PA 28-161 Carb heat on the approach
Moderator
Thread Starter
PA 28-161 Carb heat on the approach
Apologies for an intrusion into the FIs forum since I'm not an instructor, but since I've certified a few of the aeroplanes that you ladies and gents teach in I hope that I'll be forgiven.
The following is a quote from the PA28-161 POH (at the top of page 4-15), it is referring to the approach and landing.
In my experience this is different advice to that taught by most FIs. I have a suspicion that this is not because of any superior knowledge they have about how PA28s work, but because of a read-across from Cessnas which DO suffer icing during an idle approach in appropriate conditions.
Thoughts anybody?
G
The following is a quote from the PA28-161 POH (at the top of page 4-15), it is referring to the approach and landing.
The mixture control should be kept in full "RICH" position to ensure maximum acceleration if it should be necessary to open the throttle again. Carburetor heat should not be applied unless there is an indication of carburetor icing, since the use of carburettor heat causes a reduction in power which may be critical in the case of a go-around. Full throttle operation with carburetor heat can cause detonation.
Thoughts anybody?
G
I don't want people to have to think about which aircraft type they are in and whether or not it may be prone to carb ice. Nor do I want them to be on the approach at 500 ft (with carb heat cold) and find that they can't get power when they need it because they're iced-up.
A simple way round this is always to apply carb heat as part of the pre-landing checks and to leave it on until very short finals or until a go-around is initiated. This gives the best protection against carb ice and avoids the other issues mentioned in the POH extract. The only time not to do this is when the air is VERY cold because carb heat could then move the intake air into the icing region.
HFD
A simple way round this is always to apply carb heat as part of the pre-landing checks and to leave it on until very short finals or until a go-around is initiated. This gives the best protection against carb ice and avoids the other issues mentioned in the POH extract. The only time not to do this is when the air is VERY cold because carb heat could then move the intake air into the icing region.
HFD
Why do it if it's not fun?
Join Date: Jul 2001
Location: Bournemouth
Posts: 4,779
Likes: 0
Received 0 Likes
on
0 Posts
I agree with HFD.
The normal advice is always to follow the POH. In the case of the quote you give us, though, Piper have very kindly told us the reason for the instructions they give, which enables us to use their reasoning, and vary their advice in such a way that we still satisfy the reasons behind their advice albeit in a different way.
In the quote you give, the reason given for not using carb heat is because of "bad things" (loss of power, and detonation) which can happen on the go-around. So teaching people to use carb heat on the approach, but remove it immediately before adding power on a go-around, still satisfies the reasons behind what the POH says, and creates pilots who have habits ingrained into them which will work on just about any aircraft.
FFF
--------------
The normal advice is always to follow the POH. In the case of the quote you give us, though, Piper have very kindly told us the reason for the instructions they give, which enables us to use their reasoning, and vary their advice in such a way that we still satisfy the reasons behind their advice albeit in a different way.
In the quote you give, the reason given for not using carb heat is because of "bad things" (loss of power, and detonation) which can happen on the go-around. So teaching people to use carb heat on the approach, but remove it immediately before adding power on a go-around, still satisfies the reasons behind what the POH says, and creates pilots who have habits ingrained into them which will work on just about any aircraft.
FFF
--------------
Join Date: Mar 2000
Location: U.K.
Age: 46
Posts: 3,112
Likes: 0
Received 0 Likes
on
0 Posts
Read the POH. If it says do something, then there is usually a good reason for it. If it says don't then there will be an equally good reason for not doing it.
Simple really!
I don't like teaching people a "one size fits all" method of flying. Yes there are many things that are the same on all a/c, but there are an awful lot that are totally different. Cue arguments on the "standard" spin recovery technique......
Pilots should be taught to fly that particular aircraft and have it explained why a particular machine is different from another. Follow the POH and you won't go far wrong and you certainly shouldn't end up doing anything totally stupid.
Simple really!
I don't like teaching people a "one size fits all" method of flying. Yes there are many things that are the same on all a/c, but there are an awful lot that are totally different. Cue arguments on the "standard" spin recovery technique......
Pilots should be taught to fly that particular aircraft and have it explained why a particular machine is different from another. Follow the POH and you won't go far wrong and you certainly shouldn't end up doing anything totally stupid.
