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Full flap landing rquired

Posted: Wed Jun 26, 2019 9:45 pm
by rotorspeed
So I hadn't flown in 7 mos and started some commercial training today in the 172. After doing a 20° flap landing on some circuits I was told by my instructor that now transport or the examiners want all landings to be done full flap. This is in the lower mainland BC. What gives

Re: Full flap landing rquired

Posted: Wed Jun 26, 2019 10:03 pm
by kevind
I almost always land with full flaps...172 and 182 the only time i don't is when there is a strong gust differential

Re: Full flap landing rquired

Posted: Wed Jun 26, 2019 10:05 pm
by rotorspeed
When I flew in the 90s at yvr we always landed 0 flap unless short field. I guess things change

Re: Full flap landing rquired

Posted: Thu Jun 27, 2019 2:06 am
by Aviatard
rotorspeed wrote:
Wed Jun 26, 2019 9:45 pm
I was told by my instructor that now transport or the examiners want all landings to be done full flap. This is in the lower mainland BC. What gives
TP 13723 Flight Test Guide:
Changes in this edition:
Ex 18 – landings are expected to be with a full-flap configuration unless in strong crosswind or gusty wind conditions.

That's what.

Re: Full flap landing rquired

Posted: Thu Jun 27, 2019 2:07 am
by Aviatard
rotorspeed wrote:
Wed Jun 26, 2019 10:05 pm
we always landed 0 flap unless short field
Why?

Re: Full flap landing rquired

Posted: Thu Jun 27, 2019 4:45 am
by PilotDAR
Ex 18 – landings are expected to be with a full-flap configuration unless in strong crosswind or gusty wind conditions.
Excellent, hopefully all the time, not just for Ex 18. Unless there is a good reason not to, every landing I fly is full flap, as doing so is generally an element of the type design. I will occasionally practice a zero flap landing just in case of flap failure.

Re: Full flap landing rquired

Posted: Thu Jun 27, 2019 6:13 am
by Posthumane
One airplane I trained in had flap setting of Take off, Landing, and Full, where the full flap configuration was not intended for normal landings and was only used in either short field or off airport situation. I would hope that the examiner would take things like that into account when deciding what flap setting he/she wants to see.

Re: Full flap landing rquired

Posted: Thu Jun 27, 2019 7:35 am
by photofly
PilotDAR wrote:
Thu Jun 27, 2019 4:45 am
Ex 18 – landings are expected to be with a full-flap configuration unless in strong crosswind or gusty wind conditions.
Excellent, hopefully all the time, not just for Ex 18. Unless there is a good reason not to, every landing I fly is full flap, as doing so is generally an element of the type design. I will occasionally practice a zero flap landing just in case of flap failure.
I most respectfully disagree, and believe the matter should be left to the discretion and preference of the pilot, where the manufacturer allows.

For example landing a Cessna 172 with 20° flap makes it considerably easier to protect the nose gear, and full flap (40°) provides no benefit in respect of reducing airspeed during landing, or extra controllability. A late go-around is considerably easier (and therefore safer) with 20° of flap compared to 40°. I have an up-rated 182 where a full power full-flap go-around from an in-trim landing condition produces enough nose-up pitch to require heavy force with both arms to control. I don't see the safety benefit in this.

The POH also makes it clear that the aircraft can be landed safely and with manufacturer's approval with any flap setting, and there is no entry in Section 2 ("limitations") of the POH to restrict the pilot's discretion.

Late model 172 aircraft have the flap extension limited to 30°, as far as I know to support a gross weight increase by reducing drag during a "full flap" go-around. I don't see any reason not to permit extending this same benefit of improved go-around performance to older model 172 airplanes, at the pilot’s option.

From the point of view of flight testing, there's an argument to say that pilots should be stretched, and I would support the idea of requiring the demonstration of a landing and go-around with full flaps (and at close to maximum permitted weight as can be practically achieved, if conditions allow). But there's also a strong argument to have students demonstrate their ability to make appropriate choices from the options available, and if a partial flap landing is preferred for some non-trivial reason, I don't see why it shouldn't be allowed.

Overall, there are lots of different, safe ways to fly an airplane.

Re: Full flap landing rquired

Posted: Thu Jun 27, 2019 1:27 pm
by PilotDAR
But there's also a strong argument to have students demonstrate their ability to make appropriate choices from the options available, and if a partial flap landing is preferred for some non-trivial reason, I don't see why it shouldn't be allowed.
I agree, as long as the student/pilot is making a choice from the approved normal procedures of the airplane, and not avoiding certain normal procedures out of fear or doubt of their personal ability. I opine that is the point of the flight test expectation, that conditions permitting, the candidate can demonstrate the skill to land with full flaps. If their good decision making leads them to land partial flap under some circumstances (as the Cessna POH's recommend), that's good - as long as their good decision making also has them practice full flap landings for skill maintenance, from time to time.

