Update throttle
Moderators: GAHorn, Karl Towle, Bruce Fenstermacher
Update throttle
Need info and suggestions on a new throttle cable.... I drive a 1954 "B" and would like to consider a vernier cable....... Can I change without an STC or will it be one of those, more trouble than it's worth situations???
Nothing really wrong with the original door knob, existing one, just want to update it... Comments/Suggestions welcomed....
Thanks,
fansys
2521C
Nothing really wrong with the original door knob, existing one, just want to update it... Comments/Suggestions welcomed....
Thanks,
fansys
2521C
Re: Update throttle
I wouldn't call a change from the original control to a vernier an "update". I'd call it an alteration. And not a good one. But that's just my opinion.
Engine control changes using aircraft quality cable-controls are minor alterations and do not require an STC, and with your permission, I would offer further comment on your contemplated change to a vernier control.
Vernier controls work very well on fuel injected and/or turbocharged engines where small, incremental power changes are frequently made and accuracy is more important due to installations that work in conjunction with constant speed props. But they are not friendly to normally aspirated engines like ours. Here's why:
1. Power applications are locked into the vernier mode unless the entire knob is captured by the operator's hand and the central knob is held in a compressed state for the entire movement of the throttle. Any inadvertent relaxation of the operator's grip will reengage the vernier function and full power will/may be prevented unless further manipulation is made. In an emergency, such as a go-around, this can be very unfriendly and distracting. (And, even if the knob is captured and full power is requested, full control movement is not accomplished until the operator makes further efforts to "screw-in" the final movement of the vernier..... in other words, full power cannot be assured easily without manipulation.)
2. Power reductions suffer the same problem in that large power changes require special manipulation of the locking knob, and vernier operations do not provide sufficient operational control to quickly set-it-and-forget-it.
3. Vernier controls require greater operator attention to achieve the desired power setting, with resultant distraction from other duties, such as traffic watch, etc. (You'll be watching gauges and fiddling with the knob instead of setting the power and getting on with flying.)
4. Our engines do not require micrometer-like vernier controls and cannot take full advantage of the vernier feature due to the relative crudeness of our induction systems and carb.
I recall many, many flight instruction periods in which I observed students/clients twisting twisting twisting twisting then re-twisting re-twisting re-twisting re-twisting knobs until I just wanted to deliberately fail the engine so they'd stop it!
"Just set the power and leave it alone!", were my frequent thoughts. This sort of behavior never occurs in ordinary friction-throttle cockpits. (Ever notice how "real" high-performance airplanes, like recip-fighters and muti-engine models NEVER have vernier controls?)
Vernier controls were introduced in higher power applications which ordinarily provided larger magnification-order vibration which could cause friction-controls to move from selected positions. They were first offered in Beech airplanes, and the snob-factor quickly led to their adoption into high performance Cessnas. Verniers are for people who wear ascots and use cigarette holders.
But I don't really have any opinion either way....
By the way.... how are you going to attach your threaded-ended vernier control to your throttle-plate lever on your carburetor? (Hint: You are unnecessarily complicating your life.)
Engine control changes using aircraft quality cable-controls are minor alterations and do not require an STC, and with your permission, I would offer further comment on your contemplated change to a vernier control.
Vernier controls work very well on fuel injected and/or turbocharged engines where small, incremental power changes are frequently made and accuracy is more important due to installations that work in conjunction with constant speed props. But they are not friendly to normally aspirated engines like ours. Here's why:
1. Power applications are locked into the vernier mode unless the entire knob is captured by the operator's hand and the central knob is held in a compressed state for the entire movement of the throttle. Any inadvertent relaxation of the operator's grip will reengage the vernier function and full power will/may be prevented unless further manipulation is made. In an emergency, such as a go-around, this can be very unfriendly and distracting. (And, even if the knob is captured and full power is requested, full control movement is not accomplished until the operator makes further efforts to "screw-in" the final movement of the vernier..... in other words, full power cannot be assured easily without manipulation.)
2. Power reductions suffer the same problem in that large power changes require special manipulation of the locking knob, and vernier operations do not provide sufficient operational control to quickly set-it-and-forget-it.
3. Vernier controls require greater operator attention to achieve the desired power setting, with resultant distraction from other duties, such as traffic watch, etc. (You'll be watching gauges and fiddling with the knob instead of setting the power and getting on with flying.)
4. Our engines do not require micrometer-like vernier controls and cannot take full advantage of the vernier feature due to the relative crudeness of our induction systems and carb.
I recall many, many flight instruction periods in which I observed students/clients twisting twisting twisting twisting then re-twisting re-twisting re-twisting re-twisting knobs until I just wanted to deliberately fail the engine so they'd stop it!
