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Morgan aeroworks cheetah sierra 100


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lose the nose wheel and the problem goles away.............003_cheezy_grin.gif.c5a94fc2937f61b556d8146a1bc97ef8.gif

Lose pilots who are getting lazy and not landing right, force them to land right and not on the nose, there are a lot weaker nose legs around, not meant for landing on, only to steer at very very low speed at about 5 knots the rudder does the work and nose wheel should have no weight on it !

The problem does not exist, lazy pilots exist, instructors who allow pilot to get away with bad landings is not on. Seen plenty of bad landing done and the pilot thought it was good, I've never done a bad landing on purpose but not all are perfect. My point is some people accept bad landings as normal ! You think your going to land a tail wheel aeroplane easier ? Those pilots I speak of will have little or no chance !

 

 

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Post deleted. Insulting to member. If you wish to pontificate, do so with first hand, qualified knowledge and not, as appears in this case, hearsay. If you have proof, put it on the table with qualification. Until then ..post deleted. (mod)

 

 

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Hmmm

 

If you can't flair it's not an undercart issue it's a cofg or tail volume issue. If the mains are a long way behind the cofg then yes it will take longer into the take off run to get weight off the nose leg and on landing you'll not be able to hold the nose off as long.

 

But unless you have insufficient tail volume in the design or a too forward cofg on that flight you have no reason other than pilot handling technique for the nose to touch first ...

 

 

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Volume and also distance. If it's close coupled and more area, you get more downforce force on the mains but still not much pitching effect. Having the mains too far back is always a problem where it exists. So is a positive pitch when sitting on the wheels, often done for propeller clearance but results on extra loads on the nosewheel that wouldn't happen otherwise. Nev

 

 

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Volume and also distance. If it's close coupled and more area, you get more downforce force on the mains but still not much pitching effect. Having the mains too far back is always a problem where it exists. So is a positive pitch when sitting on the wheels, often done for propeller clearance but results on extra loads on the nosewheel that wouldn't happen otherwise. Nev

Sorry was not clear - the concept of tail volume includes both the size (force) and arm (distance) ... its the product of the force and distance just like the moments you use in calc of the CofG itself.

At the design stage you are working with estimates of actual CofG of the aircraft, estimates of the pitching/rotational forces around the CofG of the actual wing based on the area, shape and sectional pitch moments and using those to determine the estimate of the tail volume needed to provide the ability to pitch UP at the forward CofG extreme in the landing configuration and the ability to pitch DOWN at the rear CofG condition. Lots of fun.

 

But as pilots are able to rotate the nose up to flair the tail volume is at least minimally adequate if handling of the airframe is within the limits. Not saying its like some 'failsafe' airframes where the authority is huge and the ability is absolute regardless of how you handle the airframe.

 

After all aircraft design is always a balance and compromise ... greater tail volume always comes at a cost to performance and if you want a fast low powered airframe that can meet the stall requirements to be in our area you are going to have areas where one performance aspect of the airframe has been gained at the limitation/expense of another.

 

 

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All true and fuselage length makes a problem with the plane not stalling when sitting in the 3 point position. The problem is the gear location. Once the load transfers to the mainwheels you can't do anything to stop the nose wheel falling down on the runway if the wheels are too far back. The nosewheel's contact should be controlled and not just fall when it feels like it. Such planes have to be flown onto the runway with all wheels contacting at the same time to avoid problems. That's a bit limiting. Nev

 

 

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Limiting? how about bloody difficult to get right all the time....Should the mains not be only as far back as necessary to stop the tail dropping at a standstill? I can lift my tail dragger by the tail comfortably and wheel it around. Which must mean that the mains are very near (or on) the c of g.....By the same token how much pressure must be applied to the tail of a Morgan to lift the front wheel? If it's lots then maybe the main wheels are too far back.....Were that the case then even CFI,s might find it troublesome to land three pointed all the time.

 

 

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All true and fuselage length makes a problem with the plane not stalling when sitting in the 3 point position.

Its a design choice - really long fuselage will require longer undercarriage legs to avoid the tail strike at stall attitutde - shorter fuselage lets you have shorter undercarriage.

