Short field landing help

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iRyan

Pre-takeoff checklist
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Ryan
Hey POA members,

Still working in my cfi and having an issue with short field landings. Im flying an Arrow II and normal approach speed is 75 mph over the numbers. I pick my spot and float past it, well past the 100'. I was focusing on my speed to be sure I was not too fast in final. I was pretty close to 75 (added 8 mph for wind). I didnt use full flaps b/c of the winds were gusting to 16. I know I cant teach it unless I perfect the landing and Im pretty frustrated. Since it is just my cfi and myself, should I reduce speed a bit more? I calculated the stall speed using the lift formula an it reduced it by about 5 mph. This cert. feels so out if reach.
 
Well...

I think the dirty little secret is that a lot of instructors can't demonstrate a perfect short-field landing every time.
 
As long as I can do it for me asi lol
 
Tell your examiner you're going to touch down right on the numbers. Now focus on a spot 100 feet in front of the numbers, even if the spot is not on the actual runway. Now fly as if you are gonna land on that artificial spot. You'll float right past it and land exactly on the numbers. Try it and adjust as necessary. Rinse and repeat.
 
In your normal weight configuration go out and do some regular landings but try and hold the plane off the ground with the stall horn sounding.
How much speed do you have to loose after the stall horn sounds before you touch down?
The short field landing should be flown to the ground with a "firm" touch down, you do not want to pull the nose up and flare.
It sounds like you are carrying too much speed at landing.
Pick your landing point and aim for about a planes length short of the spot, control your speed and land on your spot, don't flare.
The speed is critical, if you are going too fast it doesn't work.
 
What Art said.

I always pick the numbers but aim just short of the runway. That way you'll round out close to your touch down point and if youre too short just add power for a couple seconds.
 
If it is a T tail Arrow then hitting a given spot on a runway is a crap shoot...... IMHO...
 
Slow down, use full flaps. Practice.
 
iRyan said:
...normal approach speed is 75 mph over the numbers. ... I was pretty close to 75 (added 8 mph for wind).
Click to expand...
There's why. You added 8 MPH, but the wind is probably measured at 50' AGL.

dtuuri
 
Watch your speed,use full flaps,should work as long as we're not talking T tail.
 
You added 8mph and don't have full flaps.

Try it at speed and with full flaps. It will plunk down where it is aimed.
 
Every time I had an issue with landing during training, it inevitably boiled down to speed control. I'm a new pilot, but, statistically, there's a good chance that's the problem.
 
Thanks all for the tips.

My cfi does not like full flaps with gusty winds b/c he likes i have rudder for control. I always followed this tip. Primacy and all. What wind speed is too much for full flaps in a non-t tail arrow?

I want to teach the correct principles as I know I had some bad instruction over the years.
 
iRyan said:
Im flying an Arrow II and normal approach speed is 75 mph over the numbers.
Click to expand...
Try 70kts. 75kts is fine for a normal and soft field approach, but with a short field approach, it's more momentum that needs to bleed off. The rule of thumb is 1.3*Vso for shorties and 1.4*Vso for softies/normals. For a precise number, the performance charts will list the approach speed for your configuration.

Hope this helps!
 
NWADC9 said:
Try 70kts. 75kts is fine for a normal and soft field approach, but with a short field approach, it's more momentum that needs to bleed off. The rule of thumb is 1.3*Vso for shorties and 1.4*Vso for softies/normals. For a precise number, the performance charts will list the approach speed for your configuration.

Hope this helps!
Click to expand...

All true, but they'll most likely list numbers for max gross. In a light Arrow, that could easily be another 5 knots (of course, do the calc, or measure it, or both).
 
I've never flown one. What is the stall speed with full flaps. It seems you might be 10 mph too fast over the numbers. Have you taken it to altitude and stalled it? Flaps on- off? How long have you flown it?
 
iRyan said:
Hey POA members,

Still working in my cfi and having an issue with short field landings. Im flying an Arrow II and normal approach speed is 75 mph over the numbers. I pick my spot and float past it, well past the 100'. I was focusing on my speed to be sure I was not too fast in final. I was pretty close to 75 (added 8 mph for wind). I didnt use full flaps b/c of the winds were gusting to 16. I know I cant teach it unless I perfect the landing and Im pretty frustrated. Since it is just my cfi and myself, should I reduce speed a bit more? I calculated the stall speed using the lift formula an it reduced it by about 5 mph. This cert. feels so out if reach.
Click to expand...

