"Performance" Landings?

[cleared4theoption]

Just got done listening to a podcast where one of the topics was Power-Off 180's and performance landings. It got me thinking.
Looking at the Glide Performance chart in the 172 PIM, it basically says at the best glide speed you can expect to glide a mile for every 1000' of altitude. This is, of course, not accounting for wind.
Since the average patern altitude and position is 1000' AGL and one mile from the runway...it seems to me, based on some quick math, that as soon as you pass abeam the end of the runway on downwind, you are increasing your distance from the field(it was already one mile). And to make matters worse, you have probably already began descending...so you won't even have 1000'. Seems like once you pass abeam the runway, you WILL NOT make the field if you lose your engine. Add in a head/cross wind, and it gets even worse.
Wouldn't in make sense then, that a performance landing is the safest way to land...all the time

 

[Sac Arrow]

I'm not familiar with the term "performance" landings. Do you mean a short approach?

I like to keep a tight pattern for that reason, however.

 

[cleared4theoption]

I'm not familiar with the term "performance" landings. Do you mean a short approach?

I like to keep a tight pattern for that reason, however.

Basically yes...you turn base right when, or shortly after, you pull power abeam the touchdown point, and then you just use forward slips to bleed off the excess altitude.

Edit...meant "turn base" not final

 

[Sac Arrow]

I think you mean pull power on downwind abeam the touchdown point, and use slips on final as needed?

 

[cleared4theoption]

I think you mean pull power on downwind abeam the touchdown point, and use slips on final as needed?

Yes...except in a power off 180, you pull power completely abeam and just do a 180...I'm sure what I am talking about isn't actually called a "performance landing" , I just kind of made that description up...if you just go back to standard power setting for landing, and turn base quickly you could make sure you never get far enough from the field, and like you said, you slip to get down. I guess it just seems to me that doing that would be much safer than a standard traffic pattern.

 

[Dave Theisen]

That's the power off 180. Performance landings refer short-field and soft-field landings.

 

[denverpilot]

I'm stuck on the question's premise that a "normal" pattern is a mile away from the runway on downwind. That's way too far out.

 

[Sac Arrow]

Problem is that doesn't always work for spacing. If you're the only one in the pattern, go for it, it's good practice. Otherwise, if you're following people, you can't just do a short approach and cut them off. If you're at a towered airport, tell them you would like to do a short approach.

 

[Dave Theisen]

A downwind a mile from the runway is way too wide for your average single engine airplane. Should be closer to a half mile.

 

[Sac Arrow]

Looking at the Glide Performance chart in the 172 PIM, it basically says at the best glide speed you can expect to glide a mile for every 1000' of altitude. This is, of course, not accounting for wind.

I'm stuck on the question's premise that a "normal" pattern is a mile away from the runway on downwind. That's way too far out.

Good catch. You won't be decending past abeam of the threshold at best glide. Your flaps will bring you down quicker than that. Roughly a half mile out is about right.

 

[poadeleted20]

The power-off 180 approach was the way we were taught for "normal" landings back in the 60's. Then the FAA started really looking into the balance between accidents due to engine failure in the pattern and the number of airplanes wrecked in botched landings where there was nothing wrong with the airplane when it hit. Essentially, they found that there were far fewer cases of engine failure in the pattern than there were of people crunching their planes due to undershoots, overruns, stall/spin, lateral excursions off-runway, etc. As a result, the FAA did an about-face in the 70's and changed their recommendation for "normal" landings to the partial-power stabilized VFR approach described in the Airplane Flying Handbook and their pamphlet "On Landings, Part I." The accident statistics since then tell us that the different approach to what should be considered a "normal" approach has dramatically decreased the number of bent airplanes. For that reason, I don't see the FAA reversing itself and returning to recommending the power-off 180 as the "normal" method for flying VFR approaches.

As for how far abeam to fly the pattern, that really depends on what you're flying. In a Cub, you might want to be inside half a mile; in a Glasair III, you might need to be a whole lot wider abeam. I fly my Tiger right around the 3/4 mile distance the AIM recommends.

 

[cleared4theoption]

Don't know why I got stuck on a one mile pattern...that is too far...DUH. .5-.75 miles is better...totally changes the math.

 

[Clark1961]

Don't know why I got stuck on a one mile pattern...that is too far...DUH. .5-.75 miles is better...totally changes the math.

3/4 mile is good. Also consider gross weight...the 172 isn't a bad kite at lower weights...

 

[brcase]

Problem is that doesn't always work for spacing. If you're the only one in the pattern, go for it, it's good practice. Otherwise, if you're following people, you can't just do a short approach and cut them off. If you're at a towered airport, tell them you would like to do a short approach.

Still good practice, fly it exactly the same way, just fly a longer downwind, perhaps even turn base and final at pattern altitude. Then reduce the power when you can make it to the runway. At least if the power quits you have one mile radius to work with (C172), even if it isn't the airport.

Also most planes have flaps you can use to control the descent as well if you know how to use them as opposed to just how to put them down. I seldom need to slip when doing power off approaches.

Brian
CFIIG/ASEL

 

[Henning]

Yes...except in a power off 180, you pull power completely abeam and just do a 180...I'm sure what I am talking about isn't actually called a "performance landing" , I just kind of made that description up...if you just go back to standard power setting for landing, and turn base quickly you could make sure you never get far enough from the field, and like you said, you slip to get down. I guess it just seems to me that doing that would be much safer than a standard traffic pattern.

Standard power setting for landing is throttle off in most situations, the difference lies in how long before the landing you put it there; one second or one minute.

 

[Skylane81E]

I try to do 180 power offs as normal practice. I try to hit the end of the runway at minimum speed and have the ability to be stopped as short as possible. I don't treat the engine like its broken and use it as needed, but I like to be used to how the thing handles power off.

 

[AggieMike88]

Power off landings reminds me of some emergency procedure practice I did recently with a CFI. We practiced engine outs from 4000' to a nearby runway that is at 850' and some where the engine quit right at pattern entry, and once on departure where we had enough altitude to come back into the pattern, but a short approach was part of the solution.

These were items that were discussed with my original instructor, practiced sorta (never landed, just "you got the idea, let's move to the next topic), but never done all the way. This instructor had me doing the entire drill, from evaluating the problem, to properly landing the aircraft to a full stop.

I don't know if that qualifies for performance landings, but it was a big training experience. And a good one. Something I recommend all sub-150 hr pilots do and older pilots practice once and a while. I learned a lot and now if it was to happen, I won't be relying on what Ron Levy calls the luck bag.

(@Troy, the CFI was GB over at 52F)