SaS - absolutely correct in my view.
On our PA28s, we apply the carb heat downwind, then do the pre-landing checks, then put the carb heat back to cold where it stays for the rest of the approach.
On rolling out of the final turn, as the hand moves off the flap lever after selecting full flap, a final check is made that the carb heat is at cold.
You are far more likely to need full power for a go-around than you are to collect carb ice in the minute or so from downwind. If you think you are, then I suggest you land as the weather must be very unpleasant!
On our PA28s, we apply the carb heat downwind, then do the pre-landing checks, then put the carb heat back to cold where it stays for the rest of the approach.
On rolling out of the final turn, as the hand moves off the flap lever after selecting full flap, a final check is made that the carb heat is at cold.
You are far more likely to need full power for a go-around than you are to collect carb ice in the minute or so from downwind. If you think you are, then I suggest you land as the weather must be very unpleasant!
Join Date: Feb 2005
Location: essex
Posts: 412
Likes: 0
Received 0 Likes
on
0 Posts
Ghengis -
Strictly speaking the POH is the Gospel and I do not wish to open the "carb heat on or off debate prior to landing"
However......from my experience of sticking to the POH as a student it wasn't worth the trouble when trying to "diplomatically" advise the all knowing Instructors of the advice of the POH (The people who made the aircraft !). Can remember one instance with a very abrasive and miserable instructor where I lost my rag and told him to look in the bloody handbook !....unfortunately his answer was that he didn't give a toss what the handbook said carb heat must be on for final approach (very exasperating).
My advice to students is to get in the habit of putting it on at the end of the downwind (to allow the heat to do it's job prior to power reduction), leave it on all the way down to the ground and if you decide to go around then get rid (ala Cessna). Main reason is to stop them having to argue the toss with an instructor or worse yet an examiner (probably won't be able to enlighten all of the instructors and examiners in the UK)
Detonation may be possible but I haven't ever experienced it due to carb heat being on.
My guess is that many FI's have assumed that it should be on and haven't bothered to read the POH properly.
Hope this helps !
Strictly speaking the POH is the Gospel and I do not wish to open the "carb heat on or off debate prior to landing"
However......from my experience of sticking to the POH as a student it wasn't worth the trouble when trying to "diplomatically" advise the all knowing Instructors of the advice of the POH (The people who made the aircraft !). Can remember one instance with a very abrasive and miserable instructor where I lost my rag and told him to look in the bloody handbook !....unfortunately his answer was that he didn't give a toss what the handbook said carb heat must be on for final approach (very exasperating).
My advice to students is to get in the habit of putting it on at the end of the downwind (to allow the heat to do it's job prior to power reduction), leave it on all the way down to the ground and if you decide to go around then get rid (ala Cessna). Main reason is to stop them having to argue the toss with an instructor or worse yet an examiner (probably won't be able to enlighten all of the instructors and examiners in the UK)
Detonation may be possible but I haven't ever experienced it due to carb heat being on.
My guess is that many FI's have assumed that it should be on and haven't bothered to read the POH properly.
Hope this helps !
Join Date: May 2001
Posts: 10,815
Likes: 0
Received 0 Likes
on
0 Posts
I agree with BEagle and SaS and teach what the POH says for the aircraft being flown.
And if a student gets bollocked by an instructor/ examiner for doing whats in the POH. Thats what chirp is for. Or if you get a fail for doing what the POH says A letter to the CAA chief examiner should solve the problem. But I am sure a letter from the CAA asking why they are teaching/ examing outside the POH will be met with suitable ill humour and grace.
MJ
And if a student gets bollocked by an instructor/ examiner for doing whats in the POH. Thats what chirp is for. Or if you get a fail for doing what the POH says A letter to the CAA chief examiner should solve the problem. But I am sure a letter from the CAA asking why they are teaching/ examing outside the POH will be met with suitable ill humour and grace.
MJ
Last edited by mad_jock; 8th Nov 2005 at 19:50.
Join Date: Feb 2005
Location: essex
Posts: 412
Likes: 0
Received 0 Likes
on
0 Posts
Mad Jock
In an ideal world maybe
But life is too short for writing letters to the CAA so it's a hell of a lot easier to stick the carb heat on.
