Short field technique poll

[MauleSkinner]

I’m struggling to find a situation you’d be forced to land that short while your engine is still useable behind the power curve. There are some, but not enough for me to want to practice it.

Where, exactly, do people think the back of the power curve starts?

 

[jsstevens]

I don't get all this tremendous fear of being behind the power curve. Yes, it puts you at risk if your engine quits. More risk than 3 minutes ago when you were just turning crosswind after takeoff?

One of my early rides with the chief instructor of the last club I was in, he challenged me to a short landing. I went in power off, full flaps and slipped to get down, slowed down and did a pretty good job of hitting the spot. He said, "Not bad but see what this airplane can do?" and proceeded to fly down final (steeply) on the back side of the power curve. When he got to the spot, he chopped power and that plane was done flying RIGHT NOW. We touched down slower than I'd ever tried. I don't plan to have to, but if I do, I've been taught how and have practiced. How is that bad?

 

[Salty]

Where, exactly, do people think the back of the power curve starts?

What I meant is the most likely reason I’m going to be forced to land that short is I have no power.

 

[dell30rb]

I understand the "back of the power curve" in this case really means you are flying somewhere at 1.2 Vso (power on), which is lower than book 1.2 Vso, because book Vso is done with no power. (does that make sense?) I don't use this technique, the shortest runway I routinely use is 2300'.

What works for me in almost any aircraft is to approach at book short field speed (reduce a knot or three if light), with a little bit of power to make the glide path less steep and to give me an easy way to manage the glide path. I use my glide path aiming point as my targeted touchdown point. At what is usually considered the roundout I will pull the throttle all the way out to the stop and begin a flare, my goal is to use the flare to keep the glidepath the same with the power removed as the aircraft slows. If i've done everything right, i'll touchdown nose high on my original aiming point just above stall.

 

[MauleSkinner]

What I meant is the most likely reason I’m going to be forced to land that short is I have no power.

So you're not going to slow below Vbg to land in that scenario?

The power curve isn't about how much power is available, it's how much power is required. Gravity provides the power in a glide.

 

[Stewartb]

My most likely cause for an unplanned landing is weather. One of the primary reasons I spent a cubic crapload of money on a seriously capable STOL airplane is that I can land this one at 20 mph with a margin of safety above the stall. That opens up a lot of landing spots. This topic is near and dear to me because I fly pretty much 100% of my flights in Cessna and Cub using short field technique. It isn't dangerous or reckless. It's how I need to fly in order to get where I want to go. Keep in mind that while the Valdez videos are fun to watch, nobody flies that technique into a big, open airport except in contests. Real life obstacles and surfaces require different techniques. What you can do on a big runway looks a lot different on a small sandbar with a sharp cut bank on one end and tall trees on the other.

 

[MauleSkinner]

I understand the "back of the power curve" in this case really means you are flying somewhere at 1.2 Vso (power on), which is lower than book 1.2 Vso, because book Vso is done with no power.

I always land at idle, unless I screw something up, so my 1.something times Vso is always the power off speed.

 

[Stewartb]

You must not fly short field technique in the wind!

In the wind? We control speed with AOA. We control AOA at the moment of touchdown by retracting flaps. With that the power setting isn't as critical.

 

[FloridaPilot]

Don't practice it much but I can see the usefulness. Suppose you are taking off in a populated area with an engine fire.....Stuff like that does happen.

 

[Half Fast]

I used to do this all the time in a Tecnam P-92. You are correct about gusts, etc. LSAs are inherently a little more susceptible to winds.
Everything in any aircraft is based on weighing risks, options and skill level, then get your best return on investment.

Yep, I'm renting a P-92 right now. I'm certain you can use this technique in a P-92; you started flying about the time my parents first said hello. With a recent SP ticket and about 120 hours in my book, I'm not ready to try it, especially at my usually-gusty-crosswinds airport.

 

[Shepherd]

I’m struggling to find a situation you’d be forced to land that short while your engine is still useable behind the power curve. There are some, but not enough for me to want to practice it.