The Arrow I and II has very little floating so I don't understand it, plus the approach speed I always used was 85mph. The airplane is very draggy at low speed. Is your airspeed indicator not accurate? When are you reducing your power?
 
I am going to go up next week an stall it with full flaps to see te speed. My cfi doesn't like to do short fields with full flaps and i think i am going to have to act like a cfi and use full flaps. I think you all are correct; I am coming in too fast. As for reducing power, he wants me to do it when I have the field made. I was reducing it over the threshold.
 
Slow it down on final. How many hours does the CFI have? Older person? Younger? How many hours does he have in this model? There are CFIs and then there are CFIs.
 
Being it in behind the power curve and chop the throttle at the numbers.

It'll stop short!

:goofy:
 
He's been at it for 30 years or so. He doesn't like full flaps b/c he feels the plane lander better with full flaps. I have always used full flaps on other planes and dragged it in. Now tht I want to teach, I am paying more attention and asking why. That's why I listened to him.

So what do you all think about using full flaps in gusty winds? Gusty for me is 15 kts. Is thAt gusty or do I need to put my big boys pants on.
 
Toss one 80# bag of dry concrete in the bag bay against the rear wall inside a trash bag. Your landing accuracy will improve 10X.
 
Been a while since I've flown an Archer, but some general observations.
1. You don't add airspeed for winds. Gust yes, winds no. Usually 1/2 the gust spread so in order to add 8 MPH you would need a 16 knot/MPH gust spread.
2. The approach speed you are using is most likely based upon maximum gross weight of 2600 lbs (or whatever the max gross weight of the model you are flying). As your weight decreases so does your stalls speed. Since approach speed is based upon 1.3xVso your approach speed should also decrease with your weight, though most older airplane POHs don't tell you this.
The formula for getting this new number is:
square root of OW/GW*book CAS. So, for example if you are operating at 2300 lbs and say the book speed is 70 MPH (I think most speeds in the older Arrow POHs are CAS), you new approach speed would be 2300/2600= .88. Square root .88= .94. .94x70=66. Then use the IAS/CAS conversion table in the POH to convert this to your desired IAS in MPH.
 
Gusty down the centerline in your face, use flaps.

Gusty with a bad X-wind component, no flaps.

just my humble opinion ....
 
Thanks for that Black. I was never taught about that formula and its use until I started prepping on my own for the CFI. Even now, my cfi doesn't calculate stall speeds based on weight. 5 knots is making a huge difference. I will be sure i stress this with my students.

Blackhawk said:
Been a while since I've flown an Archer, but some general observations.
1. You don't add airspeed for winds. Gust yes, winds no. Usually 1/2 the gust spread so in order to add 8 MPH you would need a 16 knot/MPH gust spread.
2. The approach speed you are using is most likely based upon maximum gross weight of 2600 lbs (or whatever the max gross weight of the model you are flying). As your weight decreases so does your stalls speed. Since approach speed is based upon 1.3xVso your approach speed should also decrease with your weight, though most older airplane POHs don't tell you this.
The formula for getting this new number is:
square root of OW/GW*book CAS. So, for example if you are operating at 2300 lbs and say the book speed is 70 MPH (I think most speeds in the older Arrow POHs are CAS), you new approach speed would be 2300/2600= .88. Square root .88= .94. .94x70=66. Then use the IAS/CAS conversion table in the POH to convert this to your desired IAS in MPH.
Click to expand...
 
OP is already way below book speed so I don't think that is the problem.

Where is your aiming point in relation to the selected touchdown point?
 
The whole maneuver should be renamed "Accuracy approach and landing"

It's not about how short you stop... its about flying a controlled and stabilized final so that you can touch at the same spot every time. You're constantly floating long by 100'? Back up the aim point 100'.
 
I think its a good thing to be able to choose a point on the runway and land close to it.

If you look at some of my Sky Arrow landings, you'll get the idea of how I do it - like others I begin the flare well short of that point so that I will arrive there at or very close to a full stall, as seen here (fast forward to 3:30 for the first landing).

http://www.youtube.com/watch?v=dhauE4oUeE0

But...

...that is NOT how I was taught short field landings, nor how I taught them, nor what examiners asked for.

More typically, the student would have to imagine 50' trees at the runway threshold*, and plan his final so as to arrive at a point 50' above them with little or no power at 1.2 Vso or speed as called for by the POH.

So, if the student hit 100' over the threshold with full flaps** and at or near idle, the demonstration was a success, assuming nothing went wrong in the roundout, flare, and landing. The exact point of touchdown was never a factor - except in Commercial power-off accuracy landings.

