Throttle detent (?)

[MooneyNoob]

I fly an m20k 231 with a vernier throttle.   If you've ever flown a turbo, you know you're not supposed to just firewall the throttle on take-off or you could over-boost the engine.   So that presents a problem I recently experienced and I wonder if anyone knows of a solution:

I was doing touch-and-goes on a relatively short field, which means a lot has to happen on touch-down to prep for the takeoff.  On one of the orbits, I found myself not climbing very well.   It took a scan of the situation to realize that I hadn't advanced the throttle enough and was low and slow.  I know eventually I will get this down to an automatic process and will know how much to advance the throttle "by feel" bit in the middle of a busy phase of flight, that seems like a risky thing to count on. So...

Does anyone know if there is any widget or technique to create a tangible detent (a notch you can feel) in the throttle travel so that you can set that detent about where you need it to hit take-off power (at least for sea level) without over-boosting.    And then you could push past the notch if you wanted to, but at least you'd have the tactile feedback.

Anyone hear of anything like this?

Edited April 5, 2022 by MooneyNoob

[Hank]

The only detent that I'm aware of has a sensor to check gear down when the throttle is reduced to near-landing settings. Don't think I'd mess with that . . . .

[A64Pilot]

Your finger, seriously. Point it towards the instrument panel and it will tell you where the throttle is without looking.

My finger on my left hand was feedback for a helicopter collective

[kortopates]

No, haven't. But I think most of use a finger reaching over the control to touch the end at the approximate redline. However the first step is only push it in about half before really slowing down to add the additional final amount of MAP since MAP really goes up fast during the final third control throttle movement. Remember too as your applying the final throttle you need to match power with some right rudder to stay on center line.

But personally, and just my opinion,  I wouldn't do Touch and goes till I got well practiced and accomplished at doing all this as full stops landings. As an owner, you're not paying a Hobbs meter anymore for actual time like a rental, only tach time for maintenance which does not add up taxing back; so what the rush. Take your time and complete every landing holding the nose wheel off as long as possible. Then take your time reconfiguring the aircraft for takeoff. When you really feel the need, consider the Stop and Go's instead; all you need is a long enough runway to stop and reconfigure before taking off again and much easier to avoid messing up. 

As an instructor I don't do touch and goes ever. After all we're doing all kinds of takeoff and landings to "ACS standards" including flaps less /partial flaps and go arounds /balked landings. If you fly with us at a MAPA PPP we don't do touch and goes and ditto for ABS Bonanza Pilot proficiency programs.

Lastly this won't help, but since you said "If you've ever flown a turbo" you should realize this isn't an issue with all turbo's - just those without an automatic hydraulic wastegate; such as the fixed bolt wastegate in the original 231 (also used on Turbo Arrows and the Piper Turbo Aztec) as well as the popular Merlin upgrade adding a manual pneumatic wastegate. But with an automatic hydraulic wastegate used in full turbo installations including my 252/Encore and all later Mooney's, you simply push in full throttle (slowly) just like a NA aircraft. 

[N201MKTurbo]

I personally hate vernier throttles. Spinning them is too slow and you cannot hold the button in and brace your hand on the panel. In turbulence it is almost impossible to do a non-spin throttle change. I think they are dangerous. I wouldn't do touch and go's with a vernier throttle. The strange thing is I find them mostly on 231s which is the worst place for them because you cannot accurately advance the throttle to full power except for spinning it. I don't know what people are trying to accomplish with a vernier throttle, I can set MP to within a 1/10 of an inch without a vernier.

[ArtVandelay]

I personally hate vernier throttles. Spinning them is too slow and you cannot hold the button in and brace your hand on the panel. In turbulence it is almost impossible to do a non-spin throttle change. I think they are dangerous. I wouldn't do touch and go's with a vernier throttle. The strange thing is I find them mostly on 231s which is the worst place for them because you cannot accurately advance the throttle to full power except for spinning it. I don't know what people are trying to accomplish with a vernier throttle, I can set MP to within a 1/10 of an inch without a vernier.

