The calculated distance (air line) between Frýdlant nad Ostravicí and Opava is approximately 31 miles respectively 51 kilometers.
By car or train, the actual journey to Opava is certainly longer, as only the direct route (as the crow flies) between Frýdlant nad Ostravicí and Opava has been calculated here.
Air line (approximately)
51 kilometers
27 nautical miles