COBI CH-47 Chinook Set 5807

COBI's CH-47 Chinook is a 1:48 model built from 815 blocks in US Army colours. The rotors turn, a loading flap opens, and a rope with a cargo hook hangs from the belly. Two pilot figures are included. All markings are printed.

No tail rotor means all the power lifts

A conventional helicopter has a problem: the main rotor tries to spin the fuselage in the opposite direction, and a tail rotor has to counteract it. That tail rotor consumes somewhere between 5 and 15 per cent of the engine power, and it produces no lift whatever.

The Chinook has two main rotors turning in opposite directions, one at each end. They cancel each other's torque, so there is nothing to counteract and no tail rotor to feed. Every bit of power goes into lifting.

The result is a helicopter that can carry close to its own empty weight. A Chinook lifts around eleven tonnes on the hook — artillery pieces, light vehicles, containers, other helicopters — and that hook is the reason the rope is in this set.

Tandem rotors have a second advantage nobody expects: the aircraft is far less fussy about where the load sits. A single-rotor helicopter has a narrow centre-of-gravity window; a Chinook has a long one, because there is a rotor at each end holding it up.

In production since 1961

Sixty-five years and still being built, which almost nothing else in aviation can claim. The current F model shares the shape and very little else with the ones that flew in Vietnam. Around twenty countries operate it, and the US Army expects to fly Chinooks into the 2060s — a century of service.

Specifications

Pieces: 815 · Figures: 2 pilots · Scale: 1:48 · Cargo rope and hook included