My throttle has vernier but no button…best of both worlds…but I don’t use the vernier that much.

[Tom 4536]

7 minutes ago, N201MKTurbo said:

I personally hate vernier throttles. Spinning them is too slow and you cannot hold the button in and brace your hand on the panel. In turbulence it is almost impossible to do a non-spin throttle change. I think they are dangerous. I wouldn't do touch and go's with a vernier throttle. The strange thing is I find them mostly on 231s which is the worst place for them because you cannot accurately advance the throttle to full power except for spinning it. I don't know what people are trying to accomplish with a vernier throttle, I can set MP to within a 1/10 of an inch without a vernier.

My 1979 231 has a McFarlan vernier throttle that does not have a center button. My prop & mixture do have a button. I do not use the throttle's vernier during takeoff.

[MooneyNoob]

How much does it cost to add an automatic wastegate to a m20K 231?  Is it worth it?

[StevenL757]

44 minutes ago, kortopates said:

But personally, and just my opinion,  I wouldn't do Touch and goes till I got well practiced and accomplished at doing all this as full stops landings. As an owner, you're not paying a Hobbs meter anymore for actual time like a rental, only tach time for maintenance which does not add up taxing back; so what the rush. Take your time and complete every landing holding the nose wheel off as long as possible. Then take your time reconfiguring the aircraft for takeoff. When you really feel the need, consider the Stop and Go's instead; all you need is a long enough runway to stop and reconfigure before taking off again and much easier to avoid messing up. 

Completely agree.  Additionally, T&Gs are not an "airline maneuver"...whether that's your career/intended career, or not.  Spend more time on the full stop/taxi back/reconfigure for takeoff, and subsequent departure.  Then spend time on missed approaches.

Just an editorial comment, but my guess is that a fair amount of us likely treat our approaches as landings, and give little thought to the flow of what to do if you need to go missed.  Landings are a luxury.  If we spent more time on missed approach proficiency and go-arounds (thereby reducing our levels of task saturation), rather than touch and gos, we would likely see fewer incidents and accidents in the approach-to-landing, landing, and departure phases.

[47U]

1 hour ago, MooneyNoob said:

Does anyone know if there is any widget or technique to create a tangible detent

If you have an engine monitor, does it have individual limits you can set to alert you when you’ve hit the target MP?  Either an annunciator light on the panel or an audible alarm in the headset, or both?  EI sells a voice annunciator box that connects to their engine monitors, and some others if it drives a horn or a light when the preset value is exceeded.

[Hank]

I do touch and goes, but even in my fairly simple C model, my limit is 5000'--any shorter, I stop and taxi back. Runway disappears quickly while raising flaps and retrimming, and I rarely slow below 50.

[kortopates]

43 minutes ago, MooneyNoob said:

How much does it cost to add an automatic wastegate to a m20K 231?  Is it worth it?

Years ago there was a STC to retrofit the -MB or 252 engine and cowling onto  231 to make it a 12V 252 called the 261 or 262 depending on whom did it. But its no longer possible - making the 261/262 the best of the 231's.

These days you can only trade up to either an -MB equipped 231 (261/262) or to a 252 which also allows conversion to -SB Encore to gain an 230lb max gross weight increase or straight to the Encore with 3130 max gross wt..

If you don't already have the Merlin pneumatic wastegate it's affordable and well worth it. Its still a manual wastegate but raises the GB/LB's critical altitude from approx ~15,500' to around 22K (from memory). 

 

[Mooney 217RN]

Personally, I find the vernier controls to be cumbersome, especially the throttle.  My old E Model had levers, like a throttle quadrant.  I loved it.  My Ovation has the verniers.  The nice thing about them is that you can really dial in precisely the controls.  I could do so just as well with the levers on my E Model.

As for touch & go's in a Mooney - no thank you.  it may take a little more effort, but taxi back and make each landing full stop.  T & G's are horribly tough on an engine, and you need to reconfigure for departure.  I know some people will say just do the T & G without reconfiguring, as the down flaps will offset the nose up trim.  I've done that, don't like it.

