QUESTION: Throttle Quadrant vs Push/Pull

[Mooneymite]

Just depends on the numbers.  We live, or die on the numbers.

 

Edited December 16, 2016 by Mooneymite

[Marauder]

All of us don't have that enormous pistol grip thing there . . .

I often grab the throttle by the metal,piece for small adjustments. It's just right to curl my fingers around, while resting my hand below it.

If you ask me, your's look a little limp.


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[1964-M20E]

The only plane I've flown with a quadrant was an Arrow.  I don't really care much as long as it will fly.

 

On the other hand if you have a quadrant in a Mooney you definitely do not have manual gear.

[rbuck]

Hey Jeff, 

I was the opposite. I flew a Cherokee for a while and got to like the quadrant. When I bought my plane, I only considered planes with a quadrant. Mooney did quadrants starting in 1969 and stopped later into the 70s (I believe?).

Mine looks like the one above. I don't know if it's that much less precise than a Vernier. I'll take it over the push-pull rods any day. 

[carusoam]

The precision of the vernier comes from its ability to be turned 1/8, 1/4, 1/2 or a full turn.  The increase of MP is stepwise similar.

there are similar knobs that don't have the vernier part.  The precision is lost because there is no exact method of adding a small change.  Or removing the small change by turning the knob the other direction...

If you haven't used a vernier knob. You will find the quadrant and regular knobs are similar in their inexactness.  The quadrants offer the ability to grab it low (as Hank mentioned) for a different feel while adjusting.

With regular knobs, they often mention in Start procedures 'open the throttle 1/4’....   sometimes it is 'open the throttle one 1/4" '

with vernier knobs in Moonies, people like to start the engine with the throttle open for 1000rpm.  This is similar to twist the knob one turn.

That is the precision that is nice to have.

If you are setting exactly 2550 rpm, not 2560 or 2540, vernier is the only way to go.

 

Of course, if you like to push the knobs to the firewall on T/O and only back them down as you approach TPA, no precision is going to be needed with the digital throttle, mixture and RPM settings.  1,1,1... 

 

Some people have a better feel for their planes.  I need vernier knobs and digital read outs....

Best regards,

-a-

[Hank]

You're right, Anthony. My Owners Manual says "THROTTLE--Open 1/4" but my transition CFII said that was way too much, open it 1/4"! It's generally about 1/2", if I miss it I hit 1200-1300 RPM instead of an exact 1000 on crank, but so what? This time of year I like to idle at 1100-1200 for a couple of minutes anyway, to get warmed up faster.

[Hank]

1 hour ago, Marauder said:

 

If you ask me, your's look a little limp.


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It gets very excited on the takeoff roll. Come to think of it, so do I!

Edited December 16, 2016 by Hank

[Vance Harral]

1 hour ago, carusoam said:

Some people have a better feel for their planes.  I need vernier knobs and digital read outs....

Nothing wrong with verniers and digital readouts, provided they're used appropriately.  It's not so much about having a "better feel" for the airplane as it is knowing when precision is important and when it's not.  As an instructor, I occasionally see pilots with these setups fly head-down in the traffic pattern or lose their scan on an IFR approach, because they're e.g. fixated on an MP gauge that reads 15.3" which they think needs to read exactly 15.0.  In the first place, they're confusing precision with accuracy.  But more importantly, they're spending too much energy on things that aren't important in that phase of flight, to the detriment of safety.

Not saying this is something you do, carusoam, just intended as a general comment.

1 hour ago, carusoam said:

If you are setting exactly 2550 rpm, not 2560 or 2540, vernier is the only way to go.

This is a good example of precision vs. accuracy.  No piston engine tachometer is accurate to within 10 RPM, despite some tachs having 10 RPM precision.  If a digital tach reads 2550 RPM, the prop isn't actually turning exactly 2550 RPM.  So it makes no difference if it reads 2540 RPM instead, especially in a high workload situation.  This isn't something that's meaningful to "fix".

