Spatial Disorientation: Which Way is Up? 

By By Andrew Driwega, International Bureau Chief | February 2, 2015
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AMST’s Desdemona dynamic and tactical flight simulator used by the RNLAF.  Photos courtesy AMST

What is spatial disorientation (SD)? Strictly defined, it is the inability of a person to correctly determine his body position in space. In a helicopter or aircraft, that can quickly lead to fatal consequences.

The fourth Spatial Disorientation and Night Vision Training Workshop, held in Salzburg, Austria, in November 2014 brought together aviation medical specialists to discuss The Human Factor: Enhancing Human Performance Through Simulation.


The conference is hosted by Austrian company AMST, a specialist developer of simulation products for pilots, both fixed-wing and rotary, which simulate high altitudes, spatial disorientation and variable G-forces.

According to Squadron Leader (Ret) Douglas Vine, an aeromedical consultant who works with AMST and specializes in night vision training, although aircraft are becoming safer, they are also becoming more complex, and human performance is increasingly a factor in the development of unsafe situations.

Because of the military’s technology-rich aircraft, crewmembers often experience information overload during times of high work rate. This saturation of tasks is known as helmet fire.

Vine summarized the requirement: “How can we stimulate the vestibular system through synthetic training? We need to train the brain – not polish the hands.”

Host company AMST is mostly recognized for its variety of training and simulation products, from the human training centrifuge for fast jet pilots, to the multipurpose Desdemona simulator, which addresses all levels of SD training. In terms of its applicability to helicopter aircrew, the simulator is particularly useful for hovering in challenging environments such as brownouts.

But Desdemona is not only a training device; it can also be used for research through its extended motion cueing. The device combines both a hexapod and a centrifuge and can rotate around any axis. The modular cabin layout means that military users can train both fast jet pilots and helicopter crews on the same simulator, which the UK’s Royal Air Force (RAF) does. The movement comprises two meters vertically and eight meters horizontally along a sledge (which also spins). It can generate up to three Gs.

Another simulator, the Airfox comes in two variations: the Airfox DISO and the Airfox ASD, which is a twin seat version. Basically, this simulator allows instructors to demonstrate SD in all situations from takeoff through to landing. The advantage is that SD can be induced at any time during a training mission so the pilot will immediately experience the feeling of entering spacial disorientation – and can then be trained in what to expect and how to respond to the phenomenon.

Conference highlights

The AMST disorientation trainer demonstrates and familiarizes pilots with the potentially disastrous effects of Spatial Disorientation.

The conference keynote address was presented by Brigadier General (Ret) Dr. Erich Rödig, who served as surgeon general of the German Air Force until his retirement. He pointed out that, for most military forces, night flying is now the norm, and the newest fighters are extremely agile. “The nose doesn’t give you the direction any longer due to multi-axis flying.” With the onrush of fly-by-wire aircraft added to complex avionics, he said that the basic “seat-of-the-pants” pilot was now more akin to a data manager with all the distractions that such technology can deliver – often simultaneously.

Glass cockpits meant that the cost of new aircraft equipped with digital systems could be amortized by adapting them to new roles and capabilities. This usually means enlisting more mission systems, which further increases the complexity for the aircrew. Such would be the case in systems that contribute to the overall build-up of a military force’s ISTAR (Intelligence, Surveillance, Target Acquisition and Reconnaissance) picture.

“Humans are bad monitors. We suffer from fatigue, we get bored, endure task saturation, have channelized attention, target fixation, sometimes have a lack of flight currency, all of which can contribute towards spatial distraction and psychophysical stress,” said Rödig.

He said that instances of helmet fire are an increasing problem that is particularly prevalent among some types of aircraft, such as in the F-16 community.

Rödig narrows spatial disorientation to three general areas. Type 1 is where the pilot is not aware that they are spatially disorientated. Type 2 is when the pilot can recognize what is happening and has the knowledge and ability to take corrective action. Type 3 occurs when the pilot becomes incapacitated and cannot react properly, whether it’s psychologically, physiologically and physically.

“We must have modern, capable night vision flight training at least every two years,” Rödig advised. But perhaps the solution was already on the horizon he concluded, referring to the growth of unmanned aerial systems and the speed at which they might relieve aircrew engaged in highly complex missions.

Helicopter SD training

AMST’s Airfox disorientation demonstrator.

Squadron Leader Marco Setterley said that the RAF used two Airfox simulators with a five-year refresher training cycle. Recent upgrades to the system include a wraparound screen, a control column that provides feedback to the pilot, and chin windows to assist rotary-wing pilots. All pilots are given the chance to experience one visual and one vestibular illusion as part of a much broader training synopsis. Rear-crew are also exposed to the Airfox but usually only get to experience one vestibular illusion (usually the Coriolis effect associated when a crewman’s head tilts up or down while the aircraft is turning). “We try to promote the enjoyment of training and not make it a ‘tick-box’ exercise, but we still have some difficulty selling the benefits of disorientation training,” said Setterley.

Mark Wentink, chief technology officer of the Desdemona serving the Royal Netherlands Air Force (RNLAF), said that Chinook pilots were trained through two different scenarios – reduced visibility in brownouts and flying in mountains with clouds.

According to Wentink, Boeing Apaches and Chinooks have different approaches to brownout landings. While Apache pilots were provided with a flight path vector in front of their eyes, Chinook pilots were more reliant on their own skills. In terms of training with the Desdemona system, pilots could experience breaking and acceleration. “They will a feel jerk motion as the wheels embed in soft sand (for example). But we always let them do circuits and a few landings before they try the really difficult landing in the simulator.”

Captain Ference Nihof, also with the RNLAF, said that they use both the Airfox and the Desdemona for different levels of training. The first course pilots will experience takes place in the Airfox with the second phase (pilot on instruments) taking place in the Desdemona. “They are given a basic 90-minute academic briefing on spatial disorientation, then go into the Airfox ASD and are shown different kinds of illusions. We want to educate them that they are vulnerable to SD,” Nihof said. “After two years on their aircraft type, we then have the advanced SD course for Chinook and Apache pilots (the latter has just recently been introduced). Chinook pilots experience brownouts, whitesout and mountain flying, while Apache crews experience brownout.”

In regards to reducing risk to brownout losses, Vine said the company is working on ways to improve training. “We spend a lot of time in the Airfox DISO trying to model the brownout. In the United States, analysis took place by taking sand out of the desert to analyze particle loiter rate in relation to the downwash.”

According to Vine, the Airfox can demonstrate a range of disorientation phenomena and illusions including: leans, Coriolis, black hole approach, graveyard spin, dark takeoff, nystagmus, false horizons, somatogyral, sloped runways, oculogyral and runway with autokinesis.

Night vision training

AMST’s ejection seat trainer helps pilots and aircrew obtain specialist skills that may be needed in the air.

“The risk element is never overstated when it comes to night operations,” said Vine, who experienced the transition of night vision devices and training since first using them in 1978.

“The UK has around 3,500 night vision devices, although there are around 16 different types, which means the devices have become platform specific,” Vine explained.

Night Vision Goggle (NVG) training had been left to individual units, but after an incident involving a mid-air collision between two Tornado fast jets at night in the mid-1990s, the Ministry of Defence (MoD) decided to formalize NVG training.

“NVG training has to be done under the auspices of medical risk,” said Vine, “but where should it be done?” He added that expectation versus reality was an issue in NVG training. “Perception is a very personal thing – if perception does not match reality then you have a severe situational awareness problem.”

Related: Training News

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