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Formation Flying. Why no vernier throttles

Kahuna

Moderatoring
This thread on a Bonanza flight, raised the question on vernier throttles. Figured it was worth its own thread so as not to take that one off track.

First, can a formation pilot fly good formation with a vernier throttle? Yes of course.

However, verniers reduce the ability for smooth operation(ratchity even with the button in or disabled), increases pilot workload, puts tention in a pilot that needs to relax, and can, in a maxed out pilot, cause him angst and turn into a safety of flight problem.

The more maneuvering you do, the more it comes into play. In an RV formation evaluation, with 60deg of bank and 45deg of pitch required, the vernier becomes a hindrence to precision quickly. If your doing figure 8's over Osh in Bonanzas or RV's, well it can certainly be done, and done safely by experienced pilots.

In a clinic environment, where newbees come to play and learn, the vernier is a real hindrence to the learning curve and compromises safety. We found this on many occasions years ago and banned em in the RV clinincs many of us attend.

So, can it be done? of course. But when your trying to lower risk, improve safety, and allow the learning curve of a new pilot in an RV to take place, the vernier throttle has no place in RV formation training.
 
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This explanation is what has kept me from taking a formation clinic. I have a vernier throttle. Such is life.
 
Did my transition training in a plane with a vernier throttle...just my opinion which is worthless but I have no idea why anyone would want such a thing to control their throttle. I saw no positives and many negatives in that setup.
 
Positive: Very fine throttle control.

Negative: None that I can see other than no RV formation clinics.

Ron,

Not crossing swords at all, as that was my first thought of a positive as well. I remember my first Bonanza ride (long ago), which is where I saw a vernier throttle, and thought it made for nice cruise adjustments. However, I spend so little time not at WOT when I'm climbing, cruising, and descending, that I'm wondering if it really is a benefit. I seem to do all my adjustments with prop and mixture, both of which are vernier in my -6. The times when I'm off "the wall" with the throttle (pattern and formation, etc), is when I want no hinderences to throttle movement. Would love to see ya at a clinic, but also wondering if you find the vernier a pain in the pattern. Just info collecting, not a stab at your vernier!

Cheers,
Bob
 
Not bashing em. Those that like em, like em very much. That's the great thing about having a choice!
 
Bob, the vernier throttle came with the 6A when I bought it. I believe that it was the first plane I ever flew with a vernier throttle. After ~1600 hours, it is easy to use. But I do fly with less than full throttle (fixed pitch prop...typical cruise RPM 2550 -2600).

I recently did Phase 1 on a 7A with a CS prop and "normal/non-vernier" throttle. No problem with it either. It did have a vernier mixture which I liked.

Coming into the pattern....no problems with either the vernier throttle or fixed pitch prop. But I am good.

Given all that I know now (particularly the RV formation clinic ban on vernier throttles), if I had my choice I would probably go non-vernier throttle and vernier mixture. Can't say if that would be a majority opinion.
 
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I flew Bonanzas of various stripes for quite a while and the vernier throttle was pretty nice when landing. If I hit configurations and power settings right I would just keep rolling back (unscrewing?) the throttle as I came "over the fence" and I'd run out of throttle about the time I was fully flared over the runway, It worked very smoothly and prevented big throttle changes on final.

I am not a formation pilot so won't comment on that, but I am an engineer so I would say different mission, different design intent, different configuration/hardware.
 
I had a vernier throttle (not Van's humongous beast) on mine for around 8 or 900 hours. It started to get sticky in the cable, so I replaced it. To replace with an identical one would have required a long wait, so I put in a friction lock one. I've got somewhere around 400 hours on this one now.

I've flown formation with both, and don't see any difference at all with respect to precision and/or safety. I kept the button on the vernier depressed by the cup of my hand, something trivial to do. I even made a button retainer for it, but it wasn't necessary. Of course, those teaching/certifying the formation stuff can apply any rules they see fit, I've got no problem with that.