My first Mooney flight was in an E model while I was in flight training.  It had the johnson bar gear and flaps.  The flight school made it very clear - no T & G's were permitted in the Mooney.

[A64Pilot]

I love vernier throttles, Maules come with them and at first it took a little getting used to, but you can use your finger on a vernier throttle, just use the palm of your hand to push the button in and it’s automatic, if your using your thumb you will never come to like it, just shove the thing with your palm as you push it unlocks.

If you think you may ever be Turbine bound, it’s not just boost you have to watch with a turbine, it’s torque, ITT, and Ng speed, although usually it’s torque at low altitude, but a good turbine will blow WAY past limits if your not careful.

Maybe your not ready for T&G’s yet, I don’t know you, but it’s my opinion that you should be proficient in them, they are a sort of balked landing / go around.

Not sure what Airliners have to do with anything but I’ve seen them doing T&G’s. Drive by NAS Jax and watch the 737’s in the pattern doing T&G’s

[A64Pilot]

9 minutes ago, Mooney 217RN said:

Personally, I find the vernier controls to be cumbersome, especially the throttle.  My old E Model had levers, like a throttle quadrant.  I loved it.  My Ovation has the verniers.  The nice thing about them is that you can really dial in precisely the controls.  I could do so just as well with the levers on my E Model.

As for touch & go's in a Mooney - no thank you.  it may take a little more effort, but taxi back and make each landing full stop.  T & G's are horribly tough on an engine, and you need to reconfigure for departure.  I know some people will say just do the T & G without reconfiguring, as the down flaps will offset the nose up trim.  I've done that, don't like it.

My first Mooney flight was in an E model while I was in flight training.  It had the johnson bar gear and flaps.  The flight school made it very clear - no T & G's were permitted in the Mooney.

Explain please how it’s tough on the engine, and why is it you think you have to reconfigure? If you haven’t practiced it, what’s your plan when some numbskull does a runway incursion on you, or some animal? You need to be comfortable with going immediately if the need arises

[N201MKTurbo]

I was at Pueblo CO once and watched a 737 do about 5 touch and go's.

I think they were doing the same as us, trying to save gas. 

For those with the buttonless vernier, I agree that would be nice. The ones I hate are the ones with the button.

[Mooney 217RN]

54 minutes ago, A64Pilot said:

Explain please how it’s tough on the engine, and why is it you think you have to reconfigure? If you haven’t practiced it, what’s your plan when some numbskull does a runway incursion on you, or some animal? You need to be comfortable with going immediately if the need arises

I've been told it is very tough on an engine to do T & G's by many an A&P/IA with heat being a primary concern in a tightly cowled aircraft.  Going around is something you just have to do, so you do need to be prepared to go around.  But to intentionally do T & G's in a complex/high performance aircraft isn't the brightest thing in the world.  I often will ask the tower for the option, reconfigure on roll out with a checklist, and takeoff again.  That's a lot different than a T & G.  Full disclosure - I am based at a high altitude field, and the DA is part of the issue for flight safety AND engine cooling.  I am also familiar with another airport where T & G's are prohibited due to runway length (2,600').  Pick your poison; I have done T & G's in my Mooney, just choose not to do so regularly.

[Mooney 217RN]

4 minutes ago, N201MKTurbo said:

I was at Pueblo CO once and watched a 737 do about 5 touch and go's.

I think they were doing the same as us, trying to save gas. 

For those with the buttonless vernier, I agree that would be nice. The ones I hate are the ones with the button.

I've been at KOA watching KC-135's doing T & G's.

[A64Pilot]

There should be no heat concern with a T&G, if anything the engine is cooler than in cruise as it’s been in a low power descent, and mixture is at full rich. 

You have what about a min and a half at full throttle until your at pattern altitude? 30 sec for T/O and a one min climb at 1000 ft per min. 

