Incompetent instructor?
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Incompetent instructor?
I had an interesting experience yesterday when doing a checkout in a PA28 warrior. Everything went great during the upper air work, but things went a bit pear shaped when we started the touch-and-goes. As soon as we are firmly on the ground I pushed the throttle full forward, removed one stage of flap (leaving 25 degrees), checked carb heat off, and lifted off. By this stage the instructor is bitching at me, telling me that I should always put flaps up before applying full power, and that you should always retract all of the flap before taking off again during a touch-and-go.
Personally I prefer to apply full power before retracting flaps, as this is what I was taught to do, and it makes sense to get the power on as soon as possible. But it's not a major issue, and if he wants me to retract flaps first of all that's not a problem.
What is a problem is what he said about the flaps. He said it was dangerous to leave any more than one stage of flap down during a touch and go, because you wouldn't get any lift. I pointed out that I had done all my previous flying on cessna 172s with electric flaps, where it is recommended that you only retract one stage of flap when on the runway, and retract the rest when you are over 200 feet - otherwise if you take off when the flaps are still retracting you could sink bank into the runway, which is generally bad. He said this was wrong, and that even in cessna 172s you would never take off with more than 10 degrees of flap during a touch-and-go, and you would normally retract all 3 stages when on the runway.
During the flight I condeded that I might have been wrong. However after checking things out it appears that the warrior handbook specifies 2 stages of flap for short-field takeoff, so clearly leaving two stages of flap during a touch-and-go isn't dangerous and will generate sufficient lift. Also, the cessna 172 POH specifies only retracting 1 stage of flap on the runway for a touch-and-go.
Now, if he had just told me that on the warrior you should always retract all the flap during a touch-and-go, or that he wanted me to do it that way, it wouldn't have bothered me. Clearly it is easy and safe to retract all the flap in one go on the warrior because it is mechanical. What bothered me (and frankly worries me) is that he gave me clearly wrong and frankly dangerous information regarding the use of flaps.
I don't think there is much use arguing with the instructor - he probably isn't going to listen to me (he didn't during the flight). Should I do anything about this? Discuss it with the CFI?
Personally I prefer to apply full power before retracting flaps, as this is what I was taught to do, and it makes sense to get the power on as soon as possible. But it's not a major issue, and if he wants me to retract flaps first of all that's not a problem.
What is a problem is what he said about the flaps. He said it was dangerous to leave any more than one stage of flap down during a touch and go, because you wouldn't get any lift. I pointed out that I had done all my previous flying on cessna 172s with electric flaps, where it is recommended that you only retract one stage of flap when on the runway, and retract the rest when you are over 200 feet - otherwise if you take off when the flaps are still retracting you could sink bank into the runway, which is generally bad. He said this was wrong, and that even in cessna 172s you would never take off with more than 10 degrees of flap during a touch-and-go, and you would normally retract all 3 stages when on the runway.
During the flight I condeded that I might have been wrong. However after checking things out it appears that the warrior handbook specifies 2 stages of flap for short-field takeoff, so clearly leaving two stages of flap during a touch-and-go isn't dangerous and will generate sufficient lift. Also, the cessna 172 POH specifies only retracting 1 stage of flap on the runway for a touch-and-go.
Now, if he had just told me that on the warrior you should always retract all the flap during a touch-and-go, or that he wanted me to do it that way, it wouldn't have bothered me. Clearly it is easy and safe to retract all the flap in one go on the warrior because it is mechanical. What bothered me (and frankly worries me) is that he gave me clearly wrong and frankly dangerous information regarding the use of flaps.
I don't think there is much use arguing with the instructor - he probably isn't going to listen to me (he didn't during the flight). Should I do anything about this? Discuss it with the CFI?
Sorry buddy...I have to agree with the instructor on this one! Flaps should be raised prior to applying full power (and placing the carb heat cold). In my eyes, the reason for this is if you have a flap failure, possibly with full flaps down, you may be able to catch it prior to applying full power and be able to abort the take off. Don't think a take off with full flaps would be a good idea! It's just a good practice to get into. It's not wrong to have 10 degrees of flap down for a short/soft field take off, in most aircraft that is what is specified, but you have to be realistic here. If you are actually going into a short field that requires a short field technique, are you really going to be doing touch and goes, other than for training purposes? The instructor is just trying to instill proper techniques so in the end you stay safe! And, I'm almost positive that in a Cherokee POH, a normal take off is performed with zero flap...so why argue this???
