DC-8-73    DC-10-30   
MLW            257,985      403,000        
V2               165            189               
Vat              141            140               
Vno/Mno      352              
Vmo/Mmo    0.88           530/0.88       
Vne/Mne      0.95           0.95              
Max Cruise   479/FL330  490                 
Max Alt        42,000'       42,000'           
Long Range  459/FL350  482/FL310       

                  DC-9-10   DC-9-30   DC-9-40      DC-9-50
MLW           75,000      99,225       102,092        110,030        
V2              140           155            155              160
Vat             130           135            135              138
Vno/Mno                   
Vmo/Mmo   350/0.84   350/0.84     340/0.82       340/0.82
Vne/Mne     
Max Cruise  500            501            501              501
Max Alt       35,000'       35,000'       35,000'        35,000'
Long Range 430/FL350  430/FL350   440/FL350    440/FL350

MLW = Maximum Landing Weight
MTO = Maximum Take-off Weight
V2  = Safe Climb-out speed (The speed after Vr, Rotation speed or Lift-off speed)
Vat = Landing speed at runway threshold Flap/Gear down (X-Plane @ 50'...25'...10')
Vapr= Approach Speed , just add 5-10kts to Vat with flap/gear down @ MLW or less
Vno = Normal Operating Speed
Vmo = Maximum Operating Speed
Vne = Never Exceed Speed
FL350  = Flight Level 35,000'

Thanks to Mohammed Gazzawi, Designer/Test Pilot MGXP