Pilot's Handbook of Aeronautical Knowledge (Federal Aviation Administration)
Page 68
Assembling Necessary Material
The pilot should collect the necessary material well before beginning the flight. An appropriate current sectional chart and charts for areas adjoining the flight route should be among this material if the route of flight is near the border of a chart.
Additional equipment should include a flight computer or electronic calculator, plotter, and any other item appropriate to the particular flight. For example, if a night flight is to be undertaken, carry a flashlight; if a flight is over desert country, carry a supply of water and other necessities.
Weather Check
It is wise to check the weather before continuing with other aspects of flight planning to see, first of all, if the flight is feasible and, if it is, which route is best. Chapter 12, “Aviation Weather Services,” discusses obtaining a weather briefing.
Use of Chart Supplement U.S. (formerly Airport/Facility Directory)
Study available information about each airport at which a landing is intended. This should include a study of the Notices to Airmen (NOTAMs) and the Chart Supplement U.S. (formerly Airport/Facility Directory). [Figure 16-24] This includes location, elevation, runway and lighting facilities, available services, availability of aeronautical advisory station frequency (UNICOM), types of fuel available (use to decide on refueling stops), FSS located on the airport, control tower and ground control frequencies, traffic information, remarks, and other pertinent information. The NOTAMs, issued every 28 days, should be checked for additional information on hazardous conditions or changes that have been made since issuance of the Chart Supplement U.S.
Figure 16-24. Chart Supplement U.S. (formerly Airport/Facility Directory).
The sectional chart bulletin subsection should be checked for major changes that have occurred since the last publication date of each sectional chart being used. Remember, the chart may be up to 6 months old. The effective date of the chart appears at the top of the front of the chart. The Chart Supplement U.S. generally has the latest information pertaining to such matters and should be used in preference to the information on the back of the chart, if there are differences.
Airplane Flight Manual or Pilot’s Operating Handbook (AFM/POH)
The Aircraft Flight Manual or Pilot’s Operating Handbook (AFM/POH) should be checked to determine the proper loading of the aircraft (weight and balance data). The weight of the usable fuel and drainable oil aboard must be known. Also, check the weight of the passengers, the weight of all baggage to be carried, and the empty weight of the aircraft to be sure that the total weight does not exceed the maximum allowable weight. The distribution of the load must be known to tell if the resulting center of gravity (CG) is within limits.
Be sure to use the latest weight and balance information in the FAA-approved AFM or other permanent aircraft records, as appropriate, to obtain empty weight and empty weight CG information.
Determine the takeoff and landing distances from the appropriate charts, based on the calculated load, elevation of the airport, and temperature; then compare these distances with the amount of runway available. Remember, the heavier the load and the higher the elevation, temperature, or humidity, the longer the takeoff roll and landing roll and the lower the rate of climb.
Check the fuel consumption charts to determine the rate of fuel consumption at the estimated flight altitude and power settings. Calculate the rate of fuel consumption, and compare it with the estimated time for the flight so that refueling points along the route can be included in the plan.
Charting the Course
Once the weather has been checked and some preliminary planning completed, it is time to chart the course and determine the data needed to accomplish the flight. The following sections provide a logical sequence to follow in charting the course, complete a flight log, and filing a flight plan. In the following example, a trip is planned based on the following data and the sectional chart excerpt in Figure 16-25.
Route of flight: Chickasha Airport direct to Guthrie Airport
True airspeed (TAS)
115 knots
Winds aloft
360° at 10 knots
Usable fuel
38 gallons
Fuel rate
8 GPH
Deviation
+2°
Steps in Charting the Course
The following is a suggested sequence for arriving at the pertinent information for the trip. As information is determined, it may be noted as illustrated in the example of a flight log in Figure 16-26. Where calculations are required, the pilot may use a mathematical formula or a manual or electronic flight computer. If unfamiliar with the use of a manual or electronic computer, it would be advantageous to read the operation manual and work several practice problems at this point.
First, draw a line from Chickasha Airport (point A) directly to Guthrie Airport (point F). The course line should begin at the center of the airport of departure and end at the center of the destination airport. If the route is direct, the course line consists of a single straight line. If the route is not direct, it consists of two or more straight line segments. For example, a VOR station that is off the direct route, but makes navigating easier, may be chosen (radio navigation is discussed later in this chapter).
Appropriate checkpoints should be selected along the route and noted in some way. These should be easy-to-locate points, such as large towns, large lakes and rivers, or combinations of recognizable points, such as towns with an airport, towns with a network of highways, and railroads entering and departing.