Anyway it was yours truly who pointed out this little known fact to Genghis not so long ago so I am a supporter of do what the POH say's, but if you can save yourself a lot of aggravation without endangering safety then why not
Not ideal I know but then what is.........
No sod it ! why don't we get FI's and Examiners to read the POH and do it by the book !
In an ideal world maybe
But life is too short for writing letters to the CAA so it's a hell of a lot easier to stick the carb heat on.
Anyway it was yours truly who pointed out this little known fact to Genghis not so long ago so I am a supporter of do what the POH say's, but if you can save yourself a lot of aggravation without endangering safety then why not
Not ideal I know but then what is.........
No sod it ! why don't we get FI's and Examiners to read the POH and do it by the book !
Moderator
Thread Starter
Or at-least start by having instructors read the POH and operate to it.
Follow that by having students NOT bollocked for failing to follow a POH procedure?
And then finally have everybody flying to, and using, the POH.
But what do I know, I've never been an FI, nor likely to be.
G
Follow that by having students NOT bollocked for failing to follow a POH procedure?
And then finally have everybody flying to, and using, the POH.
But what do I know, I've never been an FI, nor likely to be.
G
Join Date: May 2001
Posts: 10,815
Likes: 0
Received 0 Likes
on
0 Posts
gengis you are suffering under the belief that doing a FIC will actually impart any great skills to you in teaching flying. It makes you very good at getting various colours of white board pen all over your clothes and drawing pairs of eyes. It has very little effect on your ability to teach anything.
Unfortunatly the course presumes a level of common sense and inate ability. About 90%. The 10% added by the FIC is how to break straight and level into bits.
The actual learning how to teach someone is done with students money in the air by experence. From your previous posts I reckon your about 90% there to being a FI.
Have you thought about doing the class rating instructors course? Very cheap only 3 days and no theory pre course.
Unfortunatly the course presumes a level of common sense and inate ability. About 90%. The 10% added by the FIC is how to break straight and level into bits.
The actual learning how to teach someone is done with students money in the air by experence. From your previous posts I reckon your about 90% there to being a FI.
Have you thought about doing the class rating instructors course? Very cheap only 3 days and no theory pre course.
Moderator
Thread Starter
Have you thought about doing the class rating instructors course? Very cheap only 3 days and no theory pre course.
G
Join Date: May 2001
Posts: 10,815
Likes: 0
Received 0 Likes
on
0 Posts
It allows you to be a FI in SEPs for anything which isn't for intial license issue.
So you could do check rides, 1 hour with instructor flights, Any retraining for anyone working up for a test after being out of 2 year check. Instructor for people out of 90day check for pax carrying. People coming back from the US and needing local instruction before going solo etc etc
here is the on track web listing for it
http://www.ontrackaviation.com/CRI(SE).html
edit to add yes.
And i can put you in touch with someone who has done the course with them. And alos i believe the course hours etc will go towards a full FI if in the future they drop the CPL theory side of things. And it looks pretty easy to maintain as well. None of this flogging round the country going to seminars and the like.
And another bonus is that when ever you go places with another pilot 2 people will be able to log the hours. And alos most plane insurance will cover instructors flying them as well as the named pilots.
So you could do check rides, 1 hour with instructor flights, Any retraining for anyone working up for a test after being out of 2 year check. Instructor for people out of 90day check for pax carrying. People coming back from the US and needing local instruction before going solo etc etc
here is the on track web listing for it
http://www.ontrackaviation.com/CRI(SE).html
edit to add yes.
And i can put you in touch with someone who has done the course with them. And alos i believe the course hours etc will go towards a full FI if in the future they drop the CPL theory side of things. And it looks pretty easy to maintain as well. None of this flogging round the country going to seminars and the like.
And another bonus is that when ever you go places with another pilot 2 people will be able to log the hours. And alos most plane insurance will cover instructors flying them as well as the named pilots.
Last edited by mad_jock; 8th Nov 2005 at 19:45.
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
Our Group has always taught (and it stood me in good stead for the CPL GFT many years ago):
1. Downwind checks include - note RPM,application of full carb heat at cruise power, note RPM drop, apply carb heat for a count of 10 elephants, carb heat cold, ensure RPM returns to original value.