Fire in the ELT area.
Happened to me a couple of years ago. In the Remos GX. (Not my favorite airplane, btw)
After 54 years of this flying stuff I'm still terrible at figuring out how big something is or how far away it is when I'm flying.
I needed to get down in a big hurry and the only place available looked like it was the size of a postage stamp. It turns out it was 1900 ft of flat and smooth, but I didn't want to risk a 40 mph rollout on unknown terrain.
Nose up, throttle up, release the elevator and the throttle just before the tail touches. Total roll about 55 feet at less than 38ish mph at touchdown.
I yanked the battery box out, made sure the fire was out and took off.
Just another day in the office.
Except I fired the airplane.
Too much kept going wrong with that plane, and it had the terrible habit of the rudder stalling and dropping the nose in a really hard slip. Not cool.
Been flying the Cub (mostly) ever since. You expect weird stuff in a 77 year old, all original J3, so it's all good.

 

[Silvaire]

You can break “STOL” down into two categories, one is where you are trying to get your airplane full of stuff in and out of a short strip and the other is an exhibition for cameras (also a competition) where you have about four gallons of fuel and skipped breakfast because you don’t want the extra pound and a half of partially digested bacon and eggs onboard. You might even be in a specially modified aircraft that isn’t good at much of anything else aside from this. The techniques for both may be completely different and I think a lot of the stuff they do in the exhibition is more show than substance and I’m not knocking it or denying that I enjoy watching it, just saying...

Not all airplanes are the same, nor are pilots. My own best technique for short arrivals is to set up an attitude and descent rate that will allow me to plant it, three point, on a spot with no flare and on a line that will come just slightly short with power completely off so that the line can be fine tuned with slight power adjustments. In my particular aircraft if I push the nose forward and increase speed I will overshoot my spot so I’m not talking about dragging it in on the prop from a mile out but when you discuss being “behind the power curve” you are technically already there on final because flying any slower and maintaining flight is going to require more power. The fact that you are descending doesn’t change that.

 

[SoCal RV Flyer]

Not me. I'm loathe to drag it in...my approaches are almost always high and I use throttle/airspeed management and/or slips to hit my spot.

I just like that feeling that I can always glide to the runway.

 

[frfly172]

Maybe in a rental.

 

[FastEddieB]

Where, exactly, do people think the back of the power curve starts?

According to that, 1.2 Vso would be on the backside, at least for the airfoil used.

 

[labbadabba]

No. The LSAs I fly can land very short without coming in on the backside of the power curve. Also, they get kicked around a lot in wind gusts, and my home drome often has gusty conditions and LLWS. I'd hate to be in a slow-flight config, already at high throttle, near stall speed, and then get hit with a wind shear while only one or two hundred feet above the ground.

Bottom line: not necessary in an LSA and also too risky.

Yep, when I fly a C162, I'm actually faster over the numbers than I am in a C172 just so I have better positive control. She still gets down well under 1,000ft if I need to, but so far I haven't needed to...

 

[Lndwarrior]

So.... a few months ago I tried this STOL technique after watching some videos (and yes, I realize this WAS stupid so no need to tell me).

I almost balled up my aircraft because one, I got focused on trying to look over the nose instead of looking out the side, and two, the sight picture is completely different than a normal landing. I ended up too low, too far from the runway.

My advice would be get an instructor to go with you if you've never tried this before. There are a number of things that can go wrong. I almost learned the hard way.

 

[chemgeek]

I'm pretty sure if you follow the POH short-field procedures in an AA-5 (70 mph, 1.2 Vso) it is on the back side of the power curve. Of course one should practice and be proficient in POH short-field operation.

 

[MauleSkinner]

According to that, 1.2 Vso would be on the backside, at least for the airfoil used.

You are correct...basically anything slower than Best Glide is on the back side of the power curve.

What I'm so poorly trying to get at is that the back side of the power curve isn't inherently bad...we fly there every day. It's simply a matter of degree, or how far on the back side that can get us in trouble if we're not proficient in what we're doing.

