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dans2992
January 14th, 2013, 07:13 PM
Ok, I suspect this topic may be a bit "controversial" depending on one's preferred technique.

I fly a Comanche 260B. As far as flap use on landing, I have a few different options.

1. Use full flaps. Fly final approach at low power setting, but definitely a steeper angle than the typical 3 deg VASI on most airports I frequent.

2. Use full flaps. Follow the standard VASI approach angle with a significant amount of power all the way until starting the flare. (Dragging it in)

3. Use about 1/2 flaps and fly the standard 3 deg approach at a lower power setting.

Option 3 feels the best, but it would seem that there are undesirable things about all 3 options.

What does everyone else do?

Dan

wabower
January 14th, 2013, 07:18 PM
Your post sounds as though you think the approach and landing should be executed with a single flap setting. Is that true? If so, why?

Ok, I suspect this topic may be a bit "controversial" depending on one's preferred technique.

I fly a Comanche 260B. As far as flap use on landing, I have a few different options.

1. Use full flaps. Fly final approach at low power setting, but definitely a steeper angle than the typical 3 deg VASI on most airports I frequent.

2. Use full flaps. Follow the standard VASI approach angle with a significant amount of power all the way until starting the flare. (Dragging it in)

3. Use about 1/2 flaps and fly the standard 3 deg approach at a lower power setting.

Option 3 feels the best, but it would seem that there are undesirable things about all 3 options.

What does everyone else do?

Dan

bartmc
January 14th, 2013, 07:21 PM
1. Unless there's a compelling reason not to...i.e. crosswinds.

Fearless Tower
January 14th, 2013, 07:22 PM
Re: option 2. I have only flown the Twinkie, not a single Comanche, but do you REALLY need a significant amount of power to maintain a VASI with full flaps?

As far as your overall question, I typically select full flaps on short final in most cases.

MassPilot
January 14th, 2013, 07:24 PM
Ok, I suspect this topic may be a bit "controversial" depending on one's preferred technique.

I fly a Comanche 260B. As far as flap use on landing, I have a few different options.

1. Use full flaps. Fly final approach at low power setting, but definitely a steeper angle than the typical 3 deg VASI on most airports I frequent.

2. Use full flaps. Follow the standard VASI approach angle with a significant amount of power all the way until starting the flare. (Dragging it in)

3. Use about 1/2 flaps and fly the standard 3 deg approach at a lower power setting.

Option 3 feels the best, but it would seem that there are undesirable things about all 3 options.

What does everyone else do?

Dan

I'd go with option 1. Gives you more options if you lose the engine. I'm almost always above the PAPI or VASI until very short final and I don't see anything wrong with it. Full flaps lets you touch down at a lower speed and use less runway.

dans2992
January 14th, 2013, 07:47 PM
Changing flap setting on short final seems a bit unwise.

Wouldn't that be considered to "destabilize" the approach? (A bad thing as I was taught)

If there was an asymmetrical flap deployment, short final would not be a fun place to deal with it.

Sounds like what most are doing is full flaps, stay on the VASI, and just use whatever power is required. I don't know the exact power setting, but it does seem like a lot.

Dan

Speedy
January 14th, 2013, 07:52 PM
I fly the 180 Warrior. I've started to like landing with 2 clicks (30 degrees ?). Minimal power. Sometimes I may use full flaps on short final if Im a little fast but for the most part 2 clicks.

EdFred
January 14th, 2013, 07:53 PM
I ignore the VASI as long as it's not red/red, and fly full flaps and about 10" of MP to the numbers in my Comanche. I've never landed less than full flaps except once just to see what a 0 flap landing was going to be like.

dans2992
January 14th, 2013, 07:56 PM
BTW, I've had instructors advocate all 3 methods over the years....

Ron Levy
January 14th, 2013, 08:05 PM
Using different flap settings for the landing means different sight pictures, speeds, attitudes, and control feel. The Law of Exercise tells us that pilots who don't fly a lot (say, the typical amateur flying less than 100 hours/year) do best if they do it the same way every time. My experience as an instructor tells me that pilots who use a different flap setting for every landing don't make very good landings. So, I teach using the same set of flap settings around the pattern or through the instrument approach all the time. Typically, this means the first notch on downwind, the second notch on base, and the rest when landing is assured. Likewise, on instrument approaches, about 1/3 flaps when configuring for the approach, and full flaps when landing is assured (usually about the same place you'd be rolling out from base-to-final in the VFR pattern).

Now, there are good arguments for using full flaps every time, but that can vary between aircraft. For example, the Flight Design CTsw becomes a real express elevator down with full flaps -- 30 degrees seems to work better on that plane. You may find your aircraft also does better with something other than full flaps on normal landings, but the key to good landings is using the same setting every time, even if that isn't full flaps.

