Well the point being that if the item is used where ferrous materials could interfere with anything that involves magnetism for its function, (compass systems eg.) then being brass makes sense. Just wonder about the material and mass of the bulldog clip.
Sorry if that did not follow from my comment.

Innuendo, your 'point' was taken!

When I was first on squadron the sprogs were the ones that got lumbered with doing adjustments on the standby compasses when it was needed. We had to take an instrument tech in the back seat, (CF-100), and taxi out, both engines running and radar and other electrical systems operating, align the aircraft on a compass rose painted on the ground then adjust the standby compass over cardinal points with a brass screwdriver. We had another tech on the ground giving us hand signals for adjustments based on data that he got from a hand compass.
Come to think of it that device would have worked to pass adjustment values to the cockpit rather than the hand signals we used.
Although I may be off the mark, I guess this was what came to mind when you gave the brass hint.

Innuendo,

You are in a way absolutely correct. The item is designed NOT to affect standby compasses. But that is as much as it is to do with compasses.

Another clue, it is not a shillelagh (sp?)

So the bulldog clip held a compass correction card or similar, or instructions possibly at some stage in a compass swing?
Or was it for the Nav on a bomber to pass instructions to the bomb aimer lying in his forward position and brass so as not to upset the bomb sight?

How did the back seater in, say, a Swordfish communicate with the front seater?

Watch this space for more wild guesses!:)

The fact that only 23 or 24 were made suggests one per aircraft, which is rather a low number in (S)service,civil or mil.Which might suggest,Bevelgear,Britannia,Basset;however,since there was no direct access to the cockpit from the cabin in a Bevelgear,due to the engine/transmission,only a very narrow gap behind the co-pilot,it was probably designed as the `BLOCCTIMS`(Belvedere loss of cabin communication telescopic information management system ) which usually had chinagraph messages on a piece of perspex ,information such as` `SIDDOWN``SHUDDUP`,STANDBY`GETTOUT-NOW !`HOW MANY ?? TOO MANY-DROP2/3/4!!all accompanied by a blaring `klaxon,,and flashing of the para lights!!

Cornish Jack-My namesake,a marvellous machine,real engine,wooden blades,manual controls,big trim wheels,C of G compensator, 2-stage amber and blue goggles,and ground resonance- helo pilots these days don`t know they`re born !!! SYC

FL575

I think we've run out of ideas........

Come on now, it's time to spill the beans before we disappear into P2!

Just a couple of clues, then if we still cannot decide, I will reveal.

This was in use until the late 80s, and if there had not been 'major' modifications made where it was used, it would have been in use until mid 2006, perhaps even up to today.

Canberra PR.9 ? Nav/pilot emergency comms ?

Redsetter, absolutely correct.

The photograph shows the emergency intercom device as fitted to the CANBERRA PR9.

Should the PR9 aircraft Type A1961 electric intercom fail, communication between to two crew members was still possible through the normal UHF/VHF radio, or by the two frequency (243/243.8)emergency radio. However, in the situation of complete failure of electronic communication, the stick shown in the photograph could be used to pass messages between crew members. Cockpit noise precluded normal conversation, even by shouting.

The emergency communication stick was located in the navigator’s compartment, held in a spring clip, mounted on the floor, under the navigator’s ejection seat.

Uniquely, in the PR9, the navigator sits in front of the pilot, at his own station, access to which is by a swinging nose ‘door’. Although there is not a bulkhead, access from the navigators compartment to the pilots station is not possible. Racking behind the navigators ejection seat holds various pieces of electronic equipment, controls and kit. However, at approximately navigator head height, which was at about the height of pilot’s feet, there was a small open area just in front of the pilot’s feet, through which the end of the ‘stick’ could be pushed.

In the case of electronic intercommunication failure, the navigator was to write down (on a suitable piece of paper) whatever information that he wished to pass to the pilot. Using the ‘Bulldog’ clip, he would attach this to the ‘stick’. He would then unstrap from his seat, turn around and kneel upon it. He would then poke the ‘stick’ through the gap behind the seat, and get the pilot’s attention by banging the ‘Bulldog’ clip against the pilot’s flying boot.

At this point, the pilot was supposed to engage the autopilot, and after unstrapping, lean forward and down and remove the note, being careful not to lean too firmly against the control column, as this would disengage the autopilot and put the aircraft into a dive.

This emergency communication device was removed from PR9 aircraft in the late 1980’s, when a second UHF radio was fitted during ‘Major’ servicing.

How wonderfully 'British'! And no doubt very effective. The thought of a long metal rod, complete with large bulldog clip, poked up between the pilot's legs would certainly grab their attention! :ooh:

FL575,

Well, no wonder it looked so similar to a GAPCI that I thought it was one.

Same purpose, pretty much, just a slightly different environment.

But why did the RAF one have to be brass? You indicated that this was of importance.

onb,

Really for the same reason that brass screwdrivers were used to adjust compasses during compass swings. The theory was that anything metal that could be moved in the cockpit during flight should be made of brass in order that it did not interfere with the emergency compass (E2b in this case).

It would probably have worked in the Blenheim IV also although I am given to believe that the continuous string pulley system with a bulldog clip worked just as well and would probably have been cheaper!

Just think, someone at an MU somewhere in England probably still has about 100 Devices/Communication/Brass/Canberra PR 9 (for the use of) on his inventory.

Continuing my theme of What/Where/How. I submit the following.

The enclosed picture is of an item closely associated with aviation. It is about 5in x 4in, and made of aluminium. When new, is is painted matte black, but in this photograph the paintwork is rather flaked off in places. At the top of the picture, where the 'L' shaped two slots are, the aluminium is bent at an angle of about 30 degrees.

It is not any sort of inspection panel.

As before, some members will instantly know what it is, but if they could hold off for a day or two, we might get some interesting offers!

http://i238.photobucket.com/albums/f...gforPprune.jpg

I'm thinking it might be part of a multi-crew cockpit window 'view shield' assembly for instrument flying practice. Probably completely wrong.

Just think, someone at an MU somewhere in England probably still has about 100 Devices/Communication/Brass/Canberra PR 9 (for the use of) on his inventory.

Yes, and they will be brand new as the previous stock was life-expired after four years on the shelf.

Screen for artificial horizon for limited panel practice - JP?

You are, of course, absolutely correct.

It is a HGU/Artificial Horizon cover for the Canberra T4 aircraft. If you rotate the photograph 90 degrees anti clockwise, you will see how. The two 'L' shaped cutouts fit at two points on the instrument. The top 'L' fits over a specially extended instrument mounting bolt. The bottom 'L' fits over the Fast Erect button.

When fitted, the HGU/AH cannot be seen by the student, only by the instructor.

No wonder I recognised it, just remembered the wrong aeroplane! (Now what did I have for lunch?). Very odd going from JP to Gnat (OR946), and then to Canberra T4/B2, whose instruments pre-dated those in the JP!