Always has been the case and if you look to regional airliners ask about the rotation angle limits on the Bombardier Q400 over the earlier models ... stretch the fuselage and limit your rotation

 

The problem is the gear location. Once the load transfers to the mainwheels you can't do anything to stop the nose wheel falling down on the runway if the wheels are too far back.

Yes and no. IF you demand the need to hold the nose off after main touch then your rearward position of the mains is a criticality, if it is not and you accept that the nose is coming down then IF you design it to have the nose only a few inches above the ground in the last stages of the flair then its still safe BUT it becomes an airframe that has a criticality in its handling in the latter stages of landing.

AND if you have a very reward main landing dear with respect to the CofG you usually build the nose leg like the proverbial brick outhouse - trust me we know - all us trike flyers KNOW how hard it is to 'hold off' the nose on landing ... you CANNOT get your mains further behind the CofG for use ... out mains are at the extreme rear of the airframe after all

 

The nosewheel's contact should be controlled and not just fall when it feels like it. Such planes have to be flown onto the runway with all wheels contacting at the same time to avoid problems. That's a bit limiting. Nev

Yes and no. unless

1. the stall angle = ground angle for this aircraft; or

 

2. the max angle that can be held with available tail authority = ground angle for this aircraft

 

then its not a REQUIREMENT that its all three together ... but it MAY be a handling situation that is common in pilots who learned/operate other aircraft that are not critical in this respect

 

 

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Sorry guys, I've been reading your posts on gear location but I must be missing something.

 

What reason could there be for ever locating the main gear substantially behind CofG? It was my understanding that main gear should only just be rearward of the rear CofG limit.

 

 

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I agree, unless there's a step to get up from the rear. Tricycle gear pushers have a problem. Ezy's and Vampire (Saddler) but a tractor doesn't have a problem. It's more directionally stable if put rearwards but always better than a taildragger which is sometimes well forward (with brakes) and moreso when held off to the 3 point position . (which I consider quite normal unlike many these days )for landing

 

 

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Sorry guys, I've been reading your posts on gear location but I must be missing something.What reason could there be for ever locating the main gear substantially behind CofG? It was my understanding that main gear should only just be rearward of the rear CofG limit.

In an ideal world yes that would be where i would be planning to put the rear wheels of a nose gear aircraft

It gets mussed up by things like

 

  • pusher engine ... and wanting to not sit on tail when empty (SV2 vampire)
     
     
  • rear steps up the back of wing to enter ... and not wanting to sit on tail as people climb up (morgan seems to have this ...)
     
     
  • structures ... if you have a fuselage frame or spar layout that would more conveniently put the gear attach behind the main spar (White Lightning)
     
     
  • reuse of existing components ... if I already have an undercarraige that I intend to reuse you MIGHT put it WAY back on the fuselage to get the ground attitude you want with a BIG new prop and a new long noseleg (some homebuilts and one offs from companies)
     
     
  • asthetics (lots of cases)
     
     

 

 

lots of reasons why it is not where you might ideally put it and so long as you can flair to a nose leg high attitude it technically works.

 

 

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In an ideal world yes that would be where i would be planning to put the rear wheels of a nose gear aircraftIt gets mussed up by things like

 

  • pusher engine ... and wanting to not sit on tail when empty (SV2 vampire)
     
     
  • rear steps up the back of wing to enter ... and not wanting to sit on tail as people climb up (morgan seems to have this ...)
     
     
  • structures ... if you have a fuselage frame or spar layout that would more conveniently put the gear attach behind the main spar (White Lightning)
     
     
  • reuse of existing components ... if I already have an undercarraige that I intend to reuse you MIGHT put it WAY back on the fuselage to get the ground attitude you want with a BIG new prop and a new long noseleg (some homebuilts and one offs from companies)
     
     
  • asthetics (lots of cases)
     
     

 

 

lots of reasons why it is not where you might ideally put it and so long as you can flair to a nose leg high attitude it technically works.

Fair enough. I can see why, and never having designed a full-size aircraft perhaps I shouldn't be commenting, but I would have thought that correct placement of the main gear is a more important consideration than whether the pusher a/c sits on its tail when empty, or having a step at the trailing edge. Definitely more important than aesthetics!

 

 

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Landing nose up doesn't help if the elevator can't control the rate the nosewheel contacts the tarmac. It's also a factor in unsticking the plane on take off at the precise point you wish to do it. (As in a crosswind OR a muddy grassy field) Nev

 

 

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Yes training wheels up front are not the answer.

