Diamond Training Question - Soft Field

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newbie101
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Diamond Training Question - Soft Field

Post by newbie101 »

Question...... When I started my training at CFC at Springbank flying the D-20 I remember being taught that for soft field take off we were to roll on full power, 2000rpm min, hold the yoke back all the way, and go till the nose popped up then we would let the yoke forward to get the ground effect, get the speed up and takeoff. Was anyone else taught this way at CFC?

:?
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Last edited by newbie101 on Mon May 16, 2011 9:42 pm, edited 2 times in total.

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Re: Diamond Training Question - Short Field

Post by Shiny Side Up »

Sounds like you're mixing the short and sof techniques together.
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Re: Diamond Training Question - Short Field

Post by shitdisturber »

Shiny Side Up wrote:Sounds like you're mixing the short and sof techniques together.
Or even "soft", but yeah I suspect you've hit the nail on the head.
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Re: Diamond Training Question - Soft Field

Post by newbie101 »

Sorry I meant soft field, and it would have been a rolling start. So that the right procedure?
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Re: Diamond Training Question - Soft Field

Post by akoch »

I was taught: don't stop, always keep rolling, stick back offloading the nose wheel, and yes, get off into the ground effect as soon as possible. The idea is that the soft stuff does not let you accelerate all that well, so you want to get off of it as soon as it i practical. I'm sure there is a good number of DA20 instructors on this board, they will correct me.
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Re: Diamond Training Question - Soft Field

Post by tkdowell »

Soft field takeoffs are a bit of a conundrum in the Diamond 20. A friend of mine is a rotor/fixed-wing AME and claims there is an A/D that prohibits the use of soft or unprepared surfaces but I have not found this myself. In any case, with the wee little wheels you will pretty well want a putting green to land on in order to do it safely. The plane wasn't designed for it, unlike the Cessna.

Then along comes the flight test. Soft field landings are very straightforward - as Hedley ha said the golden rule in nose-wheel aircraft is to protect the nose wheel, period, but in a castered nose wheel even more so. With the ground idle set to 1000, a "normal" landing is often similar to the soft (hold the nose up!).

The takeoff is made difficult because of the t-tail. The fundamentals are the same; rolling start, smooth application to full power (2000 min is correct ref Part IV FM), confirm gauges, etc. And you have two options:

1) Commit fully and have the CC full aft, and any wind inputs as required. Because the elevator is above the slipstream, your attitude stays at taxi attitude. As you pick up speed your elevator will get a bit more authority, usually about 1/3 of the way down your roll. The elevator moves down, into the wash, and all of the sudden the nose will pop up. Be ready or this will result in a tail strike. The good news is that you usually wont lift off due to reduce airspeed, even at the high angle of attack. Release some back pressure and hold Vy to Vx attitude, pop into G/E, accelerate to safe A/S.

2) Hold slight aft pressure on CC. Wait for the nose wheel to feel light, then help it off the ground. Not entirely indifferent than a normal takeoff.

The problem with method one, even though it's more "pure", is that you have to go full CC back (commit fully). Even it's "almost" back, when the nose violently pops up, you'll be at a slightly higher A/S and will lift off and accelerate stall. Combined with a slight xw or poor overall directional control, and it's a food recipe for a wing strike and burning off some of the Lego.

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Re: Diamond Training Question - Soft Field

Post by newbie101 »

Hmmmm, ok.

Only reason I ask is I was taught the first method by instructor at CFC but recently while do a soft field i was rudely corrected that it was the wrong method and a recipe for disaster. I was told that CFC has even changed this method of teaching due to the fact that they have learned that T-tail shouldn't have the controls in full aft as POH doesn't suggest it.

I'm just lost at what I was taught and what I should be doing? Anyone have any further input on CFC guidelines?
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Re: Diamond Training Question - Soft Field

Post by iflyforpie »

There is no AD for soft fields in the DA20. Tiny wheels, but a light aircraft too. CTs have small wheels and they love grass. Soft fields aren't the only reason to use a soft-field technique either. An inch of sticky snow is a good reason to use it as well.