So, do what you want, but I'll bet you'll do it better if you stick with one approach.

MassPilot
January 14th, 2013, 08:07 PM
BTW, I've had instructors advocate all 3 methods over the years....

Whether or not to always use full flaps is a much debated topic. I wouldn't base your preferred method on the VASI however. My home base has a PAPI, and my CFI told me that having a two reds and two whites before short final will result in not being able to make the runway should the engine quit.

GCA319
January 14th, 2013, 08:27 PM
Changing flap setting on short final seems a bit unwise.

Wouldn't that be considered to "destabilize" the approach? (A bad thing as I was taught)

If there was an asymmetrical flap deployment, short final would not be a fun place to deal with it.

Sounds like what most are doing is full flaps, stay on the VASI, and just use whatever power is required. I don't know the exact power setting, but it does seem like a lot.

Dan
Not really. Sometimes it's unwise to put in that last notch if you are on a long final and makes alot more sense to add it on short final. BTW, some people's defintion of an "unstabilized" approach is alot different than reality..

wabower
January 14th, 2013, 08:29 PM
I owned a '64 250 for several years and agree with EF re full flaps. I can't think of a good reason other than very severe x-winds and gusts to use anything less on that slick wing that likes to stop flying all-at-once whenever it thinks it's time to do so. I had to do it once in another guy's airplane when we were low on both fuel and options, and hope it was the last time.

As to the de-stabilizing argument, it's bogus for straight-wing airplanes. The King Air B-200 SOP calls for approach flaps until landing assured, then full flaps. There's nothing destabilizing about it, as you are slowing and preparing to flare anyway.

PilotAlan
January 14th, 2013, 09:03 PM
20* flaps from long final, 30* flap when the runway's made to lower touchdown speed (less energy), shorten the transition from flying to rolling, and shorten the rollout.

Don't see the point of full flaps on long final then adding power to overcome the added drag. Add the drag when it's time to land.

comanchepilot
January 14th, 2013, 09:20 PM
I always use a higher angle - 3.5 -4.0 or so - always have - allows a better sight pic, steeper angle, and more options since you can easily then slip it in if needed against a cross wind with no power by simply starting a little later and maintaining the sight photo . . .

I have a 260C.

That said - I'm not full flaps til I'm final - the thing you can not do without significant experience in the Comanche is play the speed game - you NEED to be on speed on flare or you are going to float forever - regardless of whether you have gusts or not - if you are too fast you float and then it bangs on when the gust goes away . . . it can be done in a Comanche but requires several hundred landings to get it down.

Option 3 and you will float and then bang in a Comanche.

Option 2 is too slow - takes forever to get an airplane on the ground - its most frustrating for me landing at a place like CRQ where they turn you onto the GS 15/18 miles out and clear you for an approach - it requires you to consider perhaps reconfiguring and not slowing for the approach until the FAF and dropping the gear there - but if you are say 120-130 kts you need to pull the nose to slow down to get to gear speed without the gear horn wailing in your ear. That is going to screw up your approach at a critical point if its IFR -

Option 1 permits you to fly the approach normally and when you round out and then flare the airplane you can hit the right speeds and bleed it off quickly in the flare so you don't float.

Start Flaps 10 abeam the numbers - Flaps 1/2 - 2/3 base and the bring them down when you are at idle - the Comanche is challenging to land well and you need to use the same sight pic every single time - you can vary it a little drag it in to a 2000' runway perhaps - but consider that most landings need to eliminate non-standard things.

MachFly
January 14th, 2013, 09:29 PM
Wouldn't that be considered to "destabilize" the approach? (A bad thing as I was taught)


I wouldn't classify it as "destabilizing" because after you drop full flaps you still end up in a stabilized aircraft given that you know that the aircraft will pitch up so you apply proper corrections at the proper time.

I haven't flown the Comanche but I think this example should work anyways. Say your doing either a simulated or a real engine out landing on a short runway. You can't drop full flaps right away because you won't be able to glide to the runway due to all the extra drag, but you can't land there with no flaps or with approach flaps because the runway is too short. So you will be forced to drop full flaps on the short final.
This is why I think it's important to be able to change the configuration of your aircraft on the short final.

The way I was tough (and I still think this is a good idea) if your going to drop full flaps do it when you can already glide to the field.


These days I almost never use full flaps for normal landing (the aircraft simply does not need it), but when I land on a short field I still use the same procedure with dropping landing flaps when I know that I will defiantly make it to the field.

Fearless Tower
January 14th, 2013, 10:28 PM
Changing flap setting on short final seems a bit unwise.

