National Free Flight Society

SEN 2018

Table of Contents – SEN 2018

  1. F1C Petition
  2. The Glass is only 25% full for a Dino
  3. Still looking for a RDT explantion
  4. RDT in Practice

F1C 4 Seconds Engine Run Petition

Please sign our petition if you disagree with the new F1C rule change:

The petition originated in Canada

The Glass is only 25% full for a Dino

(with ref to Allard’s half full F1C article)

No, to the statement that shorter engine run levels the field. The direct drive conventional wing model accelerates much slower than other models. Geared flappers accelerate faster than direct drive folders for first couple seconds, then the geared flappers get to speed that drag starts slowing there acceleration down and the less drag folders start catching up.. The direct drive fixed wing accelerate slower and takes longer to reach close to maximum velocity, so shorter engine never allows them the time needed to really get near top speed… So the direct drive fixed wing model loses more ground to flappers and folders.. Less competitive now than before. But the reality is that they were marginal at best to win, now they are toast.


Still Looking for and RDT explanation

from John Lorbiecki

I still want someone to show me how the rdt will work before bunt….of course, this is with a mechanical timer…folks keep saying it can be done but no one has proven it.

Because of this, all these timers will be junk!

F1C fliers need to get their act together and work towards a decent conclusion to these rules…


Ps. These are my opinions and in no way represent NFFS…..

But probably not this one …

RDT in practice

Aram Schlosberg

Implementing an RDT on F1C models is not straight forward. Let’s assume a world in which all F1C models use electronic RDT-enabled timers and servos are immune to the engine’s vibrations.

FAI rules grant an attempt if a model RDTs meaning the engine is cutoff and the model DTs AND the flight is under 20 seconds. So the flier has an incentive to delay the RDT to increase the chance that the model lands under 20 seconds. In other words, the C-RDT rule encourages reckless behavior!

To remove such an incentive, I’m suggesting that a C flier be given a Mulligan during a contest to remove the pressure to make an attempt. In other words, if the RDT cuts the engine and the model DTs in say 25 seconds, it is still considered as an attempt. (Maybe the ceiling should be raised to 30 seconds.)

The second issue is who operates the RDT? My experience of flying an inherently unstable high powered Q model is that a flier is too busy launching the model. And even if the RDT transmitter is on one’s left wrist or the arm (brachial) it only works if it’s turned on. In addition, the flier sometimes has difficulty seeing a model climbing towards the sun.

Instead, suppose that the RDT unit is given to a safely officer, standing at a distance from the flier. The safely officer is more likely to activate the RDT (cutting off the engine) earlier while the model is still pointed upwards. Gravity and drag will jointly work to slow down the model before the stab is popped. Of course safely officers should have experience flying high powered power models. Indeed, we have actually use this practice in flying high powered Q models at Wawayanda NY and it’s very efficient.

The last issue are C folders. Spreading out their wings are too soon can rip off a wing with ugly results. Hypothetically, if the center dihedral was increased, a model could conceivably dethermalize without spreading out its wings. However, the current folders might just tumble randomly, possibly damaging themselves on landing. To address this issue, folders could be granted a second RDT channel dedicated to furl out their wings, then safer touchdowns could be achieved.

A Mulligan and safety officers can make effective usage of RDT in non-folder C models and it would be nice if they become official. However, C folders require more experimentation and development before RDT can be adopted effectively. If we don’t want to obsolete many C models and seriously shock the event, a more realistic RDT implementation mandate should be considered by CIAM in its November planning meeting.

Roger Morrell