Low Speed / High Flaps Landing

[FlyingMonkey]

Hey all...

I have said in several threads that for short field operations in calm conditions I like to use 30° flaps and very slow approach speeds 50kt and below (I like a target of 48kt when solo).  This combination works very well for me, and I have landed in fields as short as 1250ft with high trees at the approach end, by adding in a slip.  The low speed allows you to come in steeply and "stick" the landing with no float, since the airplane doesn't have much excess energy.  With a passenger or otherwise heavy I use the same technique and 52-55kt.     

So I thought folks might like an example of this.  Over the weekend I went to a fly-in at Aerie (1GA9), which is owned by a friend of mine.  It's grass and listed as 2000ft, though it's probably closer to 1800ft of usable turf, the rest being too rough.  As I approached from the north to land a Cessna was coming in from the south.  I was on heading for a good base to a long final, so I just did that as you can hear.  I usually do very tight patterns, so this 1.5 mile final was unusual for me, but made for a nice stable approach.  I usually don't go to 30° flaps until I almost have the runway made, but in this case I put the flaps in immediately and just left a little power in to keep the sink rate down.  That made for a slow approach so I could keep an eye out for the Cessna and other traffic (this fly-in often has very small airplanes with no radios).

You can almost read my speed on the Dynon in the video, it's 47-48kt pretty much all the way down, 46kt over the road and touchdown right at the POH stall speed of 42kt.  I didn't have much elevator authority at the bottom, so I kept the nose wheel up as long as possible, then you can see some slight bouncing in the grass, which was a bit lumpy.  The road near the approach end has no wires, so the only consideration is staying 25ft or so above it in case a truck comes through (both a Cub and a Bonanza have clipped trucks on approach or takeoff there, nobody injured either time!).  I look a bit low over the road in the video, but it's a slight wide angle lens so I look a bit lower than I am.  I made the midfield parking turnoff, whereas most folks had to back taxi because they went past it.  I got lots of compliments on this landing from ground observers, so that always feels good.     

As you can see, even at these lower speeds with flaps the airplane is very controllable.  The only caveat here is that this is my *calm conditions* technique.  If there were gusty winds or crosswinds I would add some speed and might even go with 15° and a fat slip instead of 30° flaps, it just depends.  With this low speed, 30° flaps, and a slip you can come down like a meteor over obstacles, and then straighten up at the bottom and land like a hero.  YMMV and everybody has their own style, but this works for me.       

 

 

[Ed Cesnalis]

That's a real nice approach and landing Andy.

I'm guessing that you used some throttle most of the way in.  Your pitch attitude looks higher than I'm used to with a closed throttle.  

At 2:50 I go 30 degrees and close my throttle and glide in at ~50kts.  Is it the camera angle or is there a big difference in pitch attitude on approach?

 

[FlyingMonkey]

Thanks, Ed.  You're correct, it was a *much* longer final than normal for me, so I had to keep some power in to make sure I ran out of distance to the runway before I ran out of altitude.  

[WmInce]

On 6/5/2017 at 9:57 AM, FlyingMonkey said:

Hey all...

I have said in several threads that for short field operations in calm conditions I like to use 30° flaps and very slow approach speeds 50kt and below (I like a target of 48kt when solo).  This combination works very well for me, and I have landed in fields as short as 1250ft with high trees at the approach end, by adding in a slip.  The low speed allows you to come in steeply and "stick" the landing with no float, since the airplane doesn't have much excess energy.  With a passenger or otherwise heavy I use the same technique and 52-55kt.     

So I thought folks might like an example of this.  Over the weekend I went to a fly-in at Aerie (1GA9), which is owned by a friend of mine.  It's grass and listed as 2000ft, though it's probably closer to 1800ft of usable turf, the rest being too rough.  As I approached from the north to land a Cessna was coming in from the south.  I was on heading for a good base to a long final, so I just did that as you can hear.  I usually do very tight patterns, so this 1.5 mile final was unusual for me, but made for a nice stable approach.  I usually don't go to 30° flaps until I almost have the runway made, but in this case I put the flaps in immediately and just left a little power in to keep the sink rate down.  That made for a slow approach so I could keep an eye out for the Cessna and other traffic (this fly-in often has very small airplanes with no radios).