"Just set the power and leave it alone!", were my frequent thoughts. This sort of behavior never occurs in ordinary friction-throttle cockpits. (Ever notice how "real" high-performance airplanes, like recip-fighters and muti-engine models NEVER have vernier controls?)
Vernier controls were introduced in higher power applications which ordinarily provided larger magnification-order vibration which could cause friction-controls to move from selected positions. They were first offered in Beech airplanes, and the snob-factor quickly led to their adoption into high performance Cessnas. Verniers are for people who wear ascots and use cigarette holders.
But I don't really have any opinion either way....
By the way.... how are you going to attach your threaded-ended vernier control to your throttle-plate lever on your carburetor? (Hint: You are unnecessarily complicating your life.)
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons.
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons.
Re: Update throttle
Had one of those in my current plane when I bought it. Found out that trying to push on the knob at the same time as pulling it out in a hurry is not good. Got the plane home and took the viernier out and tossed it first thing. Might have something to do with the plane being a minor project when I got it.
Re: Update throttle
Had one on my first 48 170 I didn't like it either. I'm going to need a new one some day where is the best place to get one. The normal one that is.
Tim
Re: Update throttle
http://aircraftspruce.com/menus/ap/controls.html
http://store.wagaero.com/index.php?cPath=37_107
http://univairparts.com/shopping_291765 ... Path=25_73
You can also buy the knob only to install on whatever cable assy you choose:
http://store.wagaero.com/product_info.p ... ts_id=2335
http://store.wagaero.com/index.php?cPath=37_107
http://univairparts.com/shopping_291765 ... Path=25_73
You can also buy the knob only to install on whatever cable assy you choose:
http://store.wagaero.com/product_info.p ... ts_id=2335
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons.
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons.
Re: Update throttle
I meant the best price. If anyone had bought one lately. I will look at the catalogs too, I know I'm lazy!gahorn wrote:http://aircraftspruce.com/menus/ap/controls.html
http://store.wagaero.com/index.php?cPath=37_107
http://univairparts.com/shopping_291765 ... Path=25_73
You can also buy the knob only to install on whatever cable assy you choose:
http://store.wagaero.com/product_info.p ... ts_id=2335
and McFarland
Tim
Re: Update throttle
Best prices are the ACS brand, you lazy cheapskate!
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons.
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons.
- Showboatsix
- Posts: 113
- Joined: Fri Jul 18, 2008 5:38 am
Re: Update throttle
I have and use a venier cable on the mixture, it allows better fine tuning of the mixture at cruise.
Dean
Dean
UAO, Aurora Oregon
Hanger 26
56' C-172, With Conventional Gear Conversion
S/N 28963
N6863A
Hanger 26
56' C-172, With Conventional Gear Conversion
S/N 28963
N6863A
- Curtis Brown
- Posts: 273
- Joined: Tue Apr 23, 2002 3:47 pm
Re: Update throttle
Me too Dean, I like it on the mixture control. Has big RED button in center on knob and it seems easier to dis-engage than the clip lock. I like my ascots and cigarette holder too.
Curtis
1950 A model 1256D
1950 A model 1256D
Re: Update throttle
Try the ACS 740 series with RATCHET action. They come in red. It does not require a locking clip, holds well to any position, and is incrementally adjustable. http://www.aircraftspruce.com/catalog/a ... ntrols.php
(I still don't like verniers, even on mixtures, although I admit they are not offensive in that position. It's like using a micrometer to adjust a grease pencil, with the lack of precision of our carb/induction systems. Just my opinion.)
(I still don't like verniers, even on mixtures, although I admit they are not offensive in that position. It's like using a micrometer to adjust a grease pencil, with the lack of precision of our carb/induction systems. Just my opinion.)
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons.
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons.
- flat country pilot
- Posts: 230
- Joined: Thu Mar 16, 2006 1:46 pm
Re: Update throttle
I like my "original door knob" throttle. Has cool factorNothing really wrong with the original door knob, existing one, just want to update it... Comments/Suggestions welcomed....
I do have a venier on the mixture, but you asked about the throttle.
If its not broke, don't fix it.
Bill
Flat Country Pilot
Farm Field PVT
54 C170B
Farm Field PVT
54 C170B
Re: Update throttle
I'll echo the suggestion not to try to repair a damaged or worn out throttle cable. Mine had gotten to where sometimes it was a bit difficult to operate & several airport folks suggested pulling the cable out and lubercating it. While pulling it out I saw a couple of places where the protective covering (rubber like coating) was damaged. I could not stand outside the cabin & reach in and push the throttle in I replaced it with a new one, and as often the case, wondered why I had put up with the old one for as long as I had. The new one works so well.
OLE POKEY
170C
Director:
2012-2018
170C
Director:
2012-2018
Re: Update throttle
Ascot and cigarette holder indeed!
I laughed so hard my monocle popped off!