What is very helpful to operating either type with precision is that I keep my forefinger on the panel. This removes the requirement that one's arm muscles be an important part of the equation. In other words, the precision comes from motor skills in the hand, not so much in the arm. I'm not sure this tight loop is available with a quadrant style, unless the geometry allows for "planting" a finger near the throttle knob.

Overall, I prefer the vernier, not for precision throttle control but because it eliminates all the putzing with turning the friction lock.
 
I have flown both and a lot with a "push pull" throttle--not necessairily a vernier as there is no center "lock" button. I like the push pull best as you can use the base and the prop knob as anchors for the rest of your hand. With a throttle quadrant, I feel less precise, as if your elbow is flying all over the place, and there is no real "anchor". I think the disqualification of the push pull has no merit. Can someone please give a valid reason for the disqualification, as I have yet to see valid reasoning regarding this.
Mark, the term "Vernier" refers to the twist-to-advance-or-retard throttles, that also have pushbuttons for fast motion. Because of the pushbutton they are sometimes referred to as "locking" throttles. They are discouraged for new formation pilots because of the extra workload in holding the button in to keep it possible to make fast motions when needed... A new pilot may not be able to pull the power fast enough (or add it fast enough) when needed.
 
Mark, the term "Vernier" refers to the twist-to-advance-or-retard throttles, that also have pushbuttons for fast motion. Because of the pushbutton they are sometimes referred to as "locking" throttles. They are discouraged for new formation pilots because of the extra workload in holding the button in to keep it possible to make fast motions when needed... A new pilot may not be able to pull the power fast enough (or add it fast enough) when needed.

Thanks Rob, however, I have heard that for the formation groups, you must have the side or center mounted "throttle quadrant" type. That was the direction of my comment.

Mark
 
The prohibition of verniers for new formation pilots is an excellent rule. New form pilots will absolutely over modulate the throttle because they have not learned to predict the changes in relative motion and to discern those changes early enough to avoid having to add/subtract large amounts of throttle very quickly. Even the slightest hesitation in throttle application when first learning is going to cause greater positional errors which amps up the workload significantly often resulting in even greater positional errors - and so on. The newbie is already trying to contain a self-induced helmut fire so he/she doesn't need any extra heat.

Absolutely once the pilot learns to quickly discern subtle changes in relative motion and can anticipate the needed power changes, any kind of throttle will work fine.

Good rule!!!
 
...snip> I like the push pull best as you can use the base and the prop knob as anchors for the rest of your hand. With a throttle quadrant, I feel less precise, as if your elbow is flying all over the place, and there is no real "anchor". I think the disqualification of the push pull has no merit. Can someone please give a valid reason for the disqualification, as I have yet to see valid reasoning regarding this.

Mark

Thanks Rob, however, I have heard that for the formation groups, you must have the side or center mounted "throttle quadrant" type. That was the direction of my comment.

Mark

Mark,

The clinics that I've been involved with, and the other clinics that train to FFI standards that I'm aware of, only prohibit verniers. I've not seen a quadrant requirement...'course that doesn't mean it doens't exist somewhere. Push-pull throttles are fine in our group...that's what I have as well.

Your point on having an anchor is spot on, and there's a similar discussion going on here in the thread Kahuna split off to discuss verniers and formation ops.

The push pull provides a great anchor (as you know) with the palm on the knob and the index finger on the friction lock, or the panel, or something similar (whatever technique works best to keep it all in the fingers and wrist).

In a tandem/centerline seat (3/4/8/Rocket) with a quadrant, I find my most comfortable position is with my fingertips around the vertical part of the throttle, and my thumb on the cross of the T-handle. Much of the movement is just between thumb and index finger, and the side of the palm (under the pinky) is the anchor. Similar can be done with the right hand on a side-by-side (SBS) with a quadrant, but care is needed not to bump the prop and mixture levers (just depends on how its set up and how well you can anchor). I do prefer the push-pull on a SBS.

