The calculated distance (air line) between Houdeng-Aimeries and Uccle is approximately 24 miles respectively 38 kilometers.
By car or train, the actual journey to Uccle is certainly longer, as only the direct route (as the crow flies) between Houdeng-Aimeries and Uccle has been calculated here.
Air line (approximately)
38 kilometers
21 nautical miles