That said, I have never landed with the greatest approved flap extension and regretted doing so. Decision making is every bit as important a skill to maintain as full flap landings!

Re: Full flap landing rquired

Posted: Thu Jun 27, 2019 2:37 pm
by digits_
On a semi-related note, I'm wondering how much weight you'd save if cessna were to build a 172 without a flap system. Let's be honest, the majority of the pilots doesn't need a flap system in a 172. Makes you wonder how much unnecessary weight you are carrying around, or how much speed and/or fuel efficiency you would gain if you could rip it out. No flap motor, no control cables/wires, less load, so possibly lighter battery and alternator. Then again, nobody would probably buy it, even though it's almost never actually needed performance wise.

Re: Full flap landing rquired

Posted: Thu Jun 27, 2019 2:39 pm
by rotorspeed
Aviatard wrote:
Thu Jun 27, 2019 2:06 am
rotorspeed wrote:
Wed Jun 26, 2019 9:45 pm
I was told by my instructor that now transport or the examiners want all landings to be done full flap. This is in the lower mainland BC. What gives
TP 13723 Flight Test Guide:
Changes in this edition:
Ex 18 – landings are expected to be with a full-flap configuration unless in strong crosswind or gusty wind conditions.

That's what.
AVU
Avatars thanks for the clarification from a official standpoint.
I agree with you guys as long as you make a safe landing then it should be fine I don't mind landing 0 flap and 20° is ok. I don't like 40° it flies like a brick and you really have to ad power to remain on glideslope at 60 knots. We already do short field training that should be good enough. I just don't understand why they changed it

Re: Full flap landing rquired

Posted: Thu Jun 27, 2019 5:35 pm
by CpnCrunch
rotorspeed wrote:
Thu Jun 27, 2019 2:39 pm

Avatars thanks for the clarification from a official standpoint.
I agree with you guys as long as you make a safe landing then it should be fine I don't mind landing 0 flap and 20° is ok. I don't like 40° it flies like a brick and you really have to ad power to remain on glideslope at 60 knots. We already do short field training that should be good enough. I just don't understand why they changed it
Just wait until you've made the runway before adding the final 40. And you shouldn't be on "glideslope"....you should be well above the PAPI slope to do a reasonable landing with 40 degrees of flap. Dragging it along a 3 degree glideslope with lots of power using 40 degrees of flap is highly unreasonable IMO, and I don't think an examiner would be too impressed. Just explain why you're not using the PAPI.

But I'm not an instructor, so you should talk to it with your instructor rather than listening to random people on the internet.

Re: Full flap landing rquired

Posted: Thu Jun 27, 2019 7:04 pm
by photofly
CpnCrunch wrote:
Thu Jun 27, 2019 5:35 pm
rotorspeed wrote:
Thu Jun 27, 2019 2:39 pm

Avatars thanks for the clarification from a official standpoint.
I agree with you guys as long as you make a safe landing then it should be fine I don't mind landing 0 flap and 20° is ok. I don't like 40° it flies like a brick and you really have to ad power to remain on glideslope at 60 knots. We already do short field training that should be good enough. I just don't understand why they changed it
Just wait until you've made the runway before adding the final 40. And you shouldn't be on "glideslope"....you should be well above the PAPI slope to do a reasonable landing with 40 degrees of flap. Dragging it along a 3 degree glideslope with lots of power using 40 degrees of flap is highly unreasonable IMO, and I don't think an examiner would be too impressed. Just explain why you're not using the PAPI.

But I'm not an instructor, so you should talk to it with your instructor rather than listening to random people on the internet.
All approaches have to be "stable" by 200 AGL, which includes "in the landing configuration" so you can't leave it too late to add full flaps.


This change in the flight test standards looks positive, to me:
"Changes to the stall recovery criteria to emphasize reducing the angle of attack instead of minimizing the loss of altitude."

What do y'all think?

Re: Full flap landing rquired

Posted: Thu Jun 27, 2019 8:20 pm
by KDewald
My thoughts...

The Pros of 40 Flap
-Shorter landing distance (at my school we train students for difficult overseas flying on very short runways, so the practice is greatly desired)
-Even on our normal runway we prefer to keep our "extra" runway margin as large as possible.
-A more predictable landing distance (as the POH only specifies 40 flap landings, and the float is more predictable).
-Students are able to practice controlling the plane at a slower speed, and demonstrate proficency on a regular basis across a broader range of flight conditions.
-Better forward visibility (to see things like coyotes and crop dusters on the runway).
-Lower energy on touchdown (less braking required).

