UIMC - After Take Off

Michel MASSON • 5 October 2023
in community Rotorcraft

EASA and ESPN-R present a series of 4 new videos with Mona Seeberger on UIMC (Unintended entry into Instruments Meteorological Conditions), also called IIMC (Inadvertent entry into Instruments Meteorological Conditions) or inadvertent VFR into IMC (Visual Flight Rules flight into Instrument Meteorological Conditions).

Despite UIMC being a well-known severe risk, fatal accidents continue to occur, calling for sustaining the efforts and promotion. These new videos remind some basic principles and actions to avoid UIMC and prevent related accidents. This second video focuses on UIMC avoidance after take-off.

UIMC: A key risk for Rotorcraft operations!

UIMC is a well-known severe risk that can result in various accident types, notably Loss of Control In-flight (LOC-I), Control Flight into Terrain CFIT, Collisions with obstacles or cables especially in Low Altitude Operations (LALT), and Mid-Air Collision (MAC).

UIMC is addressed by a variety of actors, including EASA, FAA and other National Aviation Authorities in Europe and worldwide, Accident Investigation Boards, EHEST and ESPN-R, USHST, IHST and VAST, HAI, EHA and national associations, manufacturers, operators, training schools, research organisations and academia, and pilot and operator associations. UIMC is also addressed on social media.

The risk and solutions are known but accidents continue to happen. This means it’s important to continually remind ourselves of the key messages and promote the topic of widely as possible in the Rotorcraft and VTOL Community.

This series of 4 new videos reminds some basic principles and actions to take to avoid UIMC and prevent accidents. Share the videos, the articles and other resources in your organisations and with your colleagues and friends in the industry.

Actions to take after take-off 

This second video focuses on actions to take after take-off.

Hopefully you will have already planned your flight carefully and considered what risks you might face. And if you are IFR qualified and proficient, you have picked an IFR clearance if possible.  While flying, be alert for changing conditions, follow your Enroute Decision Points and don't go below your personal minimums. Resist the pressure to overcome personal minimums because you think you can do it or because you did it before and nothing happened. Things can be different this time. Don’t take chances!

Bad weather and additional factors 

Don’t fly into bad weather. Even birds don’t.

The risk of accident substantially increases when combining bad weather with terrain and obstacles. For instance when flying in a cloudy or foggy V-shaped valley in the mountains (see the story illustrated in Sunny Swift: Exchange of experiences - Issue 10 | EASA (europa.eu)), with powerlines, cables, antennas or other hard-to-detect obstacles.

More on cable collision risks in Cable Collisions | EASA Community (europa.eu). The risk also substantially increases when flying at night in poor, or even marginal weather. Refer to Robinson Helicopter Safety Notice 26: Night Flight - USHST Tim Tucker and Night Pre-Flight | EASA Community (europa.eu). And it increases even more in poor or lack of lightening, for instance when the ground lighting network suffers an electrical blackout.

The risk also increases in heavy rain or snow because of deteriorated visibility, reflection of the helicopter light beams, and the tiring perceptual illusion that rain and snow are moving towards you.

Continue flying to destination?

Assess how the situation evolve in flight and be ready to adapt or change your plan as required.

Don’t let self-induced pressure drive your decisions. Get-there-it is (the desire to try and reach your destination no matter what the circumstances and the resistance to adapt plan when the conditions would require so) is a powerful bias that can, and did, lead to an accident. Resist the pressure to continue flying to destination when risk is unacceptable!

If the conditions deteriorate or if in doubt, your 3 options are:

  • Divert
  • Return to base, or
  • Land and LIVE: find a suitable landing site rather than pushing into bad weather where a crash could occur.

Flight planning and navigation software providing real-time weather information and maps can assist you changing your plan and select an option.

Commercial and mission pressure 

Commercial and mission pressure, including from passengers, is one of the biggest killers in aviation! Learn to recognise and resist that pressure.

Managers should backup their pilots’ decisions to redirect the flight or land when the situation requires, and risk is too high to safely reach destination and complete the mission.

Helicopter Airmanship | EASA Community (europa.eu) and From Take-Off to Landing | EASA Community (europa.eu) provide additional tips on weather and VFR navigation.

Obtaining an Instrument Rating will give you more options. 

Key points from this video

  • Resist mission pressure and stick to your personal minima.
  • Be continually alert to changing conditions. When the situation deteriorates, make a conservative decision before you get into UIMC. 
  • If in doubt, your 3 options are: divert, return to base or Land and LIVE. 

References HAI Land & LIVE Program - Helicopter Association International (rotor.org)

Helicopter Airmanship | EASA Community (europa.eu)

From Take-Off to Landing | EASA Community (europa.eu)

Cable Collisions | EASA Community (europa.eu)

Robinson Helicopter Safety Notice 26: Night Flight - USHST Tim Tucker

Night Pre-Flight | EASA Community (europa.eu).

EHEST Leaflet HE 13 Weather Threat for VMC Flights | EASA (europa.eu) EGAST Leaflet GA 3 Weather Anticipation | EASA (europa.eu)

EHEST Video Degraded Visual Environment and Loss of Control | EASA (europa.eu)

EHEST Video Decision Making | EASA (europa.eu)

Weather Threats for VMC Flights | EASA Community (europa.eu)

Weather Threats for VMC Flights - Flying Under IFR | EASA Community (europa.eu)

Unintended IMC - An Evening with Claude Vuichard | EASA Community (europa.eu)

Preventing and Recovering from Unintended IMC | EASA Community (europa.eu)

Weather in Europe can be challenging | EASA Community (europa.eu)

Rotorcraft Safety Technologies: The VAST Report | EASA Community (europa.eu)

Technologies with Safety Benefits | EASA Community (europa.eu)

Visit 56 Seconds to Live – USHST. EASA Sunny Swift issues

Intended for fixed-wing General Aviation pilots and instructors, the safety messages passed in these Sunny Swift issues well transfer to helicopter operations:

Sunny Swift: Easier and safer flying in IFR - Issue 11 | EASA (europa.eu)

Sunny Swift: Exchange of experiences - Issue 10 | EASA (europa.eu)

Sunny Swift: Horizon visibility in Night VFR - Issue 33 | EASA (europa.eu)

Sunny Swift: New Technologies - Issue 18 | EASA (europa.eu)

Visit Sunny Swift – Flight Instructor | EASA (europa.eu).


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