Now, this was quite some time ago, but it's how it was done when I was teaching.


* The logic was that most short runways are short for a reason - and that reason is often obstacles. No obstacles and they would have just made the runway longer. Not always the case, to be sure, but very often true.

**I have never heard of anything less than full flaps being specified for a short field landing.
 
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Cruiser said:
The short field landing should be flown to the ground with a "firm" touch down, you do not want to pull the nose up and flare.
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No flare? Just break the airplane? Sounds pretty sloppy to me.

Dan
 
There should be little to no floating during the flare on a short field approach. The momentum of the airplane should theoretically be going through the runway so as to have the plane dissipate its energy quickly on touchdown rather than keeping its momentum going down the runway, which is great for making soft touchdowns, but eats up runway length.
 
iRyan said:
Still working in my cfi and having an issue with short field landings. Im flying an Arrow II and normal approach speed is 75 mph over the numbers. I pick my spot and float past it, well past the 100'.
Click to expand...
That alone should a CFI candidate that s/he has too much speed over the fence.
I was focusing on my speed to be sure I was not too fast in final.
Click to expand...
Learn to focus on attitude, not the airspeed indicator. Set the right attitude and speed will take care of itself regardless of weight.

I was pretty close to 75 (added 8 mph for wind). I didnt use full flaps b/c of the winds were gusting to 16.
Click to expand...
If there was a 16-knot gust factor, then adding 8 knots would be appropriate -- half the gust factor (difference between steady state and gust velocities). But if it was only xxG16, then the gust factor was less than that (guessing much less, perhaps half or even less than that), then 8 knots (or even 8 mph) is way too much extra speed. Reducing flaps makes it even worse, as you are giving away the extra drag which shortens the flare -- the last notch being pretty much all drag and almost no lift. Unless the crosswind component is really astonishing (I'm talking like over 30 knots), you have all the lateral control you need in that Archer without reducing flaps to add more speed on final.

I know I cant teach it unless I perfect the landing and Im pretty frustrated. Since it is just my cfi and myself, should I reduce speed a bit more? I calculated the stall speed using the lift formula an it reduced it by about 5 mph. This cert. feels so out if reach.
Click to expand...
Cutting your approach speed by 1 knot per 100 pounds below max gross is a good start, but reducing flaps and adding 8 knots for gusts when the gust factor very counterproductive.
 
Thanks Ron and everyone else. I will try the options offered and let you all know the result.


Ron Levy said:
That alone should a CFI candidate that s/he has too much speed over the fence.
Learn to focus on attitude, not the airspeed indicator. Set the right attitude and speed will take care of itself regardless of weight.

If there was a 16-knot gust factor, then adding 8 knots would be appropriate -- half the gust factor (difference between steady state and gust velocities). But if it was only xxG16, then the gust factor was less than that (guessing much less, perhaps half or even less than that), then 8 knots (or even 8 mph) is way too much extra speed. Reducing flaps makes it even worse, as you are giving away the extra drag which shortens the flare -- the last notch being pretty much all drag and almost no lift. Unless the crosswind component is really astonishing (I'm talking like over 30 knots), you have all the lateral control you need in that Archer without reducing flaps to add more speed on final.

Cutting your approach speed by 1 knot per 100 pounds below max gross is a good start, but reducing flaps and adding 8 knots for gusts when the gust factor very counterproductive.
Click to expand...
 
I fly a Cherokee 235 and when I was practicing my short fields I was using 70mph (adjusting as others said for wind component) with me and my CFI in the cabin. I'd drag it in a bit knowing I was going to float some and then just chop power about 100 feet before my touchdown point and she'd come right down. (the hershey bar cherokee's - especially the 235 float with no power about like a rock with wings :))

Your short field landings will usually be a bit hard - certainly harder than a normal landing and that's OK. It was the one thing I was worried about on my checkride but I nailed it. I also extend my downwind when I'm flying a short field - I want a bit longer final to make sure I have it lined up right, have perfect speed and glideslope.

IIRC, you have 200' of margin to hit your spot on the checkride so practice various spots on the runway. I did my checkride at a remote airport relatively unfamilar to me and my DPE asked me where I was going to land it but I know some tell you where to drop it in - so be sure you can do it from multiple spots on the runway...not just on the numbers or wherever it is you are practicing now.
 