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Read my original post again: I don't have a problem with retracting flaps before applying power. I also don't have a problem with retracting full flaps on the warrior. What I do have a problem with is:
- The instructor saying that two stages of flap for takeoff is dangerous on both a warrior and C172 and will produce no lift. This is clearly wrong, as the warrior POH specifies two stages of flap for a short-field takeoff.
- The instructor saying that when doing a touch-and-go in a cessna 172 with electric flaps you should retract all the flap when on the runway. This is not true - it is quite normal to only retract one stage of flap, and leave two stages of flap for the takeoff. It is also potentially dangerous to retract all the flap in one go while on the runway because if you take off while the flaps are still retracting, the nose will sink and you could have a nasty surprise.
As I said, I don't mind doing things the instructor's way. What I do have a problem with is him giving clearly inaccurate and dangerous information.
- The instructor saying that two stages of flap for takeoff is dangerous on both a warrior and C172 and will produce no lift. This is clearly wrong, as the warrior POH specifies two stages of flap for a short-field takeoff.
- The instructor saying that when doing a touch-and-go in a cessna 172 with electric flaps you should retract all the flap when on the runway. This is not true - it is quite normal to only retract one stage of flap, and leave two stages of flap for the takeoff. It is also potentially dangerous to retract all the flap in one go while on the runway because if you take off while the flaps are still retracting, the nose will sink and you could have a nasty surprise.
As I said, I don't mind doing things the instructor's way. What I do have a problem with is him giving clearly inaccurate and dangerous information.
From all the 172's I've flown 1 notch of flap is the only approved takeoff flap (10 degrees)groupboard wrote:Read my original post again: I don't have a problem with retracting flaps before applying power. I also don't have a problem with retracting full flaps on the warrior. What I do have a problem with is:
- The instructor saying that two stages of flap for takeoff is dangerous on both a warrior and C172 and will produce no lift. This is clearly wrong, as the warrior POH specifies two stages of flap for a short-field takeoff.
- The instructor saying that when doing a touch-and-go in a cessna 172 with electric flaps you should retract all the flap when on the runway. This is not true - it is quite normal to only retract one stage of flap, and leave two stages of flap for the takeoff. It is also potentially dangerous to retract all the flap in one go while on the runway because if you take off while the flaps are still retracting, the nose will sink and you could have a nasty surprise.
As I said, I don't mind doing things the instructor's way. What I do have a problem with is him giving clearly inaccurate and dangerous information.

Instructors make mistakes.
Human nature makes some people defensive , particularily in this type of relationship (instructor-student)
That is what the CFI is for. If there is a problem with incorrect information, they can deal with the instructor to resolve the issue.
If not, they may be better able to explain it to you. Talk to them. It is better than simmering on the issue or ranting here.
Human nature makes some people defensive , particularily in this type of relationship (instructor-student)
That is what the CFI is for. If there is a problem with incorrect information, they can deal with the instructor to resolve the issue.
If not, they may be better able to explain it to you. Talk to them. It is better than simmering on the issue or ranting here.
OK...here is another post for you... Just dug up my C172N POH and had a little light reading...oh and look what I came across on page 4-14 of the Normal Procedures section.....
"Normal and short field takeoffs are performed with flaps up. Flap settings greater than 10 degrees are NOT approved for takeoff"
"Use of 10 degress of flaps is reserved for takeoff from soft or rough fields......"
Hmmm...I am really not sure where you are getting your info from regarding it being safe to take off in a C172 with 20 degrees of flap! So...my suggestion to you is the following...suck it up and just fully raise the flaps prior to adding power for the take off unless you are told out right that it will be a soft field takeoff with an obstacle and 10 degrees of flap is required! Is it that hard?
Sometimes instructors actually know what they are teaching....and if you were being checked out on the warrior...maybe, just maybe the instructor may have a little more experience then you do on the aircraft and also may know the aircraft and operating procedures a little more than you do... Also, I would suggest that you pull out your handy C172 POH, have a nice look in the normal procedures section and realize that you may not want to be taking off with 20 degrees of flap in the future!