 

I hated the setup when I saw it. The lever arm, the nose leg. No way on my plane..

 

Short back and long nose mmmmmmm.

 

Yes the last one made 18 hrs total time.

 

Local comment was landing too fast helped to complete the picture.

 

I have not flown one but whats low speed elevator authority like.

 

Chas

 

 

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Low speed elevator is fine. Plenty of control and its not twitchy. You do need to damp the elevator with bungies as the plans say. Mine has less than recommended but I have a few thousand hours in gliders and am use to sensitive elevators. Garry helped me set the neutral point too as it is an all flying tail plane. I also have limited my wt&b to 30% of chord so not to fly at the extremes. 20% of the weight is on the nose wheel so don't land on it. Its a pussy cat if you take a bit of care and don't operate it near any limits.

 

 

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Thankyou Graham,

 

I was not knocking the aircraft as such but more interested in its handling for reasons discussed.

 

My aircraft has a large volume full flying elevator. Was a stabilator but have just removed the antitab. It now sports a basic control with the existing tab.

 

The reason perhaps from also having done a lot of gliding was the pressure the antitab puts on in turns. I noted the Morgan was like this.

 

Hinge points will no doubt be different. I am here to learn and help where I can.

 

Its a big call for someone like Garry to try and market a new machine.

 

My aircraft is scratch built prototype and while happy with it I want to fine tune it.

 

Garry is no doubt the same and this is the reason a mark two is prduced.

 

Keep safe, Chas

 

 

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As a matter of interest I put the antitab back on.

 

A couple of full throttle runs down the field

 

gave not nice feelings no matter where the tab was set.

 

Taxied back in and put the old antibar back on.

 

Back to normal.

 

At least now I know.

 

Chas

 

 

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  • 1 month later...

Hello all just joined the forum. I own a Morgan sierra 200 and have been flying it now for over 4 years when time available. I have flown all versions and the view out the canopy over the nose can cause you to land flat. It takes a while to get used to the view but look down the runway and it lands very nicely. They are a great plane to fly especially across country.

 

 

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Welcome to the site Glenn.

 

Lots of great stuff in here and heaps of friendly and knowledgeable members.

 

Tell us more about your Morgan- even start your own thread in the Morgan area about your aircraft. Lots of pics really helps- just size them down to suit site needs.

 

tell us anything about it- the more the merrier.

 

More threads on individuals planes help everyone and share the love.

 

Phil

 

 

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  • 1 year later...

I have owned and flown a Morgan Sierra for several years. It is a great aeroplane, comfortable, mobile (removable wings and trailer) and easy to fly EXCEPT FOR LANDING.

 

I concur with all the above comments about difficult to land and thought it was just me. I have had such a torrid time landing this plane that all the fun has gone out of my flying and I have given up and the plane is for sale. I had extensive instruction from Gary and have done more circuits than I care to remember but to no avail. Pity, but them's the breaks. Think I will get a Mosquito.

 

 

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Here in NZ we have seen a couple of Sierras modified by moving the main gear forward, and also beefing up the nosewheel. These mods transformed the aircraft and it becomes much easier to land. The basic problem is too much weight on the nose making it very difficult to flare.

 

 

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I built a Sierra and test flew it myself & had no problems landing initially. It all came unstuck when my approach was a bit fast over the fence & I floated forever, finally getting down & didn't control it well when going on to the grass runoff at the end of the seal. Ran into a swampy area (we'd just had lots of rain) & the nose leg bent. I installed a new leg but had a bit of a brain explosion & made it 2 inches too long. This is approximately the flare attitude & on the second flight 3 pointed it, bounced & bent the new leg. The current leg is beefier at .095" wall thickness, up from the original .083" chromolly and I have had no landing issues since. The flare is subtle with the nosewheel only a few inches in the air when the mains touch down and as Graham Brown said the full flying elevator should be dampened with bungees as it is very sensitive. Once you master the flare you just hold it until the nose begins to drop then a small bit of up elevator will have you touching down perfectly. Even if you don't get it right it is still easy to control IMHO. Moving the main gear forward is an option a number of owners have used but mine are standard.

 

 

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