longline

A longline is a single cable, typically steel wire rope between 50 and 300 feet long, suspended from a helicopter's cargo hook to transport loads when landing is unsafe or impossible. The cable hangs vertically or near-vertically, with the load attached at its lower end via a bridle or spreader bar. This rigging method allows delivery to remote terrain, moving vessels, offshore platforms, or disaster sites where the aircraft cannot touch down.

The cable diameter usually ranges from 0.375 to 0.625 inches, chosen to match the helicopter's rated capacity and the anticipated load weight. A swivel or ball joint near the hook end reduces rotational stress. Most longlines incorporate a single-hook termination, though some operations use multiple pick points on a spreader bar for load distribution. The lower end often includes a quick-release mechanism or, in rescue operations, a rescue basket or net rated for personnel.

Longline operations depend on ground personnel called 'hook handlers' or 'tagline tenders' who guide the descending load and secure it at the landing zone. These workers must maintain line-of-sight communication with the aircraft crew via radio and follow strict hand signals. Wind speed and load swing present the primary hazards; unstable loads can rotate or pendulum, risking personnel injury and equipment damage.

Common applications and constraints

Industries including forestry, construction, emergency services, and military logistics rely on longline work. Forestry operations use longlines to extract timber from steep hillsides; construction crews use them to position materials on high-rise builds; rescue teams deploy them for mountain and water evacuations. Payload limits typically range from 2,000 to 10,000 pounds depending on the helicopter model. Weather is the critical limiting factor: winds above 15 to 20 knots often halt operations, and visibility must be adequate for pilot control.

The term 'longline' distinguishes this method from 'shortline' or 'direct hook' operations where a load is lifted a few feet and set down directly. Longline operations are governed by civil aviation regulations and operator manuals specific to each helicopter type. Inspection of the cable before each shift is mandatory; corrosion, kinks, or strand damage require replacement or retirement of the line.