Diversions

Introduction:

  • Diversions are deviations from the original plan which are usually due to fuel, weather, aeromedical or systems
  • While no one plans to divert, the first time the situation dictates a diversion, you should have already planned ahead
  • Practice develops skills necessary for plotting a new course and determining a new ETA while en route
  • Diversions occur due to low fuel, bad weather, fatigue, illness, airplane or system malfunction, and others
  • Although the concept is the same, their procedures can be dramatically different when flying Visual Flight Rules (VFR) or Instrument Flight Rules (IFR)

Selecting an Alternate Destination:

  • An alternate destination must be first and foremost a location that could overcome the challenges expected or likely at your original destination
  • It must be reachable, in that you have the required fuel plus reserves
  • Sometimes a diversion could be required by an external source such as an unexpected airfield closure, making more than one alternate location possible

  • Situations Requiring a Devision:

    • Personal minimums exceeded
    • Aircraft performance limitations exceeded (winds, etc.)
    • Poor weather
    • Airport closure
    • Change in mission

Diversion Planning:

  • Not every airport is a suitable divert
  • When planning, consider a pre-filled out data card which includes:
    • Airport name, including the identifier
    • Airport Diagram
    • Frequencies
    • NAVAIDs
    • Approaches available, if IFR
    • Any unusable runways/approaches you cannot accept
    • Services available (especially if this is a maintenance related divert)
    • General performance expectations based on time/distance from destination
      • Think fuel, time, etc.
      • In the airplane you may be forced to make generalized calculations in the interest of time, but here you can be more accurate
  • Ensure desired services (food, rental car, etc.) are available

Diversion Decision-Making:

  • No one wants to divert, but proper planning provides a suitable option
  • When you set your personal minimums for the day, ensure they incorporate aeronautical decision-making on when to accept a diversion
  • Diversions need not be empirical, that is, they don't need to be quantified by numbers, approach speeds, etc.
    • If uncomfortable with a situation, divert!

VFR Diversion Procedure:

  • Note the time
  • Verify the airplane's present position
  • Determine the location of the new destination
  • Turn in the appropriate direction to an estimated heading, taking into consideration: airspace, obstructions, and/or adverse weather
  • Determine the distance and compass heading to the new destination
    • Distance:
      • Plotter
      • Mileage scale on chart
      • 1 min of latitude = 1 NM
    • Compass Heading
      • Use compass rose on VOR on map
  • Turn to the compass heading
  • Select prominent land marks to aid in flying the new course
  • Compute ETE, ETA, and the fuel required to reach the new destination
  • Contact FSS to amend your flight plan

    • NOTE:
    When diverting to a nearby airport (25 NM or less) and fuel is not critical, make reasonably accurate estimates rather than performing actual computations


IFR Diversion Procedure:

  • Determine new destination
  • Request a clearance
    • This is going to sound identical to picking up an IFR clearance (even though you're already operating on one) in air
  • Execute new clearance

Diversion Common Errors:

  • En-Route Airport Legend
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  • Failure to note the time
  • Unaware of fuel before diversion
  • Improper calculations
  • Forgetting to turn toward estimated heading
  • Getting lost
  • En-Route Airport Legend
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Conclusion:

  • The decision to divert cannot be made too soon
    • Many pilots have put themselves into avoidable situations by pushing a situation that they knew to be bad
  • Consider flying into common divert airports before needed for an emergency or detereorating weather
  • When traveling cross-country, it is recommended to carry extra closes/toiletries (bingo bag) to mitigate comfort-based delays when making diversion decisions
  • When making alterations due to weather, lateral deviations of 10 or 20° of course made early enough can be made to preclude a full re-work of the previously planned flight
  • Don't just select diversion options, ensure you're familiar enough with the field to ensure a smooth transition from the original plan
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