Use of Carb Heat (merged)
Thread Starter
Join Date: Sep 2003
Location: Not NZ anymore sadly!
Age: 62
Posts: 307
Likes: 0
Received 0 Likes
on
0 Posts
Use of Carb Heat
Here's an interesting one for all.
Use of carb heat during 'stall' training.
Does it matter carb heat OFF before recovery or after?
Recover + Power + Carb Heat
Recover + Carb Heat + Power
Realising training is @ FL030
@@
Also in a go-round situation during training, shud it be firewall throttle then/as carb heat OFF, or carb heat OFF then/as firewalling throttle.
Your thoughts/training/methods?
Use of carb heat during 'stall' training.
Does it matter carb heat OFF before recovery or after?
Recover + Power + Carb Heat
Recover + Carb Heat + Power
Realising training is @ FL030
@@
Also in a go-round situation during training, shud it be firewall throttle then/as carb heat OFF, or carb heat OFF then/as firewalling throttle.
Your thoughts/training/methods?
Join Date: May 2004
Location: USA
Posts: 250
Likes: 0
Received 0 Likes
on
0 Posts
I was always taught carb heat off thru 65kts for stall training (so before stall really begins), and on finals (so usually before go around is decided) for the landing.
What makes this so urgent that you have to post it in 5 different forums?
What makes this so urgent that you have to post it in 5 different forums?
Join Date: Sep 2004
Location: Down at the sharp pointy end, where all the weather is made.
Age: 74
Posts: 1,684
Likes: 0
Received 3 Likes
on
3 Posts
Also in a go-round situation during training, shud it be firewall throttle then/as carb heat OFF, or carb heat OFF then/as firewalling throttle.
The term 'firewall' gives an impression to me of a sudden slamming of the throttle fully open. Normally aspirated engines should have the throttle advanced from idle to full power in not less than 2 seconds, to avoid a rich cut. I've witnessed an aircraft crash because of too-rapid application of power in a go-around and the subsequent rich cut.
Similar philosophy applies, I believe, in the application of power during stall recovery. You need full power ASAP. I think you get that by
a) selecting cold air
b) progressive application of power over 2 secs.
I think the above ought to be easily be accomplished whilst adjusting the attitude with the other hand.
Many a/c are placarded with a minimum time for throttle from idle to full power.
3,000' sounds a bit low for ab-initio stall training, even if you should be able to recover in a few hundred feet.
Cheers,
TheOddOne
I was always taught to put carb heat to cold before opening the throttle. My instructors said there had been cases of engines cutting out if throttled up quickly with carb heat on. Don't know if that is true but that is what I was taught.
The other solution, if throttle is next to carb heat, is as you open the throttle push the carb heat in with one of your fingers.
The other solution, if throttle is next to carb heat, is as you open the throttle push the carb heat in with one of your fingers.
Hmm, sorry, I don't think these questions are soo interesting for a lot of people in here, no offense, but this is "kindergarten stuff", although I see from your profile that you have an ATPL and that you are a pilot ?
In stall training, you turn carb heat off already when approaching the stall, typically when airspeed passes a given value depending on AC type. So when you apply full power in the recovery, the carb heat is already off.
When landing, you turn carb heat off just after turning on final. So when applying full power on goaround, carb heat is already off.
Generally in other situations, the rule is carb heat off, then full power.
In stall training, you turn carb heat off already when approaching the stall, typically when airspeed passes a given value depending on AC type. So when you apply full power in the recovery, the carb heat is already off.
When landing, you turn carb heat off just after turning on final. So when applying full power on goaround, carb heat is already off.
Generally in other situations, the rule is carb heat off, then full power.
Thread Starter
Join Date: Sep 2003
Location: Not NZ anymore sadly!
Age: 62
Posts: 307
Likes: 0
Received 0 Likes
on
0 Posts
Kindergarten
Thanks for the opinion, There's some debate amongst some of us bus drivers and airline CFI's over a current 'required teaching' from the authority. Simply wanted to gauge opinion/get thoughts.
Back to skool don't hurt anyone!
Back to skool don't hurt anyone!
Join Date: Mar 2004
Location: Gods waiting room!
Posts: 115
Likes: 0
Received 0 Likes
on
0 Posts
My understanding: Carb heat-power-recover, that way with the carb heat off, you get the max rpm from the engine. Select carb heat off in anticipation of recovery 1-2sec before. Likewise on approach at about 200ft carb heat off to anticipate a go-around.
Join Date: Jul 2000
Location: Over here but sometimes over there.
Posts: 637
Likes: 0
Received 0 Likes
on
0 Posts
I always teach a "300ft check" on final appraoch. That being 1. Carb Heat to cold. 2. Landing light checked on. 3. "Clearance" to land. 4. Runway is clear.
That way carb heat is cold in anticipation of the "go-around" and if the student later moves onto a more complex aircraft, they are used to doing a check at 300 ft which can be substituted for "Reds, Blues, Greens, Whites."
