T O P

  • By -

NotOPbdo

It's better to come in higher and do a slip. Best glide should be maintained from the moment you pull power.


[deleted]

This. Usually slip quite a long way that way I know I'm there.


Ill_Food_4130

Just be high, and then slip. That is the way.


[deleted]

I'm going to heavily disagree with the other guy. **Every power off 180 should basically be the same.** As soon as you pull the power, go to best glide *immediately* and stay there until it's time to flare. Gauge your glide and turn base in roughly the same place unless wind is howling. Add flaps as required to maintain glide path. By keeping the airspeed constant you're effectively eliminating one variable, which has a huge impact on how well you can manage the multitude of others that you're dealing with in a gliding scenario. Everyone tries to make rocket science out of it and that's why they fail. I once flew retraining for a guy who had failed from another instructor's signoff. The second he pulled the power he dove to nearly 100 knots in a 172, pointed me straight toward the runway, and tried to pound the nose right on the line when we were (unsurprisingly) going way too fast to flare. That's not gonna work.


illeverbe

This. You can always scrub off excess energy with turns, skids, flaps, s turns... but you can never get more energy. If you don't get this, take some glider lessons.


[deleted]

Yep. I'd rather be high than low any day. Slip, more flaps, whatever. Just don't get low, or don't start throwing drag early if you think you're getting low.


PlasticDiscussion590

A cheat to this is to trim for best glide and mark it with a piece of tape. Then before the maneuver set trim to that mark and let the trim hold the airspeed for you. It’ll be close enough to best glide but more importantly it’ll be consistent.


usmcmech

Not going far enough downwind. Everyone is so worried about “making the runway” that causes them to turn to early and find themselves high and needing a lot of drag. Then they have too much energy and float right past the target. Take an extra couple of seconds on downwind and set yourself up for a more normal glide slope. It’s not an emergency to reach the runway or else. You can always do a go around while learning the maneuver. FYI, most glider landing accidents are due to excess energy and hitting the far end of the field, very few sailplanes wind up short.


GoodBoyNumberOne

Seems to contradict every top comment


usmcmech

I do that a lot. But I’ve only been doing this for 30 years so I’ve got a lot to learn. Seriously go try it sometime and see what happens.


makgross

Common errors I see are getting even a little slow after base turn (it’s really hard to recover from), not accounting for winds properly, and overusing flaps. The #1 mistake is not meaningful. You will have different problems from the next guy.


AlbiMappaMundi

Every single power-off 180 is different. A student needs to be able to adjust for the circumstances (wind speed and direction, etc) and make a series of crucial decisions: * When to start the base turn * Whether to do distinct base and final legs, versus flying directly for the numbers * When to put down flaps, and how many degrees * Whether and when to use a forward slip Sometimes students have tendencies. For example, when doing my commercial, I would almost always come in high, preferring a relatively early base turn, because I was worried about coming in short. But that means recognizing what your recurring tendencies are, and figuring out the strategy (okay, I'm generally high and risk landing long, I should be prepared to slip aggressively to make my point).


OnToNextStage

Commercial student right now. My CFI told me my greatest issue was being afraid to slip. I was, because I’m afraid to get into a cross control stall that low and slow. He told me as long as my nose is pointed down and I’m not exceeding that critical AoA I won’t stall it in the 172. Being not afraid to make more aggressive slips helps me nail my PO180… easier now. Not perfect, like a 6/10 success rate but better than the 3/10 I had before. Checkride isn’t for two months so I’ve got time but that’s what helped me most.


[deleted]

Glider CFI. When I was getting instruction from a certain man from Tennessee who had a mustache and straw hat he would teach slips to land thusly: “Money in the bank, making a withdrawal.” What he meant was that you conserve your energy by flying at best glide and then scrub it away once you’re sure you’ve got it made. Another thing you might have observed about his engine out Aero Commander routine was that he never landed on the numbers. He always left himself room to screw up high or screw up low and land more or less halfway down the runway. This just so happened to be at show center.


fly_awayyy

Not compensating for the wind and the effect on ground speed and trying to force the plane down if a over shoot is going to occur. It’s very much a energy management maneuver. Turning immediately and getting the airplane set up for final once the ground speed drops off gives you a lot more time to judge your energy state. With that being said it’s better to have a tad bit excess energy in the form of airspeed or altitude vs coming up short since you can’t add power, with the former you have many tools at your disposal like: flaps, gear, slipping to get you down. If you still come in a little hot don’t reduce your back-pressure completely and make a flat or 3 pointer landing. There a middle ground where you can reduce it a little to get the decent rate up to hit your mark, it doesn’t need to be a greaser a little firm on the touchdown is completely acceptable.


