Great Video - Nose Gear Collapse Analysis

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FastEddieB
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Post by FastEddieB »

My quick observations:

1) NOT a stall - unless a strong gust from the rear caused the plane to drop in.

2) The main problem in my estimation is the lack of a proper roundout. A normal approach should be at about 1.3 vso. About one wingspan above the ground a roundout should begin. The flight path is "rounded out" so as to arrive in ground effect with a small margin above the stall. That roundout should result in a somewhat nose-high attitude once close to the ground. The flare then continues until the stick is all the way back or nearly so. Had he rounded out, he may still have dropped in and bounced, but would have done so on the main wheels. The nosewheel is NOT designed to take the full weight of the plane, which is what happened here. Add a tiny bit of drift with all the weight on the nose and this is the likely outcome.

3) If the instructor was indicating that the student should be looking down the runway to gauge his height, IMHO (and the FAA's) that's the wrong place to look. If the student was having his attention directed there (supposition on my part, but that's what it looks like), he probably didn't even sense that the plane was about to hit. I'll link to an article I wrote for the Cirrus Owner's Ass'n if anyone is interested

4) I feel for the instructor. An instructor must allow things to progress to the point that the student sees his errors. yozz25 has pointed out the feelings a student gets if he or she feels the instructor takes control too soon. I KNOW I've allowed worse landings than the one shown here to proceed. I probably would have had my hand cupped around the stick and after the first bounce would have tried to put the plane in a climb attitude and added full power, again so the next bounce would be on the main wheels - keeping the plane in a climb attitude with climb power avoids porpoising and pilot-induced-oscillations.

As a disclaimer, I have not flown a REMOS. Still, the advice given above has applied to all the planes I have flown, from LSA's up to and including Aztecs.
Fast Eddie B.
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Jim Stewart
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Post by Jim Stewart »

I'll link to an article I wrote for the Cirrus Owner's Ass'n if anyone is interested
Please do.
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FastEddieB
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Post by FastEddieB »

WHERE TO LOOK ON LANDING

Where should you look while landing a Cirrus? If your landings are consistent and you can accurately judge your height above the runway during the roundout and flare, just keep looking where you’re looking. If they could be better, read on.

As a flight instructor, I’m occasionally called upon to “troubleshoot” when a pilot is suffering inconsistent landings. Of course, in primary training the subject of where to look when landing always comes up.

WHERE NOT TO LOOK

I’ve had some pilots, including at least one flight instructor, advise that the pilot should gradually shift his view to the far end of the runway during the flare. I can think of two good reasons why this is not a good idea.

First, the far end of the runway is going to be at least a half mile away, and may literally be miles away. When looking at a point that distant, the angles involved in judging a foot or two of altitude are simply too small. Take a look at these two examples:

Image

These were taken just past the numbers on runway 2 at Copperhill, TN (1A3), a 3,500’ runway. The photo on the left was taken with the camera roughly at eye height in a Cirrus. I climbed a ladder to take the photo on the right. (I “Photoshopped” a panel into the photos to make them more realistic.)

Can you tell, looking at the far end of the runway, how far up the ladder I was? One foot? Two feet? Ten feet?

Well, I was about five feet up the ladder in the second photo. I think it’s clear the visual information available looking at the far end of the runway makes accurate height judgment extremely difficult.

Second, in many airplanes you will simply not be able to see the far end of the runway in the landing attitude. Our planes are blessed with above–average visibility, but in a slow enough landing even a pilot of average stature at some point may see something like this (a real photo of a “full-stall” landing in an SR22):

Image

OK, SO WHERE DO I LOOK?


To accurately judge height, we need to pull our vision closer to the plane, while simultaneously diverting it toward the runway edge. Exactly how far ahead of the depends on the plane’s speed, but I encourage my students to look 30 to 50 feet ahead of the plane, more or less at the runway edge.

Why not closer? Closer might work better, but for the fact that the ground becomes blurred.

A study performed by engineering students associated with the University of Michigan Flyers in the early 1970s in which a device that measured eye movement was placed on the heads of pilots who were making good landings agreed with the recommendations of this article. At that time a lot of instructors were stressing that the student should look well down the runway in the flare. When those same instructors wore the device that measured their eye movments and where they were looking, it was found that they focused near the left edge of the runway, about 200 feet ahead of the airplane.

