The Kilimanjaro Score for Assessing Fitness to Fly Paragliders at High Altitude

Introduction

High altitude paragliding expeditions are becoming more common. In August 2012, over 50 pilots flew from the summit of Mont Blanc (4810 m) on a single day. Parinacota (6300 m), Aconcagua (6962 m), Manaslu (8156 m), and Mount Everest (8848 m) have all witnessed successful launch attempts in recent years. In the year to come, high altitude paragliding expeditions have been planned to Mont Blanc, Elbrus (5642 m), Kilimanjaro once more, the Annapurnas, and the Karakorum.

The Wings of Kilimanjaro Expedition took place in January and February 2013, with the aim of launching 95 paraglider pilots from Stella point (5790 m) on the summit of Mount Kilimanjaro. The expedition was unusual both in its large size—the largest such expedition to date—and its location, since it received permission to launch from a summit that is usually barred to paragliding. The pilots would spend 7 days climbing Kilimanjaro via the Machame Route. They would then camp at Crater Camp (5640 m) for up to 3 nights waiting for a weather window, before climbing to Stella Point to launch all the pilots in rapid succession towards the landing zone in Moshi, Tanzania (850 m). Climbers do not conventionally camp in the crater due to its altitude, but in this instance it was necessary to be close to launch to take advantage of any weather window. The choice of whether to use acetazolamide (Diamox) or supplementary oxygen was left up to individual pilots, having been presented with an assessment of the risks and benefits by the medical team. Approximately 10% of pilots elected to use supplementary oxygen (most rejected it on the grounds of cost and unfamiliarity) and 40% used acetazolamide.

Paragliding is a high-risk sport, mountain flying even more so, and launch is a hazardous part of the flight (Rekand, 2012). Poor conditions or technique can lead to the paraglider being blown backwards into areas of turbulence, sideways into rocks, or dragging the pilot down the slope (BHPA, 2008). A safe launch therefore requires absolute attention and precise coordination—two attributes that can be impaired by high altitude and cold (de Aquino Lemos et al., 2012).

On Kilimanjaro, the consequences of a poor launch would be severe. While the launch site itself is scree-covered, it is bounded by rocks and the edge of the glacial ice. Casualty evacuation would be difficult. Furthermore, rapid sequential launches just above a crowded take-off, with an additional possibility of two paragliders colliding mid-flight, could lead to a multi-trauma that would overwhelm the limited medical resources present.

Apart from its sheer size, the expedition posed a unique challenge to the medical team: how to rapidly assess the fitness of the paraglider pilots to fly, in a narrow launch window, in the challenging environment of an extreme high altitude mountain summit. Any assessment tool needed to be robust and objective since each pilot had raised approximately 10,000 USD, would likely be a fairly headstrong individual by nature, and reluctant to descend (Castanier et al., 2010).

To help meet this challenge, we devised a scoring system to objectivity judge fitness to fly: the Kilimanjaro Score.

Materials and Methods

We are not aware of any pre-existing tools for assessment of paraglider pilots' fitness to fly at high altitude. When initially presented with the challenge, the medical team searched extensively for other existing instruments that would enable rapid assessment of fitness to fly. The Lake Louise Score, while commonly used to assess and grade symptoms of altitude sickness, does not assess the domains of memory and cognition that are key determinants of pilot performance (Roach et al., 1993). Other assessment tools used in non-high altitude settings include the Montreal Cognitive Assessment, which uses a multi-step test to grade various aspects of cognition and provide an overall score (Nasreddine et al., 2005). However, following discussion with the senior paraglider pilots, these were felt to be too abstract for use in the high-altitude launch setting. Safe pilots are encouraged to develop structured pre-launch routines, to ensure that all necessary checks and preparations are completed. The senior pilots were concerned that any test that drew focus away from these preparations could be unsafe (Wilkes, 2013).

Consequently, we decided to develop our own score that could be set within the context of standard paragliding launch preparations. It had to be structured such that it could be completed rapidly, as the aim was to launch one pilot every 2 minutes. It also had to be clear and easy to follow as it was to be used in a challenging environment. The final scoring system was therefore based on parameters already used during pre-launch paragliding checks. It incorporates elements of cerebellar function such as coordination, as well as higher function such as memory and cognition. It also has a component for the pilot's self-assessment of their fitness to fly.