2. Turn base. At the point at which you wish to start the descent, apply carb heat and reduce power to achieve the rate of descent required; reduce speed to below flap limiting, apply flap as desired, adjusting power & attitude to achieve ROD & speed.
3. Retain carb heat for all the time that power is below cruise until VERY short final, apply full cold, ready for the go-around. If a go-around is initiated earlier in the approach (some muppet pulls onto the runway ahead of you) then carb heat full cold BEFORE applying power.
It may sound silly, but I speak these (and all my other checks) out loud, even solo, so I don't forget them!
The above has been good for all the 'normally' aspirated a/c I've flown, various marques of Rallye, PA28s, Cessnas, T67.
Cheers,
TheOddOne
1. Downwind checks include - note RPM,application of full carb heat at cruise power, note RPM drop, apply carb heat for a count of 10 elephants, carb heat cold, ensure RPM returns to original value.
2. Turn base. At the point at which you wish to start the descent, apply carb heat and reduce power to achieve the rate of descent required; reduce speed to below flap limiting, apply flap as desired, adjusting power & attitude to achieve ROD & speed.
3. Retain carb heat for all the time that power is below cruise until VERY short final, apply full cold, ready for the go-around. If a go-around is initiated earlier in the approach (some muppet pulls onto the runway ahead of you) then carb heat full cold BEFORE applying power.
It may sound silly, but I speak these (and all my other checks) out loud, even solo, so I don't forget them!
The above has been good for all the 'normally' aspirated a/c I've flown, various marques of Rallye, PA28s, Cessnas, T67.
Cheers,
TheOddOne
Why do it if it's not fun?
Join Date: Jul 2001
Location: Bournemouth
Posts: 4,779
Likes: 0
Received 0 Likes
on
0 Posts
Ok, it seems I may be in a minority here. But can I please turn the issue on its head for a minute?
(Italics added by me.) What indication of carburetor icing should we be looking for? The only indication I know of is a decreasing RPM. But we are told to look for this decreasing RPM at a time when we are decreasing power and then shortly afterwards decreasing speed - both of which, with a constant-pitch prop, will result in decreasing RPMs which might mask any indication of carb ice, possibly until it's too late.
As I said in my first post, the advice in the POH will always result in the aircraft being operated in the "correct" way, but is it not possible that there is more than one correct way? And, as intelligent and reasonably experienced pilots, if we are given the reasons for doing something, is it "wrong" to suggest another way of operating an aircraft which achieves the same result? Maybe in a way which is "better" suited to the environment in which we operate?
FFF
--------------
Carburetor heat should not be applied unless there is an indication of carburetor icing
As I said in my first post, the advice in the POH will always result in the aircraft being operated in the "correct" way, but is it not possible that there is more than one correct way? And, as intelligent and reasonably experienced pilots, if we are given the reasons for doing something, is it "wrong" to suggest another way of operating an aircraft which achieves the same result? Maybe in a way which is "better" suited to the environment in which we operate?
FFF
--------------
Join Date: Aug 2001
Location: United Kingdom
Posts: 301
Likes: 0
Received 0 Likes
on
0 Posts
I think the best advice was given by hugh flung_dung and flying for fun.
Yes we are all agreed that followeing the POH is the way to teach and operate realistically. And we must ALL note and remember that most engine failures it seems are due fuel starvation or suspected carb ice. If one also adds into the equation the CAA safety sense info and that excellent chart on potential carb ice conditions, one will find that on nearly ANY occasion you are approaching in a Warrior or similar, that icing COULD/MAY exist.
By selecting carbheat just incase, you are covering your arse regarding what really happens in the real world (read the AAIB bulletins) and the CAA reasoning and advice. And by ensuring you deselect carb heat either on short final or on application of full power, you have respected the POH.
From my point of view, I would rather see somebody operating to the POH with an eye for "other" outside problems that exist. Remember, the POH is written to one extreme, and it takes the wise man to read between the lines and enter into the spirit of the POH and work with it.