Just one knucklehead's technique(s).

I'd like to give it a try with a tandem with a Fatboy throttle sometime, just to see how it feels! :)

Bottom line: in all the clinics I know about, you're good to go!

Cheers,
Bob
 
...snip> But I do fly with less than full throttle (fixed pitch prop...typical cruise RPM 2550 -2600).

Ah, that makes sense Ron. A FP prop is likely going to take more small throttle manipulation in various phases of a cruise-type flight, just to keep the RPM constant, or at the desired state. Not always, but the fine tuning there makes sense. And I found it nice in a Bo as well (flew a corporate-owned Bo for a bit a while back...no formation there tho ;)). It's a nice piece of gear in the right circumstances, the right mission, as Bubblehead said (just IMHO).

I think Kahuna hit the nail square here:

The more maneuvering you do, the more it comes into play. In an RV formation evaluation, with 60deg of bank and 45deg of pitch required, the vernier becomes a hindrence to precision quickly. If your doing figure 8's over Osh in Bonanzas or RV's, well it can certainly be done, and done safely by experienced pilots.

In a clinic environment, where newbees come to play and learn, the vernier is a real hindrence to the learning curve and compromises safety. We found this on many occasions years ago and banned em in the RV clinincs many of us attend.

So, can it be done? of course. But when your trying to lower risk, improve safety, and allow the learning curve of a new pilot in an RV to take place, the vernier throttle has no place in RV formation training.

As maneuvering gets more dynamic, instant response is needed. Kahuna and Team RV are the experts there, to be sure! In a training environment, if I was a safety pilot or an instructor in the plane, I'd want to know the student could make corrections no matter how sweaty the palms and fingers get (and they do), and I'd want to be able to help if needed with no hinderence. Same goes as lead...knowing there are no mechanical things in the way when 20 feet apart (or less) and closing is good...whichever side of the formation you are on!

Cheers,
Bob
 
But I do fly with less than full throttle (fixed pitch prop...typical cruise RPM 2550 -2600).
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. . . if I had my choice I would probably go non-vernier throttle and vernier mixture. Can't say if that would be a majority opinion.

Fixed pitched prop and like my vernier throttle. Really helps dial in the RPM and cruise power.
I do think the next plane will have the non-vernier just because I would probably go constant speed prop and then think the vernier does not have the advantages.
 
Another option

Here's the setup that I prefer. Since I do lots of formation and acro the quadrant mounted throttle with a wrist rest makes big or small throttle adjustments easily. The vernier controls on prop and mixture are out of the way of the throttle and unlikely to be used while in formation or doing acro yet they are great for fine tuning the prop and setting mixture LOP. FWIW, this is the setup you will likely see on many dedicated aerobatic mounts like the MX-2 and Edge-540.

This is MY preferred setup. If you like YOUR vernier throttle, well that's OK too.


paneltilt2.jpg
 
Thanks Rob, however, I have heard that for the formation groups, you must have the side or center mounted "throttle quadrant" type. That was the direction of my comment.

Mark

Mark, what bob said. There have been no bans on the use of friction throttles in rv clinics nor has there been a preferred friction vs quadrant. This issue is the twisting push button vernier throttles. A friction locking push pull is absolutely no problem at all.
 
Thanks Rob, however, I have heard that for the formation groups, you must have the side or center mounted "throttle quadrant" type. That was the direction of my comment.

I've heard this too but when you did a little deeper it seems to be peoples' confusion about what a venier throttle actually is. Some people believe that a standard push-pull throttle with a friction lock is vernier.
 
Smokey,

Been meaning to compliment you on that engine control set-up. I haven't seen that before, and after recently ferrying a Rocket for a friend, and fiddling with the standard red lever while leaning (and jones-ing for my vernier mixture), I really like what you have there. I'm sure the standard quadrant mixture becomes simple to lean with as well with use, but I like your concept a lot! Best of both worlds!

