Full Flaps on Landing... Always?

[D_C71]

Two weeks ago, I was receiving a rental checkout to authorize solo operation (1982 Cessna 172 RG II) at a local flight school/FBO.

The CFI I chose, had his ATP (mostly flew business jets) and was an insurance investigator (aviation.)

He put me through my paces with the typical slow-flight, stalls, steep-turns, emergency procedures, power-out landings, etc. Though a bit rusty, I passed his inspection, and was Ok'd to rent.

During my first "Normal" landing, on the approach, I applied 10%, then 20% of flaps. On short-final he said, "what about Full Flaps? Why aren't you applying Full-Flaps?"

Caught off-guard, I replied I don't know, it just didn't seem necessary. On roll out and taxi back, we discussed it a bit more. He said, "if you can give me a reason why not to use Full-Flaps, ... well?"

Upon reflection, it seemed to me that some CFI's I studied under, and textbooks, FAA manuals, AOPA articles suggested that less than Full-Flaps was appropriate, depending on conditions.

Perhaps his question was simply posed to make me think and reflect upon why I was using less than Full-Flaps, beyond habit.

Typically, (unless I'm doing Short or Soft-Field landings) I hold off on using Full-Flaps, unless I need them (comming in Fast and/or High on Final approach used as a tool/adjustment.) It also makes doing a Go-Around a bit easier (less than Full-Flaps.)

 

[poadeleted20]

I'm with that crusty old guy you flew with -- use 'em unless there's a good reason to not use them.

One problem I see all the time with pilots who don't fly for a living is inconsistency. The plane flies differently with partial/no vs full flaps, and the Law of Exercise says we do things best when we do them more often. Most nonprofessional (as opposed to unprofessional -- that's a whole 'nother thing) pilots don't fly enough to maintain real proficiency in multiple landing configurations. They do better if they stick to one configuration and get good at it. Sure, there may be an emergency situation which requires a no-flap landing, but that's a special case which you'll practice occastionally as with other emergency procedures, and you'll choose the airport/runway with more care. But otherwise, you gain nothing significant by landing routinely in anything other than the full-flap configuration, and you give up the exercise needed to be proficient in your landings.

And you'll probably need to go around less, too, if you stick with one configuration.

 

[D_C71]

Thanks Ron. Those are some really good points.

 

[Anthony]

What Ron said. I want to land at the lowest possible airspeed, that means full flaps every time. The only time I've used partial flaps or no flaps is practicing those other configurations that Ron addressed. My flaps are electric and I've had electrical failures (before I got the Gremlins fixed) and have not been able to deploy flaps. Its good to be proficient on how the plane acts when landing without flaps. In my Tiger its faster with a much higher nose up attitude.

 

[SkyHog]

I always use full flaps. Some people claim that using less gives you more control in gusty conditions, but I've never seen that first hand. This goes back to the whole "do you always trust your CFI" conversation, where a lot of them tell you that only because its what they heard, and they've never actually tested it themselves.

Until I fly a plane where I can actually feel a loss of stability by using full flaps in gusty conditions, I will always use full flaps in every case short of a training/practice flight where I want to be sure I can land without flaps.

All or nothing, IMHO.

 

[dmccormack]

I'll add one more data point for consideration...

I've personally abandoned the incremental flaps approach in electric-flap airplanes.

I figured out all the fiddling with trim after each 10 degree increment was pointless -- for me.

I enter the pattern at a reasonable speed, and once abeam the numbers (if flying the pattern), I add all flaps.

I fly a tight pattern, every touchdown is a short field landing (down and stopped and off long before 1/3rd of the runway is used on 4,000 foot strip), there's no undue wear on brakes or tires, and the likelihood of a go-around or float is minimal.

Now -- this is the approach I now use personally for five different airplanes (Bonanza 35, Bonanza A36, Cessna 172, Cessna 205, Piper Cherokee 160/180 -- even though the Cherokees both have Johnson bar -- manual flaps).

