The Heldeberg Marathon, also called the Blue Heron Marathon, was an American powered parachute, that was designed and produced by Heldeberg Designs of Altamont, New York.

The Marathon was designed to comply with the US FAR 103 Ultralight Vehicles two-seat trainer rules and was marketed as a light-sport aircraft. The aircraft takes its name from its design goal of an aircraft with long range and endurance and features a range of 115 mi (185 km). It features a parachute-style high-wing, two-seats-in-tandem accommodation, tricycle landing gear and originally a single 50 hp (37 kW) Rotax 503 engine in pusher configuration. The 64 hp (48 kW) Rotax 582 was the standard engine used on later models.

The aircraft is built from a combination of bolted dural aluminium and stainless steel tubing. It features a double ring propeller guard that has been roll-over tested. The 10 U.S. gallons (38 L; 8.3 imp gal) fuel tank is made from aluminium. In flight steering is accomplished via foot pedals, or optionally a control stick, that actuate the canopy brakes, creating roll and yaw. On the ground the aircraft has lever-controlled nosewheel steering. The main landing gear incorporates gas strut suspension. The aircraft is factory supplied in the form of an assembly kit that requires 30–50 hours to complete.

Originally marketed by the factory under their own name, the aircraft was later marketed under the brand name Blue Heron, although the manufacturer remained the same. The selling price was US$21,995 in 2012, though production is now completed.

Blue Heron Marathon
Powerplant: 1 × Rotax 582, 64 hp (48 kW)
Length: 9 ft 8 in (2.95 m)
Wingspan: 39 ft 6 in (12.04 m)
Height: 6 ft 6 in (1.98 m)
Wing area: 500 sq ft (46 m2)
Empty weight: 308 lb (140 kg)
Gross weight: 850 lb (386 kg)
Fuel capacity: 10 U.S. gallons (38 L; 8.3 imp gal)
Cruise speed: 32 mph (51 km/h; 28 kn)
Range: 115 mi (100 nmi; 185 km)
Rate of climb: 900 ft/min (4.6 m/s)
Wing loading: 1.7 lb/sq ft (8.3 kg/sq.m)
Crew: one
Capacity: one passenger

The Heldeberg Spirit 103, also called the Blue Heron Spirit 103, is an American powered parachute, designed and produced by Heldeberg Designs of Altamont, New York.

The Spirit 103 was designed to comply with the US FAR 103 Ultralight Vehicles rules, including the category’s maximum empty weight of 254 lb (115 kg). The aircraft has a standard empty weight of 205 lb (93 kg). It features a parachute-style high-wing, single-place accommodation, tricycle landing gear and originally a single 45 hp (34 kW) 2si 460 engine in pusher configuration. The 40 hp (30 kW) Rotax 447 and 50 hp (37 kW) Rotax 503 engines are used on current models.

Early models used a large sized 500 sq ft (46 m2) parachute, whereas current models use a smaller and faster 400 sq ft (37 sq.m) wing.

The aircraft is built from a combination of bolted 6061 T-6 aluminium and stainless steel tubing. It features a double ring propeller guard that has been roll-over tested. The 5 U.S. gallons (19 L; 4.2 imp gal) fuel tank is made from aluminium. In flight steering is accomplished via foot pedals, or optionally a control stick, that actuate the canopy brakes, creating roll and yaw. On the ground the aircraft has lever-controlled nosewheel steering. The main landing gear incorporates gas strut suspension. The aircraft was factory supplied in the form of an assembly kit that requires 30–50 hours to complete for US$12795 in 2012.

Originally marketed by the factory under their own name, the aircraft was later marketed under the brand name Blue Heron, although the manufacturer remained the same.

Blue Heron Spirit 103
Engine: 1 × Rotax 503, 50 hp (37 kW)
Wingspan: 39 ft 6 in (12.04 m)
Wing area: 400 sq ft (37 sq.m)
Length: 8 ft 6 in (2.59 m)
Height: 6 ft 0 in (1.83 m)
Empty weight: 235 lb (107 kg)
Gross weight: 580 lb (263 kg)
Fuel capacity: 5 U.S. gallons (19 L; 4.2 imp gal)
Wing loading: 1.45 lb/sq ft (7.1 kg/sq.m)
Power Loading: 11.3 lbs. per hp
Cruise speed: 32 mph (51 km/h; 28 kn)
Rate of climb: 450 ft/min
Take Off Distance: 150 ft
Landing Distance: 150 ft
Seats: one