Jump to content

ELEVATOR deflection at high speed cruise

Mike Stevens

Recommended Posts

  • 2 weeks later...
On 10/13/2019 at 5:47 PM, Mike Stevens said:

What are the fliers finding for elevator defection at their max cruise speed?

In order to answer this question in a useful manner, you have to discuss GW, CG location, which airfoil (GU or Roncz) and IAS. Without that, any comment will be meaningless.

Link to comment
Share on other sites

58 minutes ago, longezdave83 said:

Marc is correct.  I just presented a basic response.  The above that I presented is at a CG of 102.8, GW of about 1255#, Roncz canard and roughly 190 MPH indicated.  I verified all the above, except I only have screenshots near 190 MPH indicated.

Now we're getting somewhere.

At almost the aft CG limit of 103", somewhat under design MGW and an IAS substantially higher than the design cruise speed of the airplane (remember, the Long-EZ was designed for an O-235 engine of 115 HP, so has a design cruise speed in the 120 - 125 KIAS range (call it 140 mph IAS), it's not at all surprising that the elevator would be reflexed up a bit. That's 50 mph over the design IAS, give or take - the elevator trim position will need to be higher than trail.

There are O-540 powered Long-EZ's and Berkuts that will run out of up elevator at max power, and will still be climbing even with the elevator deflected full TE up (at well over 200 KIAS).

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...

Important Information