Contrast that to a normal takeoff and 5 min of climb, your hotter then.

In my opinion you should be comfortable with any normal maneuver the aircraft is certified to do, one day I promise you will have to do a T&G, you may call it a go around, last one I had to do was due to deer on the runway just after dark landing at Panacea Fl to eat seafood. I’ve also had a mower decide to cross the runway in front of me too in Albany Ga, Mower as in large farm tractor, deer saw me but just stood there looking, mower driver never did

[Hank]

1 hour ago, Mooney 217RN said:

I often will ask the tower for the option, reconfigure on roll out with a checklist, and takeoff again.  That's a lot different than a T & G. 

Sounds just like the many TnGs I did with my CFII in training. 

What do you mean by Touch n Go? I had one CFI on a flight review, because he didn't like TnG, he challenged me to set the mains on the runway, keep the nose up and takeoff without the nose touching (because then it wasn't a touch n go) (?). As a 100-hour pilot with about 40 hours in my C, it was not difficult to do.

[Utah20Gflyer]

Given an adequately long runway it's seems perfectly reasonable to do touch and goes.  I do them all the time, likely hundreds of them just this year. Once the nose gear is down, carb heat off,  flaps, nose down trim, full power. Goes pretty quick.  At least it does in a G model.  

As for too much heat I would strongly disagree.  I find that my engine runs the hottest on my first take off.   On touch and goes my engine easily runs 20-40 degrees cooler in the climb.  I suspect this is because I'm rolling down the runway at idle power doing approximately 50 mph while I quickly reconfigure.   The time at full power to go from 50 to 65 when I rotate is only seconds, then only a few more seconds and I'm at 80 maybe 10 more seconds and I'm at 100.   I think it's the 0 to 50 at full power that builds up the heat in the engine that can be difficult to get rid of 30 -60 seconds later.  

[carusoam]

Let’s see if we can summarize a few things…

There we’re a few things that probably didn’t get explained very well…

1) TC’d engines have a variety of MP controllers for them… the earlier M20Ks didn’t get the good one, or an intercooler…

2) The more simple the controller, the more work it is for the pilot to get used to…

3) TnGs put you closer to a GU landing than any other type of landing… highly NOT recommended for time or fuel saving purposes… GUs lead to higher insurance costs for everyone… there is probably one a week around here… don’t be that guy… hold off on being that guy for as long as possible….

4) Distractions, aka brain farts… are common when the brain gets overloaded…

5) If you want to tax the brain… do a few TnGs….   increase your pattern speed until you can’t finish the GUMPS check… then rely on your memory and how you feel about the gear being down….

6) If you are struggling with being the MP controller while doing TnGs… and looking for a solution…

7) The Merlin waste gate gets you the most talented solution available….

8) There is no throttle detent… because it would always be in the wrong place… and somebody would use it incorrectly believing it had a meaning…

9) Somebody gave you a finger… to know how far the throttle has been pushed in… use it… get lots of practice…

10) Recognize… you are not part of a two person crew…

11) You aren’t flying a Mooney simulator…

12) You aren’t flying a Mooney for a living…

13) It is safe to say… TnGs are a bad idea until the stress of learning/getting used to T he throttle control is out of the way…

14) Verniers are great for sneaking up on the final set point, and stepping up near the final set point in whole and half turns…

15) Keep track of all the simple errors that occur during multiple trips around the pattern…

Count everything… even skipping a simple step in the second gumps check…

16) If you don’t see a green light on the panel… the plane has not authorized you to land…

17) Summary… there is no throttle detent for getting into the area of Max MP… just because.

18) The vernier throttle works really well for setting distance from the end of travel…. Perfect for low power settings…

19) It would do the same at the high end… but, unfortunately you would over boost before getting back to your desired setting…

20) About that temperature control and TnGs… that doesn’t even make technical sense… go back to whoever recommended that and ask for a clearer explanation…

The whole point of Transition Training… is to get exposed to what works, how it works, why it works… and the different ways available to make it work…

The more Turbo Mooney Experience your  trainer has… the tougher questions you can ask them ….   
 