Wouldn't that be considered to "destabilize" the approach? (A bad thing as I was taught)

One of the problems with the idea of a 'stabilized' approach is that over the years the origins of the concept have been lost and many pilots and CFIs have developed some interesting interpretations of what it is.

The stabilized approach was created at the beginning of the jet age. Lot of accidents came from pilots flying jets like the same way they had flown pistons. Problem was that ended up in a lot of aircraft coming up short as the early jet engines had rather slow response times, particularly at low power settings. The solution was to put out full flaps early on, maintain a steady airspeed and carry enough power in the approach that your engines were always ready to respond.

Unfortunately, today we have the reverse....alot of well meaning folks have taken to the belief that you must fly pistons the same way. In general terms, there is no reason to fly a piston like that.

IMO stabilized in a piston is gradual/incremental adjustments that are done without abrupt maneuvering.

jbarrass
January 14th, 2013, 11:55 PM
I fly a 260C. Pretty much exactly the same way as Comanche Pilot.

I like the steep approach, It feels right to me......

jspilot
January 15th, 2013, 06:47 AM
20* flaps from long final, 30* flap when the runway's made to lower touchdown speed (less energy), shorten the transition from flying to rolling, and shorten the rollout.
Don't see the point of full flaps on long final then adding power to overcome the added drag. Add the drag when it's time to land.

This is basically what I do for the 172. Every instructor I've ever flown with taught me the same steps to land- abeam the numbers power to 1500 rpm first notch in, 45 degrees to the numbers turn base, speed in the white arc, next notch in, turn final, last notch in, pitch for 60-70 knots on final. I want to land with as little momentum as possible so I'll use the designs of the plane to make that possible.

On a long straight in I like to keep my speed up and the flaps in as long as possible. Having the flaps set at 20 or 30 degrees when I'm still miles from the runway just does not feel comfortable to me. I have to have the RPM setting so high that I can't help but think that if the engine died right now I'd never be able to glide to the runway. That's not a comfortable feeling so that's why I manange the flaps the way I do.

yakdriver
January 15th, 2013, 08:48 AM
I flew a Comanche 250 for several years and always used full flaps. The people that have a hard time landing a Comanche are coming over the fence much too fast. Fly it with book speeds and it will reward you with nice touchdowns. The Comanche is one of my favorite airplanes. I don't pay attention to the VASI as I normally fly power off steeper approaches in whatever airplane I'm flying. If you get dependent on the VASI to judge your approach what will you do when you fly to an airport that doesn't have one? Don

RoscoeT
January 15th, 2013, 09:37 AM
If you get dependent on the VASI to judge your approach what will you do when you fly to an airport that doesn't have one?

Those exist? :eek: :) I'm amazed at how many pilots these days rely on the VASI/PAPI for day VFR ops.

dtuuri
January 15th, 2013, 10:33 AM
Option 4. Flaps up until around 500' AGL (or so), then full. Keep your hand on the flap switch while they reposition, in case you get split flaps. The added drag should ideally bleed off your airspeed from approach speed to threshold crossing speed with no need of a power adjustment.

I didn't fly a single, though, mine was a Twinky. Can't imagine why it would make a difference.

dtuuri

EdFred
January 15th, 2013, 10:38 AM
Option 4. Flaps up until around 500' AGL (or so), then full. Keep your hand on the flap switch while they reposition, in case you get split flaps. The added drag should ideally bleed off your airspeed from approach speed to threshold crossing speed with no need of a power adjustment.

I didn't fly a single, though, mine was a Twinky. Can't imagine why it would make a difference.

dtuuri

Singles don't slow down that quick. More drag on the twink. (Yes, there's a joke just waiting in that second sentence.)

HerrGruyere
January 15th, 2013, 11:02 AM
I fly a 172. I usually select full flaps on short final after I've made my decision to land. Otherwise, it takes forever to get down.

N801BH
January 15th, 2013, 11:15 AM
I land with all different configs, depending on the situation. It's called practice for when stuff breaks....

Disclaimer: Full flap landings in my plane are dicey........ at best...:yikes:

DavidWhite
January 15th, 2013, 11:39 AM
Full flaps every landing. Even in a crosswind.

lr60plt
January 15th, 2013, 11:46 AM
Full flaps every time in the Lear 60 (unless emergency/abnormal landing).

No flaps on my Citabria.

:D

Alexb2000
January 15th, 2013, 12:12 PM
Full flaps every landing. Even in a crosswind.

+1. Keep em' short and sexy.

douglas393
January 15th, 2013, 04:27 PM
Every so often I will do a no flaps landing for the practice, otherwise abeam the numbers first notch, at base second notch, and rarely use full flaps. I fly a 182 and it seems to float nearly forever with full flaps, so I do not use them that often. In winds stronger than 8 knots I typically land with one notch. It seems to work for me well, and I am touching down just after the stall warning chirps.