The Cons
-Less control authority on approach (especially for countering crosswind)
-Possibly a "more complex" overshoot procedure.
-Control buffeting when slipping with full flap (which is why it is not advised in the POH)
-Less "float" before touchdown, this may be a pro or con depending on context.

In short I agree that it is good to have the option of choosing a flap setting appropriate for the condition. Problems arise when students are only taught to land in one set flap condition; they should understand the full extent of the plane's capabilities and when to use them.

Re: Full flap landing rquired

Posted: Thu Jun 27, 2019 10:07 pm
by rotorspeed
I don't understand what a PAPI is for if you don't use it. Several months ago when doing night training my instructor was very specific fly the PAPI correctly. It's very odd at 500 agl to drop to 40° and "push" the thing to the runway

Re: Full flap landing rquired

Posted: Thu Jun 27, 2019 11:40 pm
by PilotDAR
Just wait until you've made the runway before adding the final 40. And you shouldn't be on "glideslope"....you should be well above the PAPI slope to do a reasonable landing with 40 degrees of flap. Dragging it along a 3 degree glideslope with lots of power using 40 degrees of flap is highly unreasonable IMO, and I don't think an examiner would be too impressed.
This. If you're actually flying an approach from which an overshoot is more than remotely likely (like you don't have the runway in sight yet), it would be foolish to have full flap extended. A 172 will go around fine with full flaps (a certification requirement), but good decision making would minimize a pilot's exposure to having to do it.
I'm wondering how much weight you'd save if cessna were to build a 172 without a flap system
Not much, I'd guess 8 pounds or so. The flaps were first born on the Cessna 170B, because the plain flaps of the C 170A were considered in effective. Other types I know have had fowler flaps added to their design by STC/TC change after original certification - Found Bush Hawk, some twin Cessnas, and Thurston Teal, so they are obviously desired.
-Control buffeting when slipping with full flap (which is why it is not advised in the POH)


Hands up.... how many people posting have actually experienced this (my hand is up). This is a characteristic of only certain older models of the 172, though most models bear the placard, the later ones needlessly. Tailboom shape and dorsal fin arrangement play a role in whether that particular model of the 172 is vulnerable.

Re: Full flap landing rquired

Posted: Fri Jun 28, 2019 7:44 am
by 5x5
rotorspeed wrote:
Thu Jun 27, 2019 10:07 pm
I don't understand what a PAPI is for if you don't use it. Several months ago when doing night training my instructor was very specific fly the PAPI correctly. It's very odd at 500 agl to drop to 40° and "push" the thing to the runway
I'd strongly recommend you go back to your instructor and ask why they are using an aid designed for flying an IFR approach for a VFR approach. Maybe he doesn't know what a PAPI is for either? That is a very dangerous procedure and I hope you misinterpreted what he said. Typically "on the glideslope" you would be going much faster than 60 and you would certainly not be using full flaps. If you are using PAPIs for VFR flight it is only to insure that you don't get below the glidepath at night to insure terrain clearance. And definitely at night you don't want to be dragging in a 172 with full flaps, high power on a 3°approach angle.

Re: Full flap landing rquired

Posted: Fri Jun 28, 2019 8:29 am
by digits_
5x5 wrote:
Fri Jun 28, 2019 7:44 am
rotorspeed wrote:
Thu Jun 27, 2019 10:07 pm
I don't understand what a PAPI is for if you don't use it. Several months ago when doing night training my instructor was very specific fly the PAPI correctly. It's very odd at 500 agl to drop to 40° and "push" the thing to the runway
I'd strongly recommend you go back to your instructor and ask why they are using an aid designed for flying an IFR approach for a VFR approach. Maybe he doesn't know what a PAPI is for either? That is a very dangerous procedure and I hope you misinterpreted what he said. Typically "on the glideslope" you would be going much faster than 60 and you would certainly not be using full flaps. If you are using PAPIs for VFR flight it is only to insure that you don't get below the glidepath at night to insure terrain clearance. And definitely at night you don't want to be dragging in a 172 with full flaps, high power on a 3°approach angle.
Why would you *not* fly a papi at night? Especially when learning to fly approaches at night, it is a valuable tool to get used to what a 3 degree glideslope looks like at night. Being too high is as big of a challenge as being too low when learning to fly at night, albeit with less severe consequences when you get it wrong.