Two quick questions:

- Any pics of the wrist rest? Sounds like a great idea too.

- What, do tell, is the purpose of the q-tip in Scheck's ear (or is his ear just your q-tip holder)? :p

Happy New Year!

Cheers,
Bob

Here's the setup that I prefer. Since I do lots of formation and acro the quadrant mounted throttle with a wrist rest makes big or small throttle adjustments easily. The vernier controls on prop and mixture are out of the way of the throttle and unlikely to be used while in formation or doing acro yet they are great for fine tuning the prop and setting mixture LOP. FWIW, this is the setup you will likely see on many dedicated aerobatic mounts like the MX-2 and Edge-540.

This is MY preferred setup. If you like YOUR vernier throttle, well that's OK too.


paneltilt2.jpg
 
I really like what you have there. I'm sure the standard quadrant mixture becomes simple to lean with as well with use, but I like your concept a lot! Best of both worlds!
Happy New Year!

Cheers,
Bob

No it does not Bob. What Smokey has here is the best of the mixture control and Ive always felt the quadrant has a gross movement of mixture that does not allow for fine adjustment at all, regardless of time in use. Sure the quadrant works, but can not even come close to the fine measurement of a vernier and the mixture is the one control that is very useful for that very fine adjustment on LOP ops.

Ive never felt the need for fine adjustment of prop. Quadrant allows me to tune prop quickly and easily to the desired RPM. And in formation, there are times when I need to toss the prop all in right now which lends itself to have it on the quadrant. HOWEVER.... my case is unusual as I uaually run 2300 in formation with the 4 bangers to dumb down my engine and keeps me from surging too much. The 4 bangers are usually all in on the prop always in formation anyway so they do not need it readily available and easily accessible. Having it on the gear tower is a slight reach.
 
Smokey,

Been meaning to compliment you on that engine control set-up. I haven't seen that before, and after recently ferrying a Rocket for a friend, and fiddling with the standard red lever while leaning (and jones-ing for my vernier mixture), I really like what you have there. I'm sure the standard quadrant mixture becomes simple to lean with as well with use, but I like your concept a lot! Best of both worlds!

Two quick questions:

- Any pics of the wrist rest? Sounds like a great idea too.

- What, do tell, is the purpose of the q-tip in Scheck's ear (or is his ear just your q-tip holder)? :p

Happy New Year!

Cheers,
Bob


Hi Bob,

The wrist rest is at the very bottom left corner of the picture. It's just little padded surface covered with leather that I rest the heel of my hand on.

I am a bit hard of hearing so the Q-tip in Shrek's ear seemed appropriate.

BTW, another benefit to the throttle/prop/mixture set up I have: Because the friction knob on a quadrant adjusts all levers with one friction knob it is sometimes difficult to have all of the levers adjusted properly; one is too loose while another is too tight. My setup eliminates that issue.
 
No it does not Bob. What Smokey has here is the best of the mixture control and Ive always felt the quadrant has a gross movement of mixture that does not allow for fine adjustment at all, regardless of time in use. Sure the quadrant works, but can not even come close to the fine measurement of a vernier and the mixture is the one control that is very useful for that very fine adjustment on LOP ops.

Ive never felt the need for fine adjustment of prop. <snip>

All makes perfect sense. On that ferry I found myself leaning way too fast and too far (up high and well back on power, so all OK, but not how I like to lean...had to "bias" my hand way back to make small moves. Vernier mixture makes it more "bob-proof"! ;)

<snip> Quadrant allows me to tune prop quickly and easily to the desired RPM. And in formation, there are times when I need to toss the prop all in right now which lends itself to have it on the quadrant. HOWEVER.... my case is unusual as I uaually run 2300 in formation with the 4 bangers to dumb down my engine and keeps me from surging too much. The 4 bangers are usually all in on the prop always in formation anyway so they do not need it readily available and easily accessible. Having it on the gear tower is a slight reach.