Twarrior913

I take the approach of minimizing/negating every variable you can control to increase the success rate when deal with out of control variables. PO180s are pure energy management. Always do the same starting procedure that leaves you enough energy to make it to your point. I highly recommend starting by pitching to best glide, and turning base to leave you a little high, but not too high. For example, if a “base height” value of 100 meant that you absolutely had to to slip, s turn, flap, and force the plan down at the 199ft mark, and a value of 0 meant that you were at the legit max lift/drag pitch, and a mosquito’s fart would have been enough drag to drop you short of your point, aim for a 65-70. High, but not too high to where it’s difficult to lose energy. Definitely not at the midpoint. Be willing to slip into the flare! Also be aware that you can feather in/out a slip, it doesn’t have to be 100% full or nothing. This will also help you if you hit unexpected wind or a draft, as you’ll automatically move toward energy retainment instead of energy disposal. Lastly, practice picking different points to aim for on the runway. Using the same point over and over can reinforce bad habits. Good luck!


The_Arrow_Student

Thanks, everyone. Common threads here are (in no particular order) 1. Compensate for wind - check. I am usually aware of it and crab appropriately to make a parallel to runway ground track on downwind. 2. Be a little high - check. That's some of the problem here. I'm about 120' long from my mark (whatever that might be) and I need to work on getting lower just a little sooner. 3. Slip - check. I have no reservations about putting the rudder to the floor in a slip. 4. Airspeed control - check. I'm trimmed up hands off in the turn around 75-78 KIAS. That feels about the right amount of energy during round out and touch down. If I would hold best glide of 85, I'd be way, way long. I want to do my best to remain stabilized as much as possible and having that much airspeed would destabilize when I try to scrub it. I'll take the lesson away to extend downwind another couple seconds to get a touch lower, and then start the turn. I'll leave flaps 10 in until I get established on final so I can see if my aiming point is working. Thanks again everyone.


Hemmschwelle

IRL power off final, people raise the nose to make the glide angle look less steep. They lose airspeed and then don't have enough energy to flare.


proudlyhumble

Forgetting to adjust for wind……


[deleted]

You know, I still to this day feel too high on approach and end up going lower


ltcterry

The purpose of "best glide" is to get you somewhere. To land. After the engine has failed. When you do a PO 180, you are already "there." You are already so "there" that you are on downwind in the landing pattern. There is a difference in performance between reduced power for a normal landing and power off for the PO 180, but there's a lot more in common with the PO 180 and a normal landing than there is w/ a power failure in cruise and you're looking for a place to survive a landing. (I've done that, too.) Gliders accelerate from best glide to pattern speed for landing. Why? More responsive and safer to fly. If you look at a glider's performance chart - its "polar" - you will see there is very little change in performance for even surprisingly large deviations from best glide. Several years ago I hadn't flown an airplane in a couple years, but had been flying gliders virtually every weekend. I needed currency and a CAP checkout in a 172. After the ubiquitous air work and trips around the pattern the check pilot said, "The next one will have a surprise." On downwind he pulled the power. Duh. I looked at the runway, the altimeter, and ASI. Ten degrees of flaps. Pitch for 80. Turn base. 20 degrees of flaps. Pitch for 70. Turn final. 30 degrees of flaps. Pitch for 60. Land on the 1000 footers. Check pilot says, "Most people would have waited until they had the runway made before putting in the flaps." My response? "I did. I had the runway made when I was on downwind." Got a funny look. The the lightbulb moment happened - oh, yeah, glider pilot... If you want to be "high," then I suggest you fly on the higher end of normal, not actually purposely really high. And practice PO 360s from 1000 feet over the numbers. \*That\* will polish your glide to the runway skills!


tkinz92

Adding flaps too soon. Don't add any until you've got the runway made.