Throttle controls for formation?
 

Which type of throttle control for formation flying?

I have an RV6a and at some point would like to do some formation flying. I understand that the vernier type of throttle control is a no-no. But is there a preferred type?

How about the Van?s throttle quadrants?
http://www.aircraftspruce.com/catalo...ottlequads.php

Or friction type
http://www.aircraftspruce.com/catalo...rolscessna.php

Thanks

Somewhere around there's a set of drawings for setting up a left-side single-lever throttle that operates slaved to a quadrant mounted in the middle of the panel. I have been getting dual in an RV-6 that is equipped this way, and it works quite well. Personally I don't like the look of the quadrant in the center, but I haven't looked into any alternatives for my aircraft yet.

Some folks have made clips that go over the end of the throttle knob, holding the vernier button depressed.

Throttle for formation
 

Any throttle that is free to change power settings without buttons or hindrances will work well in formation.

The objective is to be able to make three power changes in order to accomplish the desired One power change(or flight control input).

For example: suppose that as a wingman you sense your plane is beginning to drift back in relation to lead: you desire to add some power. Therefore you must first:
1) add too much power so that you arrest the drift to back and begin to move forward.
2) as you move forward into desired position you must under power in order to stop the forward movement.
3) then the power setting needed to maintain position on lead must be set.

Flight control inputs work the same way! Elevator, aileron, rudder inputs all require the same process of three inputs for one change. Practically, they flow into what appears to be one movement.

Another point: formation flying is dangerous and needs to be treated with great respect. Like aerobatics, it is not something you teach yourself! Find an old head and get some instruction and briefings! Especially if you did not do well in geometry in school!

Throttle Type
 

Looks like you have a currently flying RV-6A, so you probably have a center throttle and, since you ask the question, a vernier throttle. As suggested, easiest solution is to simply change out the vernier with a friction throttle as shown in your second URL. The clip over the end of the vernier throttle to hold the button in is not a satisfactory solution as it leaves the throttle completely loose and has been known to malfunction.

The purpose of this is to have a free flowing but slightlly resistant throttle for the continuous throttle changes required for formation flying, most small and sometimes larger. Initially, when training in formation flight, the throttle is being constantly surged with small changes, in and out, while you adapt to staying in the correct formation position. Initially, most pilots don't see the need for throttle until too late, requiring the changes earlier described. Turns into and away, echelon turns, crossunders, trail formation all require aggressive (small but frequent) power changes. As hand eye coordination becomes better with increased training and anticipation, power surging becomes less but never stops, until you become very proficient.

Thanks
 

Thanks for all the great information. This is why VAF is so good.
Looks like a non-vernier friction type throttle is in my future.

I would never dream of doing any formation flying without some good formalized training. Now, where to get that training is another question.

The friction lock throttle is perfect. You want the throttle free like melted butter. Absolutely as free as possible. Some of us formation nuts replace the throttle cable just get get back the original free flowing throttle. Over time they begin to add friction from hundreds of hours of use. A formation pilot will use his throttle more in one flight, than the non-formation pilot is years of use.

Your in Houston, Texas is full of formation pilots, and has been the subject of an annual formation clinic of RV's for the past few years at KBWD.

Throttle Spring in Formation Flying
 

My technical advisor strongly recommended that I install a spring on the throttle linkage in case the throttle-cable broke. Is that spring a bad idea when formation flying?

He also wanted me to put a spring on the mixture control for the same reason, but I did not install that one.
Leland
-9A, 450 hours

If the throttle cable broke, it would take an awefully big spring to overcome the friction posed by the inner and outter sleve of a broken cable. There are other potential failure modes where a spring might be useful, but a broken cable?... I would not put a return spring in that big.

The non-fomation pilot would probably not notice a 1-2lb of spring force. I would get frustrated by it.

Hand vs forearm control
 

Regarding the question of a push/pull classic knob vs a quadrant:

I find that I can have much finer control over the throttle when the motion on the knob is within the confines of my hand. What I mean by this is that my pointer finger is braced against the panel while the throttle knob is grasped with the other fingers in that hand. My forearm is not really part of the throttle control. Additionally, I have a middle armrest which allows my elbow to be supported.

With most quadrants, unless I'm mistaken, the fine motion of the throttle involves moving the whole forearm. Do any quadrant/4/8 throttles have a provision for this "local" bracing or support as I've described?