Desser Tire: Americas 1st choice in Aircraft tires
  Databases  airNEWS  Contact

Hangar Talk: Editorial
  Fatigue and Go, No-Go Decisions

Expert Forums
Discussion Boards
Aviation's Directory
Reader Feedback
Your Opinion...

We would like to ask for your feedback to the editorial. What are your thoughts? (use this link -- mention what its about -- inlcude the name of the editorial).


Dr. Stephen W. Roberts, M.D., in addition to being a mult-engine, instrument rated private pilot, is also a Senior Aviation Medical Examiner for the Federal Aviation Administration. Dr. Roberts specializes in Aviation Medicine, and is considered by many to be an expert in his field, with over twelve years experience! He is also a member of the Civil Aviation Medical Association and the AOPA. He is truly an advocate of aviation medicine as well as general aviation. Dr. Roberts has also authored numerous articles in Air Progress magazine, and frequently lectures for the Department of Aviation at Mount San Antonio College.

Related Links

The Author's Expert Forum at

Dr. Roberts web site.

Disclaimer Editorials alert you to issues, link you to resources, uncover research and, provide information.

Opinions and content appearing in the editorial section of do not necessarily reflect those of, its publisher, or any other official. The author is the sole responsible entity.

     Fatigue and
   Go, No-Go Decisions

     By Stephen W. Roberts, MD, AME

... Fatigue, a normal physiological response of the human body to sleep loss and circadian rhythm disruption, is characterized by decreased physical and mental efficiency.

Common signs and symptoms of fatigue include sleeplessness, overall discomfort, irritability, depression, apathy, physical an emotional isolation from others, loss of appetite, slurred speech, visual fixation and impaired visual perception, decreased alertness, difficulty concentrating, slowed reaction time, need for increased sensory stimulation to react, impaired short-term memory, poor judgment, loss of accuracy and control smoothness, unawareness of errors, and responses to become increasingly more dependent on previously acquired habits (good or bad).

In these manifestations can be aggravated by individual exposure to other stressors, including low barometric pressure, noise, vibration, linear and angular acceleration (G forces), high ambient temperature, and low humidity. Furthermore, self-imposed stressors, such as poor physical fitness, inadequate diet or nutrition, inadequate hydration, excessive body weight, drug and alcohol use or abuse, use of medications, excessive caffeine consumption, and tobacco use can predispose you to becoming fatigued..They also can aggravate fatigue.

Sleep is a period of rest for the body and mind, during which bodily functions are partially suspended and consciousness is temporarily interrupted. Sleep is as necessary as food and water for the well-being of an individual. The average healthy adult is accustomed to a single, prolonged sleep of approximate eight hours. During a typical 24-hour day, there are two normal periods of sleepiness: between the hours of 3-5 a.m. and 3-5 p.m. Sleeping less than eight hours per day can result in sleep loss, which can become cumulative.

After sleep loss, the most notable feature of recovery sleep is its increased depth, rather than its duration. This means the following sleep loss, you do not have to sleep the same number of hours that you lost. Sleep loss can be caused by circadian rhythm disruptions, sleep disorders, stress, alcohol and drug use or abuse, excessive caffeine consumption, bad sleep habits, uncomfortable sleeping environments, use of sleeping pills, etc.. In addition, with increased age, sleep becomes less deep and more disrupted, and nocturnal sleep decreases. The main physiological effect of sleep loss is an increase in sleepiness, which causes fatigue.

Circadian rhythm defines a biological cycle of approximately 25 hours that determines the physiological behavior of all body functions. They are influenced by the succession of day and night, changes in ambient illumination, and timing of food consumption, physical activity, and social activities. Circadian rhythms can be affected by a sudden change in individual work-a rest schedules (shift work), sudden relocation to a different time zone, use of medications to sleep and stay awake, alcohol and drug use or abuse, etc.

Various factors affect your ability to adapt to new circadian rhythms:

- Adaption takes longer with increasing age.

-Different body functions adapt at different rates.

-Extroverted people adapt faster than introverts do.

-The greater the time difference between the time of origin and the local time, the longer it takes to adapt.

- Adaption into a backward schedule (longer daytime-west-bound flights) is faster than it compared to a forward schedule (shorter daytime-eastbound flights).

Manifestations of circadian desynchronization,or incomplete adaptation to a new circadian rhythm, include difficulty falling asleep, difficulty remaining asleep, daytime sleepiness, decrease physical and mental performance, gastrointestinal problems, and other signs and symptoms associated with fatigue.

Here's what you can do to prevent fatigue:

- Develop a practice of an appropriate sleep routine that includes at least eight hours of high quality sleep in a quiet, dark environment in a comfortable bed.

- Try to get as much sleep per 24 hours during a trip, as you would at home.

- Use physical or mental relaxation techniques to fall asleep. Sometimes it is as simple as a hot shower or bath before going to bed.

- Do not eat a heavy meal or drink large amounts of liquids before going to bed.

- Eat a balanced diet to prevent in-flight hypoglycemia.

- Do not consume any alcohol or caffeine for at least 3-4 hours before going to bed.