As far as t-tails go, I never really got explained the difference between a t-tail and a normal one, just as I never got explained the difference between a low wing and high wing. T-tails usually have less authority due to being placed out of the slipstream (certainly the Seminole I flew had that problem).

But if you fly correctly, the configuration shouldn't matter. Pull all the way back until the nose just lifts off, and maintain that attitude until the plane unsticks.

The best way to teach a soft field IMHO is with the plane parked and the student in the seat. The instructor then pushes down on the tail (on a structural point of course) so the nose wheel just clears the ground, and tells the student to commit that attitude to memory.

If you know the nose will come up quick, be ready for it. Even the humble 172 tail strikes pretty easily if the rear seats are occupied.
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Re: Diamond Training Question - Soft Field

Post by tkdowell »

newbie101 wrote:i'm just lost at what I was taught and what I should be doing? Anyone have any further input on CFC guidelines?
Check your PMs.
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Re: Diamond Training Question - Soft Field

Post by JDW »

I did all my training in the katana and I can tell you with that long t-tail, full aft elevator on takeoff could become very problematic, very fast. I was always taught to keep some back pressure on the stick (probably less than half way back) and usually even reduce my elevator inputs as the nose comes up. Even if youre quick enough to bring the nose down and there are no surprises like gusting wind, full aft elevator would require quite a push forward to stay in ground effect. More likely youll pull yourself out of ground effect and be riding on the prop until you gain airspeed. I can only imagine that on a very soft field this effect would be even worse.
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Re: Diamond Training Question - Soft Field

Post by hz2p »

T-tail was another idiotic idea that came from the suits in marketing during the 1970's, to make GA aircraft look racey. See the horrible t-tail Lance, Seminole, Duchess, Traumahawk and Skipper, all victims of the 1970's, like mutton-chop sideburns and bell-bottom jeans.

In fact what it did was add weight to provide the structure for the T-tail, and decreased the control effectiveness because the elevator is now out of the slipstream. A double loser with no benefits.

Like the swept vertical fin, the t-tail is yet another example of idiocy foisted upon engineering by the morons in suits from marketing.
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Re: Diamond Training Question - Soft Field

Post by trey kule »

I have never flown a katana, but I have seen many tail strikes from pilots that did not understand the technique.

Here is a few thoughts.

The idea, as some have said is to get the nose gear off the ground. where the idea goes astray, is pilots assume they should be charging down the runway with the nose gear about 2 feet off the ground and an extreme angle of attack.. That is not fineses..
You want to lift the nose wheel, just a inch or two off the ground and maintain that attituded.
You do NOT want an extreme nose high attitude. If you dont know why an extreme high angle of attack is bad on takeoff you need to do some more bookwork.
As to the elevator having udden authority and popping the nose up, then you have the controls to far aft originally. You just need enough to make the nose come off the ground. Add to much more back elevator and you are making things worse , not better.
Katanas are not 172's. Planes fly differently. Hard for some people to relly grasp the differences sometimes. But if you have a tail that suddenly takes effect (T tail), then you should not be using full back elevator, and your FTU should have practised how to do it properly, passed that info on to their instructors, and the specific technique for this aircraft should be taught.

there is simply no reason for a tail strike if you are using the specific and prper technique.
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Re: Diamond Training Question - Soft Field

Post by hairdo »

I taught on the DA20s and flew onto grass whenever possible with my students. Good aircraft on dry grass, not so good when the ground is wet, but that applies to most aircraft anyway. With the stick full aft for the start of the roll (which it really should be. Unless you're asleep at the switch, you shouldn't have any problems), the nose does pop up rather abruptly for reasons discussed by previous posters. You must be ready for this. If you are, it will be a non-event. If not, well, it's going to get interesting. As soon as the nose starts to rise, check the stick to about half the back pressure you were holding (if trimmed to neutral). (You can practice this on the ground with the engine off. It feels more or less the same. Once you have an idea of where the stick is going to be, the rest is easy.) This needs to be done quickly or you will be in tailstrike territory very, very fast. Finesse from there to keep the nose attitude constant (nosewheel slightly off the ground). Once you become airborne (actually airborne, not just from a premature bounce caused by a bump on the ground). You will need to lower the nose smoothly by gradually releasing that back pressure and, as the aircraft gains a bit of speed, a bit of forward stick. Standard climbouts from there.

