"Conclusions
- The trialed experimental prototype of the "D" tractor demonstrated satisfactory average speed characteristics, good maneuverability, simplicity of service and control, and can cross the required slopes on grassy terrain while towing divisional artillery. The performance and smoothness are a significant improvement over the STZ-5 tractor.
Tractor "D" can be accepted into service as a transport for divisional artillery.
In order to increase off-road performance, grousers must be included for tracks. - The "D" tractor is unsuitable for towing corps artillery. If the top speed is reduced, the mass of the tractor is increased to 5.5 tons, and tracks with grousers are installed, the "D" tractor would be able to tow corps artillery weighing up to 8 tons. The required changes can be quickly made to the provided prototype.
- All changes to the design requested in conclusions must be implemented in production.
- The converted "D" tractor designed for towing corps artillery must be subjected to further trials.
Commission chair:
Engineer-Captain Savelyev
Commission members:
Colonel Lapayev
Lead tractor engineer Popov
Military technician 1st Grade Bochkar"
The NATI-D tractor was later renamed to Ya-11, a precursor to the more widespread Ya-12 tractor.