Friday, September 4, 2009

[Titanaircraft] Re: tail wheel pics

--- In Titanaircraft@yahoogroups.com, Jim Covington <jim@...> wrote:
>
> A few things:
>

> 1) If you don't hit the tailwheel, you could have landed slower. Whether
> or not you chose to do so is up to you. All this talk of dissipating
> energy? Just put less into the equation by touching down at a slower
> speed. Carrying power into the landing does result in a smoother
> landing, but adds far more energy.

Well depending on the conditions having that extra energy isn't necessarily a bad thing. I.e. when it's windy and you have a lot of gusts going across the field. In a spam can it's not that big of a deal if a gust picks you up out of ground effect a foot or two. Even with a fair bit of flaps you often have enough lift still going on to save it from being a real plonker when the "valley" part of the gust comes along. Plus the gear on the typical spam can is a strong and pretty sproingy gear.

But in a lower inertia design like the titan you dissipate energy a lot faster. Sometimes you don't have enough time to spool up the motor to save it when the valley happens and you plonk it down. It's sometimes better to have that little bit of power in during the flare to slow down the energy dissipation so you can prevent the plonk-down.

This is something ultralight pilots just know for example that folks trained in high inertia planes sometimes don't. That's why UL training and experience is really helpful for some things in the titan and other light a/c.

> So anyway, I think ripping off the tailwheel on grass absorbs energy,
> but not any energy that would damage the airplane.
>
> Has anyone ever ripped off/broken an *undamaged* tailwheel with a
> landing on pavement?

I think JD told me he did once, don't know if it was on my plane or not. Seems like it was on his S. He told me he had to go find it and it was a long ways down the runway somewhere.

As for your tailskid idea, I actually kind of thought about that on my plane, except I do need to ferry it around on the ground and the skid would make that hard without a little tow truck...

LS

>
>
> ls78705 wrote:
> >
> >
> > --- In Titanaircraft@yahoogroups.com
> > <mailto:Titanaircraft%40yahoogroups.com>, "lwoods102" <lwoods102@>
> > wrote:
> > >
> > > Hi Hugh:
> > >
> > > I should have provided more information.... the picture of the tail
> > wheel installation is in the photo album entitled "Larry Woods -
> > modest Titan mods".
> > >
> > > An added comment... Yes, one can ensure that the tail wheel does not
> > contact the runway by carrying a bit of power, but there are obvious
> > negatives to so doing. Added runway is required for one thing, and the
> > touch down speed is likely to be higher than optimum. No aircraft is
> > perfect and I really love the Titan Tornado but a slightly greater
> > intersect angle between the boom tube and the fuselage chromoly steel
> > frame might haver banished the tail wheel contact.
> > >
> > > Like some others, I think the tail wheel is there for more than just
> > dragging the Tornado around on the ground. The pictured tail wheel
> > mount has a few interesting features. The machined base provides much
> > greater contact area with the boom, thus spreading the load. It is
> > also wider, to allow a wider tail wheel to be employed. The new tail
> > wheel has a wider profile and proper bearings, which ensures that it
> > spins up quickly, which reduces the shear forces when ground contact
> > occurs. There have been no problems with it since it was installed.
> > >
> > > Best,
> > > Larry
> > >
> >
> > I'd kind of have to agree with Guy on this, that the tailwheel is
> > intentionally weak to act as a shock absorber in the event of a harsh
> > hit.
> >
> > This installation looks vastly stronger. I mean it's beautiful work
> > looks like to me, ;), but then again this is a significant
> > strengthening of the wheel assy itself but without redesigning the
> > rest of the tail.... In the event of an incident, the energy is going
> > to be transferred somewhere else rather than absorbed by the tailwheel
> > like the original design intends.
> >
> > Don't know about anyone else but I'd sure like to not ever have to get
> > into any kind of repair or replacement of that boom tube..... That
> > thing is strong and it's _on_ there, glued and rivetted and bolted and
> > etc......
> >
> > I'd much rather have the tailwheel rip off instead and leave that tube
> > intact....
> >
> > As for carrying power into the flare, I sort of think of it as a
> > compromise. When it's calm I'll usually do the whole flare/touchdown
> > at engine-ldle, but when it's windy I'd rather have the extra energy
> > input to slow the maneuver down a bit. The titan is still a
> > low-inertia design (and really behaves that way with flaps deployed)
> > so you need really impeccable timing in the flare to oil it onto the
> > ground. Especially when it's windy you just don't have that loads and
> > loads of hang time in the flare that you do with a high-inertia design.
> >
> > So I think it's better to accept a little more runway use and
> > touchdown speed to be able to have a gentler touchdown. I think it's
> > harder on the airframe to plonk it down rather than carry a little
> > extra speed.
> >
> > JMO,
> >
> > LS
> > >
> > >
> > > --- In Titanaircraft@yahoogroups.com
> > <mailto:Titanaircraft%40yahoogroups.com>, Hugh Sontag <flying.hugh@>
> > wrote:
> > > >
> > > > Larry,
> > > >
> > > > If you attached pictures, they won't come through on the Yahoo list.
> > > > You could post them to the web site. If you do, please let us know, I
> > > > for one would like to see them.
> > > >
> > > > Hugh Sontag
> > > >
> > > > >Hi Greg:
> > > > >
> > > > >Re tail wheel mount.
> > > > >
> > > > >See pics of the tail wheel mount I machined. The weight difference
> > > > >is negligible and it has been bulletproof. I machined it from a
> > > > >chunk of scrap aluminum. The wheel was acquired from a local supply
> > > > >house and was very inexpensive. It has proper bearings and is wider
> > > > >than the standard tail wheel so it spins up quickly.
> > > > >
> > > > >There are times when prudence requires a slow speed approach (short
> > > > >field), which means that the tail wheel will contact the ground.
> > > > >
> > > > >Best,
> > > > >Larry
> > > > >Best
> > > > >Larry
> > > > >
> > > > >--- In
> > > >
> > ><mailto:Titanaircraft%40yahoogroups.com>Titanaircraft@yahoogroups.com
> > <mailto:Titanaircraft%40yahoogroups.com>,
> > > > >"gregburcham18" <gregburcham18@> wrote:
> > > > >>
> > > > >> Could someone please give me an alternative to the tail wheel? My
> > > > >>tail wheel is secured via 12 aluminum rivets per side which pops
> > > > >>right off anytime it is even slightly bumped (sometimes I don't
> > > > >>even know it is gone until I get out of the aircraft). I hate this
> > > > >>thing!
> > > > >>
> > > > >> Any suggestions (mechanical, not flying skills) would be greatly
> > > > >>appreciated.
> > > > >>
> > > > >> Thanks,
> > > > >>
> > > > >> Greg
> > > > >>
> > > > >
> > > > >
> > > > >
> > > >
> > >
> >
> >
>
>
> [Non-text portions of this message have been removed]
>


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