Optimal landing speed

Any DA40 related topics

Moderators: Rick, Lance Murray

Post Reply
User avatar
BlueYonder
3 Diamonds Member
3 Diamonds Member
FIRST NAME: Sara
Aircraft: DA40
Registration: N728DE
Airport: S43

Posts: 90
Joined: Sun Nov 20, 2016 12:43 am
Has thanked: 16 times
Been thanked: 11 times

Optimal landing speed

Post by BlueYonder »

I'm coming to the DA40 after several years flying Cessnas, and I'm getting conflicting information from different sources (all fairly authoritative) on the right landing speed. I've spent about 60 hours in the DA40 cockpit and set down well over 100 landings at this point, and they're not coming together the way my Cessna landings usually did.

Per one instructor, I tried for a while to come over the fence at the 70kts that's just about right for a 172. Another one (with a lot more DA40 experience) suggested I drop it to 65, which he says is Diamond's recommended over-the-fence speed. I seem to be struggling with this lower speed. The plane seems to run out of energy before I'm fully into the flare, and I end up slamming down into the runway. It's not soft, pretty, or elegant like my Cessna landings usually are -- and it's damn hard on the bird.

The fact that I am now replicating this ugly pancake landing every time, with near-perfect reliability, suggests I'm missing something big here -- and missing it with astonishing consistency. Whatever this bad habit is, I'm reinforcing it every time I land this way, which is also not a happy thought. I don't want to be this consistently good at the same ugly landing. :roll:

Any and all suggestions appreciated.
The highest art form of all is a human being in control of himself and his airplane in flight, urging the spirit of a machine to match his own. -- Richard Bach
User avatar
dafzero
3 Diamonds Member
3 Diamonds Member
FIRST NAME: David
Aircraft: DA40
Registration: N468MA
Airport: KAVL

Posts: 54
Joined: Tue Apr 05, 2016 2:22 am
Has thanked: 17 times
Been thanked: 8 times

Re: Optimal landing speed

Post by dafzero »

Hello Blueyonder,

I'm fairly new to my DA 40 is well and I did the same transaction as you did from Cessna's. I didn't find the transaction too difficult, in fact I found it easier to land than the Cessna's although with its long wings it does like to float a bit .

It may be that you're coming in a little too slowly over the fence. I shoot for 70 kn over the numbers. I found a good website by Gerry that has a lot of really useful number type information. SOP stuff. Here is the URL.

http://www.flygerry.com/configurations- ... figuration

David
David Bevan
2005 40.547
Asheville, NC
Antoine
5 Diamonds Member
5 Diamonds Member
FIRST NAME: Antoine
Aircraft: OTHER
Registration: N121AG
Airport: LSGG

Posts: 2038
Joined: Fri Oct 15, 2010 11:00 pm
Has thanked: 87 times
Been thanked: 210 times

Re: Optimal landing speed

Post by Antoine »

Hi Sara

From my experience, the DA40 has a narrow "sweet spot" for landing speed, weight dependent:

At MTOW I go for 70 KIAS at the gate
Very light, it's 65

If you come in too fast, you need to master the art of flying close to the runway in ground effect and letting speed bleed out - the plane will ultimately want to settle down.
As you feel this about to happen you should pull up gradually to dampen the touchdown. This is good in calm winds but risky in gusty conditions.
I am sure you noticed that a touchdown with excess energy will be punished by a nasty bounce.

If you come in too slow, the controls become mushy and as you said the stall is abrupt. What you want is to be so close to the runway when you stall to make the event imperceptible! ;) takes some practice!

Here's what I would try: come in slow, but with a predicted touchdown point a bit further down the runway.
This way, you won't have to stretch the remaining energy to "reach" for the runway.
A successful full stall landing close enough to the runway is impressive: the plane has so little energy left that it almost stops right after touchdown.