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kenjr said:
IIRC, you have 200' of margin to hit your spot on the checkride so practice various spots on the runway.
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Commercial PTS says at or within 100' of the selected spot. I am sure a CFI applicant would use that number. Sure the DPE/Inspector could say "show me a short field landing to the private level", but you will be expected to do it to commercial proficiency.

OP just keep the attitude held all the way through ground effect. A lot of people hold a nice attitude until crossing the fence and then dive for the runway and pick up speed. Set that attitude (speed) and adjust power to set your descent rate and right as you are getting near ground effect I go power to idle.
 
iRyan said:
I am going to go up next week an stall it with full flaps to see te speed. My cfi doesn't like to do short fields with full flaps and i think i am going to have to act like a cfi and use full flaps. I think you all are correct; I am coming in too fast. As for reducing power, he wants me to do it when I have the field made. I was reducing it over the threshold.
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First, you are too fast (is there an echo in here?). Second, pulling the throttle back to idle over the threshold is way too late. Are you familiar with flat-plate drag? When you kill the throttle with a c/s prop, it goes to fine pitch (flat), which is the equivalent of an 84" flat plate bolted to the front of the crankshaft; lots of drag, but that drag is more useful on short final than when over the threshold. Give the governor some time to flatten the pitch and you will find that slowing down is much easier.

I am 100% in agreement with aiming short of the threshold and floating onto the runway if wind conditions permit. You are an energy manager; try to have as little energy as possible to dissipate after touchdown.

Bob Gardner
 
Bob, the prop is already at fine pitch in the pattern.

Anytime a CS prop RPM drops below settings, the prop is maxed out fine.

BUT, chopping the throttle right over the numbers isn't a "stabilized approach." Even in fixed pitch, I've found I can make much better -- and shorter -- landings if I aim high compared to any PAPI (all white) and at idle or near idle power at least 200 feet up, more if the PAPI is 1000 feet past the threshold. 200 feet up may be over the fence if the airport has a significant displaced threshold. That is, ignore the PAPI unless it's all red, and use the aim point method with low power.

You can aim short, but obstacles on a "real" short field may not allow that. MUCH better is to approach near idle, steeper than the usual 4 deg. With a CS prop, it can be a lot steeper. From my experience, passengers really prefer a steeper approach over the trees, even if there is a lot of clearance, and even if the approach is really steep. They don't like slips much, though, so don't overdo it.

When you pull the power, the phugoid mode is going to try to speed you up initially, and you get to counter that with backpressure. You have to allow yourself enough time to kill the transient, or you'll still be fighting that when you touch down. Killing the power 20 feet up isn't going to do that.
 
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NJP_MAN said:
Commercial PTS says at or within 100' of the selected spot. I am sure a CFI applicant would use that number.
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Actually, the CP PTS says:
9. Touches down within the available runway, or water landing
area, within 200 feet beyond a specified point...
Click to expand...
 That means 199 feet long of the examiner-specified point is a "pass," but 1 foot short of it is a bust. Personally, I teach people to aim for the middle of that 200-foot "green" zone so they have 100 feet either way to play with (Ref: Butch Cassidy and the Sundance Kid regarding shooting someone -- "That way, if you miss, you'll still hit something"). Whether you call that within 100 feet of the wise pilot's chosen aim point or a 200 foot margin beyond the examiner's point is a matter of semantics. Just make sure you understand the space you have to play with and land inside it -- and keeping your speed from going fast is critical to accomplishing that every time you try.
 
I'm a noob so take all this with a grain of salt......

I was also taught that I needed to land in a 200 foot zone and that 1 foot shy of the start of the zone would be a fail. However, I did not adjust my intended touchdown point to the center of the 200 foot target. I aimed to touchdown at the close end of the 200'. As others have said, adjust your visual aiming point so that your touchdown point will be where you want it. My logic on aiming towards the short side is that you can always add a touch of power if you're coming up short. If you misjudge your speed, wind changes or ????, and float too far, you're hosed.

Ron Levy said:
Actually, the CP PTS says:

That means 199 feet long of the examiner-specified point is a "pass," but 1 foot short of it is a bust. Personally, I teach people to aim for the middle of that 200-foot "green" zone so they have 100 feet either way to play with (Ref: Butch Cassidy and the Sundance Kid regarding shooting someone -- "That way, if you miss, you'll still hit something"). Whether you call that within 100 feet of the wise pilot's chosen aim point or a 200 foot margin beyond the examiner's point is a matter of semantics. Just make sure you understand the space you have to play with and land inside it -- and keeping your speed from going fast is critical to accomplishing that every time you try.
Click to expand...
 
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