RPM is something I've wanted to ask you about, since I have the same motor. As a wingman I've been using 2500 RPM to allow for rapid response in both directions (acceleration and braking). As a lead, I backed it off to 2300, and had some calls for running away from wingmen on downlines with advanced angles. It seems a bit better at 2500-2600. Could be technique (always room to improve there). Is that (hi angle maneuvering) when you are pushing the prop up, or is that where you see surging with a higher RPM setting? I'm very interested in what works best, as I develop my techniques and as we get a little more dynamic in maneuvering.

And to stay near-topic...this is the area where I see vernier throttles becoming an impediment. Basic stuff, verniers OK, more maneuvering, maybe not so.

Hi Bob,

The wrist rest is at the very bottom left corner of the picture. It's just little padded surface covered with leather that I rest the heel of my hand on.

BTW, another benefit to the throttle/prop/mixture set up I have: Because the friction knob on a quadrant adjusts all levers with one friction knob it is sometimes difficult to have all of the levers adjusted properly; one is too loose while another is too tight. My setup eliminates that issue.

Both wrist/armrests look great...great idea, and thanks for the pics!

I am a bit hard of hearing so the Q-tip in Shrek's ear seemed appropriate.

What? :D

Cheers,
Bob
 
RPM is something I've wanted to ask you about, since I have the same motor. As a wingman I've been using 2500 RPM to allow for rapid response in both directions (acceleration and braking). As a lead, I backed it off to 2300, and had some calls for running away from wingmen on downlines with advanced angles. It seems a bit better at 2500-2600. Could be technique (always room to improve there). Is that (hi angle maneuvering) when you are pushing the prop up, or is that where you see surging with a higher RPM setting? I'm very interested in what works best, as I develop my techniques and as we get a little more dynamic in maneuvering.

Cheers,
Bob

Readers, this is 6 banger formation throttle talk flying with 4 bangers.

I do toss the rpm in when needed, which is never when Im lead. In our show program, I go from lead to wingman several times and we have rejoins that are close in high G. I toss the prop in to catch up when needed. I also run heavy in the show. Fuel topped. My wingman very much like it when Im fat and heavy during aerobatics in particular. The higher wingloading provides a more stable platform for them. They can tell if Im carrying 20 or 40 or 60 gallons. They like 60. I like 40.

Yes as lead 2300 down lines you have to do more throttle management for them. And the higher RPM will help with that. Any rpm movement as lead in 6cyl(not so much in the 4 bangers) causes excessive movement for them to chase. At 2300 rpm, you really cant loose them making throttle movements. They have plenty of power when Im at that setting. For normal formation ops, lead really never moves his throttle. In our show program, mine is moving constantly. A higher than 2300 RPM and the wingman really notice it. The only maneuver I use high rpm for is the line abreast hammers. I cant get my fat butt kicked around with them at 2300. I need 2700 to do it, and even then, its a real struggle for us to be in sync. My hang time is higher. Its THE maneuver where you really see the difference in weight. I always torque over ~15deg. and its annoying. That big prop, at low speeds, high rpm, in a hammer, you just cant perform consistant nice hammers. There is not enough aileron travel and size to counter the torque kicking around. And even harder to do it(kick around) to match the lighter weight 4 bangers. As with all things airplanes, weight becomes obvious in the vertical.

As wingman, 2500 would be ok, 2600 is definately too high. At the low MP we are flying at as a wingman, high RPM and low MP means every throttle movement surges the prop and plane and is a hassle. Lower RPM's solves that problem. I fly wingman at 2300 and all is good. If your needed 2500 as wingman, your moving the throttle too much and need to settle down.

When we do air to air, I stay at 2300(trying to be fair) till Im getting beat, then I toss it all in for some advantage. I may not beat them, but they cant catch me while I run away and regroup:cool:
 
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Bob You might find this of interest for your -6

controls2.jpg


I built this using the Van's -8 rear throttle kit and a few other bits. The stock arm rest works for me as a wrist rest.

