-mark-at-london-city.html

[hiss srq]

Interesting..... Very interesting... One question left unanswered though than would be the actual go around and what it does to spool times if the approach is flown with power in the idle detent... While the CFM56 is not a JT8-217 by any means it still requires a few seconds to spool to TOGA power once you click into the detents... The way I interpet this article (I could be wrong) is that the approach is flown even in the final segment at flight idle power which is automaticly the idle setting when the thrust levers are retarted to the "idle detent" I don 't have the off hand numbers and am too tired to dig for them but I beleive the CFM powered busses require something on the order of 3 to 5 seconds to go from idle to the TOGA setting..... I am curious to see what the full procedure for the LCY landing is now.... By posting this I've opened up more questions than I have answered..... Hmmmmmm......

[hiss srq]

Disreguard.... Sounds like they are not at "flight idle" during the final segment of the approach. You can hear the power changes..... Questions and curiosity cured.

[Derf]

good catch and great info. good stuff guys!