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Juliet-Echo
2nd May 2007, 13:24
Hi guys

I fly a B732 and was having an argument with my FO today about using speedbrake and flap simultaneously. I don't agree with it - because of altering the camber etc. But he claims that , according to the books, speedbrakes can be used in any config. and at any time except below 1000ft.

Just wondering what the general consensus is.

blackmail
2nd May 2007, 14:44
hello,
above 5°flaps, speedbrakes are not recommended cos too much flutter inflicted on tailplane.
if extra drag is required : drop the gear (<270kias). reminder, if raising gear again : max 235kias! f/o is right: also, no sb < 1000ft agl (limitations) to preclude high rods close to the ground.
kind regards,
bm

I-2021
3rd May 2007, 17:09
Hello,

speedbrakes should not be deployed below 500 ft AGL on the 732 and with flaps greater than 15°.

Bye.

john_tullamarine
3rd May 2007, 21:34
.. coming from another viewpoint ... if you need speedbrakes with flap close in (and they are pretty useless for other than generating discomfort at lower speeds) I would have thought that the approach has been so badly mismanaged (or ATC has thrown a late spanner in the works) that a miss (or other suitable management) would be increasingly attractive.

Surely better to be sufficiently ahead of the aircraft to predict the problem earlier and do something about it 20-30 (or more) miles out. On the FLUF gear out early, lots of flap and approaching limit speed will give you easily 1-1.5 per 1000 gradient. A while since I have played with the machine but that sort of figure sticks in my head for "get-of-jail-free-card" purposes ...

I-2021
4th May 2007, 09:27
Completely agree with john_tullamarine. To loose altitude close to the airport you have to slow down and get everything out. Try to make a flaps 40 idle descent... you will have a nice surprise :)

lenstrad
4th May 2007, 18:28
its ir written in the in the flight crw training manual , not problem at all , but using it beyond flaps 5 , the airplane shivers a lot , best regards my friend

vwreggie
7th May 2007, 20:19
same here in aus. Speed brake should not be deployed in flight at radio altitudes less than 1000'. high rates of descent is one factor although it makes more buffet than drag once you are below flaps up manoevre. Probably a missed approach consideration (remember the 757 at cali). The best recovery for a vertical offset is gear down flaps 25 165 knots thrust idle which will give you about 1500 feet per min rod ( approx twice a normal profile) and allow you to raise the nose select flaps 30 or 40 just before a 1000 feet and power up to be stable.