VFR into IMC

Details

By Paul Wiley

 

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Background:

This article addresses the subject of pilots flying inadvertently from VFR conditions into Instrument Meteorological Conditions (IMC). This is commonly referred to as: “VFR into IMC”.  Although VFR into IMC is a rather small percentage of overall accidents, it is the number 1 cause of weather-related fatal accidents.  A stunningly high percentage of VFR into IMC accidents are fatal, nearly 75%!  It is also noteworthy that approximately a third of these accidents involve instrument rated pilots.  Another stunning fact: instrument rated pilots are almost twice as likely as non-instrument rated pilots to be involved in a VFR into IMC accident. 

 

The Importance of Proper Preflight Planning:

Preflight planning skills are just as important (if not more so) than flying skills.  Why?  Because if your preflight planning is inadequate then no matter how good your flying skills are you may not be able to complete the planned flight safely.  One example would be departing into weather conditions where thunderstorms are likely to develop along your route of flight.  It is very important to establish personal minimums and to stick to them.  Depending upon a pilot’s experience, skill and proficiency these personal minimums may be above the FAA regulatory minimums for a VFR or IFR flight.  The objectives of a preflight briefing are 1) to comply with FAR 91.103, and 2) to ensure that you (the pilot) given your experience, pilot certificates, ratings, skill level and proficiency can complete the planned flight safely.  For non-instrument rated pilots the best way to avoid becoming another VFR into IMC accident statistic is to avoid flying VFR into IMC in the first place.  For instrument rated pilots the best defense is to maintain instrument flying proficiency.  AOPA’s Air Safety Institute recommends, in addition to the FAA’s IFR  currency requirements, one hour of actual or simulated instrument flight and one instrument approach in the previous 30 days, plus completing an Instrument Proficiency Check (IPC) within the previous six calendar months. So, it’s all about safety!

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Why VFR into IMC?

Flying into bad weather can sneak up on a pilot, and it is easy to imagine how this could happen.  So, what are some of the reasons these VFR into IMC accidents happen?  A common thread in these VFR into IMC accidents is the pilot’s psychology.  That is the pilot’s mind-set and attitude toward flying into and around marginal VFR conditions or “bad” weather, especially at night.  Most accidents are the result of more than one factor.  Accident investigators refer to the “accident chain”, or the series of events that ends up resulting in an accident.  VFR into IMC accidents are no exception to this rule.  Often one good decision made at the right time can break the chain and prevent an accident. For example: deciding to divert to an alternate airport instead of pressing on into worsening weather conditions whether or not you are an instrument rated and highly experienced pilot. 

Antidotally I can relate one VFR into IMC accident that was told to me by a pilot friend a few years ago.  The pilot involved in this accident was a veteran Air Force pilot who went on to fly for the airlines and was a captain for a major US airline at the time of the accident.  The pilot was returning to Arizona alone from Southern California in a high performance single-engine airplane at night on an IFR flight plan in IMC.  ATC lost radar and radio contact with this flight somewhere over the mountains in Southern California.  Searchers found the wreckage late the following day when the weather had cleared.  I heard from my friend that investigators believe the plane may have “iced up” resulting in a loss of control in flight. My friend was devastated by this accident and the loss of his long-time friend.  He bemoaned the fact that the pilot attempted this flight at night in bad weather.  He said: “why couldn’t he just wait until the following day to fly home”?  Obviously, this highly qualified and experienced pilot thought that he could complete this flight safely.  Tragicly he was dead wrong. 

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Some common causes of VFR into IMC:

  • Plan continuation bias. This is the unconscious cognitive bias to continue with the previous plan in spite of changing conditions.  Sometimes this is referred to as “get-there-itis” where the pilot allows his strong desire to get to his original destination to negatively affect his decision making; and thus his decision-making ability, situational awareness and risk management skills all suffer.  In a National Aeronautics and Space Administration (NASA) review of 37 accidents investigated by the National Transportation Safety Board, it was determined that almost 75% of the tactical decision errors involved in these 37 accidents were related to decisions to continue on the original plan. The study further noted that there were important clues suggesting an alternate course of action was needed, but these clues were ignored by the pilot(s).  This indicates a tactical loss of situational awareness which often leads to an accident.
  • Fear of Failure. Once a pilot has committed to a flight plan, especially when passengers or others are counting on the pilot to complete the planned flight, there is a strong desire not to fail to complete the flight as planned.  It is believed that the accident involving John F. Kennedy Jr. where he continued into weather conditions beyond his ability to manage, was largely due to his desire not to disappoint his wife and her sister.  His continuing into marginal weather conditions eventually resulted in a loss of control and a fatal accident.  This accident could have been prevented by a timely decision to make a 180-degree turn and divert to an airport with better weather conditions. 
  • Previous Experience. When a pilot has completed a flight successfully, especially when he has completed the same flight in similar weather conditions many times, there is a strong bias for the pilot to believe that he can complete the flight safely.  Successful experience can lull a pilot into a false sense that every similar flight will have a (similar) successful outcome.  However, changing conditions, especially unforecastable weather conditions can result in unpredictable (and bad) outcomes. 
  • Attitude. Once a pilot earns his pilot certificate(s) and starts to gain experience they become more likely to be involved in an accident, which may seem counterintuitive.  But student pilots and low time non-instrument rated pilots are more closely supervised and less likely to take chances with weather.  As a pilot gains experience, he is more likely to have the attitude of “I can do this!” for a variety of reasons.  Over-confidence can be very dangerous.  No pilot is immune to being involved in an accident.  Confidence should be based on a pilot’s ability to demonstrate acceptable knowledge, risk management and flying skills. Developing and continually practicing good Aeronautical Decision Making (ADM) skills is fundamental to safety!

