Brasilia Question

[Schinpop]

I had the opportunity to ride in a Brazilia this past weekend - sat in 8A, right behind the wing. During cruise, I noticed that the ailerons did not move much. Then, noticed that they didn't move at all. I was 15 feet away from them, in a perfect spot to see any deflection, but they didn't move. OK, smooth day, whatever. But, they didn't move even when rolling into a standard rate turn. Once the flaps came out, I could see movement in the ailerons.

Now, I understand that jet aircraft lock out the outboard ailerons, but this just didn't make sense to me since there didn't appear to be any inboard ailerons. I can believe that, at cruise speeds, the ailerons don't have to move much, but even during a standard rate turn, I could not detect any deflection - at least on the left wing. On final, they were deflecting 1-2" at the trailing edge, which seemed normal.

So what makes it roll during cruise?

[Lee D]

Ailerons. They do move while banking, but probably not much. Like you mentioned the brasilia is not fast enough for inboard ailerons. (Does around 285-290 true in cruise.) It does use the ailerons in all phases of flight for turning. I'll have to watch them on my next trip to see how much. (You've got me feeling a little curious. ) I am guessing they need less than 1/2 inch of travel for a normal bank in cruise. The amount they move in flight will be correlated with the speed of the air over the wings and the size of the control surface. (Just like everything else.) In slower flight you will see them move more than during cruise.

[WalterSobchak]

Originally Posted by Lee D

Ailerons. They do move while banking, but probably not much. Like you mentioned the brasilia is not fast enough for inboard ailerons. (Does around 285-290 true in cruise.) It does use the ailerons in all phases of flight for turning. I'll have to watch them on my next trip to see how much. (You've got me feeling a little curious. ) I am guessing they need less than 1/2 inch of travel for a normal bank in cruise. The amount they move in flight will be correlated with the speed of the air over the wings and the size of the control surface. (Just like everything else.) In slower flight you will see them move more than during cruise.

Must be loafing or really high the Saab does that. I'm uber jealous of your apu and drop down masks in back.

[citabriapilot]

I can tell you the yoke moves every time you turn... The Brasilia has a pretty big aileron and at higher speeds it doesn't take much to get a large change in roll.

Take a look at a 737 or an MD-80 in flight, they don't have inboard ailerons and their outboards don't deflect very much either.

[Lee D]

Originally Posted by WalterSobchak

Must be loafing or really high the Saab does that. I'm uber jealous of your apu and drop down masks in back.

That is based on our normal cruise settings. It could do a little more if we pushed it. (ie "Friday Power.") 300 TAS maybe a bit better. Around the Rockies we fly around FL240 on average. Out on the coast it varies a bit more.

The APU is great. I don't realize how much I love it til I fly a plane with a defered one. (Especially in when it gets hot.)

Whats the SAAB do?

[Bumblebee]

Originally Posted by Lee D

Whats the SAAB do?

Gets in my way

[WalterSobchak]

Originally Posted by Lee D

That is based on our normal cruise settings. It could do a little more if we pushed it. (ie "Friday Power.") 300 TAS maybe a bit better. Around the Rockies we fly around FL240 on average. Out on the coast it varies a bit more.

The APU is great. I don't realize how much I love it til I fly a plane with a defered one. (Especially in when it gets hot.)

Whats the SAAB do?

Ive touched 300 at 180 on a damn cold day. Usually 275 to 285 in the high teens. Our helicopter engines don't hold the power at up high and we are conservative with our ITT's. We have a ceiling of 250 due to the 10% rule for pax O2. At 240 in the winter maybe 275 is the best we are gonna see in that thing.

We do however have the exact same collins avionics and EFIS tubes.

[Baronman]

Originally Posted by WalterSobchak

Ive touched 300 at 180 on a damn cold day. Usually 275 to 285 in the high teens. Our helicopter engines don't hold the power at up high and we are conservative with our ITT's. We have a ceiling of 250 due to the 10% rule for pax O2. At 240 in the winter maybe 275 is the best we are gonna see in that thing.

We do however have the exact same collins avionics and EFIS tubes.

Mmm...you get the highest TAS while in warmer temperatures. Given the same cruising altitude the a/c in the warmer air cruising will have a higher TAS. I guess if your engines temp out through that would cause you to go slower.