"Normal and short field takeoffs are performed with flaps up. Flap settings greater than 10 degrees are NOT approved for takeoff"
"Use of 10 degress of flaps is reserved for takeoff from soft or rough fields......"
Hmmm...I am really not sure where you are getting your info from regarding it being safe to take off in a C172 with 20 degrees of flap! So...my suggestion to you is the following...suck it up and just fully raise the flaps prior to adding power for the take off unless you are told out right that it will be a soft field takeoff with an obstacle and 10 degrees of flap is required! Is it that hard?
Sometimes instructors actually know what they are teaching....and if you were being checked out on the warrior...maybe, just maybe the instructor may have a little more experience then you do on the aircraft and also may know the aircraft and operating procedures a little more than you do... Also, I would suggest that you pull out your handy C172 POH, have a nice look in the normal procedures section and realize that you may not want to be taking off with 20 degrees of flap in the future!
groupboard:
You can fly the warrior that way if you want and you're familiar with the full range of the a/c's envelope. I recall that some models approve that procedure in the POH (I don't have a PA28 POH with me right now but I know the that that procedure is approved on the PA34 and 44)
You should not, *repeat* not, take off with more than 10 degrees flap (1 stage) in a 172. The POH says don't do it. 20-30 degrees of flap in a 172 causes way to much drag and really takes a bite out of your ability to climb.
You can fly the warrior that way if you want and you're familiar with the full range of the a/c's envelope. I recall that some models approve that procedure in the POH (I don't have a PA28 POH with me right now but I know the that that procedure is approved on the PA34 and 44)
You should not, *repeat* not, take off with more than 10 degrees flap (1 stage) in a 172. The POH says don't do it. 20-30 degrees of flap in a 172 causes way to much drag and really takes a bite out of your ability to climb.
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We're talking about a touch-and-go takeoff, which is a different situation to a takeoff from standstill. As far as I know, the POH for the 172 with electric flaps states that for a touch-and-go you should only retract one stage of flap when on the ground, and retract the rest in stages when above 200 feet. I don't have the 172 POH in front of me, so I can't verify this. However it makes sense not to retract all of the flap on the ground when using electric flaps for the reason I stated in a previous post. And you will certainly get sufficient lift to be able to climb to 200 feet AGL with 2 stages of flap. Obviously you will get more lift with either one or zero stages of flap, and you would never perform a standing takeoff with more than one stage of flap, but when doing a touch-and-go with 3 stages of flap you should only ever retract one stage of flap when on the ground.
PS, as far as I know, this instructor does a lot more training on 172s than warriors, so his advice will presumably be taught to a lot of student 172 pilots.
PS, as far as I know, this instructor does a lot more training on 172s than warriors, so his advice will presumably be taught to a lot of student 172 pilots.
OK Groupboard... I am going to give you some homework seeing that you are being very stuborn here. I want you to go and find your POH...find where it is printed the arguement you are trying to back up...scan it...and then post it on this board! As far as I know, you will have a hard time finding the proper procedures for a touch and go in the POH since I really don't believe touch and go procedures are printed anywhere!
I hate to ask this, but how many hours do you have flying 172's vs. your instructor??? Maybe you will just have to accept the fact that your instructor may know somethings that you may not know due to experience!
I hate to ask this, but how many hours do you have flying 172's vs. your instructor??? Maybe you will just have to accept the fact that your instructor may know somethings that you may not know due to experience!
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FlyerGirl: I don't have a 172POH. Perhaps it doesn't mention it in the POH - I haven't seen it in the POH myself, but someone else posted in another forum saying that it is.
I only have 90 hours on a 172, and the instructor presumably has more. However I have flown with 5 other instructors in the 172 (most of whom had more experience than the instructor in question), and that is where my information comes from. It makes sense to me that it is safer to leave 2 stages of flap, but as long as you remain on the ground until the flaps are fully up it probably doesn't matter either way.
I only have 90 hours on a 172, and the instructor presumably has more. However I have flown with 5 other instructors in the 172 (most of whom had more experience than the instructor in question), and that is where my information comes from. It makes sense to me that it is safer to leave 2 stages of flap, but as long as you remain on the ground until the flaps are fully up it probably doesn't matter either way.
