RAF Chipmunks

[CoffmanStarter]

I42 ... I agree with you ... A great shame the RAF didn't opt for the 'Bubble' canopy IMHO

[Dora-9]

I42:

you can paint it any colour you like, but Shuttleworth's T10 in Canadian colours looks just wrong to me.

I could not agree more!

I could fill this entire page listing the differences between the DHC-1B-2-S5 and the T.10, so what on earth were the Shuttleworth people thinking?

Coff:

A great shame the RAF didn't opt for the 'Bubble' canopy IMHO

Such an elegant solution to the initial criticisms of the DHC-1A's lack of headroom; why not indeed? Although the Canadian "bubble" will not fiit a UK-built Chipmunk it was so obviously the way to go...

[Rosevidney1]

A great shame the RAF didn't opt for the 'Bubble' canopy IMHO


I was told that the real reason behind having a framed canopy was because it incorporated a panel device that would assist the removal in the event of having to jettison the canopy.

[RNHF_PILOT]

RNHF_PILOT,

So in your experience, is the Gypsy Major the ice generator it is reputed to be?

My military Chipmunk experience was all in the "carb air wired hot" variety and the two civil Chipmunks I flew for spinning, was so early in my flying career that I cannot remember the carb air procedures.

India Four Two, in my limited Chipmunk experience it is not the ice generator it's made out to be, I've not experienced any carb icing issues so far.

I think it might be a case of somebody somewhere in the past having a crash that was put down to carb icing and then the usual military knee jerk reaction of wirelocking the fleet, rather than properly understanding the issue and training people correctly.

[CoffmanStarter]

Originally Posted by Dora-9

Such an elegant solution to the initial criticisms of the DHC-1A's lack of headroom

It wasn't only the lack of headroom ... I believe I'm correct in saying that there was a limitation placed on the wearing of the Mk2 Boredome by pilots occupying the front seat of the UK Mil Chipmunk. Lateral 'head turning' could be restricted by the visor mechanics on the side of the helmet. Additionally, when taxiing, the ability to see around the nose, even when weaving, could be restricted ... seen here.



Even the Mk1 Bonedome had to have the visor 'sliders' filed down to help prevent a spate of cracked perspex roof panels during aerobatics.

Originally Posted by Rosevidney1

Real reason behind having a framed canopy was because it incorporated a panel device that would assist the removal in the event of having to jettison the canopy.

That 'bungee' actuated flap was very effective in helping the canopy slide back.



Image Credit : Unknown

[kenparry]

I was told that the real reason behind having a framed canopy was because it incorporated a panel device that would assist the removal in the event of having to jettison the canopy.

A small correction to that. The canopy is not jettisonable; the central top flap is there to assist in sliding open the canopy.

[CoffmanStarter]

Thanks Ken

[Dora-9]

the central top flap is there to assist in sliding open the canopy.

And that's there because, as the airspeed increases, the airflow tends to push the canopy forward, at high speed becomes very difficult to slide back and, unless you latch it open, will slam closed again - maybe the bubble canopy aerodynamics aren't the same?

[India Four Two]

The Canadian Chipmunks have a similar flap at the rear of the canopy:

[Wander00]

Silly question for the day - anyone know why the RAF/UK did not have the "Canadian canopy" Just asking.................

[India Four Two]

Wander00,

Just guessing here but it be might as simple as the fact that the Canadian prototype that was shipped to England, had a greenhouse canopy:

[Dan Winterland]

DHC were obviously prescient in anticipating the advent of ex-truckie QFIs 30 years down the road!

Oi - I resemble that remark! That entry in Dora 9'S aircraft's 700 was when it flying at Swinderby where I was one of the QFIs. I don't think I ever got that heavy. Anyway, I was a tankerwanker and not a trucky, so no real offence taken. There must be a number of my signatures in the 700s Dora 9 has with his spiders. I flew WG478 a lot.

[Dan Winterland]

Very interesting ... so is the entry above (crossed through in red) ... any other clues ? ... so is the entry above (crossed through in red) ... any other clues ?

The aircraft was reweighed and the new limit replaces the one lined through in red. I must have read that entry many times. I even recognise the writing. It belongs to a chap called Len who was the engineering manager for SERVO who had the contract for the maintenance.

[Wander00]

I42 - luck of the draw then - cock-up usually beats conspiracy

[Dan Winterland]

the central top flap is there to assist in sliding open the canopy.

The CFS wisdom had the flap functioning more as a spoiler to break the lift from the canopy allowing it to be opened in flight. As the flap was tiny, I'm inclined to believe this rather than the drag generated assisting opening.

Helmets - At Swinderby, the students mostly wore MK1 helmets. The taller ones just wore the cloth inners. One of my very lanky students was so thin, he slipped out of the harness and his head went through the canopy. After that, he wore the cloth inner only. The instructors mostly wore MK4s which were as bulky as the obsolete MK2s, but had little space problems. I wore a rare MK4b which had a larger visor mechanism allowing individual visor selection. It gave no issues.

[India Four Two]

I42 - luck of the draw then - cock-up usually beats conspiracy

Not really luck of the draw. All the early Chipmunks had a greenhouse canopy, at least up to construction number 6, maybe beyond:



CF-DJS

Presumably the bubble canopy was developed later for the first batch of RCAF Chipmunks.

[CoffmanStarter]

Hi Dan ...

Thanks for joining in

Going back to the Hood Flap for a moment ... I have a very vague recollection of a reported incident where a RAF Chipmunk was in a Flat Errect Spin and when the crew decided the best course of action was to leave the aircraft (normal recovery actions were ineffective apparently) ... the mere operation of the hood flap and subsequent opening of the canopy ... the aircraft recovered, the crew then stayed with it and recovered back to base safely.

I may be 'barking' on this one ... but something stuck with this story ... does it ring any bells with you ?

[BEagle]

Wasn't the RAF's 'wire restrained' carb air HOT more to do with Gipsy Major cylinder head materials and the RAF Avgas octane rating of the day?

[CoffmanStarter]

Thanks for that BEagle ... Still learning this end

[Wander00]

Aah, had not appreciated that early Canadian Chipmunks had the "UK style" hood