Landing Technique

[saintlfd]

A noted aviation mag recently stated that LSA pilots have found that carrying power all the way thru the flare helps with making smooth touchdowns.

Being a student pilot, that sounds to me like a training recommendation. It happens not to be what I have been taught and I am quite sure there are dissident CFI's on this forum.

I guess agreeing with the " smooth touchdown" comment is not the same as advocating it for ab initio training but students do need to learn best practices.

So, are you a " power to flare" guy or an "idle from abreast the numbers" type? Why?

[FastEddieB]

There may be rare GA planes where a touch of power may assist in the landing.

Something like a Cessna P210 may be very nose heavy when loaded at the forward CG, and a little power may help keep the nose from slamming down as the elevator runs out of authority in the landing roll.

In my experience as an instructor, however, the vast majority of GA planes do not need any power in a normal landing. Always landing power off takes one more variable out of the picture, and I have found students, and pilots in general, do better with fewer thing to futz with in the landing sequence. I know I do!

I have not heard it clearly articulated why power helps, other than some pilots find it makes things "easier". But I think it becomes a bit if a crutch or bandaid to cover up lack of proficiency in normal power off landings.

Watch any of my videos of my Sky Arrow landing. None has any power after about 50' on final, and most have power out sooner than that. I have never landed my plane with power on - I just see no reason to do so.

That said, as an instructor I recall two scenarios where I did have the student leave some power on...

1) Soft field landings. Paradoxically, leaving a tiny bit of power in can let you land more slowly if done right.

2) When teaching wheel landings in a taildragger, I would have the student leave a little power in. Though not required, it did buy some time to gently "feel" for the runway. However, it's not required and I would later try to get the student good at power off wheel landings.

[drseti]

I am quite sure there are dissident CFI's on this forum.

Dissident? Who, me?

So, are you a " power to flare" guy or an "idle from abreast the numbers" type? Why?

I am a power-to-idle convert. For the thirty years that I owned and flew my nose-heavy Beechcraft, I consistently kept in about 12 inches of manifold pressure all the way through the flare, closing the throttle only after the mains touched. Four years ago, when I made the transition to LSA, I found I would always want to have power fully back by short final. And instructing in LSAs, I have my students land (at first) with throttle closed midfield downwind - glider landings every time (at first).

Te reason for the dual "at first" emphasis is a nod to the Law of Primacy. In an emergency, everything goes out the window except what was learned first. An inflight engine failure certainly constitutes an emergency, and will require a power-off pattern followed by a power-off landing. If the student has done hundreds of power-off landings, when that emergency occurs and primacy kicks in, the procedure becomes a non-event. So, the primary student begins with very tight patterns (downwind only 1/4 mile from the runway), constant airspeed (60 KIAS), throttle fully back, managing descent with flaps alone.

Of course, traffic or local conditions might dictate an extended or wider pattern, so the student also has to know how to fly it with power (that's the "later"). And, like Eddie, I may opt for power in a soft field or wheel landing, or when descending steep and slow over an obstacle. But that usually all comes post-solo.

[FastEddieB]

If all else fails, see what the FAA recommends!

From the Airplane Flying Handbook*:

Touchdown

The touchdown is the gentle settling of the airplane onto the landing surface. The roundout and touchdown should be made with the engine idling, and the airplane at minimum controllable airspeed, so that the airplane will touch down on the main gear at approximately stalling speed.


*Available for free as a pdf online. I just grabbed that quote by going to iBooks on my iPad where I keep my training materials. Next rainy day, read the sections on landing contained therein. It really is well written and doing it the FAA way is a great place to start. Instructors should think long and hard before advocating techniques outside of that book.

[FastEddieB]

A bit of an aside, but...

A Cirrus pilot recently posted about an engine out. It happened as he turned downwind in a Cessna 177RG.

Long story short, he landed just fine power off. Even got the gear down! Credited his training and emergency practice and glider experience.

The fuel pump had apparently not been safetied and had backed off the engine.

Staying in gliding range of the runway at all times when in the pattern is an admirable goal!