My preference is to nail the speed and allow some safety margin by means of the displaced touchdown point.
And let us know when you achieve a real greaser!
User avatar
Steve
5 Diamonds Member
5 Diamonds Member
FIRST NAME: Steve
Aircraft: DA40
Registration: N432SC
Airport: 1T7

Posts: 1273
Joined: Thu Aug 12, 2010 1:23 am
Has thanked: 35 times
Been thanked: 208 times

Re: Optimal landing speed

Post by Steve »

Sara:

Antoine is right on. Final approach speed in the DA40 is weight dependent (as is best glide, Vy, Vs, etc.). It ranges from 71 KIAS at 2535 pounds GW, to as little as 58 KIAS at 1874 pounds GW (which I could only achieve with completely empty tanks and cutting off one of my legs and tossing it overboard)...

I fly these speeds (allowing for gusty conditions as necessary) as precisely as I can. I have over 1000 landings in the DA40, and without bragging, most are heard rather than felt. OK, I'm bragging a little. Concentrate on your speed control and soon your landings will be smooth as silk.

Steve
User avatar
BlueYonder
3 Diamonds Member
3 Diamonds Member
FIRST NAME: Sara
Aircraft: DA40
Registration: N728DE
Airport: S43

Posts: 90
Joined: Sun Nov 20, 2016 12:43 am
Has thanked: 16 times
Been thanked: 11 times

Re: Optimal landing speed

Post by BlueYonder »

Great input. Keep it coming.

What I'm hearing from the posts above that the pancake happens with errors in either direction: either you come down too fast and hard, and bounce; or you come down too slow, run out of energy, drop out of the air, and bounce. That's pretty consistent with my experience.

I asked about over-the-fence/over-the-numbers speeds. Since I seem to hit my target speed there fairly consistently, it may be that the problem lies in the few seconds past that point, in what I do between the numbers and the touchdown point. So: How much of that 70kts do you bleed off between the numbers and actual touchdown? What do you reckon your actual speed is when the wheels finally connect to the runway?
The highest art form of all is a human being in control of himself and his airplane in flight, urging the spirit of a machine to match his own. -- Richard Bach
User avatar
Diamond_Dan
3 Diamonds Member
3 Diamonds Member
FIRST NAME: Dan
Aircraft: DA40
Registration: N456AS
Airport: KLWM

Posts: 83
Joined: Fri Sep 23, 2016 2:20 pm
Has thanked: 51 times
Been thanked: 9 times

Re: Optimal landing speed

Post by Diamond_Dan »

I am relatively new to flying and the DA40 coming from Cessna trainers at the flight school. I can't add much to the wisdom above, but I didn't find it too difficult to land without slamming it down. Low to the runway, I try to keep it 66-69 with just me on board. Keeping center-line is another story, but I can't blame the plane for that.

The question I have is - if I flare too high or float, bleeding off too much speed, I find I can still make a reasonable touchdown by easing the stick all the way back, effectively reducing the stall speed. (A tip from my instructor) I am concerned about the pitch-up attitude - is there danger of a tail strike? The protective metal strip is pretty scratched up. If I am contributing to it, I can't tell when I am landing.
Antoine
5 Diamonds Member
5 Diamonds Member
FIRST NAME: Antoine
Aircraft: OTHER
Registration: N121AG
Airport: LSGG

Posts: 2038
Joined: Fri Oct 15, 2010 11:00 pm
Has thanked: 87 times
Been thanked: 210 times

Re: Optimal landing speed

Post by Antoine »

Sara: It's probably your flare. Try bringing the plane VERY close to the runway and flare very very slowly as speed decays. You know you flared right when the flare does not cause any height gain.
Don't do it on a windy day though.

Hint: If you ever start porpoising (bounce, land on the nose gear), please remember this:
GO AROUND - do not think, just GO AROUND NOW! Sorry for capitals, not shouting, just making placards for you ;)

Dan: yes that works, and yes you can literally land it on the tail this way (I did it once :oops: , there's enough elevator authority to achieve this). You'll be rewarded by a loud bang though ... Find a compromise. I find a touch of throttle very effective a dampening the sink rate, also after a bounce.
User avatar
BlueYonder
3 Diamonds Member
3 Diamonds Member
FIRST NAME: Sara
Aircraft: DA40
Registration: N728DE
Airport: S43

Posts: 90
Joined: Sun Nov 20, 2016 12:43 am
Has thanked: 16 times
Been thanked: 11 times

Re: Optimal landing speed

Post by BlueYonder »

I'm the queen of the go-around -- no ego about it, and not much thought. Just power up and go. Even did it on my checkride. (The examiner was pleased.)

