A fighter pilot in a turning fight is pulling seven or eight times his own body weight. His vision is narrowing. He is breathing against a system designed to stop him blacking out. And he needs to change his radar mode, select a different missile, and put out chaff.

He cannot look down. He cannot reach across the cockpit. If the switch is not under a finger already on the stick or the throttle, it may as well be in another aircraft.

That constraint produced one of the quietest and most consequential ideas in cockpit design: HOTAS.

The Problem HOTAS Solves

Look at the cockpit of a 1950s interceptor and the problem is obvious. Everything is a dial, and every dial has a switch somewhere else.

In level flight that is merely inconvenient. In combat it is disqualifying. Under high G the pilot's arms weigh several times their normal weight, his peripheral vision is closing in, and the aircraft he is fighting is moving. Every second spent locating a switch is a second not spent flying or looking.

HOTAS is the answer, and it is almost embarrassingly simple as a concept: identify every control the pilot genuinely needs while manoeuvring, and put it on the two things his hands are already holding.

What Actually Lives on the Stick and Throttle

The exact arrangement differs by aircraft, but the categories are consistent. Radar mode selection and target designation. Weapon selection and release. The radio transmit switch. Chaff and flare dispensing. Speed brake. Nosewheel steering. On tanker-capable aircraft, the air-to-air refuelling disconnect.

The crucial point is that the pilot can work the radar — arguably the most complex system aboard — without either hand leaving the controls. Combined with a head-up display, this means he can fly, search, identify and shoot while looking out of the canopy the entire time.

A walkthrough of the F-16C cockpit, which is the aircraft most often held up as the HOTAS exemplar.

Air Commodore Paul Godfrey of the RAF flew the F-16CJ on exchange with the USAF, having come from the Harrier. His verdict on the Viper's controls was unambiguous.

Switchology

There is a word for this in fighter aviation, and it is “switchology”: the learned, half-automatic knowledge of which switch does what, in which mode, without looking.

Good switchology is consistent. The same action should produce the same result regardless of what the aircraft is currently configured to do, because a pilot under pressure will revert to habit. Godfrey's description of the F-16's arrangement makes the point better than any design document.

Asked what the best thing about the F-16 was, he gave a two-item answer: the view, and the HOTAS.

It Started With a British Interceptor

HOTAS is so associated with the F-16 that its actual origin is routinely forgotten. The concept was first applied on the English Electric Lightning in the late 1950s.

That makes sense once you know what the Lightning was for. It was a point interceptor built to climb very fast, find a Soviet bomber, shoot it, and come home before the fuel ran out. The entire mission was a short, high-workload sequence under time pressure. Anything that saved the pilot from hunting for a switch was worth having.

A surviving Lightning being coaxed into life — a reminder of how much machinery sat behind those two handles.

From there the idea spread to almost everything: the F-16 Fighting Falcon, the IAI Super Phantom, the MiG-29 Fulcrum and the Eurofighter Typhoon among them.

Where It Went Next

Modern implementations do not stop at the stick and throttle. HOTAS is now routinely combined with a helmet-mounted display, so the pilot can designate a target by looking at it, and with direct voice input for functions that are not time-critical enough to justify a dedicated switch.

Lightning start-up and fast taxi, for the sound if nothing else.

The principle has also travelled well outside aviation. Steering-wheel controls in cars are HOTAS thinking applied to a commute. So is the modern games controller, which is why flight simulator manufacturers sell replica stick-and-throttle sets under the same acronym. Drone ground control stations use it too, which is a neat irony: the design philosophy built around keeping a pilot's hands on the aircraft has outlived the pilot being in it.

The measure of a good idea in cockpit design is that nobody notices it. No pilot praises HOTAS in the way they praise thrust or a bubble canopy. They only notice when it is absent — and then they notice immediately.

Sources: Hush-Kit interview with Air Commodore Paul Godfrey RAF, “Flying & Fighting in the F-16”; Wikipedia entry on HOTAS; Wikimedia Commons imagery.