You can almost read my speed on the Dynon in the video, it's 47-48kt pretty much all the way down, 46kt over the road and touchdown right at the POH stall speed of 42kt.  I didn't have much elevator authority at the bottom, so I kept the nose wheel up as long as possible, then you can see some slight bouncing in the grass, which was a bit lumpy.  The road near the approach end has no wires, so the only consideration is staying 25ft or so above it in case a truck comes through (both a Cub and a Bonanza have clipped trucks on approach or takeoff there, nobody injured either time!).  I look a bit low over the road in the video, but it's a slight wide angle lens so I look a bit lower than I am.  I made the midfield parking turnoff, whereas most folks had to back taxi because they went past it.  I got lots of compliments on this landing from ground observers, so that always feels good.     

As you can see, even at these lower speeds with flaps the airplane is very controllable.  The only caveat here is that this is my *calm conditions* technique.  If there were gusty winds or crosswinds I would add some speed and might even go with 15° and a fat slip instead of 30° flaps, it just depends.  With this low speed, 30° flaps, and a slip you can come down like a meteor over obstacles, and then straighten up at the bottom and land like a hero.  YMMV and everybody has their own style, but this works for me.

 

Nicely done, Andy.

Thanks for the video and narrative.

[FlyingMonkey]

BTW, if anybody wants to practice this kind of approach and landing, but is apprehensive about the low speeds involved, it's easy to practice and demonstrate to yourself that the CT flies well in these conditions:

Climb to 3000ft or more AGL on a calm day, and just close the throttle, slow down to 30° flaps speed, and deploy flaps to that setting.  As always, pitch sets speed and throttle sets altitude, so pitch for 50kt and keep the ball centered.  Maintain that for a bit, wiggle the ailerons and confirm you have good roll authority.  Now pitch back to 48kt and wiggle again.  Then 46kt.  Then 44kt, etc.  Somewhere around 40-42kt, you'll find the nose doesn't want to come up any more and may bob a bit, and sink rate will probably go to 800-900fpm.  That is the stall point.  Simply push forward to 44kt+ and you'll be flying again and get roll control back.  

That's all you have to do on a landing approach, find a speed you like (again, I like 48kt) and hold it.  The sink rates can be higher than you are used to, and the approach steeper; if you end up low, just add some throttle to arrest the descent until you are back on your intended glide slope, then pull the throttle back out.

I hope folks find this helpful.   

[Ed Cesnalis]

I did a minimum speed, 30* landing this morning from a strait in approach with VASI.  

I used the VASI to judge my 850' descent from pattern altitude with 30* flaps and closed throttle.  I began at 8,000' (field at this end 7,150') and four white lights.  

On a low straight in from the point where all lights are white I need to close 1/2 the distance to the field before I close my throttle and begin the descent.

30* approaches can be really steep which allows for very tight patterns and off at the 1st exit.

[FlyingMonkey]

Ed, I find VASI / PAPI lights to have too shallow a glide path for most LSA.  Because of our low inertia we tend to come in steeper.  The lights are an okay guide for long distance approaches like you mentioned, but for normal pattern operations they put me too low.  Do you see the same thing?

[Ed Cesnalis]

Sure the same thing.  Perhaps the reason in noting the closed throttle angle is to do that glide to the runway if engine out thing.

The LSA approach is steep in all or most configurations but where the angle changes dramatically is at 30* / 1.3Vso / closed throttle.  At this point all I can see is the ground until I round out.  

[Runtoeat]

Nice video and good landing Andy.  You too Ed.

[Madhatter]

Be sure to verify that you static system is tight when flying this slow, an open static will will give you a higher airspeed indication than you are actually flying. When I bought my CTSW my indicated airspeed was 10 knots higher than I was flying and I could easily tell. I Have seen this dozens of times in all types of aircraft not all as significant as the CTSW. I have IFR certified hundreds of aircraft in my repair station and I have found half with leaks but about 10-20% completely open. I had one instructor/owner tell me when flying the right approach speed he would sometimes here the stall warning, it was an open static system. That turn to final could bite you.

