I owe this one since here:
https://www.sas1946.com/main/index.php/topic,33067.msg355207.html#msg355207Switzerland bought license rights for production of MS.406 in 1938, together with two French-produced MS.406H pattern aircraft. These were actually old pre-production MS.405 airframes refurbished with uprated Hispano-Suiza 12Y-31 engines as in standard MS.406. The two pattern machines were delivered to the EKW factory for examination, and soon a pre-production run of 8 modified D.3800`s (as the locally produced MS.406 variant became known) was delivered including numerous modifications and improvements over the French original:
- locally produced variant of the Hispano engine built by Adolph Saurer AG
- EW-V3 variable pitch propellers
- new instrument suite, locally produced
- belt-fed machineguns replacing the French drum-fed ones (no wing bulges)
- tailwheel replacing tailskid
- radio antenna mast relocated in front of the windshield
After accepting the modifications the Swiss air force ordered further 74 D.3800`s, all these were delivered by end of August 1940.
http://www.amicaleaviation4.ch/html/2_3c.htmlMeanwhile in France further modifications were made on the basic MS.406 series resulting in much improved versions MS.410, MS.411 and MS.412, but the development was cut short by the war events.
MS.411 had a simplified fixed radiator, reactive exhaust and other aerodynamical improvements as well as an uprated HS 12Y-45 engine, one modified from a MS.405 and flown. MS.412 was to be generally similar but with an even stronger 1050 HP 12Y-51 engine, however this was not completed before France surrendered.
But, in Switzerland, the work on MS.412 continued, under the guise of D.8001, with a locally produced variant of the 12Y-51 engine. The prototype was built by Doflug, Swiss subsidiary of Dornier, and was test-flown in October 1940. Accepted for service and ordered into mass production, at first they had a lot of problems with engine reliability, but once these were rectified a total of 207 was delivered before the end of 1945. Another 17 were assembled from spares after the war.
In the meantime the old D.3800`s have been updated with most of the improvements installed on D.3801`s, except the engines - they kept their old 12Y-31`s.
http://www.aviastar.org/air/switzerland/morane_d-3801.phpFurther improvements on the original design were introduced on D.3802, which was a variant of MS.540 (itself a further update of the basic MS.406), 12 built, powered with a 1250 HP Saurer YS-2 engine, which could reach 630 km/h. Despite promising performance these were plagued with various problems that could never been truly overcome so no further production was ordered.
But, one of these machines was modified to D.3803 standard, with a 1500 HP Saurer YS-3 engine, cut-down rear fuselage and bubble canopy, and armed with 3x 20mm cannon. Capable of 680 km/h this was the ultimate MS.406!
http://simviation.com/fsdcbainD-3803.htm