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By Michael Oxner, September 7, 2003.


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This week's topic:
IFR Flight Part 6a: Flight Planning

Another small step in the series, one that I have received many questions on various aspects of, is Flight Planning. This week, I'll take a brief look at some Canadian regulations regarding flight planning. This is intended to serve IFR flight, not VFR, and this topic will not be all inclusive. There may be holes, but I mean to cover the most important aspects. Let's dig in. The AIP RAC 3.0 is our reference for the following information.

Basics
    Weather Briefing
    NOTAMs
    Weight & Balance
Requirements
    Filing a Flight Plan
    Fuel
    Alternate Aerodrome
        Alternate Weather Minima

Basics

First off, you know where your plane is parked, and you probably know where you want to park it when your flight is done. At least, which airport is probably known. The first step from there is to figure out a few details to fill in the blanks of a flight plan. Every pilot should take a look on the appropriate charts to examine not only the route of flight, but to get a good idea of fixes, NAVAIDs, and restricted areas that are near the intended route of flight. ATC may have to reroute you for traffic, you may request a different route for weather or whatever, so it would be good to know what's around.

Weather Briefing

The next is the weather. You should be fully aware of the weather at your point of departure, the areas along your intended route of flight, and the current and forecast conditions at your destination. This is probably the most important, since it's rough to fly a few hours only to find out that the weather at destination is crappy, and has been since you left. Especially if it's below the minima for you to land. Also, your Alternate Aerodrome's forecast should be checked to ensure if your destination gets closed for weather, and accident, etc, you know you can make it to, and land at, your alternate. More details to follow.

NOTAMs

NOTAMs, or NOtice To AirMen, should also be consulted. This can be a touch confusing. If you've never seen a real NOTAM summary, you should try to find one online sometime. There are three areas for which NOTAMs are published. The first grouping is National, which encompasses anything for all regions across the country. This could include nationwide restrictions on traffic flow (as happened following September 11, 2001), regulatory adjustments that haven't yet been published elsewhere, etc. Secondly, there is a section for each FIR. NOTAMs affecting the region are published here, and they could include a downgrade in services due to equipment outage (like ATC radar which affects more than one airport, for example), large portions of airspace that have been temporarily designated for special use (like restricted areas, already marked on charts or designated explicitly in the NOTAM), etc. Lastly, aerodrome NOTAMs may be published. These often include equipment unserviceabilities at the field, temporary changes to approach minima due to approach equipment or perhaps construction activities, or other such notes.

Weight & Balance

A pilot should always be alert to the loading of the aircraft. Many, many incidents have been attributed to the aircraft being just above safe weights. In fact, mine didn't lead to an incident, but I remember doing the weight and balance after a flight, only to realize I was just 25 lbs under Max Gross Take-Off Weight. I honestly had no idea just how close I was. Before the flight is a much better time to consider such a thing.

Requirements for Filing a Flight Plan

Normally, a flight plan must be filed for any flight. According to CARs, any flight, IFR or VFR, operating cross border to or from another country must have a flight plan on file. Also, to operate IFR, a flight plan or flight itinerary must be filed. If an IFR flight is planned to operate entirely within controlled airspace, a flight plan must be filed instead of an itinerary. I won't go into the difference, since for VatSim, they're always flight plans.

Fuel Requirements

Certain things must be considered for both VFR and IFR flights when it comes to fuel requirements. First off, both have to consider the following and carry sufficient fuel for:
  1. Taxiing and foreseeable delays prior to take-off
  2. Weather conditions
  3. Foreseeable air traffic routings and traffic delays
  4. Landing at a suitable aerodrome after a pressurization failure, or an engine failure (for multi engine, of course) at the most critical point in flight (perhaps over a large body of water, for example)
  5. Any other foreseeable conditions that could cause a delay for a flight.
Now, more specifically for IFR flight, pilots must carry enough fuel for the following:

    1. For a propeller-driven aeroplane:     2. In the case of a turbojet powered aeroplane or helicopter:
Alternate Aerodrome

Now that we've looked at fuel requirements, perhaps we should decide if we need an alternate aerodrome for our flight.

