When Not to Aim for the Numbers

[poadeleted20]

You've never flown in 00000KT conditions?

I've seen that on the surface, but just having zero wind (even all the way from TPA, which I can't remember ever having seen) isn't enough, since there are also changes in temperature and pressure.

 

[RotorAndWing]

Yup, but it's virtually impossible to do unless there is no change in wind, temperature, air pressure, etc, all the way down the approach. I've not seen that yet in over 8000 hours of flying.

I have several times in over 15,500 hours. :smile:

 

[poadeleted20]

Last time a took a check ride perfection was not required. Power adjusted to "off" is fine. Every pilot should know how to land an aircraft without power.

I agree, and the FAA says you have to, too, but I've never seen a power-off approach which qualified as "stabilized" by the FAA's definition.

I almost always land power off though I typically fly the glideslope at very low power.

I, too, typically land power-off in light planes, but I don't typically make it power-off all the way from the abeam position. It's unstabilized, and hard on the engine.

 

[poadeleted20]

I have several times in over 15,500 hours. :smile:

Oh, bogus. Unless the altimeter read the same thing all the way down, the pressure wasn't the same, and I'd like to know when you saw that happen. And even if it did once in over 15,000 hours, that's a freak occurrence, not a training goal.

 

[RotorAndWing]

I, too, typically land power-off in light planes, but I don't typically make it power-off all the way from the abeam position. It's unstabilized, and hard on the engine.

No it's not.

 

[RotorAndWing]

Oh, bogus. Unless the altimeter read the same thing all the way down, the pressure wasn't the same, and I'd like to know when you saw that happen.

You simply don't understand what a "stabilized approach" is.

Once again, the FAA definition:

The FAA's Airplane Flying Handbook (AFH) provides this definition of the stabilized approach:

A stabilized approach is one in which the pilot establishes and maintains a constant-angle glidepath towards a predetermined point on the landing runway ... the point on the ground at which, if the airplane maintained a constant glidepath and was not flared for landing, it would strike the ground.​

 

[poadeleted20]

No it's not.

Lycoming disagrees with you. Go read their Key Reprints. Power chops like that accelerate piston ring and cylinder wall wear due to different cooling rates of the heads and pistons causing the heads to contract faster than the pistons. I'm not talking about the "ohmigawd" cylinder cracking OWT, just accelerated wear.

 

[rottydaddy]

While I acknowledge there are multiple ways to do a thing right, I am not advocating you do it one specific way. In my defense, however, I am hard put to think how I would ever explain the point of the article without pointing out at least one way

LOL! for that reason alone, I'll admit it's a little unfair to critique such an article.

But my point was simply (maybe a little too simply) that everything you do on approach has only one purpose; it's all a means to an end (a nice, smooth but firm touchdown with just enough energy to deal with conditions). And ultimately, only practice and exploring the range of what the airplane can do will show you how to achieve that end consistently- it's impossible to get it from a book or article.

 

[EdFred]

I've seen that on the surface, but just having zero wind (even all the way from TPA, which I can't remember ever having seen) isn't enough, since there are also changes in temperature and pressure.

If there are changes in pressure, temperature and wind, wouldn't you also need to make changes to your pitch and power. That doesn't sound very stabilized to me. Sounds like a lot of changes being made...something stable doesn't require changes.

 

[dmccormack]

Lycoming disagrees with you. Go read their Key Reprints. Power chops like that accelerate piston ring and cylinder wall wear due to different cooling rates of the heads and pistons causing the heads to contract faster than the pistons. I'm not talking about the "ohmigawd" cylinder cracking OWT, just accelerated wear.

hang on....

I'm flying the oldest Lycoming airplane engine made, and I don't worry about "shock cooling" since I'm gradually reducing power to idle once I start to big left turn to final.

Power allows a flatter descent, period.

It's no more/less stable than a power-off approach, wind or no. If you are flying in wind then stay a bit high -- all that changes is how long you slip, period.

 

[EdFred]

Lycoming disagrees with you. Go read their Key Reprints. Power chops like that accelerate piston ring and cylinder wall wear due to different cooling rates of the heads and pistons causing the heads to contract faster than the pistons. I'm not talking about the "ohmigawd" cylinder cracking OWT, just accelerated wear.

What's the difference if I fly 12" of MP all the way down the approach and kill the power over the numbers, or if I go to idle abeam the numbers from 12" ??

I'm still reducing it to idle. Probably should never start my engine. That's the best way to avoid wear on it.

