Question on getting the A330 down

[A.FLOOR]

Assuming you are below 10000'agl in nil wind and nil atc speed control, which combination of gear, flap, speedbrake, speed will give you the maximum descent gradient?

What about the same question with speed control of 250 kts?

ie how do you get to loose the maximum amount of feet per/nm?

[popay]

A.FLOOR,
Gear down, flaps 3, speed brakes out. You will have about 2500-3000 ft/min, but be aware of exeeding 3000 ft/min below 10000 ft.
CHeers.:8

[Thunderbug]

Popay

but be aware of exeeding 3000 ft/min below 10000 ft

Is that an Airbus limitation? or company SOP?

T'bug
(Boeing Driver) :ok:

[A-FLOOR]

There was me thinking my account got hacked :O

Carry on :)

[popay]

HI there,
no its neither the airbus limitation, nor its a company one. Its just a reminder for me, as the company regulations state ROD < 3000 ft/min 3000 ft above MSA, there normally shouldn't be a necessity to have a ROD more than that below 10000 ft.
Cheers.

[jed_thrust]

popay is right: Gear down, flaps 3, speed brakes out certainly gives you the best descent gradient.

What I use is this: at Green dot, simultaneously select Flap 1, full SB, gear down, Open descent (with say MSA selected in the alt window), Flap 2 and 3. Select 179 KIAS and you should end up with about a 9 degree descent at 3600 fpm ROD. Approaching 4-5000' (depending on your MSA), wind up the selected altitude (don't pull!) to above your current height and select (don't pull) 2500 fpm VS.

With this profile you can be at 20,000' with 27 to 30 nm track miles to touchdown.

Regarding popay's 3000 fpm ROD, my other life (low level single seat over water) taught me to look out for "one minute to death": ie at 9000' alt you should have less than 9000 fpm ROD, at 5000' less than 5000 fpm ROD etc. These numbers are obviously excessive for an airline operation, but surprisingly easy to exceed below 2000' if you are trying to capture the GS from above.

[oryxbollocks]

Jed,

Am I missing something? If you don't 'pull' when you select VS, nothing will happen and 45 seconds later the VS will disappear?

If we are talking of intercepting a GS from above, the essentials are LOC or LOC star, then ALT above (don't pull), followed by selected VS. Your configuration would depend on just how 'pear shaped' the approach has become.

As far as maximum descent I agree with your plan but wonder whether we can now do better with Full Flap, as partial speedbrake is now available on the later MSN's? I don't have ready access to the Sim these days. Any comments?

GB

[catchup]

Get an Egyptian Copilot.

[popay]

oryxbollocks, that's right we actually didn't specify which conditions we are talking about. There are generally two scenarios:
1. GS interception from above using V/S dependable on the version 332/333 you have the choice whether Flaps 3 or full, like the procedure in Kathmandu. I am not very familiar with that, but from what I have heard that's what the folks on 320 are doing there. In normal circumstances you wouldn't need more than 1500 ft ROD.
2. Just killing the excessive altitude in Open Descend mode. That would be than on 332 Flaps 3 gear down speed 180 KT. Although I wouldn't really like it, since its not a very pax friendly maneuver and exposes you to the danger of exceeding the company ROD limitation.
Cheers.:8

[jed_thrust]

Re: "...Am I missing something? If you don't 'pull' when you select VS, nothing will happen and 45 seconds later the VS will disappear?..."

Sorry about the late reply. As soon as you wind up the altitude to above your current altitude the descent mode changes from Open Des to V/S, so all you should need to do is adjust the selected V/S by turning.

As for full flap and SB: don't know!

[MANTHRUST]

Speed Brake should be inhibited with full flap, I would suggest that if you feel the need for speed-brake with full flap then it is probably time to throw the approach away and start again.

[popay]

MANTHRUST, well on the A 333 speed brakes are still operable with flaps full, I'm afraid.
Cheers.:8