It seems to me that the majority always prefers full flaps whenever I read threads on this issue, maybe I will try again and see if it is any different now for me since the last time I tried full flaps was while I was still checking out the plane.

Doug

EdFred
January 15th, 2013, 04:56 PM
Every so often I will do a no flaps landing for the practice, otherwise abeam the numbers first notch, at base second notch, and rarely use full flaps. I fly a 182 and it seems to float nearly forever with full flaps, so I do not use them that often. In winds stronger than 8 knots I typically land with one notch. It seems to work for me well, and I am touching down just after the stall warning chirps.

It seems to me that the majority always prefers full flaps whenever I read threads on this issue, maybe I will try again and see if it is any different now for me since the last time I tried full flaps was while I was still checking out the plane.

Doug

Try slowing down. Float = excessive speed.

Fearless Tower
January 15th, 2013, 04:59 PM
Try slowing down. Float = excessive speed.
Definitely....if you are floating with full flaps, you have too much speed going into the flare.

tonycondon
January 15th, 2013, 05:01 PM
in the 182 towplane i tend to use one notch less than full as with full i find it impossible to not touch down flat.

RoscoeT
January 15th, 2013, 05:10 PM
I fly a 182 and it seems to float nearly forever with full flaps, so I do not use them that often.

Full flaps allow for LESS floating due to the added drag. But as others mention, your airspeed has to be right.

Alexb2000
January 15th, 2013, 05:17 PM
Every so often I will do a no flaps landing for the practice, otherwise abeam the numbers first notch, at base second notch, and rarely use full flaps. I fly a 182 and it seems to float nearly forever with full flaps, so I do not use them that often. In winds stronger than 8 knots I typically land with one notch. It seems to work for me well, and I am touching down just after the stall warning chirps.

It seems to me that the majority always prefers full flaps whenever I read threads on this issue, maybe I will try again and see if it is any different now for me since the last time I tried full flaps was while I was still checking out the plane.

Doug

Try crossing the fence no faster than 65 Knots and work down from there. Lighter weights I might expect to cross the fence at 60.

douglas393
January 15th, 2013, 05:36 PM
I do cross the fence at 65 knots. It could be my imagination that I float longer, as like I said I did that while I was getting my hours in the plane for high performance and was not real familiar with its flying character at the time. Now that I have many more hours in it I should probably try it again and see if it differs.

Alexb2000
January 15th, 2013, 05:37 PM
I do cross the fence at 65 knots. It could be my imagination that I float longer, as like I said I did that while I was getting my hours in the plane for high performance and was not real familiar with its flying character at the time. Now that I have many more hours in it I should probably try it again and see if it differs.

Do you have 40 degree flaps?

Pilawt
January 15th, 2013, 06:08 PM
Depends on the type of airplane.

The pilot should be proficient in every landing configuration allowed by the manual (e.g., Cessna 172: "Normal landing approaches can be made with power on or power off with any flap setting within the flap airspeed limits").

All else being equal I prefer full flap landings in my C-172/180. In fact, I've sacrificed 250 pounds of useful load (I have no friends anyway) to be able to keep the 40 degree setting. But, there are times when things just seem to flow better with partial flap (no significant difference in stall speed between 20° and 40°).

One should also know what to expect in case the flap motor takes the rest of the day off (which happened to me twice in the first three months of owning my Bonanza).

Know thy airplane.

wabower
January 15th, 2013, 06:09 PM
What does your book show as VSO at the weights at which you are typically flying? (If you don't have it handy, the formula is that stall speed drops by ~ half of weight reduction %, so 10% reduction in weight causes 5% reduction in VSO.)

I do cross the fence at 65 knots. It could be my imagination that I float longer, as like I said I did that while I was getting my hours in the plane for high performance and was not real familiar with its flying character at the time. Now that I have many more hours in it I should probably try it again and see if it differs.

Everskyward
January 15th, 2013, 06:14 PM
Depends on the type of airplane.

:yeahthat:

And if the airplane calls for flaps "as required", or some phraseology like that, you can use whatever you think is required for that landing.

redtail
January 15th, 2013, 06:25 PM
Option 4. Flaps up until around 500' AGL (or so), then full. Keep your hand on the flap switch while they reposition, in case you get split flaps. The added drag should ideally bleed off your airspeed from approach speed to threshold crossing speed with no need of a power adjustment.

I didn't fly a single, though, mine was a Twinky. Can't imagine why it would make a difference.

dtuuri

What should I expect with split flaps? I'm guessing a rolling moment toward the wing with the dead flap. I fly a Skyhawk.

douglas393
January 15th, 2013, 07:06 PM
Do you have 40 degree flaps?
Yes..