And it's a fairly wide range of speed...I won't say it's impossible, but going rapidly from the free by side of the curve to "hanging on the prop" takes more knowledge and expertise than the average pilot can muster up, much less do accidentally.

What @Shepherd is talking about (as it appears to me) is getting slower than even 1.2Vs, where it generally takes a higher level of skill, coordination, and timing to bring the airplane in steeply over an obstacle and arrest the sink rate at the proper time to neither hit the ground too hard nor stall several feet up. Power doesn't even have to play into that game.

 

[N659HB]

Well, if you’ve flown at MCA for the PTS/ACS you’re there, correct?

AKA the “area of reverse command?”

 

[MauleSkinner]

Well, if you’ve flown at MCA for the PTS/ACS you’re there, correct?

AKA the “area of reverse command?”

If you've done a normal landing you've been in the area of reverse command.

 

[GRG55]

It would seem that a Navy jet undershooting the deck, on the back side of the power curve, would be a bad thing and a reason to avoid the back side of the power curve.

Undershooting the deck on the front side of the power curve would seem an equally bad thing, non?

And if it's an F18 remember the recovery from slow flight is quite different from what we do (e.g. they don't necessarily have to get the nose down).

 

[dmspilot]

You are correct...basically anything slower than Best Glide is on the back side of the power curve.

Best glide is the airspeed where minimum thrust is required, not power. The airspeed for minimum power required is quite a bit lower, roughly halfway between stall speed and best glide. There is a discussion at the beginning of Chapter 2 in Aerodynamics for Naval Aviators.

 

[IK04]

Simply think of it this way: Instead of approaching at 1.3xVso, just slow to 1.0xVso with enough power to take advantage of the slower stall speed and maintain a good sink rate.

Vso is defined as the calibrated POWER-OFF stalling speed or the minimum steady flight speed at which an aircraft is controllable in the landing configuration.

Go arounds are not much fun in this configuration, unless you are really good at adjusting pitch, power, trim and flaps all at the same time...

 

[Flyhound]

I regularly land on the back side of the lift/drag curve. I fly a Maule and I do a fair amount of airplane camping in the backcountry. To be good at very precise and short landings in the backcountry, you have to practice it when you're flying at more conventional airports. One of the best descriptions of this kind of approach was produced for the backcountrypilot.org website. That video is available on YouTube and is a good introduction to the process. As with most things, some instruction from a qualified backcountry instructor would be prudent before trying this at home. Each aircraft design will respond to this kind of approach differently. My Maule develops a severe sink rate that has to be arrested with a burst of power when I'm pushing it. That does help me land short after clearing nearby obstacles, but It helped immensely training with someone with lots of experience in my make and model of plane before pushing the limits myself. I've found this type of flying immensely rewarding. It is what got me back into flying after a 10 year hiatus. Here's the introductory video:

Here's my plane at a wonderful spot in the middle of nowhere

 

[Flyhound]

In my previous post, I mentioned the need to practice very short, precise landings at your normal airfield before heading into the backcountry. When I lived in Virginia, I was invited to display my Maule at the Udvar-Hazy location of the National Air and Space Museum. The Udvar-Hazy facility is located adjacent to Dulles International airport (KIAD) and is connected to that airport with a taxiway that is normally closed off by the security fence at KIAD. Since the Smithsonian was covering my landing fees, this was going to be a special event. I decided to make what is likely the shortest landing every performed at Dulles International. I got down and stopped in about 300'. Here's a video of that flight:

 

[Silvaire]

Here are two examples I took with my new GoPro (neat little camera) that show the controlled approach in the correct attitude to spot land without flaring. Granted this is a Champ and prone to land short anyway but you can see the technique using small amounts of power to keep the glide slope on track. The first one was drug in a little more than I wanted due to the wind picking up near the ground so not perfect but still short.

 

[Witmo]

Undershooting the deck on the front side of the power curve would seem an equally bad thing, non?