I teach the incremental flap approach to students, and then later demonstrate the full flap method. I don't make it a requirement -- just offer it as an option, and also teach them that there are various ways to handle the application of flaps.

With new airplanes I do some airwork and test the behavior with full flap application before using the technique in the pattern. If I were moving frequently from one airplane that had some sort of radical pitch change with full flap application I'd probably not use this approach.

 

[SkyHog]

I'll add one more data point for consideration...

I've personally abandoned the incremental flaps approach in electric-flap airplanes.

I figured out all the fiddling with trim after each 10 degree increment was pointless -- for me.

I enter the pattern at a reasonable speed, and once abeam the numbers (if flying the pattern), I add all flaps.

I fly a tight pattern, every touchdown is a short field landing (down and stopped and off long before 1/3rd of the runway is used on 4,000 foot strip), there's no undue wear on brakes or tires, and the likelihood of a go-around or float is minimal.

Now -- this is the approach I now use personally for five different airplanes (Bonanza 35, Bonanza A36, Cessna 172, Cessna 205, Piper Cherokee 160/180 -- even though the Cherokees both have Johnson bar -- manual flaps).

I teach the incremental flap approach to students, and then later demonstrate the full flap method. I don't make it a requirement -- just offer it as an option, and also teach them that there are various ways to handle the application of flaps.

With new airplanes I do some airwork and test the behavior with full flap application before using the technique in the pattern. If I were moving frequently from one airplane that had some sort of radical pitch change with full flap application I'd probably not use this approach.

I like this. There's really no good reason to use incremental flaps, since it just elongates your pattern and therefore costs you more to do.

I fly really tight patterns, not for safety reasons (god knows the engine is just as likely to quit in a 3 mile pattern as a .5 mile pattern), but because its cheaper and I can be most certain around here that I won't hit anything since all of our CFIs teach 747 patterns.

 

[tonycondon]

i believe in full flaps every time, unless i forget. one nice thing about having a bunch of flap hanging out is that when you get into the flare the extra drag helps slow you down and get you on the ground. with flaps up or partial you just float and float. usually leading to an early/fast touchdown and problems after that.

although i guess the only airplane ive flown that i didnt always use full flaps on was Kim's Bird Dog. 60deg of Cessna fowler flaps is a little excessive. I always kept them at 30-40.

oh and for the crosswind crowd...ive landed at or above the demonstrated crosswind component with full flaps and have never experienced a problem having enough rudder authority. but thats just me.

 

[Ted]

In a 172, I can't see why you wouldn't use full flaps every time (and could see the advantages of just going straight to full flaps abeam the numbers). So, in your particular case I'd agree with what the CFI said.

Now, a few points (since we're having a discussion about the philosophy of flaps ):

1) In the Mooney, full flaps causes a very significant amount of float, unless you get the plane very close to stall speed on final, which is not something that is probably a very good idea, because it also results in a pretty high sink rate that can get away from you. The difference in ground effect with and without flaps is very noticable. In this plane, half (takeoff) flaps end up generally making for nicer landings that are spot on with little to no float if executed properly. The full flaps primarily help if you're too high and need to lose altitude fast. Also, if you're doing a faster approach due to gusting, the floating effects with the flaps will prevent you from getting on the ground as fast.

2) When doing engine out landings in the Aztec, I generally use no flaps. First off, the remaining engine is working to keep the plane going. Adding flaps adds drag which will make it more difficult to maintain altitude. Second, if the left engine is dead (and it's actually dead, which is what you practice for), the flaps will only work with the hand pump since the plane has one hydraulic pump, and it's on the left engine. Yeah, like I really want to deal with doing a go-around on my right engine only while using the hand pump to try to get the flaps back up.