 

[vontresc]

Hey I do Power off landings all the time from the abeam position.
















In the Glider

 

[RotorAndWing]

Hey I do Power off landings all the time from the abeam position.

In the Glider

How dare you!

 

[dmccormack]

What's the difference if I fly 12" of MP all the way down the approach and kill the power over the numbers, or if I go to idle abeam the numbers from 12" ??

I'm still reducing it to idle. Probably should never start my engine. That's the best way to avoid wear on it.

Is it even possible to shock cool a small mass such as an O-200?

My 0-145 has a hard time getting up to operating temps on a cold day (such as today -- 30 degrees).

 

[Lance F]

I agree, and the FAA says you have to, too, but I've never seen a power-off approach which qualified as "stabilized" by the FAA's definition.

If this from the FAA's Airplane Flying Handbook (AFH) is the definition of a stabilized approach:
A stabilized approach is one in which the pilot establishes and maintains a constant-angle glidepath towards a predetermined point on the landing runway ... the point on the ground at which, if the airplane maintained a constant glidepath and was not flared for landing, it would strike the ground.
...then I feel that I have made stabilized approaches in gliders, in a Mooney with a failed engine and in a Level C Lear 35 sim with both engines failed. All these would seem to be "power off" approaches.

I wish more power instructors would teach energy management like good glider instructors do. Most of this arguement would then go away. It's not power. It's energy. (IMHO, of course )

BTW, I thought the OP's write up was pretty darn good for a low timer. My only objection would be the statement that 3 degrees is normally correct.

 

[EdFred]

Is it even possible to shock cool a small mass such as an O-200?

My 0-145 has a hard time getting up to operating temps on a cold day (such as today -- 30 degrees).

My Comanche doesn't get real warm either. No cowl flaps and a lot of air moving over the cylinders.

 

[Larryo]

FWIW......

As far as landing on the number there's no requirement to do so.... in ANY plane. And there's only a requirement for landing in the "touchdown zone" for transport aircraft.

So, we, in GA planes can land anywhere on the runway we wish, and sometimes it's appropriate to us the middle or last third.

As for the "stabilized" approach, same thing, only required in transport planes. And there's an argument to fly an approach with a changing speed, and perhaps different descent angles, flaps, no flaps... or whatever. It depend on the goals, and all of the above can be done safely.

Also, there's no requirement to fly a power off approach, and in fact, often it's inappropriate.

 

[dmccormack]

Also, there's no requirement to fly a power off approach, and in fact, often it's inappropriate.

When would it be "Inappropriate"?

 

[Larryo]

When would it be "Inappropriate"?

In a lot of heavier aircraft, Bonanza on up.....

 

[dmccormack]

In a lot of heavier aircraft, Bonanza on up.....

I have a few hundred hours in an A36.

If I knew the engine was cool after a long descent, I had no problem pulling power to idle and dropping full flaps and landing -- with power at idle.

 

[vontresc]

Well in the 182 I fly, it helps to keep a bit of power in. It can be landed power off, but it works better with power. Plus it's easier on the firewall

 

[RotorAndWing]

I wish more power instructors would teach energy management like good glider instructors do. Most of this arguement would then go away. It's not power. It's energy. (IMHO, of course )

Yep, it's all about energy management.

 

[dmccormack]

Well in the 182 I fly, it helps to keep a bit of power in. It can be landed power off, but it works better with power. Plus it's easier on the firewall

"Easier" because the approach is flatter?

 

[brcase]

Hey I do Power off landings all the time from the abeam position.

In the Glider

Me to, and I thought I was doing "stablized" approaches. Guess I was wrong .

 

[Clark1961]

I agree, and the FAA says you have to, too, but I've never seen a power-off approach which qualified as "stabilized" by the FAA's definition.

Come on man! Stay high, chop the throttle, dump in flaps 40 and ride it down...once you're on speed the aim point doesn't change enough to matter. Perhaps you're just a tad over-critical on the definition of stabilized?

Okay, gusty conditions make things bounce around and that's why we should plan on touching down on the 1,000 ft marks. We'll have some room to give. As a side note, I don't aim for the numbers unless it's a short field. The folks that aim for the numbers aren't really planning ahead.

What about the Stearman guys who slip it in from TPA on base? They're as smoooooth as glass and barely vary the slope on approach. It's steep but it is stable. I can get similar performance from the Dakota.

