REFLECTOR: 165 kt Gear Extension Speed

[Dave Dent]

I removed my main gear doors a number of months ago.  I didn't do it for 
faster gear extension but to lesson the problem I had with fish tailing 
during low speeds.  I found that the doors surface area is close to or more 
then the rudders.  My doors were not symmetrical in any way.  So with the 
gear lowered and slow speeds it effected the yaw so much that in a cross 
wind it made the plane very  busy during landing.  The difference was a 
major improvement on the very next landing.  So even if I loose a couple of 
knots on the top end, I can live with it.  I'm not sure that even putting 
the lower end on would help much.  In fact it may degrade it some.
I use aluminum brake lines and they are very ridged on the gear and not 
concerned with them.  Have them floxed to the back side.  I think the carbon 
buildups on the doors would help a lot for the nose.
The method of using both rudders has been my best for fast descent.  I used 
it a lot during the Long EZ days and got into a habit with doing it.  That 
is the main reason for not going to the new brake and rudder system for me. 
But I can change, I may still change it out some day.
Dave



----- Original Message ----- 
From: "Scott Derrick" <scott at tnstaafl.net>
To: "Velocity Aircraft Owners and Builders list" <reflector at tvbf.org>
Sent: Sunday, December 04, 2005 6:42 PM
Subject: REFLECTOR: 165 kt Gear Extension Speed


>I have been flying a T210 lately and can't say enough about how versatile 
>the 165 Kt gear extension speed is.  Once extended you can run up to Vne. 
>This 210 does not have any main gear doors, just nose gear doors.
> Yesterday I was flying in from Las Cruces, was day dreaming and suddenly 
> realized I was 15 miles from the airport at 10,500 and needed to be down 
> to 7,500 in  10-12 miles, and slowed down to 120 kts when reaching 7,500. 
> Totally impossible in my V.   I let the gear down,  and without touching 
> anything else was descending at 800ft a minute at 150 kts indicated.  I 
> pulled 2 inches of MAP every 2 minutes, and made a straight in with no 
> problems, no stress...   All because I could extend the gear at such a 
> high speed.
>
> My V should cruise much faster once I'm back in the air and I'm concerned 
> about being able to slow down or descend rapidly if required, and not 
> abuse the engine by having to pull the throttle from 75% to idle.  The 
> only option in a Velocity cruising above 120 kts..  Well you can extend 
> both rudders but thats not nearly enough.
>
> I have considered modifying the speed brake, but not sure what would be 
> needed to insure it wouldn't depart the airframe at 165 kts if extended, 
> much less 200 Kts..
> So I'm now considering emulating the T210.
>
> First by removing most of the main doors:
>     Leave the portion that covers the brake unit attached but beef it up.
>     Leave the short portion that seals off the fuselage when the gear is 
> up, and beef that piece up too.
>     Glass the brake line onto the gear leg, or add a fiberglass channel 
> for it to sit in(not carve out but add a 'U' channel).
>   Then beef up the nose gear doors and hinge points. A couple carbon fiber 
> layers on the inside of the doors
>      Reinforce the hinges and fuselage pivot points with carbon fiber
>    I wonder if the nose gear extension mechanism(rods, sliders, hyd ram, 
> etc) would be up to a 165 kt extension?   Somebody had mentioned they were 
> testing a simplified nose gear door mechanism that used the nose strut to 
> extend the doors, is this working?
>
> I remember reading a post from Scott Baker that the gear extended speed, 
> sans doors, was Vne, like the T210.  Is this correct?
>
> I also remember reading that a couple of folks have tested their planes 
> with and without main doors with no noticable speed loss.  Correct?
>
> Sound sensible?  I really think with the high cruise speeds of the 
> Velocity, being able to extend the gear at around 165 kts, would really 
> enhance its capability and safety.
>
> Scott
>
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