Put simply, if you're IFR, you need an alternate aerodrome. The only way in Canada that you don't require one for IFR flight would be on prior approval from the Minister of Transportation in the way of a special certificate. An alternate aerodrome is one that is suitable for the aircraft (a B747 pilot can't consider a 2,000 foot grass strip as an alternate, for example) where the weather forecast for that aerodrome is expected to meet certain minima for the expected time of arrival.

Alternate Weather Minima

Now we have to see what the forecast must provide for us in order to consider an airport as an alternate. The idea for this minimum weather is to allow for a reasonable chance of completing an approach to landing if the destination airport is not available for weather or other reasons not known prior to departure. The table below gives an idea of what is required for alternate weather minima. HAT is Height Above Threshold, and HAA is Height Above Aerodrome.

ALTERNATE WEATHER MINIMA REQUIREMENTS
FACILITIES AVAILABLE AT SUITABLE ALTERNATE
 WEATHER REQUIREMENTS
TWO OR MORE USEABLE PRECISION APPROACHES each providing straight-in minima to separate suitable runways
 400-1 or 200-1/2 above lowest useable HAT and visibility, whichever is greater
ONE USEABLE PRECISION APPROACH
 600-2* or 300-1 above the lowest useable HAT and visibility, whichever is greater
NON-PRECISION ONLY AVAILABLE
 800-2* or 300-1 above the lowest useable HAT/HAA and visibility, whichever is greater
NO IFR APPROACH AVAILABLE
 Forecast weather must be no lower than 500 feet above a minimum IFR altitude that will permit a VFR approach and landing

Notes:
  1. A "useable precision approach" is one that is serviceable and within the limitations of the aircraft's equipment
  2. The bold faced values with asterisks (*) following them are considered the STANDARD ALTERNATE MINIMA. They are 400 feet above the touchdown area, and 1 SM visibility. Note that if a specific approach has higher than normal minima for the type, you may have to look at the next grouping of minima to see what you really need.
Now we get a little more involved. If the Standard Alternate Minima are applicable (meaning you didn't have to revert to the second values in the above table where 600-2 or 800-2 are useable), you have a little more flexibility. You can trade a 1/2 mile visibility off the minimum required in either case for a ceiling that's 100 feet higher. For example, if 600-2 is the value to use, you can look for weather forecast at the alternate to be 700-1 1/2, or 800-1. So visibility doesn't have to be quite as good if the ceiling will be higher. The same is true for the 800-2 minima, which allows 900-1 1/2 or 1000-1.

Additionally, the following must be met for the use of different minima mentioned in the last paragraph:
  1. The aerodrome must have its own TAF published for the period in use
  2. Ceilings are calculated by reference to the HAA or HAT in the instrument approach procedure available. Since ceilings in METAR and TAF are measured above aerodrome elevation, rather than ASL, we have to make an adjustment. In the regulations, they have allowed for a 20 foot buffer. For example, if the HAT is 415 feet, if falls within the 20 foot buffer for use of 400 feet for a ceiling. If the HAT is 422 feet, it's outside that buffer, so you have to look for a 500 foot ceiling to use that field as an alternate.
Lastly, in determining which HAA or HAT to use, the pilot must consider the following items which may be determining factors in runway usability at the desired alternate:
  1. The serviceability of the approach aid (as determined by reference to aerodrome NOTAMs for the aerodrome in question)
  2. The aircraft's equipment (if the aircraft is not ILS equipped, you can't base your alternate minima on an ILS approach)
  3. Winds at the aerodrome may be forecast at such a direction and speed that would prevent the pilot's use of a specific runway, so the HAT or HAA must be determined from a different approach procedure.
There is much more to this to give pilots flexibility in situations where a TAF is not available, and which may affect minima in the case of a TAF reporting temporary conditions (TEMPO) or changing conditions (BECMG) or possible differences in the forecast (PROB). If you really want this level of detail, you're probably operating in the real world, and the AIP should be consulted for the rest of the details. What I've provided here should be more than sufficient for the VatSimmer.




This first segment in the Flight Planning is meant to give some background. Next week, we'll get to the meat of a flight plan: the details that go in the blanks. If it seems I missed anything important, please let me know. You can e-mail me with any comments at moxner@nbnet.nb.ca. Thanks for reading!