3) When doing normal landings in the Aztec, speeds are as follows:

1/4 flaps: 160 mph
Gear: 150 mph
1/2 flaps: 140 mph
Full flaps: 125 mph

In this plane, using the incremental flaps method generally makes for a smoother approach (the flap application comes with a significant nose-up pitching moment), and also is more practical as getting down to 125 mph without pulling the power way back is difficult, and once the 50 degrees of flaps go out, you then need to put power back in, which detracts from smoothness. If you go incrementally, you pretty much just add each drag component one at a time, and once the plane settles it's at the speed for the next one. Very nice. It's not significantly more work to do the incremental flaps, and once you get into the habit of it there's no issues.

I'm just using the planes that I fly as examples of situations where one might consider deviating from the "full flaps every time" since those are what I'm familiar with. My real point is know the plane and be able to think about where it might be beneficial vs. not. I otherwise agree with what was said about consistency in pattern work, the advantages of full flaps, etc.

 

[Clark1961]

Interesting comments. I've gone full circle on the partial vs full flap landing...and will probably go full circle a time or two more.:smile:

The difference in stall speed between 25 & 40 degree flaps is minimal. The difference in drag is substantial. I find it easiest to land smoothly and keep the nose up with flaps 25. The nose gets a bit heavy with flaps 40. If I want the extra drag then I'll pull the flaps to 40 after touchdown and setting the nosewheel on the runway. I use more of a soft field technique than short since runways around here tend to be long (high DA). I also aim for and generally touchdown on the 1000 ft marks. Crosswind directional control is always a concern but proper control application pretty much solves the problems with winds less than 20 knots which is about my personal limit.

I've heard some folks advocate trim use in the flare to reduce the control force. I haven't gone there yet but it is an option now that the electric trim is working reliably.

So to boil it down to a short story, the difference in stall speed between flaps 25 and flaps 40 is minimal so I am currently setting flaps 25 for most of my landings. As always, everyone elses' mileage will vary...

 

[dmccormack]

1) In the Mooney, full flaps causes a very significant amount of float, unless you get the plane very close to stall speed on final, which is not something that is probably a very good idea, because it also results in a pretty high sink rate that can get away from you. The difference in ground effect with and without flaps is very noticable. In this plane, half (takeoff) flaps end up generally making for nicer landings that are spot on with little to no float if executed properly. The full flaps primarily help if you're too high and need to lose altitude fast. Also, if you're doing a faster approach due to gusting, the floating effects with the flaps will prevent you from getting on the ground as fast.

Ted,

I was "warned" about this in the Bonanzas by a long time Bo owner-pilot.

Full flaps with that low wing very much in ground effect means you can "fly" at a far lower speed than book stall speed.

So I flew it full flaps anyway and kept the approach speed right on the book value (The 1980 A36 POH doesn't have Short Field procedure listed -- you have to figure out 1.3 Vso for yourself given GW).

I found there was no excessive float whatsoever unless I exceeded IAS by anything more than 4-5 knots.

That's not alot, but it made a huge difference in float and pavement used.

 

[RMCN172RG]

I will interject an opposing view.

I land "normally" with 20 degrees flaps

Reasons

Cross wind and/or gusty wind landings generally the increased speed improves handling under these conditions. Normally there is always a cross wind and usually gusts.

Go arounds the flaps are already up one notch so there is one less first thing to do.

High approach you can add the last 10 when needed.

 

[Ted]

The Mooney's stall speeds with and without flaps are not significantly different (been there done that). The heavy ground effect, though, has a lot to do with the fact that the wings are so close to the ground.

Like I said, know the airplane and what works best with it.

 

[ThrashN]

That is some great info to think about.
I've been taught that Flaps are a tool to use and if I don't need them then there's no need to add them just because.

 

[dmccormack]

The Mooney's stall speeds with and without flaps are not significantly different (been there done that). The heavy ground effect, though, has a lot to do with the fact that the wings are so close to the ground.

Like I said, know the airplane and what works best with it.

I'm sure you do, and having never flown a Mooeny, I can only relay my Bonanza expereince and see if there are similarities.