That way carb heat is cold in anticipation of the "go-around" and if the student later moves onto a more complex aircraft, they are used to doing a check at 300 ft which can be substituted for "Reds, Blues, Greens, Whites."
Muggins does carb heat on on descent. Carb Heat OFF is selected at three hunded feet or therabouts as I make a consciuos decsision that my approach is OK and I am proceeding to land.
Of Course i am a sinner, and have forgotten the thing before, but I try!
Of Course i am a sinner, and have forgotten the thing before, but I try!
The Original Whirly
Join Date: Feb 1999
Location: Belper, Derbyshire, UK
Posts: 4,326
Likes: 0
Received 0 Likes
on
0 Posts
When landing, you turn carb heat off just after turning on final. So when applying full power on goaround, carb heat is already off.
Guest
Posts: n/a
Gargleblaster
Better not instruct in an 0-200 powered C150...or an 0-300 powered C172...or any small-Continental-powered Cub, Luscombe, Jodel, etc. It is not "kindergarten stuff" at all.
Too many instructors, themselves taught in C152/Tomahawk/Pa28 types with Lycomings, have never been taught the fundamental differences in construction between Continentals (up to the 0-300) and similar-sized Lycomings. Unfortunately, it is also not part of the PPL "Technical" ground school/exam either. Therefore this information is not passed on to new students, and more fundamentally, the difference in piloting technique required to prevent engine stoppage on power application if they find themselves piloting aircraft so equipped.
You beat me by a whisker, Whirly!
Edit Quite a good thread on the subject here
When landing, you turn carb heat off just after turning on final
Too many instructors, themselves taught in C152/Tomahawk/Pa28 types with Lycomings, have never been taught the fundamental differences in construction between Continentals (up to the 0-300) and similar-sized Lycomings. Unfortunately, it is also not part of the PPL "Technical" ground school/exam either. Therefore this information is not passed on to new students, and more fundamentally, the difference in piloting technique required to prevent engine stoppage on power application if they find themselves piloting aircraft so equipped.
You beat me by a whisker, Whirly!
Edit Quite a good thread on the subject here
Join Date: Aug 2004
Location: South of the border
Posts: 401
Likes: 0
Received 0 Likes
on
0 Posts
Landing in an Islander once, cold day with temp/dew point reasonably close ie lots of moisture in the air.....
...Short finals (maybe 150-200ft), carb heats off as normal....landed and realised is was a bit quiet as both props came to a stop on the landing roll!! Some funny looks from the punters as I cranked her up again and taxi'd off as if nothing had happened.
Good lesson
...Short finals (maybe 150-200ft), carb heats off as normal....landed and realised is was a bit quiet as both props came to a stop on the landing roll!! Some funny looks from the punters as I cranked her up again and taxi'd off as if nothing had happened.
Good lesson
Join Date: May 2005
Location: Brisbane
Posts: 626
Likes: 0
Received 0 Likes
on
0 Posts
The great carb heat debate!!!
Well when you apply the common sense approach from the constructive comments here, plus do some research into accidents in the circuit area that were most likely because of carby ice you view this differently.
Dixons Cider has a good point, in the right conditions with low or nil power set, ice can be quick.
I hold carby heat until over the fence, if i am busy with the landing i.e. crosswinds etc, forget the carby heat, if you land OK, if you decide to go around the plane will still perform better than that of a static ground roll even with the heat on. try it one day you will see the performance is not that bad, sure it is less, but not that much.
When you think about reducing power for decent, crosswind or where ever, pull the heat then pull the power, and leave it until you are sure you can complete the landing, then put it in. If its too busy, complete the landing and don't worry. If you need to go around the little lost will hardly be a problem. At least this gives better performance than the ice bucket you might have otherwise.
J
Well when you apply the common sense approach from the constructive comments here, plus do some research into accidents in the circuit area that were most likely because of carby ice you view this differently.
Dixons Cider has a good point, in the right conditions with low or nil power set, ice can be quick.
I hold carby heat until over the fence, if i am busy with the landing i.e. crosswinds etc, forget the carby heat, if you land OK, if you decide to go around the plane will still perform better than that of a static ground roll even with the heat on. try it one day you will see the performance is not that bad, sure it is less, but not that much.
When you think about reducing power for decent, crosswind or where ever, pull the heat then pull the power, and leave it until you are sure you can complete the landing, then put it in. If its too busy, complete the landing and don't worry. If you need to go around the little lost will hardly be a problem. At least this gives better performance than the ice bucket you might have otherwise.
J
Moderator
You could always read the POH and see what it says.
For example, you shouldn't firewall the throttle in a Tomahawk with the carby heat hot, you can get a lean cut as there is no accelerator pump. So I teach to check for ice on downwind and then leave well alone (as per POH)
Just another point, it's been a long time since I had the pleasure of flying an Islander, (I no longer have that kind of upper body strength.....) but I could have sworn it was fuel injected........?
