What I say is true. Vfe is not 115, it's 90. The FAA allows the manufacturer to define additional operating ranges (which your 10 degrees @ 115 is) but it is NOT Vfe.
How does flaps range and partial flaps work?
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What I say is true. Vfe is not 115, it's 90. The FAA allows the manufacturer to define additional operating ranges (which your 10 degrees @ 115 is) but it is NOT Vfe.
All I can say is that the POH declares 115 to be Vfe. I posted a pic above.
The ambiguity and argument stems from the FAR 1 definition of Vfe:
"Vfe means maximum flap extension speed."
Some people read that to mean the speed at which you can extend maximum flaps.
The definition could have been better written.
SkyDog58
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Canis Non Grata
The word maximum refers to your speed, not your flap position.
Correct, however the definition as written leaves it wide open for misinterpretation.
exncsurfer
Pattern Altitude
Your picture shows Vfe to be 115 for up to 10 degrees only, and also Vfe 90 at 10 degrees to 30 degrees:
They used 10 twice, I would assume they meant 0-10 for 115 kias and >10-30 for 90 kias
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SkyDog58
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Not really. Vfe stands for maximum flaps extended speed. So it is the max speed you can fly with flaps extended. Whether flaps are extended 1 degree or 45 degrees, they are still extended.
Now you can have a different Vfe for different degrees of extension as in the picture that was posted of a POH above and also in the picture of the 172 flap handle. Still, those are still Vfe. In those instances as has already been mentioned, the different speeds/flap positions will be in the POH and also next to the flap lever. Unfortunately they are not usually on the airspeed indicator which is where I believe the confusion arises in many minds as they equate Vfe merely with the top of the white arc for all flap positions. Of course, operating on that premise will keep you well within the operating limitations of the flaps which is not necessarily a bad thing but it is perfectly acceptable and legal to operate flaps above the white arc if allowed by the POH.
Your picture shows Vfe to be 115 for up to 10 degrees only, and also Vfe 90 at 10 degrees to 30 degrees:
They used 10 twice, I would assume they meant 0-10 for 115 kias and >10-30 for 90 kias
yes, exactly. Not sure what you are getting at, as I think that is what I said above.
Here's a question for y'all: Is there a difference between flap operating speed, and maximum speed with the flaps extended? In other words, do I have to slow down to the white arc before I deploy the flaps, but I can speed up after I do so as long as I stay within Vfe?
Checkout_my_Six
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I would not operate your flaps....either have them extended or extend them while outside the white arc.
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Interesting question.
I know there are retractables that have one max speed for gear operation, and another higher max speed once it's down and locked.
Don't think it applies to flaps, but it would not be unreasonable if there were cases where it did.
MAKG1
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For gear, there are transitional states while extending. In the middle of a Cessna cycle, the gear is extended further out and aft than in a locked position, and gear doors are moving. Both are supported only hydraulically during transition. Manual gear is also supported differently when not locked.
Flaps are nothing like that. With the exception of notches in Johnson bars, every flap I've used has been continuously in some legal extended state while extending.
Flaps are nothing like that. With the exception of notches in Johnson bars, every flap I've used has been continuously in some legal extended state while extending.
The White Arc represents Vfe for full flaps. If the manufacturer lists multiple Vfe points for multiple flap settings, you are restricted to that speed for that flap setting.
Taking the above example where 115 is listed as Vfe for up to 10° you can extend and operate with 10° at or below 115kts. In order to extend further, you need to get below 90kts which is where the white arc begins. If you have 20° flaps in, you should not then accelerate to a speed above 90kts again without retracting flaps to 10° or less.
no because a very loud and obnoxious warning will sound ( this means your buying that night) the PM will also have to say something ...and a FOQA "data tag" will be generated basically ratting on him..when the company gets the data download
overdrive148
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How about these flaps?
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Flaps got feet!
Checkout_my_Six
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yup....how bout that? 
How about these flaps?
overdrive148
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I'd say the correct altitude for deploying that flap is about 2 feet AGL. 
I'm not sure what airplane you are flying now, so my comments sort of vague.
First, a C-150 is a few decades old. You don't know how much strain has been put on it over the years. Fatigue must be affecting it now. I would not feel comfortable carrying a heavy load.
Second, the original engine on a lot of these older planes has been upgraded. For example, my C-172 originally had a 160 hp engine. Some had a 140 hp engine. We have upgraded to a 180 hp engine. Mine has upgraded climb capabilities and we can carry more weight than the original, but the POH shows the original limits. The new weight and balance is calculated and in the logs as well as a separate sheet somewhere in the cabin near the POH.
Third, you cannot actually believe the weight of these older machines because they have been subjected to upgrade after upgrade and not re-weighed. We re-weighed ours after the upholstery was replaced and discovered it was five pounds lighter than previously calculated.
Finally, the closer you fly to the edge of the envelope, the closer you are to danger. As a student pilot you ought to be keeping as many options open for yourself as you possibly can. Your CFI may be an old airliner captain with thousands of hours under his belt to let him get lax about the rules. Do you...
First, a C-150 is a few decades old. You don't know how much strain has been put on it over the years. Fatigue must be affecting it now. I would not feel comfortable carrying a heavy load.
Second, the original engine on a lot of these older planes has been upgraded. For example, my C-172 originally had a 160 hp engine. Some had a 140 hp engine. We have upgraded to a 180 hp engine. Mine has upgraded climb capabilities and we can carry more weight than the original, but the POH shows the original limits. The new weight and balance is calculated and in the logs as well as a separate sheet somewhere in the cabin near the POH.
Third, you cannot actually believe the weight of these older machines because they have been subjected to upgrade after upgrade and not re-weighed. We re-weighed ours after the upholstery was replaced and discovered it was five pounds lighter than previously calculated.
Finally, the closer you fly to the edge of the envelope, the closer you are to danger. As a student pilot you ought to be keeping as many options open for yourself as you possibly can. Your CFI may be an old airliner captain with thousands of hours under his belt to let him get lax about the rules. Do you...
exncsurfer
Pattern Altitude
yes, exactly. Not sure what you are getting at, as I think that is what I said above.
OK, I misunderstood you, I thought you were saying 115 was THE Vfe, for all flap ranges, you were just saying it is A listed Vfe (for 10 degrees in this case). Its kinda odd that it lists multiple Vfe's
Not really, many planes list multiple Vfe values, 2 is very typical, but bigger planes will list one for each notch.
Jim_CAK
Line Up and Wait
Thanks- I fly a 172M and have been told there is an STC out there but never looked into it. I am also not a fan of dropping them early. As others said, pulling back on the nose will quickly bleed off speed. And if you have 40 deg of flaps you can really slow it down on short final.
Yeah, remember,Vfe is Maximum, not required, speed. Fly a plane with Johnston bar flaps and you'll feel just how much strain 10-20 saves.