 

[poadeleted20]

1) In the Mooney, full flaps causes a very significant amount of float, unless you get the plane very close to stall speed on final,

I don't have a lot of Mooney time (maybe 50 hours or a little more), but I don't think that's true. Set up 1.3 Vs0 for your weight on final, and there's no significant float in the flare. Trim for speed and use proper pitch/power on final, and there's no sink problem.

2) When doing engine out landings in the Aztec, I generally use no flaps. First off, the remaining engine is working to keep the plane going. Adding flaps adds drag which will make it more difficult to maintain altitude. Second, if the left engine is dead (and it's actually dead, which is what you practice for), the flaps will only work with the hand pump since the plane has one hydraulic pump, and it's on the left engine. Yeah, like I really want to deal with doing a go-around on my right engine only while using the hand pump to try to get the flaps back up.

After 1000 hours in Aztecs, I still make full flap landings even OEI, but as with normal landings, I don't add the last increment until I have the field made on final. As for go-arounds, I don't do OEI go-arounds in light twins. If I'm operating OEI, I'm landing, period, preferably on the runway, but if someone blocks the runway, I'll take the taxiway, or the ramp, or any other level surface I can use. OEI go-arounds in light twins are where people get killed.

3) When doing normal landings in the Aztec, speeds are as follows:

1/4 flaps: 160 mph
Gear: 150 mph
1/2 flaps: 140 mph
Full flaps: 125 mph

I'm usually way slower than that in an Aztec. Typically, 100 on downwind with 1/4 flaps, and 90 on final with full flaps. The gear takes good care of getting down to pattern speed.

 

[poadeleted20]

I land "normally" with 20 degrees flaps

Reasons

Cross wind and/or gusty wind landings generally the increased speed improves handling under these conditions. Normally there is always a cross wind and usually gusts.

After 40 years of flying them from time to time, I have yet to encounter a crosswind or gust where the difference between 1.3Vs0 and 1.3Vs(20 flap) made a significant difference in control margins in a 172.

Go arounds the flaps are already up one notch so there is one less first thing to do.

You still have to get to flaps 10, and whether it's the electric or the J-bar, it's one move from either 20 or 40 to 10. Only if you forget to pitch the nose as you do that will you have a problem.

High approach you can add the last 10 when needed.

Or you can reduce power, or slip. If you're so high that the only way to get down is to go from 20 to 40 because you're already at idle in a full slip and still going long, you should go around and try it again.

 

[LearDriver]

That is some great info to think about.
I've been taught that Flaps are a tool to use and if I don't need them then there's no need to add them just because.

I tend to agree with this. Especially with a 172 with the 40 degree flaps. I don't like to go beyond 30 degrees unless its needed for a short field.

 

[SkyHog]

I tend to agree with this. Especially with a 172 with the 40 degree flaps. I don't like to go beyond 30 degrees unless its needed for a short field.

I don't understand that thought process....I want to land as slow as I can. If I could land with 80 degree flaps at 20knots, I'd do it. lol

 

[tonycondon]

I tend to agree with this. Especially with a 172 with the 40 degree flaps. I don't like to go beyond 30 degrees unless its needed for a short field.

why? i love making a nice steep safe approach. and whats wrong with treating every runway like a short field? down as soon as you can, as slow as you can. you are able to get stopped quickly that way, if needed, and save wear and tear on tires and brake pads, so that you'll have them when you really need them.

 

[wabower]

Some guy had to fly the airplane and put the number in the POH to get it certified to start with. If his number is different, who am I supposed to believe--and why?

The Mooney's stall speeds with and without flaps are not significantly different (been there done that). The heavy ground effect, though, has a lot to do with the fact that the wings are so close to the ground.

Like I said, know the airplane and what works best with it.

 

[LearDriver]

I don't understand that thought process....I want to land as slow as I can. If I could land with 80 degree flaps at 20knots, I'd do it. lol

Its just personal preference. I don't have an issue with landing at a little higher speed. Keeping in mind that the difference in speed is not the great flaps 30 vs. 40.

