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Rotec R2800 Powered Stummelflitzer Z1RA
Owner: Dudley Pattison
Status: Flying (10th Dec 2013 onwards)

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Dudley Pattison

Dudley Pattison's Stummelflitzer Z1RA Project:

Swindon Aircraft Timber Company
Ridgewood, Ham Road, Liddington, Wilts, SN4 0HH.

Telephone +44 (0)1793 791517 Mobile 0799 097 6393

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as usual click to on the bordered thumb-nails to enlarge ...

Rotec R2800 Powered Stummelflitzer Z1RA ready to take off

From: Dudley Pattison
Sent: Wednesday, 12 February 2014 3:46 AM
To: Paul Chernikeeff
Subject: G-ZIRA

Hi Paul,
I cannot remember if I sent you some shots of Stummelflitzer G-ZIRA. The fully aerobatic category has just been reinstated on the permit to test fly after a hiccup.

Due to weather and location the aircraft has not done much flying yet but the engine (I am crossing my fingers now) hasn’t faltered once. The sight and sound of it flying is straight from 1930.


Rotec R2800 Powered Stummelflitzer Z1RA in flight

From: Dudley Pattison
Sent: Tuesday, 11 December 2012 9:56 PM
To: Paul Chernikeeff
Cc: Martin Hone
Subject: FW: Z1R

Hi Paul/Marty

The animal flew yesterday with few problems. Below is the LAA chief test pilots mail to myself and the designer after the flight which may interest you.

It looked, and sounded, pure 1930’s as it flew overhead. Absolutely fantastic. It also looked like no other biplane seen around these days and I think an awful lot of head scratching will be done by folk with an aviation interest as it passes over them in future.

If either of you have any advice on the mag and mixture problem I would appreciate it. I am hoping that when I have adjusted the mixture (I think you sent me a mail on how to do that Marty) the mag will improve. And it is the ‘stand alone’ mag that is weak, not the battery powered one.

All in all though a good day and quite a relief. I will send you some decent pictures Paul when I get some. In the meantime attached is one taken by a passing aircraft being flown by a friend of mine.

Kind regards

June 2012 - Painting and Ribbing Completed:

August 2011 - Painting Done!

Project News March 2009:

(March 2009 - text as published in the LAA)

As usual click on the thumbnails with a boarder and the photo will enlarge...

The little aeroplane I am building has suddenly got a whole lot bigger. As it is due to have a Rotec R2800 radial turning a large diameter propeller, Lynn Williams, designer of the Stummelflitzer Z1R, has made sure that the prop hub is well off the ground by designing a very tall undercarriage, upon which I have recently perched the fuselage.

A few months ago, after temporarily rigging the fuselage at its finished ground angle, I got quite concerned that I wouldn't be able to get into the thing as my own broken undercarriage wouldn't allow me get my foot up to the lower longeron step, which is 26" off the ground (nigh on as much as my inside leg measurement), and then haul myself up to a vertical position in order to next place my left foot in the second step. Friends came up with all the usual remedies, a knight in armour type hoist, have someone to drive to the destination airfield with the ladder that has just been used to get me in at my base field, a rope ladder, etc.

magine my relief when, after fitting the undercarriage and 22" diameter wheels, with the aid of a hand cupped around the headrest, I could haul myself to the upright position standing on the lower step. I then experimented to find the best position for the second step. After about half an hour of moving a stool around with varying thicknesses of wood blocks perched on top I decided that the best place for it was exactly where Lynn had drawn it!

When I ordered the bungee material I was asked if I wanted hard or soft bungee. I had never been asked that before and chose the hard variety. And boy, are they hard? I always thought that bungees were made up from multi strands of rubber, a little like a golf ball. The 'strong' ones are one piece of rubber shrouded in the same way. A friend (show off) helped me wind the bungees onto the undercarriage. He then stood in the 'V' of one main u/c frame and I stood in the other. Our weights just about equalled that of the engine, the rest of the airframe and some of the pilot. The axle rode up off its bottom step by about 5mm. That seemed about right to me.

One of the differences between the standard Z21 Flitzer (which are now being built all over the place, order your plans from Lynn today) and the Z1R is the 'rounding' of the fuselage to compliment the radial engine. Lynn cleverly thought the space created on each side could be put to good use by housing pannier tanks to help feed the Rotec engine, which is going to gobble a bit more fuel than the VW of the Z21. Oh, and by the way, my aircraft is a Z1RA and I have grabbed the registration G-ZIRA, clever eh? The A stands for 'widebody'. Now, stop thinking about ten people sat across the fuselage of a jumbo as in this instance it means a 24" rather than 22" wide fuselage.

The fitting of these pannier tanks has been niggling me for some time. I allowed about 3mm tolerance in the overall thickness of them to ensure that the cover panels didn't buckle around them. I was a bit down in the mouth after they distorted slightly upon welding. I should have expected this, knowing that aluminium has a high coefficient of expansion and is not the easiest material to weld. But today I got the second tank fitted and its cover on. Happiness. I have estimated that they will carry 17 litres each, which will add nearly one and a half hours to the endurance. I know that it is not the sort of aeroplane that one would want to do three-hour flights in, but it is nice not to be constantly worried about fuel availability.

Just like the Fury that I built I thought it appropriate for this aircraft to have an abundance of aluminium at front. There will be beaten aluminium panels from the nose to the back of the engine to cover the oil tank and the ancillaries. It seemed right therefore to 'aluminise' the top decking. I firstly covered the ply decking with 0.6oz glass cloth and epoxy. This adds very little weight but completely seals the plywood and gives a good base for the contact adhesive that will affix the aluminium sheet. This sheet is litho plate, well known to aeromodellers (as is the 0.6oz glass cloth). Offset litho printers throw Litho plates away on a regular basis. If there is no prospect of a repeat order once the print run is finished they are scrapped. Being soft, malleable, light and only 03mm thick they make ideal cladding material. You will see in the photo how the material can be easily worked around an edge.

The next stage is to fit the lower wings back on the fuselage at the correct dihedral and mark the extended wing section line on the fuselage to facilitate the positioning of the supports for the wing to fuselage gap covers. The brake cable will go in soon so that the undercarriage legs can be faired in balsa (I wonder who can supply me with that????). Laurie Woodage is to visit me soon (yes, I have two friends) for a component weighing session from which I can estimate the C of G to decide on the engine mount length. Although all exciting stuff at the moment I know there is a huge amount still to do.

The Z1R is not yet an LAA approved design. I am hoping that by the time that you read this work will have started on the stress analysis of the structure by the same team that are just finishing the stress work for the Z2 two seat Flitzer, also to be Rotec radial powered.

As mentioned earlier, Lynn Williams has sold many sets of Flitzer plans and I think it is encouraging that not all LAA builders just want to assemble an 'almost ready to fly' kit made in foreign parts from tin or Tupperware, and there are still those who enjoy putting in the effort to achieve something that is traditional, and yet now a little different.

Dudley Pattison

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