Is it hard on the engine? All I can say is the Lycoming 320's and 360's don't seem to be bothered by it. The school birds run a long time with little engine work. As I understand it, there is no chance of damage if the cylinders are around 300 degrees when the throttle is chopped. Easy enough to get them there...

 

[Everskyward]

Touching down with power on is cheating to say the least...

Are there people who actually touch down with power other than at idle? I don't think I've done that in any airplane from small ones to jets. As far as technique goes I think different airplanes fly... differently and you can't apply the same technique to each one. I'm not just talking about the difference between trainers and jets either. Various small single engine planes land differently from each other too.

 

[Clark1961]

Are there people who actually touch down with power other than at idle?

Yup. See Ted, aztruck driver, 1 each.

Okay, I'm picking on Ted for choosing power over risking a firm arrival. You'd think after flying 600 hours a month he'd have the technique down but maybe he's just exhausted from all that aviatin' and can't pull hard enough?

 

[Everskyward]

Yup. See Ted, aztruck driver, 1 each.

Okay, I'm picking on Ted for choosing power over risking a firm arrival. You'd think after flying 600 hours a month he'd have the technique down but maybe he's just exhausted from all that aviatin' and can't pull hard enough?

I reread Ted's post and he said "up until the end" so I assumed he wasn't touching down with power but he can clarify.

on the Aztec I tend to keep a hair of power in up until the end.

I'm not sure how many people are going to relate to this, but in the Lears I learned to keep power until over the runway because otherwise they dropped like rocks. In the "twin Cessna" I was taught power to idle at 100-200 AGL. This felt really unnatural to me at first but it does work, probably because the wings are higher lift wings and we approach at 130 which is quite a bit above the ref speed (100-110)

 

[EdFred]

Come on man! Stay high, chop the throttle, dump in flaps 40 and ride it down...once you're on speed the aim point doesn't change enough to matter. Perhaps you're just a tad over-critical on the definition of stabilized?

Okay, gusty conditions make things bounce around and that's why we should plan on touching down on the 1,000 ft marks. We'll have some room to give. As a side note, I don't aim for the numbers unless it's a short field. The folks that aim for the numbers aren't really planning ahead.

What about the Stearman guys who slip it in from TPA on base? They're as smoooooth as glass and barely vary the slope on approach. It's steep but it is stable. I can get similar performance from the Dakota.

Is it hard on the engine? All I can say is the Lycoming 320's and 360's don't seem to be bothered by it. The school birds run a long time with little engine work. As I understand it, there is no chance of damage if the cylinders are around 300 degrees when the throttle is chopped. Easy enough to get them there...

Yes we are. Because if I touch down much past the numbers, I have to roll out to the next taxiway, which is on the wrong end of the field, then taxi all the way back across the airport to my hangar or fuel pumps. Although, I actually aim for the grass prior to the runway, so that I touchdown on the ##s.

 

[Clark1961]

Yes we are. Because if I touch down much past the numbers, I have to roll out to the next taxiway, which is on the wrong end of the field, then taxi all the way back across the airport to my hangar or fuel pumps. Although, I actually aim for the grass prior to the runway, so that I touchdown on the ##s.

I look at it the other way. I don't really care where I get off the runway but I want to be darn sure that I make it to the runway. By planning to land on the 1,000 ft marks I know that many things can go wrong and I'll still arrive on the pavement. To each their own and YMWV.

 

[EdFred]

I look at it the other way. I don't really care where I get off the runway but I want to be darn sure that I make it to the runway. By planning to land on the 1,000 ft marks I know that many things can go wrong and I'll still arrive on the pavement. To each their own and YMWV.

Yeah, but there are so many places where I won't make an airport, let alone the runway, the chances of the last few seconds of flight having a mechanical problem are pretty slim. Plus, at least at my field, if I came up short I think I might be ok. Although, the leading edge might a get a ding or 6 in it from the REILS.

 

[Clark1961]

Yeah, but there are so many places where I won't make an airport, let alone the runway, the chances of the last few seconds of flight having a mechanical problem are pretty slim. Plus, at least at my field, if I came up short I think I might be ok. Although, the leading edge might a get a ding or 6 in it from the REILS.

Very true on the no airport around to save the bacon part so I agree entirely. Another side of the problem is the hand that mother nature deals on the final approach. In the lee of the Rockies I've learned to plan on landing a bit long. I live in the land of long runways so I'm less sensitive to leaving some runway behind me. You folks with still air and short runways have a totally different perspective, I'm sure.

