REFLECTOR: Cruise speed "speed brake"

[Jim Sower]

Spoilers outboard on the wing would seriously screw up the aerodynamics, 
require a lot of structure and hideously complicate construction IMO.  
Beefing up the structure on the current belly board would be an order of 
magnitude easier and simpler.  Stronger foam, a couple of hard points 
and some carbon fiber should do the trick.  If I wanted to get really 
REALLY cute, I might consider split flaps on a foot or two of the 
inboard wing TE.  It's not a significant lifting surface and the air 
there is already pretty much separated so the hinges and what not 
wouldn't cost much in cruise.  It would still complicate construction a LOT.

I'd have to stay with a more robust belly board ... Jim S.

Terry Miles wrote:

>Chuck,
>
>You can add me to the list of interested parties.  Here is all I have.
>In a brief and non-technical exchange w/ Scott Baker on this topic back
>about 6 months ago, comments expressed at that time were that there was
>a general safety concern about the panel coming off at higher airloads
>and going into the prop.  So a conservative speed limit was established
>and no testing was done above that speed.  And further there was no
>interest in incremental deployment angles.   Another thought only, how
>about a split rudder like the B-727.  Only this one would split and the
>low half both LH and RH would deflect into the slip stream.  The problem
>solved is not it out of the prop track, but the problem created is the
>deflection is way to far from centerline in the event of assym
>deployment malfunctions.  Good luck with this.  Keep us posted.
>
>Terry 
>XL-RG with a SB 
>
>-----Original Message-----
>From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On
>Behalf Of Chuck Harbert
>Sent: Monday, September 05, 2005 3:54 AM
>To: reflector at tvbf.org
>Subject: REFLECTOR: Cruise speed "speed brake"
>
>
>Scott, I too have wondered if there was a way to install a high speed
>speed 
>brake like the one on the Mooney 201 that pops up on the upper surface
>of 
>the wing to kill the lift. It was great to get down in a hurry without 
>puting the engine at idle. I wondered if you could install this
>electrically 
>activated "fence" at the outboard edge of the strake in the wing bolt 
>cavity, or inside the wing attached to the spar? They're not that large
>as I 
>recall. They fail safe in the down position and have a warning light
>when 
>deployed, as I recall.
>
>I think that this might be a better way because it kills lift, rather
>than 
>just dirtying up the plane, and possibly making it unstable. I have the 
>underbelly speed brake in my RG and it definetely works well for
>landing, 
>but I'd love to have a real speed brake. I'll try to get a look at the 
>Mooney's speed brake and send everybody the info.
>
>Chuck H
>
>
>-------------------------
>Scott Derrick wrote:
>
>  
>
>>I think the standard speed brake is limited to 120 knot extension 
>>speed.  Which limits its uses to in the pattern.
>>
>>Has anybody experimented with beefing it up to allow higher speed 
>>extensions?  Like 175 knots?  This would make it a true speed brake.
>>
>>I would like something I could deploy at cruise to enable a cruise 
>>speed descent without shock cooling the engine.
>>
>>What would you think would be needed to do this?  bigger hinges? 
>>bigger actuator?  carbon fiber door?
>>    
>>
>
>
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