Couple of notes.
If you go for the ol Vmu type liftoff (highest possible AOA), you will probably find that it requires a very high degree of finesse to prevent the aircraft from stalling or from slamming back down on the ground from letting too much stick go. You'll likely just end up bouncing back onto the grass again anyway. Not recommended or necessary.

Don't forget that as you come up above the treeline (most grass strips seem to be bordered by trees), there is a good chance of some windshear, so having a bit of airspeed (at proper climb speed for conditions) is needed. A lack of flying in ground effect tends to get you in trouble.

When the nose pops up and you're pulling a bit of a wheelie, remember that good 'ol asymetric thrust is going to rear it's ugly head and you will need some more right rudder to correct for it. If you don't, you're going to end up in the trees and or rolled up in a ball...

JDW - on a very soft field, you need to do the above or the aircraft isn't going to accelerate and the nose will not come off. Getting that nose wheel up a bit does a world of good for the acceleration of the aircraft. A small amount of back pressure simply won't unstick the nose in these conditions, and you won't be able to get the aircraft up to a sufficient speed to provide enough airflow to raise the nose with that small amount of back pressure.
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Re: Diamond Training Question - Soft Field

Post by trey kule »

First of all, I have never really considered grass strips, for the most part, to be necessarily soft field or require a soft field technique. sometimes, but not as a rule
With regards to trees, you seem to be now talking about a short field technique. There is no need in a normal soft field takeoff to be climbing out at best angle unless there is a specific obstacle, and if that is necessary you had better be good at judging your takeoff roll and have some no go options if it is truly a soft field because assumptions can be way off.

With a soft field the object is to unstick the plane As to how much back pressure to use, surely you understand that it will take different amounts for different conditions, but it is a bit ridiculous to say that under these conditions you must use full back pressure, so you should do it in every situation....simplified flying without finese. Teach the student that every plane is different, and different situations require changes in the technique. You cant practice them all, but the student should understand. You dont want the student doing something in the future as a pilot becuase they have never been taught that different situations require different techniques.
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Re: Diamond Training Question - Soft Field

Post by Big Pistons Forever »

Sigh......

Another question where the FTU fantasy life intersects with reality. The correct answer when the examiner asks for a soft field takeoff should be "this aircraft is not suited for operations from truely soft fields due to its very small tires and the inabilty of the T tail to unload the nosewheel at the begining of the takeoff, therfore I will exercise appropriate PDM by not demonstrating a manoever which I would not use in real world operations".

The stick full back untill the elevator bites is IMO lunacy. It is the same as forcing the tail of a taildragger up before there is sufficent rudder authority to maintain directional control. The common sense method would be to wait until there is sufficent speed for the elevator to be effective and then raise the nose to the attitude which has the nosewheel positively off the ground and then hold that untill liftoff. I hate "one size fits all" FTU isms. All aircraft should be flown in accordance with the limitations of their performace and handling configurations.
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Re: Diamond Training Question - Soft Field

Post by Cat Driver »

The stick full back untill the elevator bites is IMO lunacy.
I can't believe training has come to this sad state....who is allowing such malaise to spread throughout FTU's system?

I do not blame the instructors as much as I blame the system for allowing such basic issues as this to be taught wrongly.

If only Canada allowed teaching to be conducted without the need for an FTU like they do in the U.S.A. many of us older pilots would step in and run training schools properly and you can bet such nonsense as lack of basic airmanship would soon be corrected.
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Re: Diamond Training Question - Soft Field

Post by hairdo »

BPF: Very true. Did I f*ck up and land on a surface that was too wet? Yep. Did I learn from it? Yep. Would I land on a similar surface again with a DA20 if I had a choice? Nope.
Not sure I follow your taildragger analogy here. Rudder authority isn't the issue with the DA20. Having the backpressure from the start would allow somewhat less weight on the nosewheel so if any unseen holes are in the ground, your nosewheel has less chance of being damaged by slamming into it. My thought on the matter anyway.

