Pilot reported feeling sleepy while flying and suspected that it was the covid-19 mask that was caus...

Attributes
ACN	1750245
Time
Date	202007
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.ARTCC
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Small Transport
Operating Under FAR Part	Part 91
Flight Phase	Descent
Route In Use	Direct
Flight Plan	IFR
Person 1
Function	Single Pilot Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Flight Instructor Flight Crew Instrument Flight Crew Multiengine
Experience	Flight Crew Last 90 Days 75 Flight Crew Total 4500 Flight Crew Type 1500
Events
Anomaly	No Specific Anomaly Occurred All Types

Narrative:

About 1.5 hours into my flight at FL230; and into my descent; I started feeling an urge to sleep. I was amusing myself texting and communicating and flying but nonetheless; I started to feel very; very tired. Prior to the flight; I felt fine. I think I slept my usual 7 hours of sleep the night before. I moved my covid-19 face mask aside and drank some water. That helped a little bit. But upon putting the face mask back on my face; the feeling came back and I caught myself drifting. Then I realized...it was my covid-19 mask! I removed the mask and felt fine the rest of the flight. I didn't have a pulse oxymeter handy but I wish I did. I think I was inhaling CO2 instead of oxygen. Covid strikes again!

Original NASA ASRS Text

Title: Pilot reported feeling sleepy while flying and suspected that it was the COVID-19 mask that was causing the problem. The pilot removed the mask and felt fine afterward.

Narrative: About 1.5 hours into my flight at FL230; and into my descent; I started feeling an urge to sleep. I was amusing myself texting and communicating and flying but nonetheless; I started to feel very; very tired. Prior to the flight; I felt fine. I think I slept my usual 7 hours of sleep the night before. I moved my COVID-19 face mask aside and drank some water. That helped a little bit. But upon putting the face mask back on my face; the feeling came back and I caught myself drifting. Then I realized...it was my COVID-19 MASK! I removed the mask and felt fine the rest of the flight. I didn't have a pulse oxymeter handy but I wish I did. I think I was inhaling CO2 instead of oxygen. COVID strikes again!

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Pilot reported feeling sleepy while flying and suspected that it was the covid-19 mask that was causing the problem. The pilot removed the mask and felt fine afterward.