By Paul Wiley


Most pilots are familiar with the process of the pre-flight inspection of the aircraft after their first few flying lessons. These pilots understand the purpose and process for ensuring the aircraft they are preparing to fly is in fact airworthy; and if it is not airworthy, then this is obviously a “No-Go” for the flight. Less obvious, but perhaps more important, is the requirement for the pilot to first determine if he or she is fit to fly. Since “pilot error” is a primary cause in many aircraft accidents, ensuring that the pilot is fit to fly is critical to safety.

pre flighting yourself in flight

To help pilots determine their fitness for flight, the FAA has developed an acronym: IM SAFE. This acronym should be used as a “personal checklist.” It is designed to be a part of good Aeronautical Decision Making to help pilots identify hazards which could negatively impact their ability to fly safety. Please refer to the Aeronautical Information Manual chapter 8 for more details in addition to the other references provided later in this article. This checklist is easily memorized and should be used prior to every flight.

Here is the IM SAFE acronym/checklist briefly explained:

  • pre flighting yourself health screening
  • I = Illness – Any illness can affect a pilot’s ability to safely operate an aircraft. The safest thing to do, if you feel at all ill, is not to fly. Even a minor illness should be a “no-go” item. If there is any doubt, consult an Aviation Medical Examiner (AME).
  • M = Medication – Many medications can degrade performance, especially in more demanding environments such as high altitude, night or instrument conditions. FARs prohibit pilots from performing air crew duties while using any medication that affects their ability to safely operate the aircraft. The safest thing to do is consult an AME to ensure that any medication taken will not decrease pilot performance. Other resources are also available – see references.
  • S = Stress – Stresses resulting from everyday living can seriously impair a pilot’s performance. Problems at work or home can produce enough stress to cause a pilot to be impaired to the point of being distracted and unsafe. Stress can also lead pilots to exercise poor judgement and take unnecessary risks such as flying when they are very tired or flying into poor weather conditions which are beyond the pilot’s or aircraft’s capability.
  • A = Alcohol – The hazards associated with alcohol consumption and flying are well documented. FARs prohibit pilots from performing any crewmember duties within 8 hours of alcohol consumption or while under the influence of alcohol. However, 8 hours may not be enough time under certain circumstances. A better rule is to allow 12 to 24 hours between drinking alcohol and flying, depending upon the amount of alcohol consumed. A good personal rule to follow is 12 hours “bottle to throttle.” Although intoxicated flying constitutes a small percentage of accidents, there is a strong correlation between flying while intoxicated and accidents, which are all too often fatal. 
  • F = Fatigue – Fatigue decreases alertness. It is a hazard which continues to be one of the main causal factors in many aircraft accidents as it decreases alertness. Fatigue can be insidious and thus may not be apparent to the pilot until it is too late and safety has been compromised. Preventing fatigue is best accomplished by adequate rest and sleep, proper nutrition and hydration, and regular exercise.

pre flighting yourself stress

  • Eating/Emotion – Eating: are you adequately nourished? This includes being well hydrated, which can be an issue flying for long periods at high altitude. Emotion: Strong emotions such as anger, anxiety or depression can distract a pilot and dramatically decrease their alertness. Pilots should be aware that certain life events, which can be very traumatic, may have a negative impact on a pilot’s ability to fly safely.  Some examples:  divorce, loss of a job, serious illness or death of a family member, or serious financial difficulty.  Pilots experiencing these types of life events must be aware that their emotional state may compromise their ability to fly safely.  Any pilot who experiences an emotionally upsetting event should not fly until the issue is resolved, or they should fly with a CFI or trusted pilot friend.

In using the IMSAFE checklist, pilots should also be aware that two or more of these hazards may be present at the same time. A few examples are: 1) fatigue and stress, 2) medication and emotion or 3) fatigue and emotion.  Any time a pilot self-evaluates and determines that one (and certainly 2 or more) of these physical/mental factors are present; that pilot should not fly. 

In the AIM, Section 8-1-1 sub-section i, the statement is made: “Personal Checklist.  I’m physically and mentally safe to fly; not being impaired by: Illness, Medication, Stress, Alcohol, Fatigue or Emotion.” This is a very good mantra for every pilot to follow for every flight.

pre flighting yourself cockpit

In summary, I would argue that the need for a pilot to evaluate and confirm their fitness for flying is the first thing the pilot should do prior to (and continuously during) any flight.  To put it simply: the pilot should 1) pre-flight themselves first, 2) check the weather, then 3)  if they are in fact fit to fly and the weather reports and forecasts indicate the flight can reasonably be completed safely, subject to the pilot’s certifications and experience, then and only then should the pilot proceed to the airport to preflight the aircraft.

Additional References:

  • ·Aeronautical Information Manual (AIM) chapter 8-1-1
  • ·Aircraft Owners and Pilots Association (AOPA) web site: Pilot Resources, Training and Safety, and Air Safety Institute. Searches for “IM SAFE” on the AOPA site will provide additional information, including a short video on IM SAFE from Dr. Jonathan Sackier.  Additionally, AOPA members can access the medical resources of AOPA to answer questions related a pilot’s fitness to fly.
  • ·Experimental Aircraft Association (EAA) web site: Similar to the AOPA site, the EAA site has many resources for pilots.

pre flighting yourself landed

  • · web site: This site contains a wealth of relevant safety information regarding all aspects of aviation. It is free and easily searchable; however, be aware that there is a tremendous amount of information on this site, so it can be a bit daunting until you spend some time becoming familiar with the site.
  • The Pilot’s Handbook of Aeronautical Knowledge (FAA-H-8083-25): Chapter 17 Aeromedical Factors contains detailed discussions of a variety of aeromedical factors affecting safety of flight.  There are also tables showing: the impairment scale with alcohol use, adverse effects of various (over the counter and common prescription) drugs including alcohol and nicotine and caffeine.  This handbook is an excellent resource for all pilots.

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