Build: 1.10.4 4243 Mode: Survival Mode: Single Player/Multi Player Reproducibility: Always Severity: Minor Type: Flight Model Summary: Moving cargo between a docked ship and a carrier can affect the maximum top speed of the carrier vessel, even though the combined mass of hull + cargo did not change Description: I recently learned about the alpha 12 change where cargo receives a 50% mass reduction when calculating the mass-limited top speed of a ship. While testing this however it turns out that cargo mass on docked ships does not receive this benefit, which means that when you transfer cargo from the carrier to a docked ship (say, a docked storage module) the cargo becomes "heavier" and creates inconsistent behavior in the carrier's calculated top speed. Steps to Reproduce: Load up a single player survival game with weight/volume enabled Spawn a "UCH Pelican" prefab CV and fuel it up Spawn a "REBAR MKIII" prefab CV and fuel it up Awkwardly dock the REBAR to the hull of the Pelican Sit in the pilot seat of the Pelican and observe that the maximum forward speed is 79 m/s Exit the pilot seat Spawn in a full stack of Artificial Mass Blocks and transfer them to the "Constructor Container" of the UCH Pelican (the stack should be 250t @ 20k volume) Sit in the pilot seat and observe that your top speed is reduced to 77 m/s Exit the pilot seat Transfer the Artificial Mass Blocks from the Pelican to the "Container Controller" on the REBAR. Sit in the pilot seat and observe that your top speed is now reduced to 75 m/s. Since the mass did not change, it is expected that the top speed should be 77 m/s. Screenshots: Testing rig: Cargo mass used in test: Top speed when cargo mass is in carrier (Pelican): Top speed when cargo mass is in docked ship (REBAR):