Alexb2000
January 15th, 2013, 07:17 PM
Yes..

OK, I imagine you can really bring that baby in slow. I use 65 with 30 as a starting place. I would think you could do much better with your bird. Since you now have a lot more experience in it, let us know what happens when you slow it down.

dans2992
January 15th, 2013, 08:09 PM
So, it's acceptable practice to go from 1/2 flaps to full flaps at say 200 AGL?

I was taught that was ill-advised.

Dan

Fearless Tower
January 15th, 2013, 08:50 PM
So, it's acceptable practice to go from 1/2 flaps to full flaps at say 200 AGL?

I was taught that was ill-advised.

Dan
Depends on the airplane, pilot proficiency and comfort with the configuration change, visibility....etc.

A lot if folks don't like the idea and will advise against it, but I wouldn't flat rule it out. I have gone from completely clean (flaps and gear up) at 200 AGL to full flaps and a normal touchdown in a Duchess. Not a real big deal, but not the kind of thing I would recommend a student or new private pilot do.

wabower
January 15th, 2013, 09:49 PM
The altitude is not specified, but when landing is assured it's not only acceptable it's SOP in many planes. I usually think I can reach the field from ~500' so that's where I typically go all-in.

So, it's acceptable practice to go from 1/2 flaps to full flaps at say 200 AGL?

I was taught that was ill-advised.

Dan

JBrown243
January 15th, 2013, 11:15 PM
I ignore the VASI as long as it's not red/red, and fly full flaps and about 10" of MP to the numbers in my Comanche. I've never landed less than full flaps except once just to see what a 0 flap landing was going to be like.

that's funny I'm kinda on the opposite end, when I first started flying my Comanche I used no flaps every time. It's interesting because the plane has such a shallow pitch when landing, seems to come in very flat no matter what flap setting I use

dtuuri
January 15th, 2013, 11:51 PM
What should I expect with split flaps? I'm guessing a rolling moment toward the wing with the dead flap. I fly a Skyhawk.
A serious rolling moment. Having your hand on the switch allows you to stop flap movement right away if you notice it. Leaving it split rather than retracting it to match the other may be the best choice, as long as you can control the airplane like that, since you don't know what might happen when you try to retract a broken system.

My advice for the Twin Comanche doesn't mean that's how I'd fly a Skyhawk, btw. A lot depends on the pilot's experience level too. Bouncing around in the pattern, I'm all for incrementally applying flaps for better over-the-nose visibility and settling into a nice not-too-fast airspeed for more sure control. Same goes for working on an instrument rating. You want to establish good habits to fall back on for those days when the weather is right at minimums and a missed approach due to excessive speed could mean you don't make it to a bathroom in time. :redface: Or worse.

dtuuri

Everskyward
January 16th, 2013, 12:06 AM
I had split flaps in a Twin Comanche the one and only time I flew it. It was also my first multiengine lesson. I retracted the flaps after a stall recovery and ended up with a lot of aileron. At first I thought the CFI had pulled an engine even though we had not discussed single-engine work yet. Then I remembered it was supposed to be yaw not roll so my comment to him was, "I think something is wrong." I can't even remember now what he did. I think he recycled the flaps and they came up the next time. In any case it was controllable with aileron, even in the split configuration.

spinfire
January 16th, 2013, 12:24 AM
Since the ailerons are outboard of the flaps they have a much longer arm, so split flap can be counteracted with aileron.

I land the Cardinal with flaps 20 or 30 (30 is full flaps) in a normal landing. I find timing of the flare is a bit more forgiving with flaps 20 (and my initial transition training we started with flaps 20) so I will use this if I am rusty. I've been trying to get into the habit of going all the way to full flaps on most normal landings.

MachFly
January 16th, 2013, 12:32 AM
Full flaps every landing. Even in a crosswind.

Even when you have a large gust factor?

rcpilot
January 16th, 2013, 02:03 AM
In the 172/152 I've flown I usually make the final at 30 flaps (crosswinds excepted). Technically the 172 had a 40 setting, but there's a reason they removed it in 1980.

I fly fairly short patterns though with power off so they come in high and I need the drag. I did a longer run with 10 flaps in the 152 once without much crosswind and it just felt like it took forever to slow down enough to settle out on the runway.

vintage cessna
January 16th, 2013, 02:20 AM
The C172 max flap deflection was changed from 40 degrees to 30 because the newer aircraft are about 250 lbs heavier than the older models. Conducting a go around at the higher max gross weight with 40 degrees of flaps would be challenging. No reason not to use 40 degrees of flaps on the older models even in gusty conditions.