For example, you shouldn't firewall the throttle in a Tomahawk with the carby heat hot, you can get a lean cut as there is no accelerator pump. So I teach to check for ice on downwind and then leave well alone (as per POH)
Just another point, it's been a long time since I had the pleasure of flying an Islander, (I no longer have that kind of upper body strength.....) but I could have sworn it was fuel injected........?
Join Date: Nov 2003
Location: notts
Posts: 636
Likes: 0
Received 0 Likes
on
0 Posts
Icing
Well it must be type dependant or be directly relative to the purpose of the excersize.
We teach, apply the Carb Heat on Base Leg prior to reducing power and set cold at 300ft prior to landing or 'touch and go' together with a speed check, runway clear etc. On stall training the students learns to apply heat at the time of applying power for the recovery simply because we believe thay should have that skill in the event a recovery is ever undertaken in anger at low level, during the approach, when heat will be applied, without getting finger tied.
When hot air is applied the fuel mixture is enriched and therefore the use of heat must be related to the fact that it could lead to a rich cut due to plug fowling. A balance needs to be drawn. The Continental is prone to icing more than the Lycoming but the Lycoming is more prone to running rich.
This cannot be a silly question that has been raised. Thank you for doing so.
We teach, apply the Carb Heat on Base Leg prior to reducing power and set cold at 300ft prior to landing or 'touch and go' together with a speed check, runway clear etc. On stall training the students learns to apply heat at the time of applying power for the recovery simply because we believe thay should have that skill in the event a recovery is ever undertaken in anger at low level, during the approach, when heat will be applied, without getting finger tied.
When hot air is applied the fuel mixture is enriched and therefore the use of heat must be related to the fact that it could lead to a rich cut due to plug fowling. A balance needs to be drawn. The Continental is prone to icing more than the Lycoming but the Lycoming is more prone to running rich.
This cannot be a silly question that has been raised. Thank you for doing so.
Grandpa Aerotart
Ahhhh...carb heat...don't got it my Bonanza...but seem to remember arriving back at Narabri in the dark in VH-GIL. To put some context to GIL it was a fast back C150...Gilgandra Aeroclub's first all metal tariner...for you youngters...that's a mid 1950s C150
Well we,...one of my students (I was a 270 hr grade 2 1/2 Instructor...had travelled that morning to...ummm...oh yeah...Coonabarabran, with namoi Aeroclub Pres in his almost as ancient 172, to pick up this piece of crap 150...'cause my student, a Policemen from Mungandi, was thinking about buying said aviation device....well I think we got dropped off at Coooonabarabran at about 0700...that's in the morning
...and we fecked off in this Fastback 150 for a days sorta toooling around...ssee if he really wanted the fecking thing...and after tooling around a fairly huge section of SW QLD and NW NSW we arrived back at Narrabri...we had landed on some highway somewhere and filled the tanks at a road side servo...anyway...it ws fairly fecking dark...and winter time..so fairly fecking cold....and the engine stopped on finals so we landed...and pondered why we couldn't taxi...then I thought about carby ice..so we tried to start it and it did...so we taxed in and the CFI...Glen (Opps edit!) was his name....well he sorta shook his head in...dismay maybe?...as we fronted up to the bar for this really big pissup///sorta like tonight really....anyway all was forgiven by dawn 'cause this crop duster topped us with mo visible effeort upon his part...editted....even pished what followed..while true was inappropriate
..somethings best left in the memorybanks
Well we,...one of my students (I was a 270 hr grade 2 1/2 Instructor...had travelled that morning to...ummm...oh yeah...Coonabarabran, with namoi Aeroclub Pres in his almost as ancient 172, to pick up this piece of crap 150...'cause my student, a Policemen from Mungandi, was thinking about buying said aviation device....well I think we got dropped off at Coooonabarabran at about 0700...that's in the morning
...and we fecked off in this Fastback 150 for a days sorta toooling around...ssee if he really wanted the fecking thing...and after tooling around a fairly huge section of SW QLD and NW NSW we arrived back at Narrabri...we had landed on some highway somewhere and filled the tanks at a road side servo...anyway...it ws fairly fecking dark...and winter time..so fairly fecking cold....and the engine stopped on finals so we landed...and pondered why we couldn't taxi...then I thought about carby ice..so we tried to start it and it did...so we taxed in and the CFI...Glen (Opps edit!) was his name....well he sorta shook his head in...dismay maybe?...as we fronted up to the bar for this really big pissup///sorta like tonight really....anyway all was forgiven by dawn 'cause this crop duster topped us with mo visible effeort upon his part...editted....even pished what followed..while true was inappropriate ..somethings best left in the memorybanks
Last edited by Chimbu chuckles; 6th Jul 2005 at 16:22.