[CharlieTango]

My mentality is power off from abeam the numbers and full flaps.

At flare power remains off but I am ready to advance the throttle to control unwanted sink.

I have needed as much as full throttle on landing when wind sheer is big.

[Merlinspop]

I read that, or a similar, article. The author said that the airplane rep (in the case of the article I read, Bristell) told him that the planes are so light that the have no inertia, and thus if you pulled power before the flair, it'd drop out on you. Raised my eyebrows.

[CharlieTango]

I read that, or a similar, article. The author said that the airplane rep (in the case of the article I read, Bristell) told him that the planes are so light that the have no inertia, and thus if you pulled power before the flair, it'd drop out on you. Raised my eyebrows.

Thats just silly. What if you pulled power abeam the numbers at 1,000 AGL, will it drop or fly?

If you leave power in you have both kinetic energy and energy from the prop at your disposal and you have the advantage of suddenly subtracting the energy from the prop, perhaps once your mains are on the runway to keep them there. This advantage comes at the cost of a bit more risk in case of engine failure.

If the speed is the same, the energy is the same, with power in you use a higher angle of attack at the same speed so you give up some stick travel, margin and elevator authority too.

A 720lb LSA will run out of energy quickly, energy management is more critical as a result.

[3Dreaming]

Having low inertia doesn't mean the airplane will not glide OK. It means that when you decide to change your pitch angle in the flare that it will slow down more quickly than a heavier airplane.
When I got my first CT the idle was set at 2000 rpm on the ground. I flew power off patterns all the time and it made teaching landings much easier. Now we set the idle at 1700 rpm on the ground. That 300 rpm makes a big difference. The pattern seems more rushed, and there is not as much time in transition in the flare. I can land power off both ways, but if I have a student that is having problem I sometimes will use a power setting that compares with the 2000 rpm idle.

[FastEddieB]

I read that, or a similar, article. The author said that the airplane rep (in the case of the article I read, Bristell) told him that the planes are so light that the have no inertia, and thus if you pulled power before the flair, it'd drop out on you. Raised my eyebrows.

Silly is exactly the word that popped into my mind!

Unless something was lost in translation, that makes no sense at all. A styrofoam airplane more likely to "drop out" than a lead airplane? I don't think so.

As a bonus exercise, given identical airframes, which will glide farther, a heavier plane or a lighter plane, each at their best glide speed?

[CharlieTango]

which will glide farther, a heavier plane or a lighter plane

The glide angle is determined by L/D, no weight involved so neither will win the glide distance competition.

Bonus question #2 Which aircraft will arrive at its destination at the end of the glide 1st?

[FastEddieB]

[drseti]

Which aircraft will arrive at its destination at the end of the glide 1st?

Seems to me that would be determined by the best L/D glide speed. Assuming that the heavier aircraft has a higher glide speed, it would beat the lighter aircraft to the runway. (But, that assumption is not always true - check the POH or AOI for optimum power-off glide speed. Whichever plane glides at the higher speed will win the race to the threshold, no?)

[CharlieTango]

I read that, or a similar, article. The author said that the airplane rep (in the case of the article I read, Bristell) told him that the planes are so light that the have no inertia, and thus if you pulled power before the flair, it'd drop out on you. Raised my eyebrows.

This is a self fulfilling proficy. Fly a power on approach in a Bristell or my CT and when you arrive above the runway if you chop the power your sink rate will be high, this is because of the higher angle of attack and getting behind the power curve [ assuming same approach speed ]

However -

Fly an approach at idle and when you arrive above the runway you will likely have adequate elevator to control your final sink, this is because of the lower angle of attack.

[Merlinspop]

This is a self fulfilling proficy. Fly a power on approach in a Bristell or my CT and when you arrive above the runway if you chop the power your sink rate will be high, this is because of the higher angle of attack and getting behind the power curve [ assuming same approach speed ]

Agreed - Maybe the author was dragging it in on the backside of the power curve.

An approach at idle should be capable of a perfectly satisfying landing, if you mind your airspeed. If it can't, I'd suspect the pilot before the airplane.