Review twice… the stuff written by that guy Kortopates above…. He flys an M20K, has a background in flying and maintenance, and knows turbo engine ops at the highest level…

 

PP summary only, let me know what I missed…

Go MS!

Best regards,

-a-

[Will.iam]

5 hours ago, A64Pilot said:

I love vernier throttles, Maules come with them and at first it took a little getting used to, but you can use your finger on a vernier throttle, just use the palm of your hand to push the button in and it’s automatic, if your using your thumb you will never come to like it, just shove the thing with your palm as you push it unlocks.

If you think you may ever be Turbine bound, it’s not just boost you have to watch with a turbine, it’s torque, ITT, and Ng speed, although usually it’s torque at low altitude, but a good turbine will blow WAY past limits if your not careful.

Maybe your not ready for T&G’s yet, I don’t know you, but it’s my opinion that you should be proficient in them, they are a sort of balked landing / go around.

Not sure what Airliners have to do with anything but I’ve seen them doing T&G’s. Drive by NAS Jax and watch the 737’s in the pattern doing T&G’s

The military has a certain number of approaches missed approaches and landings and takeoffs per every 6 months. We used to call them beans but in the tanker we has to get 18 approaches 6 go arounds and 24 landings IIRC every 6 months. If we all did full stop taxi backs there would not be enough time in 6 months to get everybody’s bean done. We even had a sortie called an m10 which was 3 hours of beating the pattern up doing loc, ils, vor, vis traffic patterns and simulated engine failures on takeoff and landing and go-arounds. When we did checkrides it was the easiest checkrides in my career as we had already practiced everything every month before the check. 
airlines have to worry about profit so much cheaper to check in a simulator than in the plane but i got to do three bounces (touch & goes) in a DC-8 as they did not have the simulator time available and there was a spare aircraft on the ramp that day so we got to do them in the aircraft even though it was more expensive, company needed those new FO asap. 

[carusoam]

9 hours ago, MooneyNoob said:

1) I fly an m20k 231 with a vernier throttle.  (Good place to start)
 

 2) If you've ever flown a turbo.  (Not even required for this discussion)

3) you know you're not supposed to just firewall the throttle on take-off or you could over-boost the engine.   (Expect you will overboost)
 

4) So that presents a problem I recently experienced and I wonder if anyone knows of a solution:  (see all the posts above)

5) I was doing touch-and-goes on a relatively short field… (use the search function to see how often this gets discussed)

6) which means a lot has to happen on touch-down to prep for the takeoff.  (Set up for a bad situation to occur)
 

7) On one of the orbits, I found myself not climbing very well.   (This is where the bad situation occurred)
 

8) It took a scan of the situation to realize that I hadn't advanced the throttle enough and was low and slow.  (Nice recovery)
 

9) I know eventually I will get this down to an automatic process….  (Eventually?  Proper use of checklists can be helpful, a quick review prior to execution?)

10) and will know how much to advance the throttle "by feel" bit in the middle of a busy phase of flight, that seems like a risky thing to count on. So...  (kind of defined the risk issue for yourself )

11) Does anyone know if there is any widget or technique to…. (Finger and MP controller… one is more expensive than the other)

12) create a tangible detent (a notch you can feel) in the throttle travel so that you can set that detent about where you need it to hit take-off power (at least for sea level) without over-boosting.    And then you could push past.  the notch if you wanted to, but at least you'd have the tactile feedback.  (Even a simple idea connected to an airplane’s controls… goes the STC route…. Experimenting in this area can lead to a simple throttle failure)

13) Anyone hear of anything like this?  (Yes, many people have given you some valid feed back…)

Noob, you have done a great job of covering the details…

Well asked question!

See the 13 topics you covered… the bold responses after each one are summaries from reading MS a lot…. They will get you further in your journey… but not exactly answer your questions…

Click on the expand button to see them all…

Best regards,

-a-