REFLECTOR: Questions for those already flying

Thu Mar 15 19:49:24 CDT 2007

Ben,

I have a Lycoming IO360 200 HP with a climb prop (short runway).  66" dia x 70" pitch.  That is turning 2600 rpm and about 65%.  I have the long wings on my standard elite.  Max cruise - WOT and 2700 rpm is 165. I had a 66" x 72" pitch Catto  which had too low of  static RPM - only about 2200 rpm which made for an anemic take off. The top speed was about 172 knots, but could only pull 2550 rpm at Wide Open Throttle. 

The repitch changed the take off from starting in "2nd gear instead of high gear".  With a MT constant speed prop, you can take off in "1st gear" but max cruise speed will be about the same as the Catto or a bit less.  The MT blades are optomized for take off - not high cruise speeds.  From my experience on the Reflector and talking to various builders, I think these numbers are pretty typical.

An RG with standard wings and standard fuselage will push 185 knots or so.  

If you want high speed and crisp take off, hang an IO 540 and an MT on the back.   Should get you over 200 knots.  But the heavier the plane, the faster the rotation and landing speeds. But might be a bit much for the short wings. Or perhaps a hopped up 360 or 390 or 400 with M/T to keep your weight down.

Decisions, Decisons, Decisions!!!!

Ask lots of questions and seek lots of opinions - then make up your own mind!!!!

Enjoy the Journey!!!!
Ronnie 
  ----- Original Message ----- 
  From: Benedikt Harren 
  To: 'Velocity Aircraft Owners and Builders list' 
  Sent: Thursday, March 15, 2007 5:25 PM
  Subject: Re: REFLECTOR: Questions for those already flying

  Ronnie,

  what kind of engine do you have? What's your cruise power setting (%)? 155kts sounds awefully slow for an RG...

  Ben Harren
  ( Std RG Elite N888GF / just getting started)

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  Von: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] Im Auftrag von Ronnie Brown
  Gesendet: Donnerstag, 15. März 2007 23:38
  An: Velocity Aircraft Owners and Builders list
  Betreff: Re: REFLECTOR: Questions for those already flying

  I have a 173 Elite RG with fixed prop Catto.

  I have the speed brake - it is somewhat helpful if you a bit high and fast on a short runway, but as Larry says, with good planning (but not getting TOO slow), 1500-2000 foot roll outs are achieveable although I try not to work the brakes too hard.  Typically I will use 3000 feet with easy braking. 

  I fly IFR and have never had any problems meeting a controller's descent (or ascent!!!!) requests - without using the speedbrake or extending the gear.  It is a fast airplane - plan ahead!

  My cabin heat works reasonably well - I have found that if I open it completely - which blocks off the exit air from the cooler - and forcing all of the air into the cabin it provides decent heat.  If the sun is shining - it gets too warm, with outside temps in the 25-30 deg.  You will need to work on minimizing cold air leaks into the cabin from the nose gear area and from the elevator torque tubes.  I built up the outside of the fuselage at the torque tube exits to create a negative pressure area at the torque tube.  Basically, a lttle hump in front of the torque tube with a sliver of foam and covered with micro.

  I have good engine cooling with a single oil cooler mounted up front - separate oil lines down each side of the fuselage and carefully fitting the cooling plenum to the engine with wraps under the cylinders.  Summer temps run about 200-205, 210-215 on a hard climbout, but CHT's are kept bleow 360 degrees by increasing the cruise climb speed and /or pulling back on the power a bit during climbs.  I agree with Scott, if you have good EGT instruments, you can run lean of peak and keep the heads even cooler.  I can cruise at 310 deg CHT's, burning 7.5 GPH and cruising at 155 knots at 7-9000 MSL.

  At 320 hours and LOVING IT!!!!
  Ronnie Brown  
    ----- Original Message ----- 
    From: Laurence Coen 
    To: Velocity Aircraft Owners and Builders list 
    Sent: Thursday, March 15, 2007 1:35 PM
    Subject: Re: REFLECTOR: Questions for those already flying

    Jack,

    I have a standard RG and no speed brake.  Conventional wisdom at the time I was making the same decision, was that it was not necessary on an RG.  If I do it just right I have made a 1500 ft. turnoff with liberal use of brakes.  2000 ft. is normal.  When my nose gear jammed 800 ft. was enough.  If you're high and hot on approach you will use a lot of runway.  IMHO a good approach is easier to do than building a speed brake.

    The heater is useful in the summer for altitudes above 10,000 ft.  In the winter you need to dress appropriately.  Partially blocking air flow through the oil cooler to raise the oil temp. will help.  The oil cooler up front also helps the CG location.

    Larry Coen
    N136LC
      ----- Original Message ----- 
      From: Jack Prock 
      To: Velocity Aircraft Owners and Builders list 
      Sent: Wednesday, March 14, 2007 8:16 PM
      Subject: REFLECTOR: Questions for those already flying

      Hi,

      A couple questions for those already flying...

      If you didn't install a speedbrake, if you were to do it again would you install it? 

      If you did install a speedbrake, are you glad you did? Do you use it often?

      I have heard that with RG's it is hard to heat the cabin at altitude and/or winter. If you could do
      it again, would you still cut the NACA for the oil cooler? I have heard people using two coolers,
      one near the engine to be used during the summer,  and another in the nose that
      is used as a heater during the winter. Any thoughts? 

      Thanks,

      Jack Prock

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