Precision take-off and landing distances

[Madhatter]

2 hours ago, Tom Baker said:

I'm just relaying what was said when the CTLS was introduced at Sebring in 2008. I don't recall whether it was one of the engineers at the show, or during dealer training. The results of that testing led to the winglets, squared off corner where the fuselage meets the wing, and the little fence at the inboard end of the flap. It also led to the reduction of maximum flap angle from 40° to 35°, and then later to 30°.

 

I agree with you. I guess I forgot to mention Is Tom told me the entire aircraft was wind tunnel tested which is a huge and expensive project. I'm sure a lot of testing is done on individual components. I guess time will tell as more F2's are delivered. I am not an aerodynamics engineer so I couldn't tell you of the whole process.

[Mike Koerner]

Madhatter,

We also have a stall strip on the wing inboard leading edges that seems likely to mess up the flow over the stabilator at high angles of attack. Did you see this?

[Anticept]

Being a high wing with a standard tail, I'd like to know how stall strips would interfere with the stabilator at high AoA. I guess it could a tiny bit in theory, but is it really of significance or is it ignorable?

If this were a low wing with a cruciform/T-tail, I could see that being much more likely.

[Madhatter]

29 minutes ago, Mike Koerner said:

Madhatter,

We also have a stall strip on the wing inboard leading edges that seems likely to mess up the flow over the stabilator at high angles of attack. Did you see this?

No way to determine that and be practical in the testing but I doubt it. That stall strip is not something you would want to mess with anyway, unless you want spins for fun.

[Mike Koerner]

I don't know Corey, but it's about the same height as the top of the cabin. And I misspoke when I said, "high angle of attack". My tail losses control authority on landing with the deck angle at zero. That's the point at which I drop in in for a 3-point landing.

 

[Anticept]

Usually stall strips have a pretty small area of effect. The tomahawk for example has two sets of them by AD. One set inboard, and one set mid position. Encourages better stall characteristics.

Usually stall strips are to help exaggerate early warnings signs of an impending stall, very useful on square wings which like to stall at the tips first, but quickly across the whole wing.

But overall, the wake of the wing itself is huge compared to a tiny strip on the wing.

[Mike Koerner]

Thanks Corey. Thanks Hatter.

 

[GlennM]

On 1/25/2023 at 2:22 PM, Madhatter said:

I did the analysis for stick bump at the request of Tom Peghiny and did not find any boundry layer separation or disturbance in cruise. 

What, then, causes the stick bump?

[Madhatter]

15 minutes ago, GlennM said:

What, then, causes the stick bump?

It's never happened to me, must be aerodynamic gremlins