And if it's an F18 remember the recovery from slow flight is quite different from what we do (e.g. they don't necessarily have to get the nose down).

I don't know what the recovery from slow flight for an F-18 would look like. I'd like to hear from a naval aviator. Seems to me they fly the jet onto the deck so that they can go around if they miss a wire. The Maule with a STOL kit plopping down on a sand bar isn't concerned with missing a wire and taking a swim with a BFB about to steam over him. I really doubt an F-18 lands at the slowest possible speed.

 

[jsstevens]

I don't know what the recovery from slow flight for an F-18 would look like. I'd like to hear from a naval aviator. Seems to me they fly the jet onto the deck so that they can go around if they miss a wire. The Maule with a STOL kit plopping down on a sand bar isn't concerned with missing a wire and taking a swim with a BFB about to steam over him. I really doubt an F-18 lands at the slowest possible speed.

I'm not a naval aviator, but they do land pretty close to the slowest speed. They also go full throttle as soon as they touch the deck so if the cable doesn't catch, they can go up off the (angled) end of the deck.

 

[GeorgeC]

Nose up, throttle up...

What kind of power setting are you talking about?

Yep, when I fly a C162, I'm actually faster over the numbers than I am in a C172 just so I have better positive control. She still gets down well under 1,000ft if I need to, but so far I haven't needed to...

Solo on a calm day, it's fun flying final at 50 indicated in the 162.

 

[alfadog]

For me, that curve is about level flight and the concept of "back side" has to do maintaining level flight or some descent rate well below a power-off descent rate. So I do not see it as simply "1.2so is back side", it has to do with how the a/c responds to an increase in power. You can approach power-off at any speed at or above stall but I would not call that "back-side". Correct me if I am wrong.

According to that, 1.2 Vso would be on the backside, at least for the airfoil used.

 

[Mike Blackburn]

Nope. But then my normal standard landing distance (braked) is 820ft MAUW at 7000ftDA.
Even if it wasn’t I think being on the back side of the power curve close to the ground is a recipe for disaster.

 

[Stewartb]

Trying to land at the front side of the power curve and driving off the end into trees doesn't sound like any bargain.

Internet short field discussions are amusing.

 

[Silvaire]

“Back side of the power curve” simply means that if you want to fly at a slower speed than what you are currently at you would have to add, rather than reduce power. This is where you are at on final whether you realize it or not and even if you leave the throttle at idle you will need to add “power” - in this case kinetic energy - by increasing your descent rate to fly slower.

I understand most people think of “behind the power curve” as dragging it along with the prop as you do when practicing MCA and it is for level flight but it also pertains to descending flight. You can fly at MCA with the throttle at idle by expending altitude which is stored “power”

 

[Stewartb]

Simplified. Ahead of the curve if you pull on the yoke you go up. Behind it when you pull on the yoke you go down. The initial question referred to nose high. That's where many here have no experience and human nature is to fear the unknown.

 

[Lachlan]

So, nose up and lean of peak, full rich, or idle cutoff? Short field technique is cool, but I like practicing short field with tall trees over the approach end, because that's how my home field is. So, every time I fly I practice short field technique when I get home. I a real jen-u-wine bush pilot, I tellyawut!

 

[IK04]

When I watch most videos on YouTube, I am usually cringing at how much excess energy (speed) they all have. Watching them float halfway down a short runway gets me hovering in my chair...

 

[kyleb]

I just use the technique SWA uses at Burbank.

Roll off the end and let the frangible concrete stop me.

Works every time.

 

[Doug Jackson]

I have a Cessna 340 and an experimental STOL plane that I compete in. Both are based on a 2,300' grass strip, so short field technique is necessity. I never drag the 340 in on the negative side of the power curve since an engine failure would likely be fatal, but even so, I can land over the trees and stop in 1,000- 1,500' depending on temps and winds. I drag the STOL plane in regularly for practice and can stop it in 75-100' easily.

 

[motoadve]

Nose high behind the power curve if you want your shortest landings.