Speedbrakes / DLC for homebuilt?

[Bob Martin]

I got to thinking the other day on the way to work... would it be
feasable to implement:

1. A set of speedbrakes, say on the fuselage of something like an RV-6,
operated by a parking-brake style handle (where the flap handle
currently is, necessitating electric flaps)? Could be useful if you
need to lose altitude in a hurry or if you get too close to redline
during maneuvers.

2. Direct lift control, a la L-1011 or F-14. Basically you put
spoilers on the wing, then rig them up so that on approach they deploy a
few degrees. Then, you can raise them further for a second to
compensate for being high, or stow them if you're low. Avoids having to
make pitch changes or power corrections, depending on how you fly
approaches. AFAIK, such a system was integrated into the controls on
said aircraft; I was thinking a simple "arm" switch that deploys the
spoilers a few degrees, then a slider switch on the stick for the
adjustment.

[Rich S.]

"Bob Martin" > wrote in message
...
>I got to thinking the other day on the way to work... would it be feasable
>to implement:
>
> 1. A set of speedbrakes, say on the fuselage of something like an RV-6,
> operated by a parking-brake style handle (where the flap handle currently
> is, necessitating electric flaps)? Could be useful if you need to lose
> altitude in a hurry or if you get too close to redline during maneuvers.
>
> 2. Direct lift control, a la L-1011 or F-14. Basically you put spoilers
> on the wing, then rig them up so that on approach they deploy a few
> degrees. Then, you can raise them further for a second to compensate for
> being high, or stow them if you're low. Avoids having to make pitch
> changes or power corrections, depending on how you fly approaches. AFAIK,
> such a system was integrated into the controls on said aircraft; I was
> thinking a simple "arm" switch that deploys the spoilers a few degrees,
> then a slider switch on the stick for the adjustment.

Anchor on a rope???

Rich S. :))

[Bill Daniels]

"Bob Martin" > wrote in message
...
> I got to thinking the other day on the way to work... would it be
> feasable to implement:
>
> 1. A set of speedbrakes, say on the fuselage of something like an RV-6,
> operated by a parking-brake style handle (where the flap handle
> currently is, necessitating electric flaps)? Could be useful if you
> need to lose altitude in a hurry or if you get too close to redline
> during maneuvers.
>
> 2. Direct lift control, a la L-1011 or F-14. Basically you put
> spoilers on the wing, then rig them up so that on approach they deploy a
> few degrees. Then, you can raise them further for a second to
> compensate for being high, or stow them if you're low. Avoids having to
> make pitch changes or power corrections, depending on how you fly
> approaches. AFAIK, such a system was integrated into the controls on
> said aircraft; I was thinking a simple "arm" switch that deploys the
> spoilers a few degrees, then a slider switch on the stick for the
> adjustment.

Not a bad idea. As a glider pilot, I use these things every time I fly.
They're called Spoilers/Airbrakes and allow extremely precise landings.

I'd suggest taking a look at the flapped Shempp-Hirth gliders like the
Ventus. The speed brake is on the upper surface hinged at the rear on the
same spanwise line as the flap hinge and interconnected with the flaps.
Deploying the speed brakes causes the flaps to also deploy just enough to
cancel any up/down transient so the aircraft just slows down and glides
steeper. They can be yanked full on with no G forces. The effect is like
deploying a tail 'chute.

I'd also suggest interconnecting them with the throttle. When the throttle
is pulled back past idle, the brakes would deploy. That way there's no
problem with them open during a go-around since they would close when the
throttle is pushed forward.

If you need to keep the engine warm during a descent, a pushbutton on the
throttle or stick could partially deploy them but they must close if the
throttle is moved forward.

Bill Daniels

[flybynightkarmarepair]

http://www.preciseflight.com/sb.html

They've been fitting these to Lancair and Glasairs for at least 15
years.

[rpellicciotti]

My experience with RV-6s and constant speed props says that speed
brakes are not required. Since the prop is almost 25% of the wingspan
and goes flat when you pull the power off, it is a very effective speed
brake. That said, the Precise Flight speed brakes seem to be a good
solution.

Rick Pellicciotti
LightSportFlying.com