I like having the "stock" verier prop and mixture on the center console. The red vernier below the panel and ahead of the throttle is a variable door for my oil cooler. Need it to get temps up on all but the hottest days.

The little panel directly above the throttle mounts the flap switch. I can have my hand on the throttle and "thumb" the flaps. Not quite HOTAS, but gets the job done.
 
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Readers, this is 6 banger formation throttle talk flying with 4 bangers.

I do toss the rpm in when needed, which is never when Im lead. In our show program, I go from lead to wingman several times and we have rejoins that are close in high G. I toss the prop in to catch up when needed. I also run heavy in the show. Fuel topped. My wingman very much like it when Im fat and heavy during aerobatics in particular. The higher wingloading provides a more stable platform for them. They can tell if Im carrying 20 or 40 or 60 gallons. They like 60. I like 40.

Yes as lead 2300 down lines you have to do more throttle management for them. And the higher RPM will help with that. Any rpm movement as lead in 6cyl(not so much in the 4 bangers) causes excessive movement for them to chase. At 2300 rpm, you really cant loose them making throttle movements. They have plenty of power when Im at that setting. For normal formation ops, lead really never moves his throttle. In our show program, mine is moving constantly. A higher than 2300 RPM and the wingman really notice it. The only maneuver I use high rpm for is the line abreast hammers. I cant get my fat butt kicked around with them at 2300. I need 2700 to do it, and even then, its a real struggle for us to be in sync. My hang time is higher. Its THE maneuver where you really see the difference in weight. I always torque over ~15deg. and its annoying. That big prop, at low speeds, high rpm, in a hammer, you just cant perform consistant nice hammers. There is not enough aileron travel and size to counter the torque kicking around. And even harder to do it(kick around) to match the lighter weight 4 bangers. As with all things airplanes, weight becomes obvious in the vertical.

My wing loading may be a little higher with the HRII/F1 Sport-style clipped wing, but I often am light on gas, since I fly over the hill to practice, etc. I'll fill-up and run 2300, then experiment with a little light throttle modulation as lead on downlines. What you said about throttle manipulation at higher RPM makes perfect sense, and I can hear the "gimme one" calls coming if I was to try that. Some good things to try there...thanks!

As wingman, 2500 would be ok, 2600 is definately too high. At the low MP we are flying at as a wingman, high RPM and low MP means every throttle movement surges the prop and plane and is a hassle. Lower RPM's solves that problem. I fly wingman at 2300 and all is good. If your needed 2500 as wingman, your moving the throttle too much and need to settle down.

I tried 2600 as lead for the downline braking (so-so results), but will try the above technique (2300 + small throttle moves) as an alternative. 2500 as a wingman works pretty well, and gets me in faster if I'm out (almost in time for Slick not to holler at me...almost :p). Perhaps it is cheating a bit: and as 3, I'm sure a big dash to get back in leaves 4 hangin' a bit. Will work with 2300 as a way to step up technique...good stuff.

When we do air to air, I stay at 2300(trying to be fair) till Im getting beat, then I toss it all in for some advantage. I may not beat them, but they cant catch me while I run away and regroup:cool:

You play fair with guys like Widget, Subob and Smokey?!? :eek: :p

Bob You might find this of interest for your -6

I built this using the Van's -8 rear throttle kit and a few other bits. The stock arm rest works for me as a wrist rest.

I like having the "stock" verier prop and mixture on the center console. The red vernier below the panel and ahead of the throttle is a variable door for my oil cooler. Need it to get temps up on all but the hottest days.

The little panel directly above the throttle mounts the flap switch. I can have my hand on the throttle and "thumb" the flaps. Not quite HOTAS, but gets the job done.

Gary,

I've considered the left hand throttle mod, and yours looks great...but I think I'd like all the controls by one hand. Might take right-seat flying out of the game though.