Adding in a little throttle when that final bad sink first starts is a good suggestion. It's also probably true that part of the problem is re-calibrating my physical sense of where the wings should be in relation to the ground, which I have to think is a common issue for those of us transitioning from high-wing planes. My landings have consistently improved as I've learned to trust just how low you can go -- but it may be that I'm not entirely there yet, and need to keep pushing myself downward even farther before the flare.
The highest art form of all is a human being in control of himself and his airplane in flight, urging the spirit of a machine to match his own. -- Richard Bach
User avatar
Colin
5 Diamonds Member
5 Diamonds Member
FIRST NAME: Colin
Aircraft: DA42
Registration: N972RD
Airport: KSMO

Posts: 1544
Joined: Sat Aug 21, 2010 8:37 pm
Has thanked: 176 times
Been thanked: 297 times

Re: Optimal landing speed

Post by Colin »

It was eleven years and 1,600hrs in the DA40. By the end I *almost* had the landings where I wanted them during the first three months of flying.

I come over the fence too fast. I really appreciate feeling the control forces and that happens more with airspeed over the control surfaces. So after my first six months I did some work to get slower. That was difficult. I think I was 85kts over the fence for the first hundred landings.

The real key was the advice that I got when I was first transitioning (and I think ignored): Fly the plane onto the runway. Cessna and Piper planes you come down, flare, and then plane settles or drops that last foot. The DA40 (and Mooneys), you carry power all the way into the flare. It didn't always work out that way for me, I reflexively pull all power as I cross the numbers, but I am always fast, but I got the idea. You keep the nose lower than you think.

You have a mile long runway. This was the thing that helped the most for me, which I did at KCMA's 6,000 foot runway, was to try to stay a foot off the runway. The speed control and feeling of bring in ground effect were key to understanding what was happening in the last two feet of getting the wheels on the ground.

By the very end I was usually able to put the wheels on the pavement at 50kts or a little less. You should hear the stall horn continuously for the last two feet, if you don't, you're too fast.

My third landing in a DA40 was in the demonstration plane at the dealer after a two hour flight back from Vegas. I dropped N181EB from eight feet (it felt like) onto the runway. One big bounce and we were down. I said, "Glad it's not my plane," and the salesman said they were really tough machines. I wound up buying that plane with 115hrs on it. Probably a few hard landings in those 115hrs.
Colin Summers, PP Multi-Engine IFR, ~2,600hrs
colin@mightycheese.com
http://www.flyingsummers.com
N972RD DA42 G1000 2.0 s/n 42.AC100
N971RD DA40 G1000 s/n 40.508 (traded)
User avatar
Chris B
5 Diamonds Member
5 Diamonds Member
FIRST NAME: Chris
Aircraft: DA40
Registration: N171CB
Airport: KRHV

Posts: 816
Joined: Wed Sep 26, 2012 1:52 am
Has thanked: 185 times
Been thanked: 187 times

Re: Optimal landing speed

Post by Chris B »

Hi Sara -

IMO many DA40 pilots come in way too fast. Once the long wings get into ground-effect, induced drag evaporates and the DA40 wants to float, and/or balloon.

Take advantage of the stall warning horn. It should be chirping (not blaring!) on short final when you are on-speed for your current weight. Try this at altitude until you are comfortable at low speed, where the DA40 has exceptional handling. See how slow you can fly after descending to an arbitrary "deck," and how loud the stall warning horn must be screaming before you actually stall.

Also, try holding the nose gear off the runway until you run out of pitch authority. Unlike a C182, this does not pose a risk to the firewall. ;)

Chris
Post Reply