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Wull that ther's yer problum! Y'all don't know that flaps INCREASE lift! You don't have more lift with zero flaps, you just have less drag, induced drag that is. It is excess power that allows you to climb. With increased drag, the power required is also increased, decreasing your excess power availible, reducing the rate of climb, and bingo was his name-o.groupboard wrote:And you will certainly get sufficient lift to be able to climb to 200 feet AGL with 2 stages of flap. Obviously you will get more lift with either one or zero stages of flap, and you would never perform a standing takeoff with more than one stage of flap, but when doing a touch-and-go with 3 stages of flap you should only ever retract one stage of flap when on the ground.
It's the excess drag that's the problem, not less lift. Ever froget to put flaps up after a practice forced? Trust me when I say, you'll only do it once. Lose the drag!
Y'all com back now, ya hir!
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For a touch and go, you do the take off procedure stuff before taking off again. Flaps, mixture, carb heat, all that jazz- whatever it says in the POH. Otherwise, it's wrong, and bad form, IMHO.
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Last edited by . ._ on Tue Aug 22, 2006 3:04 pm, edited 1 time in total.
From experience I find the 172 with just 2 on board will levitate on the go when full power is set with full flaps. As the flaps retract the aircraft will bounce or the horn will sound before it climbs out.
The Warrior doesn't do this and is good to go with the 2nd notch in. I don't think the instructor should have "bitched" about it. If anything, it gets the Warrior in the air sooner and doesn't sink like a 172 when the flaps are retracted in stages.
The Warrior doesn't do this and is good to go with the 2nd notch in. I don't think the instructor should have "bitched" about it. If anything, it gets the Warrior in the air sooner and doesn't sink like a 172 when the flaps are retracted in stages.
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istp: if you do the takeoff procedure on a touch-and-go on a 172 you will let yourself into two potentially dangerous situations if you land with full flap and flick the swtich up to zero flap. First, if you takeoff again before the flaps come up then the aircraft will sink - if you're close to the ground and you don't pull the nose up, you'll be in trouble.
Second, raising the flaps increases stall speed. If the flaps are still coming up when you are off the ground, if your speed is close to the stall then you will be in the stall when the flaps come up. Very bad.
Overall, the increased drag and resultant lower lift caused by having two stages of flap is safer than trying to remove all 3 stages of flap at once on an electric flap system.
A good pilot takes on board what is said in the POH (including warnings about retracting flaps in stages, and the sink associated with raising flaps), and where the POH negelects to mention something (such as touch-and-go landings) you use your judgement and experience, as well as the input of more experienced pilots.
Second, raising the flaps increases stall speed. If the flaps are still coming up when you are off the ground, if your speed is close to the stall then you will be in the stall when the flaps come up. Very bad.
Overall, the increased drag and resultant lower lift caused by having two stages of flap is safer than trying to remove all 3 stages of flap at once on an electric flap system.
A good pilot takes on board what is said in the POH (including warnings about retracting flaps in stages, and the sink associated with raising flaps), and where the POH negelects to mention something (such as touch-and-go landings) you use your judgement and experience, as well as the input of more experienced pilots.
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Love to see that POH...Far as I know all 172's (& I've flown a lot of different models) all say 10- The instructor saying that two stages of flap for takeoff is dangerous on both a warrior and C172 and will produce no lift. This is clearly wrong, as the warrior POH specifies two stages of flap for a short-field takeoff.
BUT that aside lets talk about flaps shall we?...what do they do?...well they increase the camber of hte wing...thus increasing lift BUT also increasing DRAG....the more flaps you have the more DRAG. If you look carefuly at your 172 POH it will probably mention (unless it's an early 172 with those skinny lil POH's) that your climb is reduced by flaps. The only reason they want you to use 10 flaps is to reduce ground roll....your accual climb is reduced with flaps..It just happens that on Soft Takeoff what you save by getting off the ground is more then what you loose climbing.