Though I thought a left hand stick would be an odd feel before I bought the six, it was quickly a non-issue, including formation, acro, and ACM. In fact, now I think it might feel funny flying as left wing, looking across cockpit at lead, and having and the throttle in the left hand. Not so in a tandem, but perhaps in a side-by-side...perhaps.

I would like to see more of your oil cooler door. Is your cooler baffle-mounted or firewall-mounted. Any pics? If you want to spin off a new thread, would love to see what you've done, as I'm installing new baffles and have always run cool on oil, so it might be time to incorporate a cockpit controllable door. I know there have been other threads on it as well.

Thanks for the thoughts from both of you guys!! Really appreciate it!

Cheers,
Bob
 
I always torque over ~15deg. and its annoying. That big prop, at low speeds, high rpm, in a hammer, you just cant perform consistant nice hammers. There is not enough aileron travel and size to counter the torque kicking around.

Are you running a composite prop? Difficulty controlling hammer torque is typically associated with metal props. Unless you had full-span ailerons that extended into the propwash, more aileron wouldn't help, since they're practically dead during the pivot. Full deflection should already be at max efficiency anyway. Aside from using full right aileron, the main contributing factor to torquing is the timing of the pivot and getting in sufficient forward stick soon enough.

It took me while to learn to pivot my S-1S without torquing a little and without kicking too early. With a 76" metal prop and the stubby wings and light weight, it's very torque affected with 180 hp and full power. Waiting a second too late to pivot will cause uncontrollable torquing. Also, if you don't apply forward stick simultaneous with rudder, this can contribute to torquing. Applying rudder and then a moment later applying forward stick can cause problems. This delay will allow a slight gyroscopic pitch back to develop, which puts some positive AOA on the wings if you've flown a perfect zero AOA upline. This change in AOA will cause the plane to roll a little even if you've timed the pivot correctly and have full aileron in. Something to pay attention to. Some folks reduce power slightly during the pivot, but of course, this may affect pivot rate. This torquing can usually be fixed with technique, timing, and of course lots of repetition. Though getting a consistent perfect hammer is always a challenge regardless of the aircraft being flown.
 
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MIXTURE SETTING ?

Tried a search on the formation threads for mixture setting and this is the best result.

I fly an RV-7 from the right seat with centre push/pull throttle (friction), prop & mixture (both vernier). The engine is an Aerosport IO-360M, 180hp, parallel valve, 8.5:1. Prop is Hartzell BA CS. Basic weight 1085lb.

I am happy with 2500RPM (and the throttle) but I have been running full rich mixture because I have been chasing two IO-540s, usually below 2000ft MSL.

What mixture setting(s) do you experts use/recommend and why ?

Thanks in anticipation.
 
Well the engine does not know you are in formation. You should operate your engine prop within the manufacturers recommend power range.
If you are looking for best power, you should be leaned for best power. Generally thats in the ~100ROP range. You are C/S prop. Your leaving a lot of power on the table at 2500RPM. A LOT measured in wingman station keeping opportunity. I would know instantly if anyone of my wingman were operating with that low a HP output. Your greatest first opportunity , from your post, for more speed, is a much higher RPM.
 
Twoop! 2500 and full rich would leave me screwed on every flight. You don't want to know what kind of RPM I'm turning in order to make it happen in airshows.
 
THANKS

Thank you gentlemen,

2600 (Pmags), and leaned to 100F RofP it is.

First formation for many years - & first using a Lycoming, so I left it rich. Then others noticed deteriorating radio transmission power & readability. Fixed the radio problem by cleaning all the soot off the bent whip on the belly.

Best regards.
 
Just some personal experience with the change

When Jeanine and I built our RV-6A I had no intention of ever flying formation and we installed vernier controls for throttle, prop and mixture. For 8 years I flew it with nothing but smooth dependable performance. Then last year I made a decision to try to fly in the Pylon Racing Seminar and ultimately the Sport Class at Reno. It can be done and slower planes than mine have done it.