Fearless Tower
January 16th, 2013, 06:46 AM
No reason not to use 40 degrees of flaps on the older models even in gusty conditions.
I can think of one....you fly somewhere with a fleet that has a mix of 172s and you only occasionally fly the 40 flaps model. In that case, consistency with the flap setting is better.

One thing I have noticed about the 172s with 40 degrees of flaps is that there is a noticeable difference in elevator authority at flaps 40 than 30. A lot easier to bang the nose wheel or plant it in a three point with all 40 hanging out. If you are proficient in landing with las 40 no big deal, but if you jump around between planes, it is probably better limit flaps to 30.


Sent from my iPad using Tapatalk HD

Fearless Tower
January 16th, 2013, 06:49 AM
I had split flaps in a Twin Comanche the one and only time I flew it. It was also my first multiengine lesson. I retracted the flaps after a stall recovery and ended up with a lot of aileron. At first I thought the CFI had pulled an engine even though we had not discussed single-engine work yet. Then I remembered it was supposed to be yaw not roll so my comment to him was, "I think something is wrong." I can't even remember now what he did. I think he recycled the flaps and they came up the next time. In any case it was controllable with aileron, even in the split configuration.

I think the particularly airplane design has a big determining factor in how much of an effect split flaps is. I have heard of a few fatals in 172s with split flaps.


Sent from my iPad using Tapatalk HD

redtail
January 16th, 2013, 11:52 AM
A serious rolling moment. Having your hand on the switch allows you to stop flap movement right away if you notice it. Leaving it split rather than retracting it to match the other may be the best choice, as long as you can control the airplane like that, since you don't know what might happen when you try to retract a broken system.

My advice for the Twin Comanche doesn't mean that's how I'd fly a Skyhawk, btw. A lot depends on the pilot's experience level too. Bouncing around in the pattern, I'm all for incrementally applying flaps for better over-the-nose visibility and settling into a nice not-too-fast airspeed for more sure control. Same goes for working on an instrument rating. You want to establish good habits to fall back on for those days when the weather is right at minimums and a missed approach due to excessive speed could mean you don't make it to a bathroom in time. :redface: Or worse.

dtuuri

Oh ok. I was thinking retract back a notch but you're probably right. I'll admit, when I'm short final and dump in the last notch, I never really thought much about keeping my hand on the flap lever for the possibility of split flaps.

spiderweb
January 16th, 2013, 10:28 PM
As others probably have said above, the answer depends on your aircraft. Read the POH, work with an instructor or someone very familiar with the model, and practice what is best for various situations.

It varies so much, that it is hard to generalize. For example, in the C172, I nearly always landed with 40 degrees of flaps and loved the steep approach it allowed me. With the newer C172s, that option was gone. But with both, you could land with little fuss with NO flaps, if you wanted to (for whatever reason).

With the SR20, however, a no-flaps landing is a long, long waiting game and you enjoy thousands of feet of runway sliding by, a tantalizing few inches from the wheels but never in contact with them, until the Cirrus finally decides to stop flying. You MUST land with full flaps on the SR20, unless you're really into low passes.

gismo
January 16th, 2013, 11:18 PM
I think the particularly airplane design has a big determining factor in how much of an effect split flaps is. I have heard of a few fatals in 172s with split flaps.


Sent from my iPad using Tapatalk HD
I believe that Part 23 requires that airplanes be controllable with a split flap configuration if the design can allow that to happen. I don't know if CAR 3 had similar requirements but it seem likely.

dtuuri
January 17th, 2013, 01:06 AM
I believe that Part 23 requires that airplanes be controllable with a split flap configuration if the design can allow that to happen. I don't know if CAR 3 had similar requirements but it seem likely.
Only if there's no mechanical interconnenct. A failure of an interconnect isn't covered by that requirement:
§ 23.701 Flap interconnection.

(a) The main wing flaps and related movable surfaces as a system must—

(1) Be synchronized by a mechanical interconnection between the movable flap surfaces that is independent of the flap drive system; or by an approved equivalent means; or

(2) Be designed so that the occurrence of any failure of the flap system that would result in an unsafe flight characteristic of the airplane is extremely improbable; or

(b) The airplane must be shown to have safe flight characteristics with any combination of extreme positions of individual movable surfaces (mechanically interconnected surfaces are to be considered as a single surface).

(c) If an interconnection is used in multiengine airplanes, it must be designed to account for the unsummetrical loads resulting from flight with the engines on one side of the plane of symmetry inoperative and the remaining engines at takeoff power. For single-engine airplanes, and multiengine airplanes with no slipstream effects on the flaps, it may be assumed that 100 percent of the critical air load acts on one side and 70 percent on the other.

I've noticed that some design features billed as preventing split flaps--don't, under all failure modes. The Navajo comes to mind, IIRC. Maybe the Comanche too? Stopping the actuator from causing structural damage due to a faulty limit switch seemed to be the design objective instead, if my memory is right.

dtuuri

wickedsprint
January 17th, 2013, 01:19 AM
If I need or want to...sure.