Re: Full flap landing rquired

Posted: Fri Jun 28, 2019 4:31 pm
by photofly
PAPI's aren't very useful if you're flying circuits in a small plane. Actually they're not very useful in a small plane at all, unless you enjoy being a mile final at 300' AGL. They also take you to a touchdown zone typically 1000' feet from the threshold, which is a waste of runway.

They're helpful for long straight-in approach at night, which can be hard to judge visually. In that scenario misjudging the approach is probably the biggest danger so it makes sense to mitigate this risk at the small expense of the others.

Re: Full flap landing rquired

Posted: Fri Jun 28, 2019 9:57 pm
by fish4life
If your approach speed is 60kts and you have 10 kts of headwind your V/S on a 3 degree would only be 250 FPM. That is not a natural or reasonable decent rate in a small aircraft

Re: Full flap landing rquired

Posted: Sat Jun 29, 2019 6:22 am
by digits_
fish4life wrote:
Fri Jun 28, 2019 9:57 pm
If your approach speed is 60kts and you have 10 kts of headwind your V/S on a 3 degree would only be 250 FPM. That is not a natural or reasonable decent rate in a small aircraft
So what is a natural or reasonable descent rate in a small aircraft? How many degrees glideslope should one use?

What about IFR approaches in small aircraft?

Re: Full flap landing rquired

Posted: Sat Jun 29, 2019 7:04 am
by GoinVertical
When I was instructing, we used to teach students to maintain 3 white, 1 red on the PAPIs. Keeps you a bit steeper than 3 degrees while allowing them to still show deviation.

Re: Full flap landing rquired

Posted: Sat Jun 29, 2019 11:13 am
by digits_
GoinVertical wrote:
Sat Jun 29, 2019 7:04 am
When I was instructing, we used to teach students to maintain 3 white, 1 red on the PAPIs. Keeps you a bit steeper than 3 degrees while allowing them to still show deviation.
Why? Why not 2 white 2 red like they were designed? If you fly 2 white 2 red you'll be flying a bit steeper than a 737 anyway.

Sure, you could throw away 1000 ft on an 8000 ft runway, but at the majority (all?) runways with papis, that shouldn't be a problem in a light airplane.

If necessary for obstacles, short field, soft field, whatever, go ahead and change the approach path, but unless there is an important reason for it, I don't see why you would intentionally deviate from a 3 degree glideslope. Especially at night.

Re: Full flap landing rquired

Posted: Sat Jun 29, 2019 11:34 am
by photofly
digits_ wrote:
Sat Jun 29, 2019 6:22 am

So what is a natural or reasonable descent rate in a small aircraft? How many degrees glideslope should one use?
500fpm, at 60 kts g/s is 5°. Steeper if you like power-off approaches.
If you fly a 3° approach in a circuit from 1000 agl you're flying more than three track miles from the point when you start your descent, which is quite absurd: it's a space-shuttle sized circuit and will thoroughly piss off everyone else in the same air as you.
digits_ wrote:
Sat Jun 29, 2019 6:22 am
What about IFR approaches in small aircraft?
IFR approaches are all designed for transport aircraft, but a Cessna 172 is not a Boeing 737. Of course you can emulate their approach path, if you have to, but it's a terrible way to fly in VFR conditions.

Re: Full flap landing rquired

Posted: Sat Jun 29, 2019 12:28 pm
by digits_
photofly wrote:
Sat Jun 29, 2019 11:34 am
digits_ wrote:
Sat Jun 29, 2019 6:22 am

So what is a natural or reasonable descent rate in a small aircraft? How many degrees glideslope should one use?
500fpm, at 60 kts g/s is 5°. Steeper if you like power-off approaches.
If you fly a 3° approach in a circuit from 1000 agl you're flying more than three track miles from the point when you start your descent, which is quite absurd: it's a space-shuttle sized circuit and will thoroughly piss off everyone else in the same air as you.
You are not flying the whole approach at 60 kts. Only the last part. If you calculate it with an average 75 kts (80kts downwind-base, 70 base-final), which seems to be the speed FTUs around here use for a 172, you end up with a 75*5.5 = 413 ftpm. I don't find that too silly or absurd. The initial part from the descent can be a bit steeper, on base, and then line you up for a nice 3 degree final approach. No space shuttle sized circuits required. I've always found it important to show what the standard 3 degree approach looks like. A big part of students will end up commercially at some point, getting used to a 3 degree glide slope right away is pretty valuable.

Including take off and landing, the circuits at the airport where I used to instruct were about 8 nm each. Students still wanted to make it bigger to get more time to set up the plane. Another airpot mandated a strict circuit pattern that was about 6.5 NM long. That one only allowed a 3 degree glidepath on one runway, for the other one the base-final was too short to do it properly.