The Murphy Builders Site

Hi All,
I left the list for a while when my voyager e-mail address fell
over and I have only just got back on, I am interested in the line of
discussion regarding gear issues on the Super Rebel.

I saw the Moose prototype and a fast build Super Rebel kit at Oshkosh last
year and was completely underwhelmed with the attachment of the gear to the
fuse. The Moose prototype had damage around the gear attach area and an 'add
on' was riveted in to strengthen the area (was this the Drag link you talk
about?) I didn't have any confidence that the 'add on' was a long term
solution. It appears not a lot was learnt from the Rebel spring gear.

My spring gear Rebel had a history of attachment problem that was only
solved after I placed a beam from the straddle bolts back to a hard point
where the rear bungee gear attach point would normally be, The gear is now
bullet proof and I have over 300hrs on the mod on all grass and rough
fields. (450hrs total)

Sure, the attachment box on the Super rebel/Moose looks very substantial,
but have you seen the length of those legs! and the weight of the aircraft!!
The issues will be just about the same as my Rebel, the most damaging loads
are the braking loads on the legs ( backward twisting of the legs caused by
braking, rough ground, rocks etc.) These loads are proportionally worse if a
wheel type landing technique is used. A drop test will not go anywhere near
simulating these loads.

The Super Rebel design simply does not have a system in place to distribute
these loads, compare it with the likes of a Cessna180 which has a major
'horseshoe' running right up the doorpost to about wing hight to distribute
these particular loads.

What is required is an internal structure that somehow can distribute these
loads along the rear fuse a fair distance (say about a metre) or even up the
doorpost maybe?( I don't really think thats the direction to go)

I love the look and idea of the Moose/Super Rebel and would be prepared to
take one on, but I decided last year at Oshkosh it might pay to wait until
the gear bugs shake out before I proceed.

And a question, what would the estimated cruise speed be on a 300hp lycoming
powered ( say 70% power) SR or Moose?

Cheers

Alister


----- Original Message -----
From: S & L Aldrich <flynski@peoplepc.com>
To: <murphy-rebel@dcsol.com>
Sent: Thursday, July 18, 2002 1:31 PM
Subject: RE: SR3500 SB0002270602 Fuselage

Hi Wayne,
Brian must have known I was going to ask about this too.. I am sure he

saw

me "inspecting" everything very closely. I have a picture showing that

the

left main gear strut was moving back far enough to bend the panel aft of

it.

He sent me that impending bulletin along with the reply to you. I am
concerned that they are getting this kind of movement with a very
experienced pilot in type and most likely on fairly smooth runways. I

want

to be able to dork one up, plop it in, roll over lumps and rocks on a

rough

runway and know that the only thing that is hurt is my pride.

I am wonder if we should do more than just add the inter rivet spacing.
Gussets maybe? I don't know. I would add as much as it takes and not

worry

about the extra weight to not have any gear or float attach problems. I
understand that the float attachment that MAM had on the prototype 3500
strait floats in Arlington was not necessarily the final product. They

just

wanted it up for display. But I do know that nothing I have seen so far
looks as beefy or as rugged as the ones I have been looking at closely on
C-185s, etc.

Scott Aldrich
#174




-----Original Message-----
From: murphy-rebel@dcsol.com [mailto:murphy-rebel@dcsol.com]On Behalf Of
Wayne G. O'Shea
Sent: Wednesday, July 17, 2002 2:54 PM
To: murphy-rebel@dcsol.com
Subject: SR3500 SB0002270602 Fuselage


Have attached below a copy of a SB that is coming out from MAM, but not
posted on their site yet. Pretty self explainatory with the picture, but
it's not here so I will explain. The Drag Link is the SB090520SR that was
asked for some time ago to strenghten the gear on the 2500. When I did the
3500 upgrades I milled the face of this part by the thickness of the

FUS-703

steel plate and put it back into the same door sill "wrap" rivet holes, so
not hard to do guys and gals. The "inter-pitching" is simply adding

another

rivet between each existing rivet in the forward door post closest to the
door (as I have done on Rebel's for 7 years) for LARGE tire operations and
also on both of the door post bulkheads immediately behind the door for
float operations. I would do them both no matter what configuration you

plan

to fly! Without the extra rivets the skin apparently tries to buckle in

the

inch or so gap between rivets.

Cheers,
Wayne G. O'Shea
www.irishfield.on.ca

***SAFETY BULLETIN***
MURPHY AIRCRAFT MFG. Ltd., DATE: 27 June 2002
8155 AITKEN ROAD,
CHILLIWACK,
B.C.
CANADA V2R 4H5
Tel: (604) 792-5855
Fax: (604) 792-7006
Murtech@murphyair.com

AIRCRAFT AFFECTED: SUPER REBEL 3500
Owners of SR3500's who are intending to fit the large "Alaska" wheels and
tires to their aircraft, should complete the following modifications.
Due to the greatly increased initial drag of the tires on touch down and

the

extra weight of the rims, our demonstrator aircraft has shown slight
movement of the gear legs, and some inter-rivet buckling in the vertical
rivet line on the aft channel of the lift cage.
1/ The 2500 drag link should be installed as per bulletin 090520SR. This
will prevent any flexing of the steel plates FUS-703.
2/ Inter-pitching (installing an additional rivet between the existing
rivets) of the existing rivets with RV-1410's in the rivet lines indicated
in Fig. 1.
These modifications can be completed by all owners if desired.
Owners who intend going on floats should also complete inter-pitching of

the

rivets in the two bulkheads indicated in Fig. 1.

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