Shepherd
January 17th, 2013, 01:12 PM
I go out of my way to fly a different approach every landing. It keeps me agile, and it keeps my brain from engaging the "auto pilot".

Glenn

MAKG1
January 18th, 2013, 12:24 PM
Try crossing the fence no faster than 65 Knots and work down from there. Lighter weights I might expect to cross the fence at 60.

Full flaps, engine at idle, and 60 knots over the fence in a 182 (light) will plop you on the runway during the flare. ONE of those has to give in a 182. The one that seems to work best is to keep in a little power until the wheels touch. It doesn't seem to take much.

It works fine in a 172.

wabower
January 18th, 2013, 01:19 PM
How far from the fence to the threshold? Would the same technique be applicable for KADS 15 as KGLE 17?

Full flaps, engine at idle, and 60 knots over the fence in a 182 (light) will plop you on the runway during the flare. ONE of those has to give in a 182. The one that seems to work best is to keep in a little power until the wheels touch. It doesn't seem to take much.

It works fine in a 172.

Alexb2000
January 18th, 2013, 02:27 PM
Full flaps, engine at idle, and 60 knots over the fence in a 182 (light) will plop you on the runway during the flare. ONE of those has to give in a 182. The one that seems to work best is to keep in a little power until the wheels touch. It doesn't seem to take much.

It works fine in a 172.

Not to argue, but I land my heavy T206, full flaps, 65 crossing the fence, near gross, engine at idle all the time and I don't drop it in. If I want to get short 60ish depending on weight. When I had a 182 it was even better. My flair is not just hauling back on the yoke, finesse it a little bit, keep the stall horn going but not too much (don't let it brake and drop). Just as she's about to touch, tease in that last bit of elevator to soften the descent and roll it on. I'll fly exactly the same profile in a stiff crosswind. My goal is to be in the habit of touching down with the least amount of energy, short rolls, easy on brakes and tires, and most importantly in an emergency when I can't choose the winds or runway length I'll be able to put it down in ~500'.

denverpilot
January 18th, 2013, 05:39 PM
Wouldn't that be considered to "destabilize" the approach? (A bad thing as I was taught)


A poorly worded technique for early in the aviation skillset. There's a number of us who'd like to "destabilize" the idiots that started applying that phrase to light aircraft.

Originally intended for Transport Category crews as a sanity check, that phrase has grown more legs than an irradiated rabbit living on the Chernobyl grounds.

If you're "stable" at half flaps and need to slow, you will be "stable" at full flaps.

Jumping Jeebus on a Pogo Stick, I hate the weird training side effects of this silly phrase.

As far as your concern about asymmetric flap deployment, look over the flap system of your aircraft carefully in an exploded diagram or ask your mechanic to show you whether or not it's even possible. On many light aircraft some damn heavy metal stuff would have to break loudly to even make it a possibility.

Knowing your specific system is better than a blanket fear. Grab the books. :)

N801BH
January 18th, 2013, 05:53 PM
...... grown more legs than an irradiated rabbit living on the Chernobyl grounds.

......

Jumping Jeebus on a Pogo Stick,..... :)


Nate is on a roll with some great one liners...:yes::):thumbsup::thumbsup::thumbsup:

sdflyer
January 18th, 2013, 07:08 PM
I fly a 172. I usually select full flaps on short final after I've made my decision to land. Otherwise, it takes forever to get down.


It really depends for 172 model you fly. N model has 40 degree flaps. 40 degrees flaps in my opinion is more like dive breaks. You either round up quick or stall :)

Threefingeredjack
January 18th, 2013, 07:34 PM
It really depends for 172 model you fly. N model has 40 degree flaps. 40 degrees flaps in my opinion is more like dive breaks. You either round up quick or stall :)

But they sure are handy coming in over an obstacle. Slow down, (60 or less), get all 40 out, and then push over once you clear the obstacle. You won't gather much speed and if you time your pull out properly you dump all the energy in the flare and touch softly with a very short roll out.

wabower
January 18th, 2013, 07:49 PM
That method is taught/preferred in some CFI/DPE jurisdictions as best short-field technique. I was never sure about the difference in wear-and-tear absorbed by the trainers in which it was practiced, but it was interesting to say the least.

Full flaps, engine at idle, and 60 knots over the fence in a 182 (light) will plop you on the runway during the flare. ONE of those has to give in a 182. The one that seems to work best is to keep in a little power until the wheels touch. It doesn't seem to take much.

It works fine in a 172.