[Ed Cesnalis]

42 minutes ago, Madhatter said:

Be sure to verify that you static system is tight when flying this slow, an open static will will give you a higher airspeed indication than you are actually flying. When I bought my CTSW my indicated airspeed was 10 knots higher than I was flying and I could easily tell. I Have seen this dozens of times in all types of aircraft not all as significant as the CTSW. I have IFR certified hundreds of aircraft in my repair station and I have found half with leaks but about 10-20% completely open. I had one instructor/owner tell me when flying the right approach speed he would sometimes here the stall warning, it was an open static system. That turn to final could bite you.

The pitot static system isn't even needed for low speed high flap approach and landings in a CTSW. I prefer not to rely on the ASI when landing.

There is a pretty big pitch change at 30* and closed throttle and you can check it visually. The right attitude produces a normally drooped wingtip that is now level with the horizon. 

 

 

[FlyingMonkey]

Of course you want your instruments to be accurate, but Ed is right.  You are not going to be this slow until established on final, so no turns.  You can tell by the sink rate what the airplane is doing, and adjust with pitch and power changes.

I glance at airspeed periodically on the approach, but you don't really need to.

[Madhatter]

Good luck

[Ed Cesnalis]

6 hours ago, FlyingMonkey said:

Of course you want your instruments to be accurate, but Ed is right.  You are not going to be this slow until established on final, so no turns.  You can tell by the sink rate what the airplane is doing, and adjust with pitch and power changes.

I glance at airspeed periodically on the approach, but you don't really need to.

I routinely go to 30* and closed throttle on downwind when abeam.  Turns are not a problem as long as you coordinate and maintain the nose low pitch attitude.

I have even had my pitch trim  changed to allow more nose down so I can trim for a minimum speed approach.   

[Ed Cesnalis]

46 minutes ago, JohnnyBlackCT said:

I do 10 degrees flaps abeam the numbers, 20 degrees on base, and 30 degrees on final when the field is made.  I see no reason to add more flaps than needed, sooner than needed.

 

Going 30* and closed throttle from abeam means I fly a tighter pattern it doesn't mean I am add more flaps than needed. I am adding the same amount as you.  I am not adding them sooner than needed, once I past the point abeam my need is to land as expeditiously as possible because the guy behind me is likely much faster.  If there is a need to extend my downwind then I will wait longer on the flaps.

 

------------------------------------

 

Once past the point abeam the numbers any delay is only taking you farther from the runway and increasing the amount of glide required to get there.  I had a CT quit on final on my first ride but because it was a normal power off glide to the numbers it didn't cause an issue or even a need to try to restart.

 

 

 

[Tom Baker]

1 hour ago, JohnnyBlackCT said:

I do 10 degrees flaps abeam the numbers, 20 degrees on base, and 30 degrees on final when the field is made.  I see no reason to add more flaps than needed, sooner than needed.

The CT doesn't have 10° or 20° flap settings.

[FlyingMonkey]

14 hours ago, Ed Cesnalis said:

I routinely go to 30* and closed throttle on downwind when abeam.  Turns are not a problem as long as you coordinate and maintain the nose low pitch attitude.

I have even had my pitch trim  changed to allow more nose down so I can trim for a minimum speed approach.   

I usually go 15° abeam the numbers and close the throttle, and then go to 30° on final.  I just like that because it gives me a bit more gliding range until final, but with a close enough base it doesn't matter much.  Potato, potahto.

I have to keep a little back pressure in to maintain these low speeds, but I like the feel of that and if I ever get lazy the airplane tends to nose down instead of pitching back more toward the stall.  Again, dealer's choice on technique, it's just preference. 

[Doug G.]

3 hours ago, JohnnyBlackCT said:

I don't fly a CT.  Never been in one.

I think most here would agree that although basic techniques are the same the characteristics of the CTs are somewhat unique. One of the reasons for this is visual. (Few other LSAs give you a view where you don't see the nose of the plane, for one example.) Another is that CTs have flaperons where the ailerons droop with the flaps, and, they have a stabilator with no horizontal stabilizer. Three axis trim is another uncommon feature as is a steerable nose wheel with non-differential braking.

All planes are not the same.

 I am curious about your moniker and what brings you to this site?