Aero Commander 680FL

Overview

The Aero Commander 680FL, marketed as the Grand Commander, is the stretched, cabin-class evolution of the Aero Commander line. Type-certified in May 1963 under CAR 3, it added a 44-inch fuselage section forward of the front spar (with additional structural rework aft) over the 680F, plus a larger horizontal stabilizer, creating a true executive transport with a separate flight deck and high-density seating for up to nine passengers.

It is powered by twin supercharged, geared Lycoming IGSO-540-B1A engines (later production used the IGSO-540-B1C), each rated 380 hp at sea level and driving three-blade Hartzell propellers. The supercharger and reduction gear give the 680FL meaningful high-altitude capability and the cabin presence required for corporate or heavy-duty utility missions, at the cost of powerplant complexity. In Aero Commander’s final two production years (1968-69) the model was rebranded Courser Commander.

Key Features for GA Buyers

• Massive Cabin. The 44-inch stretch produces a true aisle feel and executive club seating that rivals the cabin volume of light turboprops.
• High-Wing Visibility. Passengers get an unobstructed view of the ground, and the low cabin floor with airstair door makes entry and exit exceptionally easy.
• Rugged Heritage. Robust airframe used historically for executive transport, freight, and check hauling, with continuing manufacturer-successor support through Twin Commander Aircraft.
• High-Altitude Performance. Supercharged engines allow efficient cruise in the mid-teen altitudes, above much standard GA weather, with a service ceiling around FL 200 typical of in-service operations.

Trade-offs

• Engine Complexity. The geared and supercharged Lycoming IGSO-540s are sophisticated powerplants requiring meticulous pilot management; overhauls are expensive and shops familiar with the geared Lycoming family are increasingly scarce.
• Operating Costs. Combined fuel burn often exceeds 40 GPH, and the maintenance load on the geared engines, hydraulics, and cabin systems put the 680FL firmly in the deep-pockets bracket.
• Runway Requirements. Unlike the shorter Commanders, which retain STOL character, the 680FL at gross weight needs healthy runway, particularly when accelerate-stop is computed against the 8,500 lb MTOW.
• Variant Confusion. Buyers should confirm exact model designation on the data plate: 680F, 680FL (stretched), 680FL(P) (stretched and pressurized), and the later Rockwell 685 (Continental-powered, pressurized) all carry similar marketing names but have meaningfully different airframe, engine, and pressurization specifications.

See Also

• Aero Commander 680FP – Pressurized, non-stretched sibling in the 500 family; useful when cabin volume vs pressurization is the trade-off. Compare
• Aero Commander 500 – Lighter, smaller-cabin predecessor from which the 680 series evolved. Compare
• Aero Commander 560 – Earlier mid-size cabin twin with less powerplant complexity. Compare
• Beech King Air 90 – Natural turbine step-up for the same cabin-class mission, with simpler turboprop operation and pressurization. Compare