There are many airplanes that are operated like that, with an option on which final flap setting that you can use.

 

[tonycondon]

almost every time ive flown a 30 deg flap 172 ive turned final, selected full flaps, and said "dang i wish i had 40 deg"

different strokes for different folks i guess.

 

[Pilawt]

why? i love making a nice steep safe approach. and whats wrong with treating every runway like a short field? down as soon as you can, as slow as you can. you are able to get stopped quickly that way, if needed, and save wear and tear on tires and brake pads, so that you'll have them when you really need them.

Depends on the airport and the airplane. If the first turnoff is 600 feet down the runway, full flaps are great. If like at my airport it's 1500 feet away, a full flap landing in a C-150 or C-172 might slow things down, require the use of power to 'expedite' to the turnoff, and increase pilot workload.

Is touchdown faster at flaps 20? More wear and tear on the gear and brakes? According to the C-150 manual there is a one mph (0.87 knot) difference between power-off stall at flaps 20 vs flaps 40. So if a proper approach speed is maintained on final, there will not be excessive float and the full-stall touchdown speed will be virtually the same as at flaps 40. I would routinely land my C-150F with flaps 20, gently on the mains with stall horn blaring, and hold the nose off until elevator power dissipated (longer than is possible at flaps 40) and the nose gear touched at a speed barely above a fast walk, and make the first turnoff with no braking or added power at all. I'd submit that's easier on the undercarriage (especially the relatively fragile nose gear). Less wear on the flap motor and flap tracks, too.

That said, please don't interpret my comments as disdain for the use of full flaps, and I certainly don't agree with training for only flaps 20 landings. I used full flaps all the time in my Cheetah and Bonanza (except the two times when the flap motor quit), and 90%+ of the time in my Sport Cub. The pilot should be proficient in all of the configurations as recommended by the manufacturer, so that he/she is familiar with all of the options available to complete a safe flight with minimal physical or emotional trauma to machine and occupants. Full flap? Partial flap? No flap? Sideslip? Forward slip? No slip? Oversquare or undersquare with a controllable prop? Wheel landing or full-stall in a taildragger? If it's recommended or permitted by the book (as it is in the case of the airplanes we're discussing), be familiar with it, know its advantages and disadvantages, and use your judgment to fly the way that is best for you under the circumstances.

 

[Trapper John]

why? i love making a nice steep safe approach. and whats wrong with treating every runway like a short field? down as soon as you can, as slow as you can. you are able to get stopped quickly that way, if needed, and save wear and tear on tires and brake pads, so that you'll have them when you really need them.

I can really only come up with two reasons not to use full flaps.

1. Small Cessnas don't climb very well with full flaps. If the need for a go-around arises and the flaps don't come up (which is pretty unlikely, but not impossible), that's not so good.

2. Passenger comfort. Steep approaches spook some people.


Trapper John

 

[SCCutler]

Full flaps every time unless there is a compelling reason not to use them.

I rarely use my brakes, at all, on roll out, rarely need to.

If my turn-off is pretty far down the runway, I'll extend my touchdown point to accommodate.

 

[TMetzinger]

In a 172, I can't see why you wouldn't use full flaps every time (and could see the advantages of just going straight to full flaps abeam the numbers). So, in your particular case I'd agree with what the CFI said.

Now, a few points (since we're having a discussion about the philosophy of flaps ):

1) In the Mooney, full flaps causes a very significant amount of float, unless you get the plane very close to stall speed on final, which is not something that is probably a very good idea, because it also results in a pretty high sink rate that can get away from you. The difference in ground effect with and without flaps is very noticable. In this plane, half (takeoff) flaps end up generally making for nicer landings that are spot on with little to no float if executed properly. The full flaps primarily help if you're too high and need to lose altitude fast. Also, if you're doing a faster approach due to gusting, the floating effects with the flaps will prevent you from getting on the ground as fast.