Normally, choose only towns indicated by splashes of yellow on the chart. Do not choose towns represented by a small circle—these may turn out to be only a half-dozen houses. (In isolated areas, however, towns represented by a small circle can be prominent checkpoints.) For this trip, four checkpoints have been selected. Checkpoint 1 consists of a tower located east of the course and can be further identified by the highway and railroad track, which almost parallels the course at this point. Checkpoint 2 is the obstruction just to the west of the course and can be further identified by Will Rogers World Airport, which is directly to the east. Checkpoint 3 is Wiley Post Airport, which the aircraft should fly directly over. Checkpoint 4 is a private, non-surfaced airport to the west of the course and can be further identified by the railroad track and highway to the east of the course.
The course and areas on either side of the planned route should be checked to determine if there is any type of airspace with which the pilot should be concerned or which has special operational requirements. For this trip, it should be noted that the course passes through a segment of the Class C airspace surrounding Will Rogers World Airport where the floor of the airspace is 2,500 feet mean sea level (MSL) and the ceiling is 5,300 feet MSL (point B). Also, there is Class D airspace from the surface to 3,800 feet MSL surrounding Wiley Post Airport (point C) during the time the control tower is in operation.
Study the terrain and obstructions along the route. This is necessary to determine the highest and lowest elevations, as well as the highest obstruction to be encountered so an appropriate altitude that conforms to 14 CFR part 91 regulations can be selected. If the flight is to be flown at an altitude of more than 3,000 feet above the terrain, conformance to the cruising altitude appropriate to the direction of flight is required. Check the route for particularly rugged terrain so it can be avoided. Areas where a takeoff or landing is made should be carefully checked for tall obstructions. Television transmitting towers may extend to altitudes over 1,500 feet above the surrounding terrain. It is essential that pilots be aware of their presence and location. For this trip, it should be noted that the tallest obstruction is part of a series of antennas with a height of 2,749 feet MSL (point D). The highest elevation should be located in the northeast quadrant and is 2,900 feet MSL (point E).
Figure 16-25. Sectional chart excerpt.
Figure 16-26. Pilot’s planning sheet and visual flight log.
Since the wind is n
o factor and it is desirable and within the aircraft’s capability to fly above the Class C and D airspace to be encountered, an altitude of 5,500 feet MSL is chosen. This altitude also gives adequate clearance of all obstructions, as well as conforms to the 14 CFR part 91 requirement to fly at an altitude of odd thousand plus 500 feet when on a magnetic course between 0 and 179°.
Next, the pilot should measure the total distance of the course, as well as the distance between checkpoints. The total distance is 53 NM, and the distance between checkpoints is as noted on the flight log in Figure 16-26.
After determining the distance, the TC should be measured. If using a plotter, follow the directions on the plotter. The TC is 031°. Once the TH is established, the pilot can determine the compass heading. This is done by following the formula given earlier in this chapter.
The formula is:
TC ± WCA = TH ± V = MH ± D = CH
The WCA can be determined by using a manual or electronic flight computer. Using a wind of 360° at 10 knots, it is determined the WCA is 3° left. This is subtracted from the TC making the TH 28°. Next, the pilot should locate the isogonic line closest to the route of the flight to determine variation. Figure 16-25 shows the variation to be 6.30° E (rounded to 7° E), which means it should be subtracted from the TH, giving an MH of 21°. Next, add 2° to the MH for the deviation correction. This gives the pilot the compass heading of 23°.
Now, the GS can be determined. This is done using a manual or electronic calculator. The GS is determined to be 106 knots. Based on this information, the total trip time, as well as time between checkpoints, and the fuel burned can be determined. These numbers can be calculated by using a manual or electronic calculator.
For this trip, the GS is 106 knots and the total time is 35 minutes (30 minutes plus 5 minutes for climb) with a fuel burn of 4.7 gallons. Refer to the flight log in Figure 16-26 for the time between checkpoints.
As the trip progresses, the pilot can note headings and time and make adjustments in heading, GS, and time.
Filing a VFR Flight Plan
Filing a flight plan is not required by regulations; however, it is a good operating practice since the information contained in the flight plan can be used in search and rescue in the event of an emergency.
Flight plans can be filed in the air by radio, but it is best to file a flight plan by phone just before departing. After takeoff, contact the FSS by radio and give them the takeoff time so the flight plan can be activated.
When a VFR flight plan is filed, it is held by the FSS until 1 hour after the proposed departure time and then canceled unless: the actual departure time is received; a revised proposed departure time is received; or at the time of filing, the FSS is informed that the proposed departure time is met, but actual time cannot be given because of inadequate communication. The FSS specialist who accepts the flight plan does not inform the pilot of this procedure, however.
Figure 16-27 shows the flight plan form a pilot files with the FSS. When filing a flight plan by telephone or radio, give the information in the order of the numbered spaces. This enables the FSS specialist to copy the information more efficiently. Most of the fields are either self-explanatory or non-applicable to the VFR flight plan (such as item 13). However, some fields may need explanation.
• Item 3 is the aircraft type and special equipment. An example would be C-150/X, which means the aircraft has no transponder. A listing of special equipment codes is found in the Aeronautical Information Manual (AIM).