I laughed so hard my monocle popped off!
Tracy Ake
1955 cessna 170b
sn26936
N2993D
1955 cessna 170b
sn26936
N2993D
-
- Posts: 3481
- Joined: Sat May 06, 2006 6:05 pm
Re: Update throttle
Just to give a different point of view, I have a vernier throttle on my C-170. My C-180 came from the factory with a vernier, some Bonanzas and Maules do too. I like them. It was on the 170 when I bought it in 1973 and I didn't know any better, having a grand total of about 200 hours at the time. I found it very easy to get used to and never had any panic moments where the throttle "stuck" because I didn't push the button before trying to change the throttle. I make it a habit to make throttle adjustments with two fingers behind the knob and thumb on the push button. And if for some reason you get excited and need full throttle RIGHT NOW, It will always increase if you push on it and with no throttle lock to impede the action there is no delay. Or if you choose to make fine adjustments, just turn it with two fingers.
I find it especially handy now that the plane has a digital tach and I want to make small adjustments in cruise or on approach. Sometimes a quarter of a twist is all that is needed. It is much more precise than pushing or pulling which is often accompanied by over/undershooting the desired rpm several times. And there is no lock that has to be un-locked then re-locked to change throttle position.
I use it frequently during cruise to tweak the rpm. With the digital tach you're not, as George puts it, trying to measure precisely with a grease pencil anymore. I know, it doesn't matter that much if the rpm is off a little but there is usually not much else to keep me amused in cruise and the digital tach is exact. So why not use it?
On approach it is especially handy, allowing very small precise changes to rpm in order to maintain glideslope. You don't have to distract your scan to any other guages to make the desired changes and much more desirable than trying to unlock, re-set, then re-lock a standard throttle. Its one more thing to reduce workload in actual IFR situations.
I use the ACS 740 series rachet-stop mixture control that George refers to above and it works very well.
I find it especially handy now that the plane has a digital tach and I want to make small adjustments in cruise or on approach. Sometimes a quarter of a twist is all that is needed. It is much more precise than pushing or pulling which is often accompanied by over/undershooting the desired rpm several times. And there is no lock that has to be un-locked then re-locked to change throttle position.
I use it frequently during cruise to tweak the rpm. With the digital tach you're not, as George puts it, trying to measure precisely with a grease pencil anymore. I know, it doesn't matter that much if the rpm is off a little but there is usually not much else to keep me amused in cruise and the digital tach is exact. So why not use it?
On approach it is especially handy, allowing very small precise changes to rpm in order to maintain glideslope. You don't have to distract your scan to any other guages to make the desired changes and much more desirable than trying to unlock, re-set, then re-lock a standard throttle. Its one more thing to reduce workload in actual IFR situations.
I use the ACS 740 series rachet-stop mixture control that George refers to above and it works very well.
Richard Pulley
2014-2016 TIC170A Past President
1951 170A, N1715D, s/n 20158, O-300D
Owned from 1973 to 1984.
Bought again in 2006 after 22 years.
It's not for sale!
2014-2016 TIC170A Past President
1951 170A, N1715D, s/n 20158, O-300D
Owned from 1973 to 1984.
Bought again in 2006 after 22 years.
It's not for sale!
Re: Update throttle
But if you have to suddenly RIGHT NOW reduce throttle (because a brake hanged up or a tire went flat etc. on takeoff) to avoid a ground loop.... you'd better remember to mash that center button or it's gonna take a little time to reduce to idle.hilltop170 wrote:.... And if for some reason you get excited and need full throttle RIGHT NOW, It will always increase if you push on it and with no throttle lock to impede the action there is no delay. Or if you choose to make fine adjustments, just turn it with two fingers.....
Here's a fatality partially blamed on vernier:
http://aviation-safety.net/wikibase/wiki.php?id=10052
Here's another accident:
http://www.ntsb.gov/ntsb/brief.asp?ev_id=68520&key=0
REMARKS- VERNIER TYPE THROTTLE DID NOT REDUCE THROTTLE FULLY LNDD WITH PWR ON.CUT SWITCH.ROLLED INTO BUSHES
From the formation-flying instructor at the RV-6 club :
"The 'STANDARD' is NO vernier throttle in formation training aircraft. NO EXCEPTION.
Vernier throttle is too difficult to make changes FAST. PUSH Button then pull or push throttle in. It the amount of time that it takes the pilot to do that, he just flew into another airplane or is so far out of position that it takes a lot of work to get back in. We are flying 140 to 150 mph close to another airplane. At 150 mph, you are moving 220 feet per second. That extra second needed to change the vernier throttle takes away from your concentration is DANGEROUS!
NO VERNIER throttles for newbie in any of my formation flights. NO Vernier throttle in formation training aircraft. NO exception."
Ok. I'll quit for now.
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons.
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons.