SOP to land with 10 degrees of flaps in 172?
Moderators: sky's the limit, sepia, Sulako, Right Seat Captain, lilfssister, North Shore
SOP to land with 10 degrees of flaps in 172?
I see a number of flight schools here have an SOP that says to land their 172s with 10 degrees of flaps unless doing a short field landing. I'm curious what the reason is. They don't mind if you land with more flap even if it's not short field, but they teach their students to do normal landings with 10 degrees.
-
Cat Driver
- Top Poster
- Posts: 18921
- Joined: Sun Feb 15, 2004 8:31 pm
Re: SOP to land with 10 degrees of flaps in 172?
Could you explain why?Easier on the nosewheel
The hardest thing about flying is knowing when to say no
After over a half a century of flying no one ever died because of my decision not to fly.
After over a half a century of flying no one ever died because of my decision not to fly.
Re: SOP to land with 10 degrees of flaps in 172?
Higher nose at touchdown. Less chance of landing on the nosewheel
When I owned my 172, every landing was no flap, unless I was dealing with a runway under 1500 feet.
When I owned my 172, every landing was no flap, unless I was dealing with a runway under 1500 feet.
Re: SOP to land with 10 degrees of flaps in 172?
I don't know why FTUs would reccomend this practice, but I know when I bombed around the country in my own 172, I very rarely had any reason to land with full flaps.
A couple rough runways, gravel runways where I wanted to touch down as slow as possible. But anything paved there was never any reason for me to use flaps. I much preferred to slip it if I needed to get down without gaining speed
A couple rough runways, gravel runways where I wanted to touch down as slow as possible. But anything paved there was never any reason for me to use flaps. I much preferred to slip it if I needed to get down without gaining speed
Re: SOP to land with 10 degrees of flaps in 172?
What a poor idea! Every landing I have flow in a Cessna has been at the maximum permitted flap extension - and in 40 years, I've never hurt a nosewheel. Any Cessna is flap position vs landing gear damage idiot proof if flown by the POH. If flap position has been attributed to landing gear, or any other damage, it was rather inadequate pilot training. I'm not advocating silly STOL attempts, but rather neat, controlled flying of the aircraft, within the intended Cessna design. Note that Robertson high performance Cessnas do require a special touch with full flaps, which is a training issue - the plane meets the requirements for handling...
Some Cessnas as floatplanes/amphibs are full flaps limited (not 10), that is appropriate, as flight test demonstrated the need for a bit less flap to assure a safe landing attitude.
If you're being trained, or otherwise guided, to fly a plane not to the limits of the normal procedures, ask why....
Some Cessnas as floatplanes/amphibs are full flaps limited (not 10), that is appropriate, as flight test demonstrated the need for a bit less flap to assure a safe landing attitude.
If you're being trained, or otherwise guided, to fly a plane not to the limits of the normal procedures, ask why....
Re: SOP to land with 10 degrees of flaps in 172?
Is it not the opposite? I've always thought that the nose is higher in the flare with flaps, as you need a higher AoA to keep flying at the lower speed. Landing with zero flaps always seems flatter. I guess it could be a factor if the student didn't bother flaring at all.dirtdr wrote:Higher nose at touchdown. Less chance of landing on the nosewheel
When I owned my 172, every landing was no flap, unless I was dealing with a runway under 1500 feet.
I find that 20 degrees of flaps in a 172 works well for normal landings...more than that you don't get any reduction in stall speed, just a steeper approach. I think with 10 degrees you'll probably float more. With no flaps you're touching down at a higher speed, which isn't ideal unless there's a strong wind.
Re: SOP to land with 10 degrees of flaps in 172?
Not using full flaps on every landing isn't the same as never being taught how to use full flaps, nor the same as being taught never to use full flaps to land.
172s can do very nice landings with any flap setting available, as the POH makes clear. On can make a clear argument that always using full flaps is failing to fly the plane to the limits of normal procedures.
Practicing landings without flaps is also a good idea- they do jam, sometimes, and it's feasible to find oneself in a situation where there's no electrical power to extend them.
Personally I use 20 degrees of flap unless I can think of a reason not to. But more important than teaching students to use one particular flap setting as routine is to make sure they know what factors influence an appropriate choice of flap setting.
172s can do very nice landings with any flap setting available, as the POH makes clear. On can make a clear argument that always using full flaps is failing to fly the plane to the limits of normal procedures.
Practicing landings without flaps is also a good idea- they do jam, sometimes, and it's feasible to find oneself in a situation where there's no electrical power to extend them.
Personally I use 20 degrees of flap unless I can think of a reason not to. But more important than teaching students to use one particular flap setting as routine is to make sure they know what factors influence an appropriate choice of flap setting.
DId you hear the one about the jurisprudence fetishist? He got off on a technicality.
Re: SOP to land with 10 degrees of flaps in 172?
ps. It's nice to have PilotDAR back to argue with. I've missed him.
DId you hear the one about the jurisprudence fetishist? He got off on a technicality.
Re: SOP to land with 10 degrees of flaps in 172?
The flaps have the effect of rotating the chord line of the wing in the nose-up direction because the trailing edge of the flapped section goes down. This means the aircraft fuselage has a lower nose position for the same angle of attack. Bluntly, lowering some flap improves your view of the runway.Is it not the opposite? I've always thought that the nose is higher in the flare with flaps, as you need a higher AoA to keep flying at the lower speed.
Many students are uncomfortable with the relative poorer view in the flare, the higher ground speed, and the runway eaten and put the plane on too fast when no flaps are deployed.Landing with zero flaps always seems flatter. I guess it could be a factor if the student didn't bother flaring at all.
DId you hear the one about the jurisprudence fetishist? He got off on a technicality.
-
youhavecontrol
- Rank 5
- Posts: 397
- Joined: Thu Jul 27, 2017 8:17 am
Re: SOP to land with 10 degrees of flaps in 172?
It seems silly to me to suggest one setting every time. It's ok to have a standard practice, but it's good to know the differences between settings and when to use them.
I know the POH says for normal landings, it's "as required" Flaps have their pro's and cons, but for the most part, using less flaps results in approaching at a faster landing speed. The faster speed gives you more control response, and a bit more energy to help with flare timing, but it also can tempt students to 'plant' the aircraft flat on the runway while they are waiting for it to touch-down because of the excess speed. (the Diamond Eclipse floats in the flare for a ridiculous amount of time with no flaps) Landing with more speed can make the aircraft more prone to nosewheel shimmy, and excessive wear on the tires and brakes, not to mention a longer flare and ground roll. But again, it does give a bit more energy and control response on landing, so I can see how some like to use less flaps, if they have a longer runway.
I usually use full flaps in the 172 because of the nose-down attitude on approach and the slower approach speed. The only time I raised them, for the most part, was if there was a strong crosswind. In a sideslip, the asymmetric drag from the flaps can make directional control more difficult.
I know the POH says for normal landings, it's "as required" Flaps have their pro's and cons, but for the most part, using less flaps results in approaching at a faster landing speed. The faster speed gives you more control response, and a bit more energy to help with flare timing, but it also can tempt students to 'plant' the aircraft flat on the runway while they are waiting for it to touch-down because of the excess speed. (the Diamond Eclipse floats in the flare for a ridiculous amount of time with no flaps) Landing with more speed can make the aircraft more prone to nosewheel shimmy, and excessive wear on the tires and brakes, not to mention a longer flare and ground roll. But again, it does give a bit more energy and control response on landing, so I can see how some like to use less flaps, if they have a longer runway.
I usually use full flaps in the 172 because of the nose-down attitude on approach and the slower approach speed. The only time I raised them, for the most part, was if there was a strong crosswind. In a sideslip, the asymmetric drag from the flaps can make directional control more difficult.
"I found that Right Rudder you kept asking for."
Re: SOP to land with 10 degrees of flaps in 172?
Yes, you're right. I was thinking about the flare rather than the approach, as it always seems that the nose is higher in a full flap landing. However that doesn't make sense aerodynamically, as the critical AoA is the same with or without flaps, which should result in a lower pitch attitude at stall with more flaps. Perhaps it's just easier to do a full-stall landing with flaps, whereas with less flaps there's more of a tendency to just let the plane land.photofly wrote:The flaps have the effect of rotating the chord line of the wing in the nose-up direction because the trailing edge of the flapped section goes down. This means the aircraft fuselage has a lower nose position for the same angle of attack. Bluntly, lowering some flap improves your view of the runway.
-
Cat Driver
- Top Poster
- Posts: 18921
- Joined: Sun Feb 15, 2004 8:31 pm
Re: SOP to land with 10 degrees of flaps in 172?
Here is a suggestion about using flaps on a Cessna 172.
Get a 172 on floats and see what happens on take off with various flap settings.
Start with zero flap and then every setting up to full flap.
If possible do this experiment with zero wind and glassy water.
Get back to me and let me know what you learned.
Get a 172 on floats and see what happens on take off with various flap settings.
Start with zero flap and then every setting up to full flap.
If possible do this experiment with zero wind and glassy water.
Get back to me and let me know what you learned.
The hardest thing about flying is knowing when to say no
After over a half a century of flying no one ever died because of my decision not to fly.
After over a half a century of flying no one ever died because of my decision not to fly.
Re: SOP to land with 10 degrees of flaps in 172?
Full flaps - unless I feel the need to reduce them in higher cross winds. I always aim for smooth low energy landings and flaps certainly assist that.
"Carelessness and overconfidence are more dangerous than deliberately accepted risk." -Wilbur Wright
-
Cat Driver
- Top Poster
- Posts: 18921
- Joined: Sun Feb 15, 2004 8:31 pm
Re: SOP to land with 10 degrees of flaps in 172?
That is why Cessna designed it that way.Full flaps - unless I feel the need to reduce them in higher cross winds. I always aim for smooth low energy landings and flaps certainly assist that.
The hardest thing about flying is knowing when to say no
After over a half a century of flying no one ever died because of my decision not to fly.
After over a half a century of flying no one ever died because of my decision not to fly.
-
Big Pistons Forever
- Top Poster
- Posts: 5869
- Joined: Wed Feb 18, 2004 7:17 pm
- Location: West Coast
Re: SOP to land with 10 degrees of flaps in 172?
The 10 dedree flap issue is as was already pointed out, aresponse to damaged firewalls resulting in from nose wheel first landings. The cause of this damage is not the amount of flap used but rather excessive approach speeds.
More flaps exacerbates a too fast approach because the aircraft will float in ground effect in a nose low attitude due to the effect on the wing chord line as was described in photo's post, thus setting up the nose wheel first hit and subsequent bounces off the nose wheel. The third hit is usually when the damage occurs
The reduced flap landing reduces the potential for this incident because the aircraft will be in a more nose high attitude even with the extra excessive speed.
Re teaching landings, my 02 cents
When I instructed in C 172's I taught new pilots to use 10 deg of flap for crosswind, 20 deg for normal landings and 30 deg for short field. The only time 40 deg was used ( if available) was for forced approaches.
20 flap Approach speed was 65 kts, + 0 and - 5. I found that an on speed approach required a proper flare, resulted in enough float so that the student could learn to manage the aircraft in the flare, yet the time in the flare wasn't so excessive that the student was likely to over control, so that in my mind maximum learning occurred.
More flaps exacerbates a too fast approach because the aircraft will float in ground effect in a nose low attitude due to the effect on the wing chord line as was described in photo's post, thus setting up the nose wheel first hit and subsequent bounces off the nose wheel. The third hit is usually when the damage occurs
The reduced flap landing reduces the potential for this incident because the aircraft will be in a more nose high attitude even with the extra excessive speed.
Re teaching landings, my 02 cents
When I instructed in C 172's I taught new pilots to use 10 deg of flap for crosswind, 20 deg for normal landings and 30 deg for short field. The only time 40 deg was used ( if available) was for forced approaches.
20 flap Approach speed was 65 kts, + 0 and - 5. I found that an on speed approach required a proper flare, resulted in enough float so that the student could learn to manage the aircraft in the flare, yet the time in the flare wasn't so excessive that the student was likely to over control, so that in my mind maximum learning occurred.
-
Schooner69A
- Rank 7
- Posts: 639
- Joined: Thu Nov 06, 2008 5:17 pm
- Location: The Okanagan
Re: SOP to land with 10 degrees of flaps in 172?
Worst thing Cessna ever did on the 172 was to restrict the flaps to 30 degrees.
I owned the predecessor of the 172 and every landing was with full (40) flap. It were great! (;>0)
I owned the predecessor of the 172 and every landing was with full (40) flap. It were great! (;>0)
Re: SOP to land with 10 degrees of flaps in 172?
Occasionally I fly a 172M with 40deg flaps. It's kind of nice when you're used to a Cherokee that sinks like a rock when you pull the power with the barn doors out. Helps get you out of the sky quicker 
"Carelessness and overconfidence are more dangerous than deliberately accepted risk." -Wilbur Wright
Re: SOP to land with 10 degrees of flaps in 172?
I find this just as silly as "banning" wheel landings because you are more susceptible to nosing over.
Stop dumbing it down and restricting, and start increasing training quality.
Stop dumbing it down and restricting, and start increasing training quality.
--Air to Ground Chemical Transfer Technician turned 4 Bar Switch Flicker and Flap Operator--
Re: SOP to land with 10 degrees of flaps in 172?
Seems like the right thing to do, modify SOP instead of getting the student to do it right.CpnCrunch wrote:I see a number of flight schools here have an SOP that says to land their 172s with 10 degrees of flaps unless doing a short field landing. I'm curious what the reason is. They don't mind if you land with more flap even if it's not short field, but they teach their students to do normal landings with 10 degrees.
