Cliff,
Could not agree more. I discarded the fuel sight tube and fitted capacitive
fuel gauging.
regards,
Mike
----- Original Message -----
From: "Cliff Shaw" <flyinggpa@comcast.net>
Subject: Europa-List: Mikes Fears, Mod 70
>
> All and Mike
>
> Your fears are shared in my hanger as well. In that I am in the USA, I
> will
> take my new stronger mass balance arm to my trusty welder and have a cable
> attachment flange put on it. As you so wisely concluded, the cable
> installation was not designed well. The idea is fine, but if a builder can
> not do it well, it is a bad design. I installed the turnbuckles and feel
> that fixed the design problem.
>
> (another example is the fuel sight tube that runs under the floor mat and
> up
> and over the top of the cockpit.) Here in the USA we don't built it that
> way either.
>
> Just my thought. Remember "I am an amateur"
>
> Cliff Shaw
> 1041 Euclid ave.
> Edmonds, WA 98020
> 425 776 5555
> http://www.europaowners.org/WileE
>
>
> ----- Original Message -----
> From: "MICHAEL PARKIN" <mikenjulie.parkin@btopenworld.com>
> To: <europa-list@matronics.com>
> Subject: Re: Europa-List: Mod 70
>
>
>> <mikenjulie.parkin@btopenworld.com>
>>
>> Jeremy,
>>
>> I have been away on business and so have not been around to join the
>> discussion about MOD 70 but I have to say I am very unhappy about the Mod
>> and its possible implications. I appreciate that being a non current
>> engineer makes my opinion of little value to Europa 2004 or Francis
>> Donaldson, but that never stopped me before.
>>
>> Firstly, the installation of the cables on the Mass Balance arm during
>> the
>> build struck me as very much hit or miss procedure at best. Page 20-2 of
>> the
>> builders manual- quote- " Make the cable as tight as possible before
>> swaging
>> the sleeve. This operation is almost certainly a two person job, holding
>> the
>> cable and swaging tool at the same time." When I came to that, it seemed
>> to
>> me that obtaining a reasonable cable tension and getting the the mass
>> balance arm normal to the tailplane torque tube was almost mutually
>> exclusive. It was for that reason that I installed a turnbuckle in each
>> cable - this enabled precise measurement of the mass balance arm and
>> allowed for a predictable tension to be set. I don't know how many
>> builders
>> adopted the same approach, but I know I am not alone with this idea.
>>
>> The requirement for a stronger mass balance arm was decided following the
>> failure of one classic that had suffered ' a number of landing
>> incidents'.
>> OK, I can accept that without a problem.
>>
>> Last monday I drove up to Kirbymoorside to speak to Andy about the Mod
>> and
>> my misgivings about it. Andy has done a lot of testing on the setup and
>> he
>> showed me the new balance arm. It is made of thicker wall tubing and has
>> a
>> considerably more substantial adjuster assembly replacing the original
>> TP18A
>> adjuster. Andy also conducted some load tests on the original arm (in
>> the
>> vertical plane) he found that the test arm initialy twisted and then the
>> lower tube buckled - he showed me the failed item. I am not sure
>> whether
>> the arm was installed in the aircraft, with cables attached, or whether
>> it
>> was just a straightforward bench test - if it was a bench test I doubt
>> whether any cables were installed - perhaps if cables had been attached
>> the
>> inital twist prior to failure might have been delayed. However, the new
>> arm
>> is much stronger and should do the job nicely - but there are no cable
>> attachment lugs.
>>
>> I asked Andy why he had discarded the cables? His reason was purely to
>> make
>> the installation easier for owners. I explained my turnbuckle
>> arrangement.
>> to which he replied that it was not a problem and Europa could easily put
>> the cable attachment lugs on the new arm. Remember that the identified
>> weakness is in the vertical plane of the mass balance arm not in the
>> cable
>> system. I asked if he would contact Francis Donaldson, but he said that
>> he
>> would be happy for me to do it - as the new arm would be fitted with the
>> existing, proven engineering - it should require no flight testing. As
>> it
>> happens my aircraft is in the workshop for its' permit renewal so I
>> removed
>> the D panel and the fuselage access panels and had a good look around.
>> The
>> fitting of the turnbuckles to install the new balance arm would actually
>> be
>> quite easy. After carefully measuring and marking the cables so that the
>> end of the turnbuckle can be fitted in the correct place, the cables can
>> be
>> cut as far forward as possible, that is just short of the cable lugs.
>> Now
>> if the fuselage access panel, on the right side by the tail is in the
>> standard position, the cut end of the cables can be brought outside the
>> fuselage and the turnbuckle end swaged in comfort. The other end of the
>> turnbuckle can be fitted to the attachment lug on the arm using a
>> standard
>> fork fitting, cotter pin and split pin. The new arm is then installed
>> onto
>> the torque tube and with minimal time in the rear fuselage, the barrels
>> of
>> the turnbuckle are fitted, the arm is adjusted to the centre of the
>> pushrod
>> containment assembly, the tension set on the cables and finally locking
>> wires fitted to the turnbuckles. It may be necessary to drill a little
>> out
>> of the mass balance weights to reset the balance.