But they sure are handy coming in over an obstacle. Slow down, (60 or less), get all 40 out, and then push over once you clear the obstacle. You won't gather much speed and if you time your pull out properly you dump all the energy in the flare and touch softly with a very short roll out.

denverpilot
January 20th, 2013, 05:16 AM
Full flaps, engine at idle, and 60 knots over the fence in a 182 (light) will plop you on the runway during the flare. ONE of those has to give in a 182. The one that seems to work best is to keep in a little power until the wheels touch. It doesn't seem to take much.

I missed this one.

For slow approaches in the 182... Steeper. The answer is steeper. No plop necessary. Just pull the yoke for the flare at the right time. Maintain energy and flare at the right height. Land it on the mains, don't plop it. The 182 with her bigger wing chord and area will fly a lot slower than anyone trained in 172s is comfortable with.

But I'll show you why it has this undeserved reputation of "plopping" on. It isn't the airplane.

Cessna says 60 knots and 40 deg flap, right in the POH for short-field landings.

http://img.tapatalk.com/d/13/01/20/vudege7y.jpg

http://img.tapatalk.com/d/13/01/20/atejagaz.jpg

Another hint in the POH is the Airspeed calibration table. Flaps 40, KCAS 50 is KIAS 40. Hmm... Oh yeah, that pitot tube is sticking up at a funny angle... ;)

http://img.tapatalk.com/d/13/01/20/e2a8e2eb.jpg

If you're at Flaps 40 and flying it 60 knots indicated you're probably fast.

Here's one of the traps that causes folks to not have consistent landings in the 182...

Note the huge difference between full rear center of gravity and full forward...

http://img.tapatalk.com/d/13/01/20/ehe2abyv.jpg

There's almost a ten knot difference between stall speeds as you move CG rearward.

Most folks train with themselves and a CFI up front and they're way forward on the CG envelope graph. Then they wonder why they float and float and float when they finally haul some more humans and stuff, using the 182 in its intended dump truck role, hauling stuff.

They're flying the same approach speed they always have, 60 or even 65 indicated (remember the error gets greater at higher angles on attack...) and they need to slow at touchdown to 40 indicated, at touchdown. That's a lot of energy to slough off on short final.

Note if you limit the bank angle to 30 degrees as you slow up on final and don't horse around and it's a calm day, at full forward CG stall is 52 indicated. Full aft is 43 indicated.

Now, what the table doesn't say is how fast you'll scrub off energy at those low speeds and lots of drag hanging out if you're power-off, and Flaps 40. And, that's where I believe folks get the impression the 182 likes to "plop" on. The plop is flaring at the wrong height (too high) and often just not aggressive enough to both arrest the sink-rate and get down to landing speed. You want to be done flying at touchdown.

Not being ready with immediate power to catch the huge increase in drag, as the huge barn doors suck away airspeed in mere moments, is also a common mistake. Just don't get wild with it. Power when trimmed for landing in the 182 will almost always cause a pitch up and can be accidentally tuned into a full-grown. The more pitch oscillations and power changes, the more hints screaming you should go around.

But done right, you really can make a very steep power off approach and flare just a few inches above the runway, and you're instantly done flying and you're rolling on the mains. (Keep Mr. Yoke coming back or the nose gear isn't going to so much land, as it will "arrive" and near the crap out of you and the airframe.

--- STOL kit side notes ---

The Robertson addendum for our little beastie says 65 MPH/56 knots for final approach speed. It also specifically calls out a touchdown speed of 54 MPH/46 knots. She'll fly even slower than her sisters without the STOL kit on them.

Flaps 40 stall speed, wings level, is 50 MPH/44 knots.

She'll fly really slow, and we have to watch it when flying normal 182s that we don't slow up quite that much.

(By the way the Robertson STOL takeoff is "Begin liftoff at 45 MPH, flaps 30. Initial climb, 50 MPH while clearing obstacles. Retract flaps to 20 and accelerate to 75 MPH. I usually get it off by about 50 MPH and don't try to horse it off and it comes off nose-flat with almost no upward deck angle at first.).

STOL landing, touchdown speed is 49 MPH. It says, "Flare with elevator AND power to arrest rate-of-sink, main wheels first."

nosehair
January 20th, 2013, 05:44 PM
So, it's acceptable practice to go from 1/2 flaps to full flaps at say 200 AGL?

I was taught that was ill-advised.

Dan
For the Commercial and Flight Instructor Certificate PTS power off 180 approach, and for any emergency approach training, you will, or should, learn to put flaps on during short short finals, even into the flare, to get the airplane on the spot with no power. The very discrete use of flaps during the last 200 feet is what makes the spot every time.

wickedsprint
January 20th, 2013, 08:22 PM
I have no problem with adding full flaps late in the approach. Whatever it takes to hit the spot.