Flight instructors sometimes note that their student’s night landings are better and more consistent than their daytime landings. The common explanation for this is the student’s vision is being pulled closer to the plane by the landing light – usually (and not coincidentally) right about where they should be looking in the first place!

One word of caution if you go out and practice looking ahead and to the side: our bodies tend to follow our eyes. If shifting your view to the left runway edge is new to you, you may find the nose of the plane being “pulled” that way. It’s subtle, and once you’re aware of it, it should be easy to compensate for.

And finally, this is the FAA's take (From the Flight Training Handbook):

Image

Now, go have some fun!











..
Fast Eddie B.
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yozz25
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landings

Post by yozz25 »

Thinking about it, in doing landings, the student is trying to accomplish 2 things at once.

One is to judge the height above runway as mentioned by Eddie, and round out correctly to effect a soft landing.

While doing this, he is also trying to keep the nose straight.

I think the answer,as I have read elsewhere, is to practice on a runway that is very wide. Not worry so much about straight nose, but concentrate on that soft landing.

My latest instructor said she learned landings at an abandoned military airfield, the width was huge, over perhaps 125 feet, maybe even more.

Here you can practice one aspect until you got it down pat, then you go on to working on the straight nose.

The problem is getting such a runway.

If all you had to do was practice say on a huge rectangle, not worrying at all about the staight nose, just the touchdown, then it would come. Once done, then we straighten the nose.
yozz
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FastEddieB
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Post by FastEddieB »

yozz,

The issue is both to have the nose "straight" (i.e. aligned with the runway)...

...and...

...to not allow lateral drift.

If the plane is drifting, the gear can be subjected to possibly damaging side loads, even if the nose is "straight". In a tailwheel aircraft, you're seconds away from a ground loop as well.

I agree that having a large rectangle (or an aircraft carrier!) could at least allow landings to always be practiced into the wind.

But in real life, nearly every landing has some crosswind involved.

Landing is a lot like juggling. In a power-off landing, there are basically three balls that have to be kept in the air, so to speak:

1) The student must get the feel for how much rear stick/yoke movement is required to hold the plane off the ground in the flare. He must be looking in the right place, but even then it takes "feel" to get the hang of the need for increasing rate of stick travel as the speed decreases (which is non-linear).

2) The student must use rudder, and rudder alone, to keep the nose straight.

3) The student must use aileron, and aileron alone, to keep the plane centered on the runway.

None of this is easy at first - each "ball" affects the other two. Need right aileron because the plane is drifting left? Then more left rudder will be needed to keep the nose straight and to keep the plane from turning. And all things being equal, both the rudder and aileron deflection needed will increase as the speed decreases.

With practice, however, it will eventually "click" and become so second-nature that you don't even think about it.

Really.
Fast Eddie B.
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yozz25
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whatever

Post by yozz25 »

Well, being what it is, you, Eddie are the expert, I'm the sudent.

I take it philosophically, it will come to each student in his or her time, I guess just about everyone "gets it" sooner or later.

In my own case, I still have to master it, seems like in flight school basic training, landing is the cherry on top, but like you say, a juggling act that eventually clicks. I choose for the time being to just lay low, let the landing devils back off of me with their little pitchforks for a while, lick my wounds, and when the old dawg gets some spark in his loins, the fog lifts from my exhausted brain, and the wife stops nagging, I'll give it another go.

In learning anything, got to know when to back off and not take it too seriously.

yozz 8)
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drseti
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Re: whatever

Post by drseti »

yozz25 wrote: In learning anything, got to know when to back off and not take it too seriously.
Good pholosophy, Yozz. Or, more properly for aviation: take it very seriously, but don't take it personally when things don't quite work out. :wink:
We have all experienced learning plateaus. Patience and persistence will see you through them. It's a juggling act.
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yozz25
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oh, just one other thing

Post by yozz25 »

Insurance.

I'm assuming the CFI and fight school have insurance policies of their own covering damage to aircraft.

Ok, if I were the CFI's insurance agent, I would take him out to the woodshed.

You never admit liability. You say nothing, that is your duty to the insurer, READ YOUR POLICIES. Here the school's policy will initially pick up the tab. However, they can now easily subrogate damages from the CFI's policy.

An insured's primary duty is to say nothing, let the insurer do the work. When you get into an auto accident, the worst thing you can do is say it's your fault, let alone have this recorded for all the world to see.