>> Now the point is that if some europas, because arranging the mass balance
>> arm normal to the torque shaft is not a given, and the containment
>> assemble
>> was built around the already installed mass balance arm. It is quite
>> likely
>> that the resting place of the new uncabled arm is not going to be in the
>> same place. This means that the pitch tube containment attachment
>> brackets
>> will have to be moved, and quite likely the fit of the ply around the
>> pitch
>> tube itself may need adjusting. How much time will be required down the
>> black hole to do that!!! Using the existing cables would avoid all those
>> problems. I asked Andy why he hadn't considered using turnbuckles, his
>> comment - - "Well people might not have any turnbuckles."
>>
>> What worries me is that this big lump of steel is going to be free to
>> move
>> left and right at will, perhaps hundreds of times in an hour in
>> opposition
>> to the slightest yaw of the aircraft. How much could it move? I noted
>> that
>> a value of 4mm was mentioned on this forum. In fact, Para 5 of step 3 of
>> the modification leaflet states - "The diameter of the mass balance
>> weights
>> is 50mm, and the nominal clearance is 2mm each side - check that the
>> clearance achieved is between 1mm and 4mm each side". I interpret that
>> to
>> mean that the lateral movement of the arm could be 8 mm. Such a movement
>> does not take into account the flexing of the plywood of the pitch
>> containment assembly - not the sturdiest of structures. In real terms
>> this
>> new arrangement could have these not insignificant balance weights
>> 'clonking' left and right by maybe 12mm. Is this movement likely to
>> cause
>> any fatigue problems at the attachment points on the torque shaft -
>> perhaps
>> one of the forum metallurgists could advise.
>>
>> I discussed this movement with Andy and he said that the weight moves
>> even
>> with the cables. If they are fitted in the manner described in the build
>> manual I can see that there might be some movement. With properly
>> tensioned
>> cables, there is negligible movement.
>>
>> Actually, it is not outside the realms of possibility that a fracture of
>> the original TP18A could be accellerated because of lateral movement
>> caused
>> by slack cables.
>>
>> The bottom line is that, the history of why the cables were originally
>> fitted to the mass balance arm is irrelevant. Many Europas have done may
>> thousands of hours flying with he current mass balance arm configuration
>> without a problem. Now following the fracture of one TP18A on an
>> aircraft
>> that has suffered 1 or more landing incidents we are all to fit stronger
>> mass balance arms. Changing the arm is the right thing to do. But I
>> totally disagree that discarding the cables is the right thing to do. It
>> is
>> one aircraft modified and tested at the factory for a few hours against
>> the
>> experience of the whole fleet.
>>
>> I understand from Bob Harrison that since I spoke to Andy Draper he has
>> been
>> told by his boss that he cannot put the lugs on the new arms as he
>> promised
>> me. It seems that the only way we can incorporate this modified
>> component
>> is the way Europa 2004 say, because that is what they have worked out and
>> tested. I smell commercial pressure here.
>>
>> I fear we are in danger of throwing the baby out with the bath water!!!!
>>
>> I have sent this email to the forum in the hope that someone can allay my
>> fears about MOD 70 - perhaps it might generate some positive comment.
>>
>>
>> regards,
>>
>> Mike Parkin (G-JULZ - hiding in the corner of the workshop with cables a
>> quivering.)
>>
>>
>> ----- Original Message -----
>> From: "Jeremy Davey" <EuropaFlyer_3@msn.com>
>> To: <europa-list@matronics.com>
>> Subject: RE: Europa-List: Mod 70
>>
>>
>>> <EuropaFlyer_3@msn.com>
>>>
>>> Fred,
>>>
>>> It wasn't stripped threads - the threaded portion sheared in two.
>>>
>>> Tim,
>>>
>>> I offered and you declined. OK, I'm 6' and 220lbs, but I still contend
>>> you're being fussy! :-)
>>>
>>> Cheers,
>>> Jeremy
>>>
>>> Jeremy Davey
>>> Europa Monowheel 537M G-EZZA
>>> Europa Club Vice-Chairman, Webmaster, PFA NC Representative
>>> PFA EC Member
>>> If you can keep your head when all about you are losing theirs, then it
>>> is
>>> possible you haven't grasped the severity of the situation.
>>> Tail done
>>> Standard XS wings with mods underway
>>> CM installed in fuse (with airbrakes fittings)
>>> 1390 build hours to date
>>> Intended fit:
>>> Rotax 914 turbo, Airmaster CS fully-feathering prop
>>> Lots of lights, buttons, switches, gizmos, and alarms
>>>
>>>
>>> -----Original Message-----
>>> From: owner-europa-list-server@matronics.com
>>> [mailto:owner-europa-list-server@matronics.com] On Behalf Of Fred
>>> Fillinger
>>> To: europa-list@matronics.com
>>> Subject: Re: Europa-List: Mod 70
>>>
>>>
>>> "R.C.Harrison" <ptag.dev@tiscali.co.uk> wrote:
>>>> ...
>>>> I understand that the part that broke ( Having been previously under
>>>> extraneous circumstances!) was actually the adjuster screw thread,
>>>
>>> I think I'm beginning to understand. There is considerable inertia in
>>> the counterweight, and a few good whacks to the tail in occasional
>>> hard landings would put the lower arm components in compression once
>>> too often, stripping threads? The rebound may not help either. I
>>> know this is amateur engineering, but perhaps the trigear doesn't
>>> suffer as badly in ungraceful handling, because the force exerted on
>>> the counterweight will be less abrupt. Hope so.
>>>
>>> Reg,
>>> Fred F.
>>>
>>>
>>>
>>
>>
>>
>
>
>
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