Someone made the point here too that they didnt agree with one size fits all etc. Well that maybe true, but you have to consider that we are teaching/refering in most cases here to the SEP(L) Class Rating. We must give the student a firm and solid grounding to "get away with it" in any SEP (L) that they are legally allowed to fly. So sometimes, people teach these techniques that are not dangerous, or opposing the POH but if ingrained, will stop the poor sod from killing themselves in something far less forgiving...Such as the good old Continental engined Cessna's/Luscombe's and the like. There is simply not enough scope/time in the PPL to train for everysingle aircraft that can be flown within the rating priviledges.
Yes we are all agreed that followeing the POH is the way to teach and operate realistically. And we must ALL note and remember that most engine failures it seems are due fuel starvation or suspected carb ice. If one also adds into the equation the CAA safety sense info and that excellent chart on potential carb ice conditions, one will find that on nearly ANY occasion you are approaching in a Warrior or similar, that icing COULD/MAY exist.
By selecting carbheat just incase, you are covering your arse regarding what really happens in the real world (read the AAIB bulletins) and the CAA reasoning and advice. And by ensuring you deselect carb heat either on short final or on application of full power, you have respected the POH.
From my point of view, I would rather see somebody operating to the POH with an eye for "other" outside problems that exist. Remember, the POH is written to one extreme, and it takes the wise man to read between the lines and enter into the spirit of the POH and work with it.
Someone made the point here too that they didnt agree with one size fits all etc. Well that maybe true, but you have to consider that we are teaching/refering in most cases here to the SEP(L) Class Rating. We must give the student a firm and solid grounding to "get away with it" in any SEP (L) that they are legally allowed to fly. So sometimes, people teach these techniques that are not dangerous, or opposing the POH but if ingrained, will stop the poor sod from killing themselves in something far less forgiving...Such as the good old Continental engined Cessna's/Luscombe's and the like. There is simply not enough scope/time in the PPL to train for everysingle aircraft that can be flown within the rating priviledges.
Join Date: Feb 2005
Location: essex
Posts: 412
Likes: 0
Received 0 Likes
on
0 Posts
Excuse me if I am wrong but I was under the impression that this forum was for professional flying instructors to discuss aspects of their profession ? It is a tad tedious to log on and see Mad Jock ranting on and slagging off instructors.
Rant by all means, but why not go elsewhere to do it ? As someone who has learned from true professionals who had tons of experience of military and civvy flying I for one definitely do not fit your perceived notion "illusion" of what flying instructors are.
Sod off and be a saddo elsewhere !
Rant by all means, but why not go elsewhere to do it ? As someone who has learned from true professionals who had tons of experience of military and civvy flying I for one definitely do not fit your perceived notion "illusion" of what flying instructors are.
Sod off and be a saddo elsewhere !
If a stude (or experienced pilot) does something that's different to what I would prefer I will ask them why they did it that way - providing it's safe, achieves the aim and they know why they're doing it then it's OK. Skinning cats and pink pussies come to mind again.
With carb heat we have to consider the impact of the alternatives during the approach.
- C/Ht on:
HFD
With carb heat we have to consider the impact of the alternatives during the approach.
- C/Ht on:
- potential detonation at high power: very damaging, the pilot is not aware it is happening, only relevant in go-around so avoided by selecting C/Ht off with full power
- risk of raising very cold air into the icing range: avoided by engagement of brain and looking at OAT gauge
- lack of air filter: only normally an issue on the ground
- reduced power available: avoided by selecting C/Ht off with full power
- risk of icing: only detected when late in the approach and power needed - no options - crash burn die
HFD
Join Date: Mar 2000
Location: U.K.
Age: 46
Posts: 3,112
Likes: 0
Received 0 Likes
on
0 Posts
We must give the student a firm and solid grounding to "get away with it" in any SEP (L) that they are legally allowed to fly.
What we need to teach is an understanding that people can't just jump into any a/c and "give it a go." Whilst the CAA have given us this catch all SEP rating, it doesn't mean that we are all competent to fly every single SEP class machine.
I hope that FI's aren't telling people methods that will just let them "get away" with anything.
We aren't just teaching the mechanics of how to push and pull flying controls and get the thing safely off the ground and back down again (though this obviously helps!), but also the mindset that ALL pilots should have. (Licence type being an irrelevance here.)
General principles are all well and good, but specifics are very important. Therefore, teach to the POH and explain why you are doing so, or why you may disagree with it and teach something different, but always use the POH as a starting point.
None of this "one size fits all" garbage.