Flight Performance During Exposure to Acute Hypobaric Hypoxia

Abstract

The present study did not provide decisive evidence for a decrease in flight performance during exposure to simulated altitudes of 3048 and 4572 m. However, large interindividual variation in pilots' flight performance combined with a gradual decrease in alertness levels observed in the present study puts into question the ability of pilots to safely fly an aircraft while exposed to these altitudes without supplemental oxygen.Steinman Y, van den Oord MHAH, Frings-Dresen MHW, Sluiter JK. Flight performance during exposure to acute hypobaric hypoxia. Aerosp Med Hum Perform. 2017; 88(8):760-767.

Exposure to hypoxia impairs helicopter pilots’ awareness of environment

“…In line with our expectations, this simulator study showed that exposure to hypoxic conditions (4572 m) significantly affected the AoE of helicopter crews during operationally relevant flight scenarios. In addition, similar to previous observations (Steinman et al 2017), the alertness of the pilots was significantly reduced after the 4572 m flight, but not after the 0 m flight. It is likely that the reduced alertness contributed to the impairment of AoE, because alertness is required to maintain vigilance and attention (Wright and McGown 2001), both of which are essential for AoE (Shook et al 2000;Vidulich et al 2010).…”

“…The sample size was calculated with an a-priori power analysis using a power of 0.8, an alpha of 0.05, and an effect size of 0.4. The effect size was calculated using previously reported data on the effect of hypoxia on pilot alertness (Steinman et al 2017).…”

“…However, most of the research used standard cognitive tests, and it is unclear if the results of these tests can be translated to tasks that pilots perform during operational flight (Petrassi et al 2012). A few studies specifically investigated the effects of hypoxia on pilot performance in a simulated flight environment (Bouak et al 2018;Gold and Kulak 1972;Nesthus, Rush, and Wreggit 1997;Peacock et al 2017;Steinman et al 2017;Temme, Still, and Acromite 2010). In some of these studies, hypoxia induced significant errors in flight performance, such as larger deviations in airspeed and altitude (Gold and Kulak 1972;Temme, Still, and Acromite 2010), or an increased number of procedural errors (Bouak et al 2018;Nesthus, Rush, and Wreggit 1997).…”

“…In some of these studies, hypoxia induced significant errors in flight performance, such as larger deviations in airspeed and altitude (Gold and Kulak 1972;Temme, Still, and Acromite 2010), or an increased number of procedural errors (Bouak et al 2018;Nesthus, Rush, and Wreggit 1997). In other studies, no significant effects on flight performance were found (Peacock et al 2017;Steinman et al 2017). The emphasis in these simulator studies was on pilots' technical skills (TS), i.e.…”

“…In a recent study, helicopter flight instructors of the Royal Netherlands Air Force (RNLAF) concluded that pilots' NTS are most important during operational flight, and are highly sensitive for reduced alertness (Steinman et al 2019). Reduced alertness can occur during flight under hypoxic conditions (Steinman et al 2017). The flight instructors considered awareness of environment (AoE) to be the NTS most sensitive to reduced alertness.…”