I take issue with this. Floating in a mooney means you're too fast. In windy conditions partial flaps make sense - just like they do in other airplanes.

But for "normal" conditions, the Mooney comes down final just fine with full flaps at 1.3 vs0 just like any other airplane. Now, I will admit it feels strange to go THAT slowly after going THAT fast earlier.

I base my comments on several hundred hours of J time and another 50ish in other M20 models. ALL of them require concious effort to slow appropriately in the pattern, and speed control when flying an instrument approach is where I know I would get lazy. Speed brakes helped when I'd forget to slow down, but not all Mooneys have them.

 

[flyingcheesehead]

Full flaps with that low wing very much in ground effect means you can "fly" at a far lower speed than book stall speed.

So I flew it full flaps anyway and kept the approach speed right on the book value (The 1980 A36 POH doesn't have Short Field procedure listed -- you have to figure out 1.3 Vso for yourself given GW).

I found there was no excessive float whatsoever unless I exceeded IAS by anything more than 4-5 knots.

That's not alot, but it made a huge difference in float and pavement used.

I was gonna say the same thing. When I flew Ed G's Mooney, he told me a speed to fly on final, "and not one knot faster." We used full flaps on every landing, and it didn't float any farther than a Cessna drag-o-matic. In fact, it landed just beautifully! I loved it.

 

[Ted]

Floating in any plane means you're "too fast."

So, 1.3 Vso in the mooney comes out to 83.4 mph. The book recommends 80 mph on short final. Yep, do that and there's still float. Maybe my technique's not perfect, but after 80 hours or so in this plane (an M20F), I've found fairly consistently that I get the best greaser landings with least float with flaps at takeoff setting. The owner has found the same thing. Note, this is our experience in this particular M20F. Your mileage may vary. The Mooney Missile (a J) I flew did fly somewhat differently, but I only have 1 hour and 1 landing in it.

I'm not sure what issue people take with knowing what works for your airplane...

 

[flyingcheesehead]

I take issue with this. Floating in a mooney means you're too fast.

Agreed...

In windy conditions partial flaps make sense - just like they do in other airplanes.

Disagree. At least, I've never been given any good reason for partial flaps in windy conditions. When it's gusty, I want to get from flying speed to not-flying speed as fast as possible lest a gust pick me back up - and that means using full flaps.

FWIW, I've landed the 182 in 21G30 direct crosswind, 21G29 60 degree crosswind, and 20G28 somewhat closer to the nose. I've also landed a 172 in 25G31 30 degrees off the nose. Full flaps every time, never had an issue. The only reason I can think of for using less than full flaps due to wind is if there is so much crosswind that you run out of rudder - And in that case, you ought to be picking a different place to land. Most small airplanes only have a 5 or so knot difference between no-flaps stall and full-flaps stall, and if that 5 knots makes enough of a difference in rudder authority, you're a bit too close to the edge of the envelope already. Go elsewhere.

 

[RMCN172RG]

The thoery on higher speed in gusts is if the gust stops and you are flying into the wind the plane may fly like a rock. The higher air speed is a margin for safety, i.e. the increase your speed by 50% of the gust.

The theory on cross winds is that at slower speeds the wind has more time to act on the aircraft therefore a larger effect.

That's the theory, actual results may vary.

 

[Dave Krall CFII]

<snip>
Or you can reduce power, or slip. If you're so high that the only way to get down is to go from 20 to 40 because you're already at idle in a full slip and still going long, you should go around and try it again.

Or simply add S turns on final as needed and land, especially where go around is not an option.

 

[Fast n' Furious]

Unless I'm practicing for or dealing with a flap abnormal condition, it's full flaps for me every time regardless of what I'm flying. Visual patterns or approach procedures get gear and flaps at the same places regardless of what I'm flying as well. Standardizes my life a bit and helps maintain that good ole predictable habit pattern thingie.

