SEB 1668

Friday, July 27, 2012 10:51 AM
Table of Contents - SEN 1668

  1.  FF or Opers
  2. California Invitational
  3. F1B Stab Whiplashing
  4. New Site and new stuff for AA and OK


FF or Opera ?

no matter which the flying and  food will be great.


38th. California F.A.I. Invitational

October 5th. And 6th. 2012


FOR CLASSES: F1-A, F1-B, F1-C, F1-G, F1-H, F1-J and Nostalgia Wakefield


FRIDAY OCT. 5TH. F1-A, F1-B and F1-C

SATURDAY OCT. 6TH. F1-G, F1-H and F1-J


Nostalgia Wakefield can be flown both days, (But must finish the same day)

Flt. Duration as per NFFS Rules. 2 min, 3 min. 4 min. 4 min. etc.


First Flight Duration: F1-A 210 Seconds, F1-B 240 Seconds, F1-C 240 Seconds

-7- One hour rounds starting at 08:00 hours


Fly-Offs will start at 4:30 PM “FIRM” as schedule, BRING YOUR TIMER

Friday: F1-A = 4:30 to 4:40 ** F1-B = 4:45 to 4:55 ** F1-C = 5:00 to 5:10

5:15 to 5:25 “ 5:30 to 5:40 “ 5:45 to 5:55


F1-G, F1-H and F1-J Saturday October 6th. 2012

First flight ONLY, for all Mini events will TIMED TO THE GROUND

starting at 800 hours fallowed by -5- flights of 2 minutes, all rounds 45 minutes long

Total time of the 6 flights will determine the winner


***There will be NO timers provided, please find someone to fly and time with you***



Perpetual Trophies to winners for all FAI events

Medals to 1st. place for all big FAI , Certificates for 2nd. and 3rd place

Certificates 1st through 3rd for all Mini events and Nostalgia Wakefield


Note: Per AMA directive, all competitors must have AMA Insurance


Entry Fee US $20:00 for F1-A, F1-B and F1-C

$10:00 for F1-G and F1-H and Nostalgia Wakefield


Contest Director: Juan A. Livotto, 13212 Lake St. LA, CA, 90066

Phone (310) 391-5986……..e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.


AMA Sanction # 12-0209

Year 2011 Winners




Nos. Wakefield: LAIRD, T.

F1B stab whiplashing

Over this weekend at a contest, I had two horrible consecutive flights on one of my F1Bs, caused by the hammer piercing through the Mylar covering on the right side of center rib pair, causing the model to serially stall down. The question, of course, is that caused it.

It turns out my monofilament lines to the rudder were too tight (it was very hot and dry).  As a result, the tail boom (a standard Ukrainian Aluminum/CF tail boom, 12 mm at its base) was slightly bowed under tension.  Consequently, at the instant the rudder line was released, the tail boom had a whiplash reaction.  The stab, preached over a stab mount and held down by the hammer’s screw, attached to the tail boom with a rubber band loop, can pivot against the front edges of the stab’s mount. These pivoting movements are elastically constrained by the stab’s rubber band loop. Because the stab is an independent object, its inertia causes it to counter rotate the initial whiplash of the tail boom projected into stab’s plain.  With the right combination of these factors the stab’s sideway pivot could be large enough to allow the hammer’s screw to pierce into the adjacent Mylar covering.

The simplest solution is to stick a piece of tape or thick Mylar over the back of the stab extending the range under the hammer’s screw, left and right. One can also add small balsa triangles at each side of the center rib pair for better support. The top surface has to be very smooth.

The other issue is the line tension that can trigger the sideway whiplashing.  I’m using a raw 8 Lb monofilament line. A thinner monofilament line (6 Lb) is stretchier and it can’t build such high tension.  Some fliers use non-stretching woven Dacron lines which require appropriate tube-guides at the points the lines enter and exit the tail boom to reduce abrasion plus an element giving them their elasticity on the timer’s side. The line release allows the elastic element to contract and the tube-guides add line friction, slowing the line’s sudden release thus damping the tail boom’s whiplash reaction.  Maybe one should continue using monofilament lines to the rudder together with small tube-guides at the entry and exit points to dampen the line’s release speed?



New Site and new stuff for AA and OK

Please visit my new web site at
You can find there information about our "SIMPLICITY" electronic
timer, ICAREX covering material and tons of other things.

Alex Andriukov
This email address is being protected from spambots. You need JavaScript enabled to view it.

Roger Morrell