Cessna 421C
Primary Specifications Cessna 421C RAM 421C RAM 421CW - Winglets
Engine Model: Continental GTSIO-520-L & -N 375 hp 375 hp 375 hp
TBO hrs. 1,600 1,600 1,600
Takeoff Manifold Pressure @ 2235 rpm 39” 39” 39”
Twin Engine Climb - fpm 1210 1290 1450
Single Engine Climb - fpm 250 250 315
Cruise Climb Power - RPM & MP 1900 & 32.5” 1900 & 35.0” 1900 & 35.0”
Cruise Climb to 20,000 ft - min. 22 20 17
Cruise @ 75% - 20,000 ft. - ktas 223 223 228
Cruise @ 65% - 20,000 ft. - ktas 213 213 223
Useful Load Increase - lbs. NA +110 +50
Ramp weight - lbs. 7,500 7,610 7,610
Gross weight - lbs. 7,450 7,560 7,560
Max. landing weight - lbs. 7,200 7,200 7,200
Zero Fuel Weight when operating at:
Above 7,450 lbs. Takeoff Wt. - S/N all NA 6,533 6,533
At or below 7,450 lbs. Takeoff Wt. - S/N 0001 to 0800 6,733 6,733 6,733
At or below 7,450 lbs. Takeoff Wt. - S/N 0801 and up 6,733 6,733 NA
Wing Span 41’ 41’ 44’
Hangar clearance@ top of winglets NA NA 45’ - 4.8”
Wing Aspect Ratio 7.86 7.86 8.62
Effective Wing Aspect Ratio 7.86 7.86 9.74
SOURCE: Sources

Performance is based on a mid CG with mid cabin and fuel weight on an average day. Performance should always be calculated per flight environment while referring to the Manufacturer’s Pilots Operating Handbook and applicable Flight Manual Supplements for the particular airplane. Aircraft Manufacturer’s Pilot Operating Handbooks and Aircraft Owner’s Manuals should always be available and adhered to by the aircraft Pilot in Command, including attention to applicable FAA approved Flight Manual Supplements and emergency procedures for each individual aircraft. Performance should vary from airplane to airplane, atmospheric day to atmospheric day, one gross weight and CG to another, and pilot to pilot.