If this had been an incident involving serious injury, the CFI may well have been in deep goo, since his insurer may well be able to deny coverage due to the insured CFI admitting fault, and getting the same out of the mouth of babes, namely the student via his u tube presentation.

Aircraft insurance is a study in itself, my worst fear of training was actually stepping out of the Warrior onto that thin little strip of metal worrying that a misstep could end in a pretty serious leg fracture among other things. I would then have to hire some shyster to shuffle through the myriad of policies, if there are any, to pay me while I sit with a fracture from the tip of my toe up to my keister.

In any case, insurance by it's nature is very complex, and I noticed a blatant error by the CFI that would make any agent worth his salt cringe.

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Post by Cub flyer »

Anybody fly a Remos like in the movie. Similar serial numbers and loading?

How is the elevator response in the flare? In those conditions?

On some other airplanes if the CG is forward the elevator will be sensitive into the flare and suddenly the stick goes loose and there is no elevator authority. Stick hits the aft stop with no additional effect.

The deflection comes to the point that the underside of the elevator or stabilator stalls.

I have found this more than I really want to but it will go down as pilot error. The effects are sudden and without warning. Also a wing mounted stall warner may not go off.

Quite often the horizontal tail stalls before the wing. The pitch down sensation is quite different between the two.

That's why VG kits commonly put the VG's under the horizontal tail.

Did this happen here? I don't know without flying the actual airplane at that loading.

Airplanes I have had this happen on, PA-11 with nosewheel installed, Beech Musketeer, Queen Air, 05 CTSW, Beech 18, Cherokee 180, Cessna T206. Usually at the forward CG limit is where you find this problem.

Skydive airplanes land at max forward CG all the time so you find things.

The Cessna Cardinal also had a problem but they installed slots in the stabilator leading edge to fix. The Beech Sierra they installed a lead weight in the tail. Piper increased the horizontal tail span on the Cherokee, Cessna changed the horizontal tail span and balance design on the 206 and 210. CT increased the stabilator tab span, Moved the stabilator back 18 or so inches on the LS and changed the CG limits on the CTSW.

I'm using it for an example but I'm NOT starting the CT argument again. Just changes observed.

The Stinson 108 has elevator stops that move when the flaps are extended.

I wish the NTSB or FAA would conduct a test for this before just running it into the Pilot Error category. If it is the case the "Pilot Errors" will continue.

The stall in ground effect may be quite different than at altitude.
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stall warning

Post by yozz25 »

". The effects are sudden and without warning. Also a wing mounted stall warner may not go off"

Remos has no stall warning beeper

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Post by Cub flyer »

I forgot another. The Maxair Drifter on Lotus amphib floats. The horizontal tail will stall on landing when flown solo. Even with the weight of the 912 in back. I never flew it with two people so I don't know the characteristics.

I did not stall it at altitude so I'm not sure how it reacts there either.

No stall warning is needed. You can feel it starting to go in the stick.

Beyond about 1/2 to 2/3 back the stick has no effect in the landing flare.
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Re: stall warning

Post by drseti »

yozz25 wrote:Remos has no stall warning beeper
Neither does my SportStar. Nor does it need one. Whole plane is a stall warning shaker.
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Post by ibgarrett »

Maybe the Remos you're flying doesn't have one, but the Remos I've flown has one. It sort of sounds like static from a cell phone over the radio. It's very low and relatively quiet. The Sportstar I've been training in (got my ticket on Thursday - WHEEE!!) has one as well - but I agree. The entire plane shudders when it's getting ready to stall. :D
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Post by drseti »

ibgarrett wrote:(got my ticket on Thursday - WHEEE!!)
Hey, congratulations, Brian!
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Post by bitten192 »

I own a REMOS G3/600 ser #192, and I'm a CFI. The numbers for my G3 are in mph not knots. 75 on downwind, 65 on final, slow and rotate on final, keep the nose up and land on the main wheels at about 40mph. The G3 floats but thats OK because you don't use a lot of runway at 35-40 mph. The sight picture on the video looked like he came in very flat (did he use flaps?) and it looks like he pushed the nose down after the first bounce. He should have pulled the stick back and let it settle on the mains. The elevator has excellent control on flair even at low speeds.

How much flaps did he use? He should have had full flaps and full nose up trim, and idle power. I could not tell on the video what he had for flaps, trim and power.

Ernie
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