Short field landing technique...am I being taught wrong?

We used to have a 1966 C-172. I did experience the "funny feeling" in the elevator slipping with full flaps. As Ron says, not a big deal.

Getting back on topic, the short field technique the OP outlines seems to me to not be correct. Technically, the C-152 POH is being followed, but being 100' AGL with full flaps, stabilized on the approach, then pulling power to idle and having to radically adjust the pitch attitude to maintain AOA seems basically wrong to me. It seems better (to me) to establish farther back on the approach the intended landing spot, then adjust power (maintaining 1.15 to 1.3 VSo or so) to hit that spot as you are coming in. When a few feet off the pavement, then pull power to idle, flare, land and stop. The 100' AGL thing bothers me a little. I can understand the OP's trepidation. Dangerous, in my mind.
 
I recently had an instructor get me to do this obstructed landing thing

What gives with holding in some power until you 'clear the obstacle'. If you had an engine failure, you'd have nowhere to go but right into the obstacle.

I've made plenty of landings at fields with trees close to the threshold and I don't see what's wrong with going ahead and pulling the power down to idle and picking an aiming point that has you clearing the obstacle. You'd make a nice steep approach in over the obstacle, and you would land at the same spot as the other technique
 
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somorris said:
Getting back on topic, the short field technique the OP outlines seems to me to not be correct. Technically, the C-152 POH is being followed, but being 100' AGL with full flaps, stabilized on the approach, then pulling power to idle and having to radically adjust the pitch attitude to maintain AOA seems basically wrong to me.
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If you do it right, the change in pitch attitude isn't "radical." The only way that happens is if you level off just above the trees (which takes a lot of power with full flaps), drive to the end of the trees, and then chop the power, and that isn't how the FAA wants it done.

The best technique I've found is once you turn final, keep the planned touchdown point in sight a bit above the treetops so you're flying a straight line down over the tops of the trees to that point. Then, when you pass the trees, smoothly reduce power to idle (or as appropriate for higher performance aircraft than a 152) so your descent angle increases to get you down closer to the end of the runway, and then flare at the normal height so your float in the roundout takes you to the planned touchdown point.
 
Ron Levy said:
If you do it right, the change in pitch attitude isn't "radical." The only way that happens is if you level off just above the trees (which takes a lot of power with full flaps), drive to the end of the trees, and then chop the power, and that isn't how the FAA wants it done.

The best technique I've found is once you turn final, keep the planned touchdown point in sight a bit above the treetops so you're flying a straight line down over the tops of the trees to that point. Then, when you pass the trees, smoothly reduce power to idle (or as appropriate for higher performance aircraft than a 152) so your descent angle increases to get you down closer to the end of the runway, and then flare at the normal height so your float in the roundout takes you to the planned touchdown point.
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Ron-

Could you expand on the difference in your technique for short field with obstacle vs. just an obstacle?
 
Alexb2000 said:
Could you expand on the difference in your technique for short field with obstacle vs. just an obstacle?
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Not much to expand -- with a short field, you use a lower approach speed (reducing energy to be shed after touchdown, thus reducing rollout) and steeper glide path over the obstacle (thus moving the aim point closer to the obstacle) than normal, since minimizing both runway behind you at touchdown and runway needed to stop is a lot more significant when there's less runway in front of you.
 
mchesney said:
For short-field landings with an obstruction....it seems dragging it in on the backside of the powercurve is very effective but is that good practice?
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This is what my examiner wanted to see during my checkride. It was not how I was trained, nor is it how I perform these landings now. I think there are safer ways of doing them.

That said, you can get down and stopped very quickly, in little distance, by dragging it in like this.
 
Tommy3 said:
This is what my examiner wanted to see during my checkride. It was not how I was trained, nor is it how I perform these landings now. I think there are safer ways of doing them.
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Unfortunately, not all examiners are happy with a safe method which complies with the PTS, but want you to use some technique they favor personally. I learned about that on my own PP ride in 1970 -- a truly hellish experience I would not wish on anyone else.

That said, you can get down and stopped very quickly, in little distance, by dragging it in like this.
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You can also end up in the trees very quickly with one burp of the engine or one slight error in technique, which is why I recommend against it.
 
For some reason I've allways treated my short field landings as though the field was not only short but soft too. Which allways worked well for me. Even on my checkride. The examiner saw it as a 2 for one, and we went on to do other stuff.

The "stabilized approach" works well for that, I usually fly a tad longer, higher final, to give me a little more time to set it up. Now for an actual emergency, landing in a short cotton field, all bets are off, but I'll still treat it as a short/soft field which it most likely will be.
 
Anybody who wonders why GA training and checking is such a mish-mash need look no further than this thread.
 
wabower said:
Anybody who wonders why GA training and checking is such a mish-mash need look no further than this thread.
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Wait, you think there should be standards or something? What do you think this is? Not like we're working at a McJunkfood here.
 
MultiMediaWill said:
Haha yea that awkward moment when you retract the gear instead of the flaps... well look on the bright side, you'll probably stop sooner in that case ;)
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Probaby slide farther on the belly than on the tires. Aluminum has less traction than rubber. Take a look at that 182RG wheels-up landing on Youtube and see how far the thing slides.

The reason for teaching a student to leave the flaps alone in the rollout is to prevent the habit of reaching for the flap switch, which might turn out to be the gear handle instead. All of our students were headed for the Commercial and complex/multi stuff; other students that showed up with Private tickets already often had the habit of raising the flaps in the rollout. We had a couple of close calls there with the retractable when they got the gear switch instead and the instructor caught it in time.

Electric flaps take so long to retract that raising them gains pretty much nothing. On the Cessna singles, max lift is around 20° flap, so as they come up the weight on the wheels lessens as the flaps pass through that setting. The older airplanes and the 180/185 series had manual flaps and raising them definitely shortened the rollout, and there was no risk of developing a habit of reaching for some control on the panel.

Dan
 
Max L/D is at 20 deg flap. Max LIFT is at 40 deg. It's also max drag....but drag doesn't affect "normal" force on the tires (it sure affects the brakes, though).

But, they do retract very slowly, comparable to the rollout. The only reason to retract Cessna flaps in a short field landing is to satisfy an examiner, because that's what the POH says. On the other hand, you can retract them instantly in a Warrior.
 
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Ron Levy said:
If that were true, then Cessna would tell you to extend 20 flaps for best glide, and they don't do that. Max L/D is still attained with zero flap in the light single Cessnas.
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20 deg flaps is the configuration that gives you the shortest takeoff roll on SOME of the Cessna singles (e.g., 182). But, we're landing, so the lack of full power is likely going to change the equation, as you say. Landing is closer to glide than taking off....
 
MAKG1 said:
20 deg flaps is the configuration that gives you the shortest takeoff roll on SOME of the Cessna singles (e.g., 182).
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L/D ratio is not the only factor in takeoff roll. In fact, drag isn't that much of a factor at all during the initial roll, due to the low speed and low pitch attitude. The dominant factor is lift coefficient. Of course, we also have to keep drag low enough that we don't stagnate once we lift off, which is why we don't use full flaps for short field takeoffs in planes like that.

But, we're landing, so the lack of full power is likely going to change the equation, as you say. Landing is closer to glide than taking off....
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We're not looking to maximize L/D ratio during landing -- that doesn't gain anything. We are, however, looking to minimize landing distance, so accepting a lower L/D ratio with a higher lift coefficient helps us fly a lower airspeed on final, which shortens both obstacle clearance and landing roll distances.
 
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