On a side note, the REILS at GLD and I nearly got acquainted on day. The headwind nearly ate my lunch but I did get off at the first taxiway! The power wasn't on at touchdown but it was on until about five feet up. That's as close as I want to get (nothing to do with weird winds, just bad planning on my part).

 

[Ted]

Yup. See Ted, aztruck driver, 1 each.

Okay, I'm picking on Ted for choosing power over risking a firm arrival. You'd think after flying 600 hours a month he'd have the technique down but maybe he's just exhausted from all that aviatin' and can't pull hard enough?

Tell ya what, Clark, come fly my Aztec and show me how you'll land it, then I'll show you how I land it. If you can do better than me, I'll buy you a beer. It ain't your Dakota, even though it does generally fly like an oversized Cherokee. My point is that you are making a generalized statement that does not apply to all aircraft. Your Cherokee is not an Aztec is not a King Air is not a Citation is not a 747.

Mari is correct. I don't land with power, I just use power throughout the pattern and only pull it back for that last bit once close to the runway. Have you flown anything much larger or having a much greater sink rate than your Cherokee? I have about 130 hours in one, and the technique I use for greasers on it is different than on the Mooney and Aztec.

If you're so concerned with "proper technique" then I'd question your focus on "fly the plane," which is more important. Do what it's asking you to do. That may not be completely in line with what "proper technique" states, at least per your book. Your passengers care about what they perceive as a controlled, safe flight, not about you following a book of suggested techniques that they've never read. I'd argue that if you pull the power back to idle abeam the numbers and come in you'll arouse a lot more concern from many than if you bring it back slowly, and getting that last bit done over the numbers.

 

[Larryo]

I have a few hundred hours in an A36.

If I knew the engine was cool after a long descent, I had no problem pulling power to idle and dropping full flaps and landing -- with power at idle.

Dan,

You can... but I'll bet you don't do that as SOP from pattern altitude. Perhaps short final, works fine.

 

[EdFred]

Dan,

You can... but I'll bet you don't do that as SOP from pattern altitude. Perhaps short final, works fine.

I'm slowing working my way to the power-off 180 in the Comanche as SOP just as I did with my Cherokee. My finals are becoming shorter and shorter. I'm only at about 200' of final at this point. The base leg is non-existant anymore.

 

[Larryo]

Very true on the no airport around to save the bacon part so I agree entirely. Another side of the problem is the hand that mother nature deals on the final approach. In the lee of the Rockies I've learned to plan on landing a bit long. I live in the land of long runways so I'm less sensitive to leaving some runway behind me. You folks with still air and short runways have a totally different perspective, I'm sure.

On a side note, the REILS at GLD and I nearly got acquainted on day. The headwind nearly ate my lunch but I did get off at the first taxiway! The power wasn't on at touchdown but it was on until about five feet up. That's as close as I want to get (nothing to do with weird winds, just bad planning on my part).

Dakota,

You approach is just fine, you do a good job and your planning give you the option of adjusting should things change.

Keep up the good work.

 

[dmccormack]

Dan,

You can... but I'll bet you don't do that as SOP from pattern altitude. Perhaps short final, works fine.

If it's me all alone in the pattern? It is SOP in everything I fly.

If there is other traffic, I fly a squared off pattern to be predictable.

I only have 20 hours in my Chief but I think I've learned more in those 20 than I learned in the previous 200 about stick and rudder. One thing you'll learn flying behind a 70 year old engine and lots of drag is energy management.

 

[tdager]

Are there people who actually touch down with power other than at idle? I don't think I've done that in any airplane from small ones to jets. As far as technique goes I think different airplanes fly... differently and you can't apply the same technique to each one. I'm not just talking about the difference between trainers and jets either. Various small single engine planes land differently from each other too.

Yup...I do. It helps with elevator authority in my C182. I have a STOL kit, and 40 degrees of flaps.....a tad bit of power and 30 degrees of flaps makes for SMOOTH landings. Without it, and at 40 degrees, welcome to the elevator ride down, with some pretty firm landings.

Almost (*but not all*) C182 drivers I know use a tad bit of power on landing...as stated it helps the firewall!

 

[EdFred]

I never noticed the 182 being nose heavy.

 

[dmccormack]

I never noticed the 182 being nose heavy.

There's a limit on the amount of nose up trim, so you need to exert a bit more force to keep the nose up on the larger Cessnas. I don't think this is fixed by power as much as muscle.