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Old 02-28-2005, 08:56 AM
  #54  
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Default RE: new Arf Boomerang 14lb thrust


ORIGINAL: john agnew

Guys

Now for the bad news! To achieve the suggested CG of 150 mm back from the leading edge I will have to add 1 1/2 lbs of lead to the nose, this is not good! Alternatively by my calculation a 25 % CG would be 187.5mm back from the LE . The root chord is 450mm the tip 250mm giving an average of 350mm at mid span 25% 0f this is 87.5mm plus the difference between the mean chord and LE is 100mm giving 187.5mm.
This can be achieved with only12oz of lead giving a dry weight of 14lb 8oz with a full hopper tank.

Would any one like to confirm my CG calculation before the model is flown? I cetainly feel that 150mm is too conservative if my calcs. are correct.

To be fair to Allan he suggests moving the CG rearwards after initial flights without giving a specific figure.

John Agnew
Bummers! AND this is with a manual start W54? WOW! what kind of weight is needed for an auto start P60????
Alan tells me the plane in the video is box stock with retracts and weighs in at 14#. Maybe Alan can shed some light on this? How about some pictures of the insides of the plane shown on the video? I understand it is powered with a P60?

Dave Rigotti