Zodiac CH 601 HD

The Zodiac CH 601 HD is the baseline model of the Zodiac line and descends directly from the CH 600, which first flew in 1984. "HD" stands for Heavy Duty: the airframe is designed to take engines from 65 to 115 hp. Alongside the HD, the family includes the lighter CH 601 UL, the CH 601 HDS with shortened tapered "speed" wings, and later the CH 601 XL. In 1992 Chris Heintz licensed manufacture and marketing of the ZODIAC CH 601 to Zenith Aircraft Company in Mexico, Missouri – since then the HD has circulated mainly as a kit aircraft.

That is exactly the point that matters when buying: no German type data sheet specifically for the "CH 601 HD" series can be found. The German ultralight approvals in the Zodiac family cover the CH-601XL (61196 and 61196.1), the CH-650 E (61196.2) and Roland Aircraft's 601-D (61144), while the CH-650 Ei is treated as a type of its own. The figures given here come from the factory manual and the works specification table for experimental or kit operation – the kit takeoff weight of 544 kg sits well above the German ultralight limit of 472.5 kg. Before viewing, establish under which approval, with which operating limits and at what takeoff weight the specific aircraft is registered in Germany.

Structurally the HD is an all-metal low-wing aircraft with a NACA 65018 mod. airfoil, 8.20 m span, 12 m² of wing area and an aspect ratio of 5.58. The cabin is 1.12 m wide; the works table quotes 1.68 m for the cabin top and 2.08 m for the rudder tip above ground, with two side-by-side seats. Factory empty weight figures disagree: depending on the source they range from 530 to 590 lbs, roughly 240 to 267 kg – for a kit aircraft there is no type value, only the individual aircraft's weighing report is binding, and that is also what determines real useful load. The works table further quotes 45 kg/m² wing loading and 6.8 kg/hp power loading. The standard tank holds 60.5 l; with optional wing tanks the works table shows about 113 l total. Operating load factors are +4/-2 with a 1.5 safety factor for ultimate load; aerobatics are prohibited.

For performance the works table quotes a 217 km/h top speed, 193 km/h cruise (with no power setting stated), 7.1 m/s climb rate and roughly 110 m takeoff and 137 m landing distance. The factory manual, published as a draft and sample document, is more conservative and quotes – in a table for the lighter CH 601 UL with a Rotax 912 at 1,058 lb – 1,200 ft/min climb at sea level, 850 ft/min at 3,000 ft, 550 ft/min at 6,000 ft and a 550 ft takeoff distance at sea level; the manual states these values must be verified on the individual aircraft. Only the airspeed indicator markings are explicitly identified as HD figures: VNE 150 mph CAS, manoeuvring speed 115 mph, best rate of climb 65 mph, best angle 60 mph, stall at 44 mph CAS and a service ceiling of 12,000 ft density altitude.

Strengths are a rugged airframe built for stronger engines, plain riveted construction that is easy to repair, a wide choice of powerplants and continued kit support through Zenith. The weaknesses carry real weight though: with a kit aircraft, quality depends entirely on the individual builder, empty weights vary accordingly, and there are no type values for empty weight, overall height or approved engine and propeller combinations – the manual explicitly refers you to the documentation of the engine actually installed. On top of that comes the family's structural history: the 2010 FAA review concerns the 601 and 601 XL, so every purchase should establish whether and which wing reinforcements are fitted. The CH 601 HD is therefore an aircraft for technically confident buyers who can read build documentation, judge riveting and scrutinise paperwork – not a quick first step into ultralight ownership.