I decided to determine the full set of requirements and one was formation flying ability. The formation flying groups I am aware of do not allow vernier throttle controls. A lot of things had to be accomplished in the off season of the Sport Air Racing League to meet the requirements and to improve the performance of the airplane. I flew from northwest Arkansas to northern California to work with Red Hamilton to install high compression pistons and at the same time replace the vernier throttle control with a friction lock throttle control. We had bought the original from Van's but Red offered to buy the new cable from Wicks.

I knew from the part number what length I needed but the exact same length was not available from Wicks. I determined that a slightly different length would work because the cable routing was not direct and slack could be easily added or taken out of the original path. An order was placed for a cable manufactured by the same manufacturer (ACS) with a slightly different length.

When the cable arrived it looked like the same high quality cable but where the original had a threaded termination at the remote end of the cable housing (sheath) upon which nuts could be adjusted to vary the termination support position the new cable had a circumferential grove machined into the end piece of the sheath.

The support bracket that I had made for the adjustable sheath termination on the vernier was not in perfect position for the new cable slot and I had to develop a two piece bracket to mate with the slot on the sheath and a spacer to position the cable end at the correct location and angle to form a straight line connection with the throttle lever on the carburetor.

After a lot of small part detail work I got it rigged for non binding full range of motion throttle control. When we completed the engine work I did a ground test run, thorough inspection and two test flights along the coast around Fort Bragg. Then I flew home via Prescott, AZ and Amarillo, TX.

Back at home I decided to make a test flight of something I was working on but when I started the engine I could not get it back to slow idle. My immediate destination was the self service fuel pump so I started taxiing there at a higher that desired RPM. I could increase the speed of the engine but I could not slow it down to a normal idle on the ramp - I don't remember the number any more but as I recall it was well over 1000 rpm. I thought this was just some minor binding so I really pulled on the control and then it became jammed solid in one position. I knew this was a serious problem so I taxied back to the hangar to start the trouble shooting process.

I pounded on the knob to try to get it back to the panel but it was frozen solid. When I had it disconnected at the carburetor end I pulled on that end of the cable and it came loose but it would always bind at the slow speed (closed throttle) end of the travel. I removed the cable and shipped it to Wicks and asked for failure analysis and told them I would pay a reasonable price for that work. So far as I know no failure analysis was performed. Since I was not the customer that bought it I can see their reluctance to deal with me.

I needed a good friction lock throttle cable so I called Van's and ordered one with the threaded sheath termination and installed it with all of the proper rigging adjustments. It has worked smoothly and correctly for over 250 flight hours but I still had some personal adapting to do.

Where I had three parallel vernier controls I now have one friction lock and two verniers. Not a problem but early on I found myself wanting to turn the throttle control and being reminded of its proper operation when there was no response.

In July I was flying in the Mount Vernon 100 air race the day before the AirVenture Cup Race and on the first leg Gary Wilcox in his RV-7 called to announce he was passing on my right. Well I know Gary is very fast and it is not the first time he has passed me but it was disturbing to see it happening so early. He went by and he was moving. I looked at my GPS ground speed and it was down to 154 kts. How can this be? Then I saw the throttle knob was on the order of 2 inches out of the panel. You really have to lock it down not just position it and forget it like a vernier. I have experience that a couple of times since but my internal reaction to throttle changes is not to passively trust the variable friction drag to hold position - I always give the lock a little twist.

So having flown the same plane with both configurations ... It was a change I had to make to get the experience and I'm glad I did it for that reason only. Either version works fine but neither is worth the trouble of making the change unless you are forced to do it to achieve some other than performance objective.

Bob Axsom

P.S. I am not a formation pilot in spite of my training but because of my personal experience in that training I agree with the wisdom of the formation flight restriction to friction lock throttle control.

B.A.
 
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