To be clear, my point isn't to disparage vernier controls or discourage precision.  It's useful and fun to set the controls as precisely as possible in cruise and try to exactly match book performance numbers, and vernier controls make that easier.  But cruise is the time to do that, when you have plenty of spare brain cycles and low probability of traffic conflicts.  When things get busy, a different approach is better.  It's the difference between "give the throttle vernier three CCW twists every 1000' in descent" (good) vs. "maintain 21.0 MP throughout the descent using the vernier throttle" (not so much).

I do have a love/hate relationship with vernier throttles, at least the common type with a push-button to disengage the vernier.  I like to be able to easily and quickly add or subtract just a tad of power in the flare when necessary.  Seems very awkward to do this with a push-button vernier throttle, but maybe that's just due to minimal time making landings in such airplanes.  My understanding is there are aftermarket friction verniers that don't have the push knob which I think would be better for throttle control, but I've never actually laid hands on one.

Edited December 16, 2016 by Vance Harral

[carusoam]

Nicely explained Vance.

I'll have to check if I can adjust the friction on mine.

The control of my C, the friction locks were adjusted each time I flew it...

With the O, I don't remember adjusting friction locks.  Could be an aging memory challenge.

I have only recently begun having a need to adjust prop RPM.  It used to be a set it and forget it 2500 rpm.

Best regards,

-a-

[Bob_Belville]

8 hours ago, Vance Harral said:

I do have a love/hate relationship with vernier throttles, at least the common type with a push-button to disengage the vernier.  I like to be able to easily and quickly add or subtract just a tad of power in the flare when necessary.  Seems very awkward to do this with a push-button vernier throttle, but maybe that's just due to minimal time making landings in such airplanes.  My understanding is there are aftermarket friction verniers that don't have the push knob which I think would be better for throttle control, but I've never actually laid hands on one.

I replaced all 3 cables last year with McFarlane. who offers a vernier throttle cable as an option. While vernier is very desirable for prop and mixture and is the standard spec,  I agree that that's a bad idea for the throttle. The throttle cable has it's own friction knob which also has advantages over the quadrant's friction lock which affects all three.  

[PTK]

I have push pull knobs, non-vernier throttle, vernier prop and mixture. I wouldn't change a thong. I'm always wot pulling back only for approach and land. 

Vernier RPM and mixture is wonderful. 

[Vance Harral]

2 hours ago, Bob_Belville said:

While vernier is very desirable for prop and mixture and is the standard spec,  I agree that that's a bad idea for the throttle.

I expect one of our turbocharged brethren will be along shortly with a different opinion.  I understand the appeal of a vernier throttle in turbo'd engines, particularly like those in the original 231 with the fixed wastegate.  In the absence of a perfect upper-deck pressure controller (and even the later -MB engine and the aftermarket Merlyn mod aren't perfect), it can be tough to avoid "bootstrapping", and the vernier throttle helps with that.  The one guy I know well and fly with regularly in a 262 conversion seems to like his vernier throttle.  As with push/pull knobs vs. throttle quadrant, I'm sure it's something you get used to relatively quickly.  I just don't have a lot of experience with them, particularly sitting in the right seat.

[cctsurf]

I switch regularly between flying my M20C with push-pull controls and a Cherokee with a quadrant.  I like them both and for different reasons.  I have many more hours with the quadrant and it took some time for me to get used to the push-pull controls, but I feel very comfortable with both now.  I'm afraid that this whole thread is pretty much a religious crusade over personal preferences.

The fact that the mooney quadrant precludes the possibility of having manual gear makes it a non-starter for me.  I love me my manual gear...  I have seriously considered redesigning the homebuilt I am building to use Al's retraction mechanism.  So simple, yet so effective.

I have mentioned elsewhere that I am hoping to change the mixture cable on my 'C, I want to move to a vernier control for the mixture.  The current control is newer, but I have yet to do what I consider a good job leaning it.  I look forward to much more granular control.