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Recommendations

  • With the help of your CFI: Develop a training strategy and a plan that is tailored to your experience level to avoid flying VFR into IMC. Practice the 180-degree turn in simulated instrument conditions with your CFI. Discuss scenarios related to VFR into IMC with your CFI and how to avoid VFR into IMC.
  • Establish personal minimums based on your personal experience level. The Aircraft Owners and Pilots Association’s Air Safety Institute (ASI) has developed a checklist which documents some of these required minimums as well as ASI’s recommendations.  This checklist can be found at: www.airsafetyinstitute.org.  Once established stick to your personal minimums. 
  • Practice Recovery from Unusual Flight Attitudes with your CFI until proficient to ACS standards
  • When planning a flight into marginal VFR conditions, or IMC on an IFR flight plan, self-brief first and then follow up by speaking with an FAA certified weather specialist to obtain a briefing to confirm your analysis of the weather forecast and conditions for your flight. Then make your GO/NO GO decision.
  • Complete the AOPA Air Safety Institute’s VFR into IMC syllabus with your CFI
  • Use the IMSAFE checklist to evaluate your fitness for flight prior to and during each flight.
  • Pilots are encouraged to provide Pilot Reports (PIREPS) to the FAA to help other pilots understand actual weather conditions along the route of flight. See AIM section 7-1-18 through 7-1-29
  • Know your airplane’s systems and especially autopilot (if so equipped) prior to flight. Special attention should be given to instruments, avionics or navigation equipment with which you may not be familiar.  This is especially important for Technically Advanced Aircraft (TAA) which may have sophisticated avionics (think “glass cockpit”) and automated flight control systems.  It often requires a significant amount of time and practice to master this technology and to become proficient in its operation. Sophisticated IFR capable airplanes are involved in more VFR into IMC accidents than simpler “VFR only” airplanes.  This suggests that it is the limitations of the pilot and not the airplane that results in the VFR into IMC accident.  Training to proficiency is the antidote to these accidents.
  • If the weather briefer uses the term: “VFR not recommended” and you are not instrument rated, or if instrument rated and not current and proficient, do not attempt this flight at this time.
  • Take advantage of technology including ADS-B and Flight Information Services (FIS-B) capabilities and other FAA and commercially available Inflight Weather Advisory Broadcast services when possible.  See AIM section 7-1-9.  But understand the limitations of in-flight weather services.  There may be a significant delay (up to 20 minutes) in the time a weather report is generated and when it reaches your airplane. In-flight weather services should be used for strategic planning and not for tactical maneuvering around or through hazardous weather. It is very risky to attempt to maneuver around thunderstorm cells, especially at night, using only in-flight weather services.  Also do not rely on ATC to guide you around hazardous weather, as ATC radar is not optimized to allow the controller to accurately see hazardous weather on his radar scope.  ATC radar cannot detect turbulence.  Some ATC radar systems can determine the intensity of a precipitation area, but the specific character of that area (snow, rain, hail, VIRGA, etc.) cannot be determined.  For this reason ATC refers to all weather areas displayed on ATC radar as “precipitation”.  Avoid any thunderstorm by at least 20 miles. 

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References

  • ·AOPA Air Safety Institute: www.airsafetyinstitute.org Various articles and videos
  • ·AOPA Air Safety Institute VFR into IMC – Safety Syllabus
  • ·Advisory Circular (AC) 90-92 Pilot’s Guide to Preflight Briefing
  • ·Airman Certification Standards Private Pilot Airplane – FAA-S-ACS-6C
  • ·Airman Certification Standards Instrument Rating Pilot Airplane – FAA-S-ACS-8C
  • ·The Richard McSpadden Report
  • ·FAA Safety: www.faasafety.gov
  • ·Federal Aviation Regulations/Aeronautical Information Manual (FAR/AIM) 2026 edition (especially chapter 7 – Safety of Flight)

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