Trey: We were talking about a DA20, so I discussed DA20 methods. Would I recommend it for a 172? No. I don't think full back pressure would be necessary in most cases with that aircraft. As far as trees, I wasn't speaking of obstacles. I was talking about having 40-50ft tall trees bordering a sufficiently long field. It shelters the strip from the full wind strength, and you may end up with some windshear as you clear the treetops (call me crazy if you like, but I have experienced it to a mild degree on a few occations). So what I'm saying, is that, unless you have an obstacle to clear, you should not be climbing at Vx. A faster speed would be more appropriate.

I don't know everything here guys, I'm just trying to share the bit that I do know (or at least think I know). If you have differing experiences and/or knowledge, I would love to hear it.
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Re: Diamond Training Question - Soft Field

Post by trey kule »

hairdo, dont sweat the small things. We are not picking on you, though with a few of us jumping all over some of the comments, I can understand you might feel that way.

With regard to BPF mentioning lifting the tail on a taildragger. It too, is an unfortunate thing that FTUs do..Stick full forward, tail up to quick.. I understand his frustration, and if you have ever checked out pilots who claim 50 hours on a taildragger and the resulting surprises you would understand his comment.

As to the stick fully aft. That is usually excessive . And the resulting quick authority and overcontrol people posted about is a good example of why not to do it. Catch a wind gust or do it in windy conditions and you easily get a tail scape.

So here is a couple of tips from an old guy who has done more than a few take offs and landing into and out of real soft fields.
You put in control inputs to make the plane do what you want it to. And you learn with each time, how to do it with more finess and less skill. Any time you hear simple things like full backpressure or full forward pressure...you are typically dealing with someone who really does not understand what they are doing. There are other planes around with t-tails. They are more demanding of proper aft pressure as their authority becomes sudden, so it behooves one to look at the wind etc. and use the proper amount. Ask yourself this. If the t tail has no authority at slow speeds what the heck is holding full aft going to accomplish except to cause to much pitch when it suddenly does become effective.

I was going to give an example here, but suffice it to say that the first step in teaching soft fiel techniques is to understand what a soft field is...And grass fields, as a rule, dont necessarily fall into that catagory. The first thing you are going to see is some poor student roaring down a nice packed dry grass field with full back pressure and the nose sticking about 2 feet off the gound and the angle of attack so high that the poor plane will take forever to get off the ground..(excessive angle of attack can really increase the takeoff distance).

What an instructor should be striving for is to have the student get the nose wheel an inch or two above the surface and maintain that attitude until takeoff. The criteria is to get the nose wheel light and off, and to maintainl that attitude. Remeber that old attitudes and movements things from the first lesson plan...super important.

My ramble for the evening
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Re: Diamond Training Question - Soft Field

Post by Shiny Side Up »

Cat Driver wrote: If only Canada allowed teaching to be conducted without the need for an FTU like they do in the U.S.A. many of us older pilots would step in and run training schools properly and you can bet such nonsense as lack of basic airmanship would soon be corrected.
I doubt that this would be the case if only because my experience flying with American pilots, hasn't shown that they benefit from this arrangement so that they are uniformly better. They are, of course, not uniformly worse either. It would be nice to see the removal of the whole FTU OC nonsense, but I feel that would only really benefit us with an increase in more botique flight training that would improve a few pilots, but the general mass produced pilot product would stay the same.

Unfortunately the best way to make money with flight training is to either go very large scale or very small scale. The larger the scale you go the more you run the risk of losing quality, as is often shown. Motivated individuals, as has been shown, can overcome the deficiencies of such a set up and still become greater than the sum of their training. Small scale costs the consumer more, so only those motivated to get the best go for it.

