WilliamF wrote:
In the context of bush/STOL operations a hard landing isn’t necessary. FE Potts Guide to Bush Flying covered this point. Even if you watch videos of those mavericks in South America bringing Cessnas into 160m ish one way strips they don’t hammer them on. I once landed on a 173m strip for model airplanes and buttered it. Even by dropping all flaps in the flare which was my SOP in a tricycle gear going in tight, I don’t recall any hard landings being necessary.
Indeed, dropping flaps should arrest descent when steep & slow, but you can also raise flaps if it floats forever at 1ft agl if you come fast in gusty winds to hug the ground, altough better to just sideslip it to kiss the ground 
All depends on speed, pitch, wind, gust, sink rate and if you gun with power…
MedEwok wrote:
At any landing you must transform potential energy (altitude) and kinetic energy (speed) into friction to come to a stop
Not necessarily true or entirely correct 
A landing is the process of going from one frame of reference – the mass of air, to another frame of reference – the ground. The easiest way to minimize runway is to land in a headwind, that’s because the kinetic energy is not fixed, but relative to the frame of reference. Another easy (and extremely efficient way) way is to land uphill, that’s because you convert relative kinetic energy to potential energy (alt, which by the way is defined with reference to the ground only). The best way is to land uphill in a headwind
Then there is reverse thrust.
But, I take it none of those methods are available, then the best way is to reduce runway length is to come in relatively slow and relatively steep. That is, you have a Vx and a Vy, which by themselves individually are not enough to keep the airplane flying, but the “sum”, square root (Vx^2 + Vy^2) is. Then, just before touch down, you flare. The flaring is the process of converting Vy to drag, or to aerodynamically dissipate the relative kinetic energy in the y-direction. When touching the ground, your relative airspeed is then too small to fly, it’s only Vx left (parallel to the ground), which can be dissipated aerodynamically further also. The landing will be 100% smooth, if done correctly, and very little wheel breaking is necessary Also, in the flaring part you will/can force the aircraft, the CG, “uphill” a bit even though the trajectory of the wheels are parallel and constant to the ground, which will also help a little bit I would think.
The “normal” way of landing is coming in way too fast, and flaring forever to dissipate energy.
GA: Shallow arrival and dragging it in using power usually results in longer landings than steeper arrival at idle, right?
CAT: IIRC landing performance calculation allows for 6 seconds from flare to touchdown, and yes, a positive landing is the standard, as it guarantees immediate wheel spin up, speedkbrakes/spoiler deployment and autobrake activation. I can tell when flying as a passenger if airlines have positive landings as SOP or not. LH has it (I believe due to the 320 accident in the 90s).
Snoopy wrote:
Shallow arrival and dragging it in using power usually results in longer landings than steeper arrival at idle, right?
Don’t know about that actually. With full flaps, and using power to stay afloat, you can fly incredibly slow. Slower than when at idle. But if the engine quit, or simply miss some beats, you will be going down fast (since you already are low, you will hit the ground fast). A steep angle is safer for sure.
Even with CAT it depends on the operator and the crew. Some go for a positive touchdown at the desired point every time. This can be faulted, it is textbook. Others will allow a little bit more flexibility. One large airline I worked for actively encouraged ‘dropping into 3 reds’ to land a bit closer to the numbers when there were no other factors if it allowed better performance or earlier runway turnoffs. For the avoidance of doubt, everyone was content with how this was implemented and there was no ‘cowboying’ about it. The airline I work for now wouldn’t recommend it, but wouldn’t take issue with it as long as it is done safely. On more length limiting runways, this gives more margin. On longer runway doing the same allows more time to try and grease it on whilst not straying outside of the touchdown zone. Some pilots care more about trying to grease it on than others, and frankly the best I have ever flown with tend not to care about this.
That’s all speaking about CAT though, with lots of energy and generally speaking your aiming point is 400m down the runway to start with. With GA there is a lot less energy involved and I think you make a performance landing that is quite nice, but everything has to be just right to do so. Any excess speed and you are going to stay airborne to bleed it off. Variable or gusty winds cause problems too. The most consistent way is just to put it down positively where you want it.
I’m also not so sure about the steep vs shallow approach. If obstacles are not a factor I think there is some merit in coming in shallower with more power and then ‘chopping’ the power where you want to touchdown. I was shown this during training and I think it is pretty consistent as I find it tends to allow a better control of speed, which is the most important thing IMO. All that said, I am no bush pilot nor strip flyer, so that’s just my own experience.
Minimizing runway used during landing is best achieved by practice and attention, not a forceful arrival. If your short landing has to follow a steep approach for obstacle clearance, it’ll be a bit more work to make it soft, but there’s not reason not to. There is never a time while flying when I think to myself, or say to a candidate pilot “it’s okay if this landing is hard.”. I expect every landing to be planned to be as gentle as possible, regardless of intended distance. Sure, we bounce or bump occasionally, so make it better next time.
