Topic: Mk20/MK22 What's the difference?

[fallalloveryou]

Hello everyone,
I am a new member and happy to join this group. I am the proud owner as of April/11 of an ex Burma Air Force Mk10 Trainer chipmunk that I recently imported from USA to Canada where it is now in the amateur bult (experimental) category. I have been spending the time since doing research,restoration/re-configuring etc etc and installing most of the Mk22 mod's and AD's.  Question:Why is the Vne and Cof G of these two models so different?  I can't find any structural differences in my research.  Also, while im here, is there any real need to install the anti spin stakes?  Afterall, all the Canadian chips don't have them and apparently this UK built chipmunk has survied 2200 hrs of air force training without them as well.  Transport Canada says I can do what I want so Im just deciding on my options and which manual to use.

Am I missing something or is it just politics?
Thanks guys,

[rjtjrt]

Sorry I don't know your name so can't address you by name.
I can't answer your question directly.
John Sims operated an ex Portuguese/ex British Chipmunk at Oshawa on Canadian amateaur built registration until I bought it from him last year.
He may/would have a lot of info you may find helpful.
I can give you his contact details (my email is trus9119atbigponddotnetdotau).
He does frequent Caledonian Chipmunks to but I can't recal his username here.
Hope this helps
Regards
John

[john henderson]

Hi there.

So far as the anti spin strakes are concerned, you need to read the TNS which sets out the whole ethos of spin recovery following some adverse reports from Australia.  In the UK if the aircraft does not have them it must be placarded "Spins in this aircraft are prohibited".   The report on the testing of the installation refers to the complete removal of buffet after fitting and comments that students are more likely to apply full forward stick for recovery in the absence of buffet.

I thought that the major difference between Mk 22 and Mk22A was the increase in allowable gross weight to 2200 lbs (100lb extra) and larger fuel tanks in the latter.  Note you cannot aerobat at full gross weight! 

The Vne was reduced to 155mph by TNS many years ago for the civilian Chipmunks.  i thought that the UK military also reduced in conformity.

According to Rod Brown's wonderful book on the Chipmunk, the MK 10 was the UK military version, and the Mk20 was the export equivalent.  The Mk 21 was the equivalent aircraft originally built for civilian use and was endowed with 12 gallon tanks, whereas the Mk 22 was the official civilian conversion of the military Mk 10.  The 22A was a civilian conversion of the Mk 10, but rebuilt with 12 gallon tanks and other sundry improvments.

My Mk 22A has the Masefield bubble canopy and the wing luggage lockers approved, but so far I have been unable to find the paperwork to install either.

The CAA set out a long list of changes required to convert a MK 10 (or presumably a Mk20) to civilian status.

Hope this helps.

[Nigel Stevens]

The main difference between the Mk 10 and the Mk 20 is the starter. The Mk 10 uses a cartridge starter and the Mk 20 had an electric Rotax starter fitted as standard with heavy duty cabling to the batteries, plus a funny little notice that says the engine should only be started on internal batteries in an emergency!
Nigel

[fallalloveryou]

Ok. let me get this straight.

Different size fuel tanks (weight issue), different starter(convenience issue), different pilot i.e. civilian vs military

hence the reason for changing to a more conservative VNE and different C.G. limit

I didn't know that military pilots fly Chipmunks so differently then civilian pilots.

Hmmmmm....   p o l i t i c s
Rick