PD-8 Engine vs. SaM146: No Gearbox for SJ 100

[@zubi234a]

The Sam Engine is much older than the PD8 .. there's a possibility that the gear box was intentionally excluded..

[@jeffhedrich3551]

Russia needs a reliable, in service jet, more than it needs a higher efficiency jet on the drawing board. If you look at Leap engines vs GTF, I think it's pretty obvious that the gear box is a long way from perfect.

[@anonymouse8565]

That Geared TurboFan Engine has bankrupted airlines. My take would be - less complications, more simplicity, better materials and structures, easier maintenance and operability.

[@GaryKennedy-g7p]

PD-8 is twin-spool design so doesn't need a gearbox to run the front fan at diff revs to the hot core. That PW engine you mention on the A-220 is 50% bigger diameter front fan than the PD-8/Sam-146. So it has planetary gears due to issues with the tips of the fan blades speed getting too high. A-220 is an usual spec 5-abreast seating for 200 passengers .... Russia has no aircraft that size so there is no need for a geared PD-8 version.

[@Macaktom1]

It will be if it lowers maintenence requirements...