Some think that getting down and on the brakes quick will stop you in less distance – well, maybe a couple of feet shorter for a much higher maintenance cost. Whether the wheels are on or off the surface at around touchdown speed won’t affect touchdown distance much, as the nigh nose is slowing the plane anyway with the throttle closed. The only way to transfer weight to the wheels for heavy braking quickly is to completely retract the flaps. This is really poor practice in any plane, and hardly practical if your plane has electric flaps (they’ll take too long anyway). The Cessna 310 I used to fly did say in the POH for a shorter landing, retract the flaps and apply heavy braking, but a 310 is not known for good aerodynamic braking, and has big mainwheels and brakes. But still, the risk of retracting the wheels in error makes this a bad idea unless you’re desperate.
If you want nice short landings, practice nice regular landings lots, and as you perfect the “nice” part of the landing, the “short” will come with focus and practice. My home runway is 2100 feet over a 30 foot obstacle, with a slight downhill slope in the normal landing direction. One of my planes has a 60 MPH approach speed, the other 70 MPH. I rarely use brakes at all to clear gently at the 1900 foot (from obstacle) apron, and I never plan a hard landing.
Pilot_DAR wrote:
The only way to transfer weight to the wheels for heavy braking quickly is to completely retract the flaps
What about lifting the tail? Obviously then there has to be a balance with stick and brakes as you get onto them
Off_Field wrote:
What about lifting the tail? Obviously then there has to be a balance with stick and brakes as you get onto them
If I am landing my taildragger, the tail will be off, as I always wheel land. If I felt the need to use more than a small amount of brake, I would let the tail down, then hold it there for heavy braking, though I can’t recall ever having to do that.
When landing my tricycle, I would already be holding the nosewheel high, and will continue to do so, until the elevator is no longer effective, so if I needed to maximize braking with weight on the mainwheels, I would already be where I needed to be.
I recall an accident decades back, in a very short runway I used to fly the 182 into, it was 700 feet of grass from the base of the 50 foot tree line, with a 500 foot rough over run which we really tried to not have to enter. That runway did require the use of brakes to stop. Honestly, I avoided the place, as it was more scary to take off from than land into, the trees at the far end were more than 50 feet high. Anyway, an “instructor” runs off the end very badly in a 172, I was surprised that he did not hurt himself, as the cabin was badly damaged hitting the big maple trees. When the accident investigators interviewed the only witness, an older lady (non pilot), she was reported to have asked the investigator: “Don’t the mainwheels have to be on the ground for the brakes to work? He went the whole length of the runway on the nosewheel only.”
One airline I worked for the 3 red on final was not allowed (reason was less margin to obstacles in case of downdrafts). I can see it done as you described just as well though, without over defining every aspect of flying and leaving it to good judgement of the pilot(s).
shallower with more power and then ‘chopping’ the power where you want to touchdown.
I showed that to last two students as their technique of „chopping“ power and simultaneously aggressively flaring led to rising again and then dropping uncontrollably (also blown of centreline by the wind).
This is what separates pilots from the birds. Just watch a bird land… definitely very short and very soft. The perfect flare to the exact moment lift is lost.
You can see this with very experienced pilots. Just sit at a GA airport and watch the length of the ‘float’ part of the landing for an afternoon. Here is how I would rank the likely shortness of landing with various techniques:
1) The long landings with massive float are approaches that carried excess speed.
2) Then there is a normal range, with a small amount of excess speed giving a bit of gust protection in the approach and adequate time for a moderately skilled pilot to find the ground gently.
3) Then there is the better side of normal, with no excess speed which results in a flare and touch down in a short period. This requires a bit more currency and practice, because you must be right on.
4) Then there is skill… watch closely as the angle of attack changes in a smooth motion from the approach angle, to the flare (with almost no change in trajectory as the angle of attack is being increased as the speed slows). You have to watch out, because the drag is increasing and if you don’t get it right you will run out of speed and smack it on hard. When you see this done smoothly, it is probably an experienced pilot who has been flying tailwheel for a while, e.g. a three pointer with no float.
5) Then there is extra skill where you are right on the edge, you are already at a high angle of attack in the approach and you are going to need throttle to arrest the descent.
6) Then there is dragging in it in on the prop and cutting the throttle (Alaskan short landing competition style).
My view is that I generally work in the 2 to 3 range. Technique 3 with good braking will give a very acceptable short landing. Technique 4 is what I aspire to later in the season when I have been doing lots of flying, I think this is beautiful to see in steady wind conditions. Technique 5 is probably best reserved for bush necessities…. one day you might misjudge it and bend something. Technique 6 – if you are at this level you know the risk :-) and you can probably fix your plane when something breaks!
To be nice to the airframe I always aim for a soft landing and don’t usually use brakes. But if you are going to brake hard, an appropriate approach speed will mean there is not much float and the wheels will become weighted quickly.
I once accidentally landed a Cherokee with the (hand) brakes on (or partially on). Thankfully it wasn’t a floater otherwise I would have flat spotted the tires. Geez did it stop short… I don’t recommend it. For ‘I learned something about flying from that’, this was the culmination of two mistakes… I had been stuck in the mud at the top of a downhill grass take off. Evidently I had put the hand brakes on as part of the faffing around after getting unstuck. I then took off downhill on wet muddy grass with the brakes on… and didn’t realise it until I landed on pavement. Presumably, I left big skidding ruts on the wet grass. Thankfully it wasn’t a tailwheel where I might have ended up on my nose!