 

[docmirror]

1 Reduced elevator effectiveness with full flaps.

2 High sink rate on final at airports with gusty winds(Avalon comes to mind).

I don't fly a Cessna 172, so can't comment on that. In an early Bonanza with load at forward CG, full flaps will run out of elevator at 1.3VsO approach when the power is off. Bad mojo.

YMMV.

 

[N1347B]

Full flaps every time unless there is a compelling reason not to use them.

I rarely use my brakes, at all, on roll out, rarely need to.

If my turn-off is pretty far down the runway, I'll extend my touchdown point to accommodate.

Full flaps always, unless you don't have any. Then use partial.

I only use my brakes to turn my tail around prettily in from of the FBO, and then I make sure there's a crowd on the porch to see.

I land on the numbers and taxi slowly to annoy others

Deb

 

[dmccormack]

Full flaps always, unless you don't have any. Then use partial.

I only use my brakes to turn my tail around prettily in from of the FBO, and then I make sure there's a crowd on the porch to see.

I land on the numbers and taxi slowly to annoy others

Deb

Well said...

You need to post more, Deb!

 

[jmaynard]

You need to post more, Deb!

Seconded. After all, where else would you get more column ideas?

 

[timwinters]

Now for a totally different perspective...

I'd bet that most people here fly a lot more than the average Joe and, this being the case, I believe a lot of valuable training opportunities are lost when a pilot uses the exact same configuration during every approach and landing. Besides, that's really boring!

I fly almost every week and average about 20 landings a month. I regularly and purposely fly my approaches and land in a different configuration...this at airports that I am familar with. No flaps, full flaps, turn base to final at 500' AGL, turn base to final at 800' AGL and kick it into a full slip, purposely under/overshoot the base leg, etc.

In all cases though I try to fly no more than a 1/2 to 3/4 mile pattern, land short and stop within 1000', with little or no brakes.

But speaking of brakes...they're cheap...why worry about them?

C182A straight tail here with 40 degrees of flaps.

At an unfamiliar airport I fly a standard pattern every time. And my "standard" pattern includes 30 degrees of flaps on any runway over 2500'. 40 degrees of flaps in a straight tail 182 requres much more precision in the round out and flare than 30 degrees does. This combined with the extreme nose down attitude produced by 40 degrees of flaps isn't worth the less than 1kt difference in stall speed when I'm at an unfamiliar airport. A greased landing with 30 degrees produces much less wear and tear than a "thump" with 40 degrees.

 

[citationxjl]

Full flaps unless a reason not too. Can not really think of any for me. I have landed full flaps in the caravan with gusty crosswinds. Save tires, save brakes, get below flying speed the quickest.

But whoever is flying the plane can choose how many flaps to use!! They are PIC.

 

[wabower]

Maybe because their experience in one just like it was different? Are the published book speeds that you're quoting adjusted for landing weight?

I have 400+ hours in a 20F, quite a bit of it onto a short old army surplus metal "landing mat" runway with grass growing up through the holes in the metal. Slicker'n snot and any extra speed or float, especially in X/W, meant no grip on the tires (due to water in the grass blades) and sliding off the side. Speed and configuration had to be just right to make it work. Full flaps and slowing down was the only way it was going to happen. We had heard all that partial flap stuff too, and found that those who advocated it simply didn't slow down sufficiently to eliminate the float. That said, ground effect on all the Mooneys and Comanches was as pronounced as any I can remember.

Floating in any plane means you're "too fast."

So, 1.3 Vso in the mooney comes out to 83.4 mph. The book recommends 80 mph on short final. Yep, do that and there's still float. Maybe my technique's not perfect, but after 80 hours or so in this plane (an M20F), I've found fairly consistently that I get the best greaser landings with least float with flaps at takeoff setting. The owner has found the same thing. Note, this is our experience in this particular M20F. Your mileage may vary. The Mooney Missile (a J) I flew did fly somewhat differently, but I only have 1 hour and 1 landing in it.

I'm not sure what issue people take with knowing what works for your airplane...