Page 144 - PPL-engelsk 2025
P. 144
Human Performance
Although consciousness is maintained at this stage, it only lasts for a few
seconds. If the aircraft is not leveled in time, unconsciousness (GLOC = Gravity-
induced Loss of Consciousness) follows.
In cases of outward loops, blood may be forced into the head, risking a “Red-
out” due to blood accumulation in the retina.
2.3.5.2 Hyperventilation
In cases where individuals panic, become anxious, or nervous, their breathing
rate may increase without a physiological need.
Hyperventilation lowers the concentration of CO2 in the blood, potentially
leading to unconsciousness.
Hyperventilation can be alleviated by breathing into a bag. This increases CO2
levels and improves the condition.
It can be difficult to distinguish between hyperventilation and hypoxia.
If you are unsure whether someone is experiencing hypoxia or
hyperventilation, remember that hypoxia is fatal - so if you have oxygen
available, administer it first!
If this does not help, hyperventilation might be the cause.
2.3.5.3 Problems with pressure changes
Pressure drops cause blood vessels to expand, reducing circulation in areas like
the legs. Air trapped in body cavities, such as the sinuses and middle ear,
expands. Nitrogen bubbles may also be released from the blood.
These changes can lead to physiological problems such as:
- Ear problems – pressure, temporary hearing loss
- Oxygen deficiency – fatigue, dizziness, shortness of breath, difficulty
concentrating
- Dehydration – dry skin and eyes, increased thirst, headaches
- Swelling – legs, hands, feet
Flight Theory PPL(A)(UL)/LAPL Henning Andersen, Midtjysk Flyveskole© 2025 144
