Frise Aileron assembled in Hawker Hind wing 1936 & close up of relative dimensions between rear spar and aileron gap. Ed 2
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Hurricane engine mount. The big steel lug goes off to near wing root as were.

I am wrong. It is late at night here in Oz. My eyesight is deeply affected after drinking too much beer watching the ,ahem, Ashes.

Few guesses

The problem: the depth of the Bulldog aileron on the Mk II series. Does anyone have any insight to ailerons actually being thinner than the adjoining wing? Most ailerons are either
the same size, or slightly larger than the adjoining wing. As there are no known drawings of the Mk II/IIa aileron rib all that is given is an illustration in the A.P. manual showing the
aileron slightly thinner than the wing rib. Did Bristol experiment with this idea? Bristol did one experiment with the Hartshorn aileron, but no information in that paper talks about the
original aileron. I have checked with some of the most knowledgable individuals around who were kind enough to contemplate the question. But nothing definite.
So I am hoping someone out there just happens to know, or knows who knows the answer.
Cheers

Ed

A few guesses :

1. Bulldog II sent to US Navy for testing in 1930 crashed when aileron failed in terminal velocity dive. “tests at Filton resulted in a modification and a replacement was shipped in February 1930” – Bristol Bulldog, A Granger 1973
and
“The Bureau of Naval Aeronautics placed an order for a Mark II in order to evaluate it at Anacostia Naval Air Station…given registration A8485..on 25 Nov it experienced aileron flutter in a terminal velocity dive and crashed….This was the first fatal accident due to aileron flutter on a Bulldog and no doubt much heart searching took place at Filton. Modifications to wing and aileron spars were quickly incorporated after static testing of the wing structure…a replacement aircraft A8607 was used to continue the evaluation trials before being struck off charge on 27th August 1931…the airframe was tested to destruction, results shared with manufacturers and RAF.” – Bulldog, David Luff, pg 120

So perhaps the US Navy will have some records that shed light on Bulldog II ailerons.

NACA has some wind tunnel tests on the Frise type ailerons originated by Leslie Frise at Bristols.
NACA TR 422, Slotted ailerons and Frise ailerons, 1932

Bristol’s thought processes might be apparent in this excerpt from trade literature for Bulldog IIA which I believe was printed around the time of the US Navy experience :

“Flying qualities.The degree of balance and amount of shielding has been carefully decided upon, after model and full scale work, to give a light control at all speeds and yet prevent any suggestion of hunting or flutter in a terminal nose dive”

Given this it is plausible that Leslie Frise, on the staff of Bristols, was probably the most qualified person on the planet to experiment with his Frise aileron designs, and given this design would have been a trade advantage in the highly competitive world of aircraft sales in the Depression, it would also seem plausible that improvements were not documented for the benefit of competitors.

I would trust that the APs, in the sense that they ‘cut and pasted’ manufacturers drawings, do indicate that there is a change in aileron designs, and in the context of the US Navy experience and Frise being employed at Bristols, eliminating aileron flutter drove evolutions in the design.

Dimensions ? Ha ! Maybe chalk the aerofoil on the floor and place the tail of the known aileron at the tail of the aerofoil to figure if gap between wing and aileron was one of the changes. My understanding is that the Frise aileron followed the aerofoil section and what is implied by a thinner aileron is a different aerofoil for the aileron ? Maybe reference to later Bristol designs or other aircraft using Frise ailerons will indicate whether the concept of ‘thinner’ ailerons travelled through. There are some further NACA reports on Frise type ailerons in 1941-2 that may have been prompted by evolutions in the design.

Machining up oil cooler segments now, lots of pieces, all in good time,
Ed

Plasticizers

The question is what caused it?

I often think old aeroplane smell should be made into an underarm deodourant : a combination of dust, plasticizers, radon gas called “Ace”.

Like ‘new car’ smell a lot of it is caused by plasticizers, volatile compounds that make plastic flexible, released into the air. US EPA studies identified a locked car in the sunlight generating a more toxic micro environment in respect of plasticizers than general smog. Current concerns about the plasticizer BPA leaching out of the soft plastics used in food jar lid seals and baby feed bottles is another thing to add to your list of things to worry about.

The sense of smell has an amazing connection to emotional brain centres, triggering memory recall.