The Kilimanjaro Score included a subjective assessment of fitness, four questions assessing cognition and memory, and two assessing visual-spatial skill (Fig. 1). In particular, we looked at the pilot's ability to attach their harness easily and to conduct a “line check.” Paragliding harnesses contain several loops and buckles that must be correctly put together. Leg straps especially prevent the pilot falling from the harness after a take-off—a significant cause of accidents (BHPA, 2008). A “line check” involves the spreading out of the wing component of the paraglider, followed by a systematic freeing and checking of the lines attaching the harness to the wing. Both the harness and the line check require a logical approach as well as manual dexterity and coordination.

OPEN IN VIEWER

FIG. 1.

The Kilimanjaro Score.

Given the large nature of the group, and the potential liabilities resulting from a crash, the flight safety officer requested a “tickbox” section at the bottom of the questionnaire, as a written record of the checks made before launch. We feel that it should be included in future versions of the score, as an aide-memoir acknowledging that all involved in a launch at high altitude can be impaired to some degree and require prompting for a safe launch.

The score was discussed extensively with leading paraglider pilots and met with widespread approval (Wilkes, 2013). As our score was new, we set no specific 'pass mark' for the test. Instead, those with evidence of impairments identified by the Kilimanjaro Score were to be subjected to further investigations, including the Lake Louise Score and overall clinical assessment before a final fit-to-fly decision was made.

The scoring process was piloted successfully on the summit during a dummy launch attempt by Mike Küng, a world-renowned pilot. He scored 1/14, as he rated himself as only “moderately fit to fly.” Informed consent was obtained from all 95 pilots on the expedition to validate the Kilimanjaro Score by analyzing their results.

Discussion

The Kilimanjaro Score represents a novel tool for rapid assessment of paraglider pilots' fitness to fly in the high altitude context. It is simple and clear and can be performed by personnel with minimal training. As it is based on observing standard pre-flight checks, it causes minimal disruption to the important sequence of launch preparation. By incorporating aspects of cognition, visual-spatial skill and memory, it assesses important neurological functions necessary for a safe flight. A high score triggers implementation of further assessment of the pilot by use of the Lake Louise Score and general clinical examination. The score could be easily implemented in all high altitude paragliding expeditions. Although the Kilimanjaro Score is presented in English, it can easily be translated for use in other languages.

It should be noted that the effects of exposure to extreme high altitude can affect the assessors as well as the pilots. During the expedition, no formal assessment was made of those using the Kilimanjaro Score. Whilst there was no subjective impairment of the clinical capacity of these assessors during this study, future studies may wish to consider initial objective testing of assessors before they use the score sheet. The Kilimanjaro Score is designed primarily to recognize symptoms arising as a result of neurological impairment due to the effects of high altitude. Clearly other features of a mountain launch may also impair fitness to fly, such as low temperatures, poor sleep and fatigue and, on Kilimanjaro, infectious diarrhea. Whilst the Kilimanjaro Score may identify some impairment as a result of these conditions, further clinical assessment may be required to provide a more complete investigation.

Unfortunately, there was no suitable weather window for the group launch, and despite all 95 participants summiting and spending at least one night at Crater Camp, only one pilot was able to launch. The remainder went on to descend safely on foot. Due to wind conditions at the summit, after Mike Küng's dummy launch attempt, we deemed it unsafe to attempt to score the remainder of the pilots on this expedition. Unpacking a large number of paragliders in very high, unflyable winds could have led to pilots being dragged and colliding when performing the line check.

Whilst the Kilimanjaro Score was developed to meet a particular need arising as a result of the Wings of Kilimanjaro expedition, the scoring system can clearly be utilized in any high altitude environment to assess paragliding pilots' fitness to fly. Indeed, the score could be used equally well on smaller scale expeditions. To this end, we would welcome any comments regarding the score's design and any attempts to use it in the field. A Kilimanjaro Score worksheet (with the Lake Louise Score on the reverse) has been made available for download at www.paraglidingmedicine.org.