So listen to what FlyerGirl said & SUCK IT UP...Your instructor has more experience then you do. Instructors are human & can make mistakes BUT first look into it, & then ask him to show you what he's talk'n about. If you still confused, ask other instructors BUT don't go around bashing your instructor when you don't know what your talk'n about
PS
In theory the drag can be
predicted by using a simple
parabolic drag assumption



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I said that the warrior POH states two stages of flap for a short-field takeoff. I never said that the 172 POH states two stages of flap for a short-field takeoff. Pay attention.Justwannafly wrote:Love to see that POH...Far as I know all 172's (& I've flown a lot of different models) all say 10- The instructor saying that two stages of flap for takeoff is dangerous on both a warrior and C172 and will produce no lift. This is clearly wrong, as the warrior POH specifies two stages of flap for a short-field takeoff.
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Yes, that is something the instructor pointed out to me. We didn't use carb heat for the landing, but I checked to make sure it was off before the takeoff. Probably not necessary on the warrior, but it's a good habit to check it anyway so that you don't forgot to do it when you fly a 172.C-GPFG wrote:Carb heat cold before power is applied on the go?
Warriors land with carb heat off so that's not an issue.
As far as students go, and the POH, sure flaps 10.
However I know for a fact we used 20 (TC approved SOP) on the 182, and the plane made it off the ground just fine. Bush flying wether in cubs or a cessna, and yes 172, the plane definitely takes off sooner with more than 10, probably somewhere in the 18/20 range, once you're at takeoff speed. In a float plane the benefits are very noticeable. Keep it in ground effect bring it to 10 and then climb out at published speeds.
As far as the overshoot side of things... at least in cessnas, I would think you want to put the power on first before pulling up your flaps! Just think; your are 5 above stall, lots of flap.... hmm... pull up flaps or add power first??
Take it one step further.. imagine you just touched down when that cow steps onto the runway. Do you waste time with your head down in the cockpit pulling flaps up (maybe pulling up all the flap in haste) and loosing momentum, or get the power on right away???
However I know for a fact we used 20 (TC approved SOP) on the 182, and the plane made it off the ground just fine. Bush flying wether in cubs or a cessna, and yes 172, the plane definitely takes off sooner with more than 10, probably somewhere in the 18/20 range, once you're at takeoff speed. In a float plane the benefits are very noticeable. Keep it in ground effect bring it to 10 and then climb out at published speeds.
As far as the overshoot side of things... at least in cessnas, I would think you want to put the power on first before pulling up your flaps! Just think; your are 5 above stall, lots of flap.... hmm... pull up flaps or add power first??
Take it one step further.. imagine you just touched down when that cow steps onto the runway. Do you waste time with your head down in the cockpit pulling flaps up (maybe pulling up all the flap in haste) and loosing momentum, or get the power on right away???
I'm sure you meant parasite drag, but otherwise basically correct. Flaps actualy increase co-efficient of lift though.mellow_pilot wrote:
Wull that ther's yer problum! Y'all don't know that flaps INCREASE lift! You don't have more lift with zero flaps, you just have less drag, induced drag that is. It is excess power that allows you to climb. With increased drag, the power required is also increased, decreasing your excess power availible, reducing the rate of climb, and bingo was his name-o.
The idea that a touch and go is not really a take-off and therefore the POH instructions for take-off do not apply is rediculous. Your on the runway, then your not. You have done a take-off.
The argument about retracting only some flaps in a C172 befor the go in a T&G because you don't want flaps still retracting once you are airborne again also is flawed. If you are doing T&G's in a 172 you (in my humbled opinion) wait until flaps are fully retracted prior to the go. If you do not have enough runway for this, stop, taxiback and takeoff again.
Every C172 POH I have seen says max 10 degrees flap for t/o (soft field / min ground run).
Don't know about Warrior, but the C140 and the six both say use 2 stages (25 degrees?) for obst clearance. Using 2 stages of flap in a T&G for these a/c I would think should be ok. If using mech flaps, why not make it easy and fully retract them though?
Agree with above statements - retract flaps first, then apply power for the go. It's not a race to get airborne.
Once you do apply full power - go throttle first, then carb heat. Throttle of course gives you the majority of power, carb heat off brings it to max.
Lastly, do not just take the word of this or any other matter of flying as gospel because it come from an internet forum. This is a dangerous practice. Read, learn, and heed your POH. Talk to a/several QFI's. Just because you read something (yes even this) on an internet forum does not make it right. (yes I see the irony here)
My thoughts, for what its worth.
Wahunga!