From ‘Plastics Explained’ 1946, Henry Taylor, Lewes Press :

Thermo setting – Phenol Formaldehyde (bakelite), Urea Formaldehyde, Melamine Formaldehyde.
Both phenol -carbolic acid (disinfectant) and formaldehyde (preservative) have distinctive odours that are part of the 1930- 50’s industrial smell-scape

Thermo plastic – Cellulose Acetate, Polystyrene ( not necessarily the white expanded polystyrene- EPS – we are more familiar with, but a sheet like yoghurt container material, high impact polystyrene- HIPS), Methyl Methacrylate, Poly Vinyl Chloride (PVC – think of the smell of new shower curtains or above ground pool liner or transparent strip curtains in a food shop, Polythene (plastic bread bags or stretchy -not crinkly- shopping bags), Cellulose Acetate Butyrate, Ethyl Cellulose

Cast Phenolic plastics – bakelite, typically old radio cases

Cellulose Nitrate – old film

Casein plastics – made out of milk

Shellac plastic – made out of an insect

A lot of these plastics were wood based (cellulose) which were replaced by oil based plastics in the 60’s. The key ingredient formaldehyde could be distilled from wood or coal, and no doubt different processes for making raw ingredients created different distinctive odours. A surprising amount of information can be gleaned from US strategic bombing surveys compiled immediately after the war. These involved interviewing captured German military folk, scientists and industrialists to determine how effective the US daylight bombing campaign was in respect of disrupting German industrial production. Key resources, industries and the context of material use and application to the Nazi war effort are examined. This can shed some light on the key industrial plastics, paints etc used in the Nazi war effort, which might provide a basis for determining the components of the ‘smell’. A key differentiator was the significant use of magnesium in German aircraft, perhaps part of it might be magnesium oxide. Identify the plasticizers – compounds which make plastic flexible- used in German plastic materials, toss in some saurkraut, beer and sausage and you will probably have most of your answer.

Does anybody have any information on Aviation Archeology in Poland? The reason I ask is that I was recently in Przemysl (South East Poland) and meet with a very interesting Guy who has recovered several large pieces of various JU 87″s including a complete tail unit.

I have also been informed about 2 sites that contain the remains of a PZL P11c and a Karas.

If anybody is interested in more details please PM me

Many thanks in advance

Zawsze cziekawo

AP 1275 1930

[QUOTE=aircraftclocks;2096121]I am looking for someone who lives in the Cleveland area to have a look at the contents of a book dated from the 1930’s in the Cleveland library. The information given is vague and I am not able to identify if this was an air publication etc.

Not in Cleveland but somewhere better with AP1275 1930 : “General Instrument Equipment for Aircraft ” in hand if you want to scan…

Individually they can be very harmful!
I wouldnt even consider buying and shipping them if they are Radon instruments. They are all at leasy 60 years old

PS nit just gamma detectors, they can pick up Alpha and Beta nowadays too. Gamma sticks out a mile.

There is enough technical knowledge on this forum to embrace a solution to this issue :

1. Recommendations on safe handling, distributed through museums. Include identification, using low cost UV flashlights that excite radium and allow quick identification, storage recommendations, risk factors. Sort of a Standard.

2. Get someone in each country to put their hand up to engage with local postal authorities, courier companies to come up with an international postal agreement amendment in a few years that will establish protocols for packaging, labelling, reporting and handling of radium contaminated historical artifacts – including watches and clocks.

3. Because this issue recurs, and because there needs to be a better solution to relics than just ‘don’t touch it’ or put it in a concrete barrel at great cost, services need to be established to safely decontaminate dials. They can never be fully made safe, as radiation is absorbed into the parent metal of the dial face, but radium can be removed and disposed off safely, seals checked etc. This may cost a lot, but there is a core level of activity performing such a task for museum collections, which private collectors may then leverage off. This is a micro business, a kind of hobby turned into a long term secondary income stream. At the end of the day gauges can never be decontaminated, but they can be stabilised and derisked to an acceptable level.
It requires setting up a facility akin to the handling of medical imaging isotopes, keeping the operator safe and handling radioactive waste safely, with high transparency for government. Support this with international postage arrangements to allow collectors to send things and sleep at night. Get on the front foot before government confiscates it all.

That’s where my mind is.
Maybe it will only do 100 gauges a year, but at least some will be saved.
As a straw poll how many would pay 500 to stabilise a gauge ?