Impending Firm Landing and Salvation-Jet Muti Crew

[titaniumwings]

This discussion is focused on jet landings in a multi-crew environment.

Pilots are trained to use peripheral vision to judge and react accordingly to sink rate. Many pilots use RA callouts too.

On Boeing, some commanders may help with the landing if there is observed to be a lack of the connected control column's movement to commensurate with the sink rate. Some delay the retardation of thrust via the assisted thrust lever to cushion an impending firm landing.

Can such techniques be duplicated or applied on the Airbus? Any strategies for suggestion? Is there a "lag" when the takeover button is initiated? If there is, then anyone who tried the "tap" method? Anyone tried to cushion landing via thrust on the Airbus?

Thanks for the inputs on advance.

ps: I am talking about a stabilized approach with a "senior" partner below 40' RA.

[vilas]

If airbus has to be faulted then this one is a definite draw back. During initial training sometime there can be follow me on controls stage, which is not possible on AB FBW because side stick movements are not duplicated and dual input is absolute no, no as it doubles or cancels the input. You can only press take over button and do the needful. There is no lag but you may forget to press so need to be ready with the button. Also the other pilot doesn't learn much as his stick remains unmoved. In airbus you perceive everything through eyes.

[titaniumwings]

That's a nail on the head. I am just amazed at your use of "sometime" in your reply. I had thought that all initial training was like that. I show you, follow me through, you do it (with correction if necessary). Aviation has moved on...=)

On my initial jet training, non Boeing or Airbus, I was thought of the technique of residual thrust/slow retardation to cushion landing. Maybe that has been left behind too by Airbus.

However you want to see it, Airbus is just different. No negativity intended at all.

[Sore Higher]

Over the years I've used the take over pb in the flare maybe 10 times and never noticed a lag, but I think in the very dynamic situation of the flare, with not knowing what is happening on the other stick, it would be very difficult (impossible?) to tell if there is a lag.

Using thrust to cushion a potential heavy landing may work if timed just right, but really is not a wise thing to try. The reason being that if the thrust levers are not at idle the ground spoilers do not come up when the aircraft touches down, which can then result in a higher bounce, then if the thrust levers are set to idle just after the bounce the ground spoilers will deploy as there is a slight lag in the on ground to airborne sensing. If the ground spoilers do deploy when airborne a very heavy arrival on terra firma will result, as has happened in at least one airline I have heard of :ooh:

In the flare, if you need to take over, TOGA 10 is the best option.... least likely to result in addition engineering checks, and a chat with the management :)

[TheiC]

http://www.aaib.gov.uk/cms_resources.cfm?file=/Airbus%20A320,%20G-DHJZ%2012-08.pdf might be of interest to you, both on the sidesticks and TOGA10