Could you really say that the old experienced pilot population would really be taking to managing large groups of pilot candidates - even if the money is there? Which would you rather do, a Super Cub with a few students or an air regiment of Da-20s with a lot of students?
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Re: Diamond Training Question - Soft Field

Post by Cat Driver »

Could you really say that the old experienced pilot population would really be taking to managing large groups of pilot candidates -


I sure wouldn't I was thinking along the small one or two person kind of school.
even if the money is there?
There would never be any real money to earn, but for sure the net profit would be lot higher without all the B.S. paper work and other requirements especially in maintenance where you have to have an AMO and a PRM and all the other stuff T.C. requires.

Would it not stand to reason that some of us older retired or semi retired pilots remember enough about how to teach flying that we would be able to turn out very well trained and knowledgeable students?
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Re: Diamond Training Question - Soft Field

Post by 2R »

Another attempt to pick the flyshit out of the pepper while ignoring the main course.
If you think that either technique would keep you safe in a soft field with an airplane with TINY wheels you have missed the point that BPF made.
A very accurate assessment whose truth is hiden in its simplicity.
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Small wheeled airplanes belong on pavement, not fields that may have gopher holes bigger that your wheels.
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Re: Diamond Training Question - Soft Field

Post by trey kule »

2r

Exactly what do gopher holes have to do with soft fields? I sometimes wonder how many instructors, or even pilots, actually know what a soft field is.

The tiny wheels remaining on pavement is true enough. But in flight training, one has to learn the technique for soft field take offs and landings, even if one does not really understand what a soft field is and thinks that grass or gopher holes are indicative of that!!! And one can demonstrate that they know the object and principles of soft field take offs and landings in a small wheeled plane that is not suitable for actually using soft fields.

It was the technique we were discussing. And you can practice the technique on nice hard pavement with a tiny wheeled airplane. Which actually I think might be better than an instructor induced fantasy that a nice solid piece of grass is soft, or that wet grass suddenly makes the ground super soft..slippery yes...not necessarily soft.

The whole issue of this thread was the technique being taught of full aft controls without doing any common sense thinking. Knowledge and thinking are good things.

One of the things that would help is if instructors would spend more time teaching the object and principles that apply, and then practice them without the "scenarios". This whole scenario thing is great....once a person has the knowledge and skills to make the plane fly the way they want.

Imagine how the new CPL is going to get through their initial interview with a CP if they talk about gopher holes being an indication of a soft field!
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Re: Diamond Training Question - Soft Field

Post by hairdo »

Trey, your comments are appreciated. While I don't fly the 20s or fly onto soft fields (although I guess you could say I do in the winter with the snow) anymore, I still like to hear the methods/techniques of others. When all you've heard is one way to do things, you begin to think that is the only way to do things. Again, thanks.

2R, I know that tiny wheels don't belong on anything other than pavement or dry grass. I learned that the hard way by landing on a grass strip after several days of rain. The performance of the aircraft in those conditions was not exactly stellar (or me on that day either, obviously).
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Re: Diamond Training Question - Soft Field

Post by Shiny Side Up »

Cat Driver wrote: Would it not stand to reason that some of us older retired or semi retired pilots remember enough about how to teach flying that we would be able to turn out very well trained and knowledgeable students?
By all means it would, but you have to remember the numbers of pilot trainees out there that we're talking about improving. To put it simply, we'd have to dragoon all the old experienced guys out there and put them into the flight training industry to make for a definite change. Lets face it, most retired/semi-retired pilots I know are pretty busy enjoying themselves to really put up with the headache of running a flight school - even if we could get rid of some of the baloney that TC additionally foists upon us to make our lives difficult.

To be honest, even with the small operation I run, maintaining the quality of the product is a challenge and a full time task. I can't directly (and no longer want to) do all the flight training myself after all. I can only imagine the difficulty with some of the larger operations out there - hence the ultimate cause of this thread and the associated arguement with the confusion of a simple subject of "soft fields".

To some degree, flying (and the associated teaching people to fly) is an artform. You can mass produce art, but masterpieces still come in unique form.
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Re: Diamond Training Question - Soft Field

Post by trey kule »

Complete digression here SSU.

Are you old and over the hill if you actually know what you are referring to by the group W bench.?.. :!: :!: You can get anything that you want.....
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