- If you're having difficulty getting to sleep, get up and try activity that helps you fall asleep. For example you could read, listen to soft music, watch a relaxing television program, take a hot bath etc. Counting sheep only works for a few.

- Avoid using sleeping pills to promote sleep and stimulants to promote wakefullness unless they are prescribed by flight surgeon (not likely). The same advice applies to the use of melatonin.

- Take a nap of no longer than 40 minutes immediately before your scheduled flight, if you didn't get enough sleep the night before. A nap can acutely improve alertness because it decreases the length of continuous wake fullness before a flight. Consider it a re-charge of your batteries.

Common misconceptions about fatigue:

- Eight hours of rest are as beneficial as eight hours of sleep.

- I know exactly how tired I am.

- I have lost sleep before, and I did just fine.

- I motivated enough to just push through it.

- I am a highly experienced and capable pilot and can still fly aircraft even if I am tired.

- I don't need more than three or four hours of sleep every night.

- If I'm tired, all that I need is a cup of coffee (or two... or three) to feel better.

- There is a quick and easy fix for fatigue.

- One cure will work for everyone.

Stephen W. Roberts, MD, AME


Ch: Aviation (more->)

Tony Tyler: Aviation industry will handle over 3 billion passengers in ... (NWST)

Heathrow runway delay is hurting aviation industry, warns Iata chief (GUAR)

Raytheon increases pilot situational awareness with Aviation ... (AVIO)

Embraer jets receive Russian certification (JRLA)

Plymouth Airport celebrates its pioneers by naming gates for them (BOST)

Ajit Singh writes to UP CM on land for airport at Allahabad (INDI)

Airline profits pick up in 2012: IATA (TMSE)

Contract with the SAAF terminated Denel (POLI)

Denel aircraft specialists receive retrenchment notices Solidarity (POLI)

GAA signs up for BIAS2014 (BNA_)

Jet Aviation Dubai signs agreement with FEAG (CORP)

Marines hone command capabilities for Afghanistan (DVID)

Analysis: China acquires 90 ILFC stake (JRLA)

Dassault Falcon sells two jets to Wallan (TRAD)

AviancaTaca orders ATR 72 600s (JRLA)

New Issue Milestone Aviation sells 250 mln notes (RTRS)

A Chance for Ugandans to Fly (ALLA)

Col. Michael Musiol takes over 82nd Combat Aviation Brigade (OBRF)

General Aviation Taking off at MacArthur (AVIA)

Lady Antebellum chooses Skynet Aviation (REVI)

Future of GA sparks debate at Wichita event (AOPA)

The many sides of airlines (TTGA)

Ma speaks out on ICAO exclusion (TMST)

MEBA to move to dedicated Dubai world central expo site (ZAWY)

MEBAA Elects Two to Board, Ups Insurance Cover (ONLA)

Roundtable: Aviation 2013 The Latest Legal Features, Research ... (WHOS)

Research Trends and Conclusions: Aviation 2013 (WHOS)

Most Highly Regarded Firms: Aviation 2013 (WHOS)

BAE Systems Wins 400 Million US Navy Aircraft Maintenance ... (AVIA)

Natca: Sequestration Would Cripple ATC, NextGen (ONLA)

Ch: Incidents (more->)

Banner year for safety in global aviation (TN)

2012 named safest year in civil aviation history (_PST)

Neema Swai a Woman Flying Her Dream (ALLA)

Cessna aircraft makes crash landing in Malir Cantt (NWS_)

HAMM member and passenger killed in small plane crash (TYLE)

World War II Fighter Raised From Lake Michigan (CHIC)

WWII era plane recovered from depths of Lake Michigan (WREX)

Pearl Harbor Day event pulls up old fighter plane, and zebra ... (WBEZ)

WWII era plane found at bottom of lake (WZZM)

Strengthen English Skills in China's Aviation Industry (ENGL)

 [Quick NAV | Aviation's Directroy]MAY ALL YOUR LANDINGS BE GOOD ONES!
News/Forums Search/Ref Pilot-Supplies Aircraft/Parts Services Gen.-Aviation Gov./Military
GA-News Search Supplies Manufacturers A/C-Sales Helicopters Government
Forums Databases GPS/Tech. Parts A/C-Values Gyrocopters Research
Hangar-Talk Regulations Simulators Avionics Var-Services Aerobatics Military
Events/Airshows Reports Flight Tools Classifieds Homebuilding General
Offers Alerts Weather Engines Var-Products Ultralights Images
Promotions Publications Planning Mods/Restor. FBOs Soaring Miscellaneous
SITES Museums Clubs AirTransport Travel/Tours Hanggliding GA
Contact/Info History FBOs Airlines Insurance Paragliding Travel/Tours
Add-Link Organizations Flight-Schls Airports Medical Srvcs Parachute Safety
Logbook Companies Training Live-ATC Financing Balloons  
Awards Directory Simulators   Fuel    
Credits   Schools        
Contact   Safety        

   Sponsored links:
     Aircraft For Sale - FREE 90-day photo ads -
     Pilot Jobs - America's Pilot Employment Network - Free Access -
LANDINGS.COM Copyright © 1994-2012
Explicit permission required for any duplication or usage