• Item 6 is the proposed departure time in UTC (indicated by the “Z”).
• Item 7 is the cruising altitude. Normally, “VFR” can be entered in this block since the pilot chooses a cruising altitude to conform to FAA regulations.
Figure 16-27. Domestic flight plan form.
• Item 8 is the route of flight. If the flight is to be direct, enter the word “direct;” if not, enter the actual route to be followed, such as via certain towns or navigation aids.
• Item 10 is the estimated time en route. In the sample flight plan, 5 minutes was added to the total time to allow for the climb.
• Item 12 is the fuel on board in hours and minutes. This is determined by dividing the total usable fuel aboard in gallons by the estimated rate of fuel consumption in gallons.
Remember, there is every advantage in filing a flight plan; but do not forget to close the flight plan upon arrival. This should be done via telephone to avoid radio congestion.
Ground-Based Navigation
Advances in navigational radio receivers installed in aircraft, the development of aeronautical charts that show the exact location of ground transmitting stations and their frequencies, along with refined flight deck instrumentation make it possible for pilots to navigate with precision to almost any point desired. Although precision in navigation is obtainable through the proper use of this equipment, beginning pilots should use this equipment to supplement navigation by visual reference to the ground (pilotage). This method provides the pilot with an effective safeguard against disorientation in the event of radio malfunction.
There are three radio navigation systems available for use for VFR navigation. These are:
• VHF Omnidirectional Range (VOR)
• Nondirectional Radio Beacon (NDB)
• Global Positioning System (GPS)
Very High Frequency (VHF) Omnidirectional Range (VOR)
The VOR system is present in three slightly different navigation aids (NAVAIDs): VOR, VOR/distance measuring equipment (DME)(discussed in a later section), and VORTAC. By itself it is known as a VOR, and it provides magnetic bearing information to and from the station. When DME is also installed with a VOR, the NAVAID is referred to as a VOR/DME. When military tactical air navigation (TACAN) equipment is installed with a VOR, the NAVAID is known as a VORTAC. DME is always an integral part of a VORTAC. Regardless of the type of NAVAID utilized (VOR, VOR/DME, or VORTAC), the VOR indicator behaves the same. Unless otherwise noted in this section, VOR, VOR/DME, and VORTAC NAVAIDs are all referred to hereafter as VORs.
The prefix “omni-” means all, and an omnidirectional range is a VHF radio transmitting ground station that projects straight line courses (radials) from the station in all directions. From a top view, it can be visualized as being similar to the spokes from the hub of a wheel. The distance VOR radials are projected depends upon the power output of the transmitter.
The course or radials projected from the station are referenced to MN. Therefore, a radial is defined as a line of magnetic bearing extending outward from the VOR station. Radials are identified by numbers beginning with 001, which is 1° east of MN and progress in sequence through all the degrees of a circle until reaching 360. To aid in orientation, a compass rose reference to magnetic north is superimposed on aeronautical charts at the station location.
VOR ground stations transmit within a VHF frequency band of 108.0–117.95 MHz. Because the equipment is VHF, the signals transmitted are subject to line-of-sight restrictions. Therefore, its range varies in direct proportion to the altitude of receiving equipment. Generally, the reception range of the signals at an altitude of 1,000 feet above ground level (AGL) is about 40 to 45 miles. This distance increases with altitude. [Figure 16-28]
Figure 16-28. VHF transmissions follow a line-of-sight course.
VORs and VORTACs are classed according to operational use. There are three classes:
• T (Terminal)
• L (Low altitude)
• H (High altitude)
The normal useful range for the various classes is shown in the following table:
VOR/VORTAC NAVAIDS
Normal Usable Altitudes and Radius Distances
Class
Altitudes
Distance (Miles)
T
12,000’ and below
25
L
Below 18,000’
40
H
Below 14,500’
40
Within the conterminous 48 states only, between 14,500 and 17,999’
100
H
18,000’—FL 450
130
H
FL 450—60,000’
100
The useful range of certain facilities may be less than 50 miles. For further information concerning these restrictions, refer to the Communication/NAVAID Remarks in the Chart Supplement U.S.
The accuracy of course alignment of VOR radials is considered to be excellent. It is generally within plus or minus 1°. However, certain parts of the VOR receiver equipment deteriorate, affecting its accuracy. This is particularly true at great distances from the VOR station. The best assurance of maintaining an accurate VOR receiver is periodic checks and calibrations. VOR accuracy checks are not a regulatory requirement for VFR flight. However, to assure accuracy of the equipment, these checks should be accomplished quite frequently and a complete calibration should be performed each year. The following means are provided for pilots to check VOR accuracy:
• FAA VOR test facility (VOT)
• Certified airborne checkpoints
• Certified ground checkpoints located on airport surfaces