Last Night I started a CFS conversion of a Ki-100-Ib.
What I found was quite interesting.
The MDL was apparently built by someone who used good references.
My guess is that this started as a FS98 aircraft. The prior conversion to CFS was done by someone who did NOT use good references.
The Ki-100 was descended from the Ki-61-I by way of the Ki-61-II. I figured a copy of the AIR file for my Ki-61-Id would be a good starting point.
It turns out I was more or less correct. The modifications I had to make were consistent with a visual model that had a Center of Gravity that was noticeably higher and further aft than for my Ki-61.
The Scrape Points, Landing Gear contacts and Cockpit Viewpoint needed some substantial modification but so far that is about it.
Interestingly enough, the Ki-100-Ib is only about 1/2 inch shorter than the Ki-61-Id.
How that came about is an interesting story:
The Ki-61-Ia,b,c were 8.74 meters long.
They were armed with a pair of Ho-103 12.7 mm HMG firing through the propeller and a pair of Ho-103 mounted in the wings free firing.
A German submarine brought 800 MG151/20 20 mm cannon to Japan.
Those were mounted into the wings of 400 Ki-61-Ic.
Since the MG151/20 was not manufactured in Japan, that was all there were ever likely to be.
The next update to the Ki-61 was to simplify the tail structure by substituting a fixed tail wheel AND
by increasing the length of the nose to allow longer (front to rear) ammunition boxes to be fitted to hold shells for the Ho-5 20 mm cannon.
The shell boxes sat side by side and each held 120 rounds. These changes made for a longer and slightly heavier aeroplane.
The new Ki-61-Id was 8.94 Meters long.
When the Ki-61 was redesigned to the -II model, it appears that substantial portions of the fuselage were changed. The frame locations are not nearly the same. The shape of the vertical tail is noticeably different. The nose was lengthened to house the Ha-140 engine AND the nose was also stretched to allow the Ho-5 ammunition boxes to sit one behind the other instead of side by side. This increased the ammunition capacity to 250 rounds per gun.
About 100 of these Ki-61-II were completed before a bombing raid destroyed their engine factory.
This left 300 airframes with no engine and nothing suitable to substitute.
The solution was a bit ugly but practical. The engine bearers were cut off and a new more standard frame type engine mounting system was fitted.
The engine selected was the Mitsubishi Ha-112-II Model 62 Kinsei (Venus).
The new engine had about the same engine power as the Ha-140 but was much more reliable. The net effect was a much lighter aircraft with a bit more drag and with a much more reliable engine.
The obligatory screenshot shows the same model as before but with a modified (unfinished) Ki-61-Id AIR file.
The new engine has not yet been fitted so there is no point in a test flight yet.
- Ivan
What I found was quite interesting.
The MDL was apparently built by someone who used good references.
My guess is that this started as a FS98 aircraft. The prior conversion to CFS was done by someone who did NOT use good references.
The Ki-100 was descended from the Ki-61-I by way of the Ki-61-II. I figured a copy of the AIR file for my Ki-61-Id would be a good starting point.
It turns out I was more or less correct. The modifications I had to make were consistent with a visual model that had a Center of Gravity that was noticeably higher and further aft than for my Ki-61.
The Scrape Points, Landing Gear contacts and Cockpit Viewpoint needed some substantial modification but so far that is about it.
Interestingly enough, the Ki-100-Ib is only about 1/2 inch shorter than the Ki-61-Id.
How that came about is an interesting story:
The Ki-61-Ia,b,c were 8.74 meters long.
They were armed with a pair of Ho-103 12.7 mm HMG firing through the propeller and a pair of Ho-103 mounted in the wings free firing.
A German submarine brought 800 MG151/20 20 mm cannon to Japan.
Those were mounted into the wings of 400 Ki-61-Ic.
Since the MG151/20 was not manufactured in Japan, that was all there were ever likely to be.
The next update to the Ki-61 was to simplify the tail structure by substituting a fixed tail wheel AND
by increasing the length of the nose to allow longer (front to rear) ammunition boxes to be fitted to hold shells for the Ho-5 20 mm cannon.
The shell boxes sat side by side and each held 120 rounds. These changes made for a longer and slightly heavier aeroplane.
The new Ki-61-Id was 8.94 Meters long.
When the Ki-61 was redesigned to the -II model, it appears that substantial portions of the fuselage were changed. The frame locations are not nearly the same. The shape of the vertical tail is noticeably different. The nose was lengthened to house the Ha-140 engine AND the nose was also stretched to allow the Ho-5 ammunition boxes to sit one behind the other instead of side by side. This increased the ammunition capacity to 250 rounds per gun.
About 100 of these Ki-61-II were completed before a bombing raid destroyed their engine factory.
This left 300 airframes with no engine and nothing suitable to substitute.
The solution was a bit ugly but practical. The engine bearers were cut off and a new more standard frame type engine mounting system was fitted.
The engine selected was the Mitsubishi Ha-112-II Model 62 Kinsei (Venus).
The new engine had about the same engine power as the Ha-140 but was much more reliable. The net effect was a much lighter aircraft with a bit more drag and with a much more reliable engine.
The obligatory screenshot shows the same model as before but with a modified (unfinished) Ki-61-Id AIR file.
The new engine has not yet been fitted so there is no point in a test flight yet.
- Ivan
