Page 142 - PPL-engelsk 2025

Human Performance

2.3.4.3 Symptoms of oxygen deficiency

What symptoms should you be aware of when it comes to oxygen deficiency?

Symptoms of Oxygen deficiency

Observed Self-experienced

Mental Elevated mood Confusion

Poor performance Elevated mood
Poor judgment Good performance

Physical Increased breathing rate Dizziness

Poor coordination Nausea
Unconsciousness Headache

Ringing in ears

Other Aggressive behavior Blurred vision
Faded colors

Tunnel vision
Tingling in arms and fingers

Blue lips and fingers

Oxygen deficiency can cause unconsciousness and death.

2.3.4.4 Time of useful consciousness

There is a concept called Time of Useful
Relationship Between Altitude
Consciousness (TUC). and TUC

This refers to the time during which a Altitude TUC
(feet)
person remains capable of taking
50.000 9 – 12 sek
purposeful action in an oxygen-deficient
43.000 9 – 12 sek
environment.
40.000 15 – 20 sek

35.000 30 – 60 sek
30.000 1 – 2 min
This table shows the relationship between 28.000 2,5 – 3 min
altitude and TUC. 25.000 4 – 6 min

22.000 8 – 10 min
18.000 20 – 30 min

Flight Theory PPL(A)(UL)/LAPL Henning Andersen, Midtjysk Flyveskole© 2025 142