instrument ground training module 3

Instrument Ground Training Module 3

Randy Schoephoersterwww.airtreknorth.com

Agenda

• ADF (Today)• VOR (Today and Wednesday)• RMI (Wednesday)• HIS (Wednesday)• DME (Wednesday)

CAUTION…………………..

• The sole purpose of this class is to expedite your passing the FAA

knowledge test. With that said, all extra material not directly tested

on the FAA knowledge test is omitted, even though much more

information and knowledge is necessary to fly safely. Consult the

FAR/AIM (CFR) and other FAA Handbooks for further information along

with a Flight Instruction course.

• Instrument Knowledge Test is good for 24 calendar months.

FAA-G-8082-13d

CFR 61.65 (d) Instrument Practical Test Requirements

• (d) Aeronautical experience for the instrument-airplane rating. A person who applies for an instrument-airplane rating must have logged:– (1) Fifty hours of cross country flight time as pilot in command, of which 10

hours must have been in an airplane; and– (2) Forty hours of actual or simulated instrument time in the areas of operation

listed in paragraph (c) of this section, of which 15 hours must have been received from an authorized instructor who holds an instrument-airplane rating, and the instrument time includes:

• (i) Three hours of instrument flight training from an authorized instructor in an airplane that is appropriate to the instrument-airplane rating within 2 calendar months before the date of the practical test; and

• (ii) Instrument flight training on cross country flight procedures, including one cross country flight in an airplane with an authorized instructor, that is performed under instrument flight rules, when a flight plan has been filed with an air traffic control facility, and that involves—

– (A) A flight of 250 nautical miles along airways or by directed routing from an air traffic control facility;

– (B) An instrument approach at each airport; and

– (C) Three different kinds of approaches with the use of navigation systems.

ADF: Automatic Direction FinderNDB: Non-Directional Beacon

3.2 AUTOMATIC DIRECTION FINDER (ADF)

1. The ADF indicator always has its needle pointing toward the NDB station (nondirectional beacon, also known as a radio beacon).

a. If the NDB is directly in front of the airplane, the needle will point straight up.

b. If the NDB is directly off the right wing, i.e., 3 o'clock, the needle will point directly to the right.

c. If the NDB is directly behind the aircraft, the needle will point straight down, etc.

2. Relative bearing (RB) to the station is the number of degrees you would have to turn to the right to fly directly to the NDB.

a. Relative bearing TO the station is shown by the head of the needle.1) In the figure below, the RB to the station is 220° (Heading of airplane is 50deg, needle

pointing at 270deg).b. Relative bearing FROM the station is given by the tail of the needle.

1) In the figure below, the RB from the station is 40° (220 - 180) or (90-50).

3. Magnetic bearing (MB) to the station is the actual heading you would have to fly to the station.

a. If you turn right from your present heading to fly to the station, you are adding the number of degrees of turn to your heading.

b. Thus, magnetic heading + relative bearing = magnetic bearing to the station, or MH + RB = MB (TO).

1) For MB (FROM), subtract or add 180°.

2) EXAMPLE: If the airplane shown above has an MH of 40° and an RB of 220°, the MB (TO) is 260° (40 + 220). The MB (FROM) is 80° (260 - 180).

c. If MH and MB (TO) are known, use the formula: RB = MB (TO) - MH.

1) Add or subtract 360° to obtain a figure between 0° and 360°, if needed.

MyHouse + youRBeer = MyBeer

MH + RB = MB

4. A fixed card ADF always shows 0° at the top.a. Thus, RB may be read directly from the card, and MB must be calculated using

the formula above.b. If the MB is given, the MH may be calculated as follows: MB - RB = MH.

5. A movable card ADF always shows magnetic heading (MH) at the top.a. Thus, MB (TO) may be read directly from the card under the head of the needle.b. MB (FROM) is indicated by the tail of the needle.c. RB may be calculated as follows: MB - MH = RB.

6. When working ADF problems, it is often helpful to draw the information given (as on previous slide) to provide a picture of the airplane's position relative to the NDB station.

• MyHouse + youRBeer = MyBeer• Magnetic Heading + Relative Bearing = Magnetic Bearing TO


MH = 215

RBto = 140 215 + 140 = ?


MH = 215

RBto = 140 215 + 140 = Magetic Bearing TO

355 – 180 = MB FROM


MH = 330

RBto = 270 330 + 270 = 600 so we need a number between 0 and 360. Subtract 600 – 360 = 240


MH = 330

RBto = 270 We found Magnetic Bearing TO was 240 so we just need to subtract 180 so… 240 – 180 = 60


MH = 350

RBto = 270

350 + 270 = 620 so we need a number between 0 and 360. Subtract 620 – 360 = 260

3.4 VOR RECEIVER CHECK. (Required every 30 days for Part 91)

1. The Airport/Facility Directory provides a listing of available VOR receiver ground checkpoints and VOTs (VOR receiver test facilities).a. Maximum error for Ground Checks is 4° of the designated radial.

2. Over airborne checkpoints designated by the FAA, the maximum permissible bearing error for the VOR receiver is plus or minus 6° of the designated radial.a. An alternative to a certified airborne checkpoint is a prominent ground reference

point that is more than 20 NM from a VOR station that is along an established VOR airway.

1) Once over this point with the CDI needle centered, the OBS should indicate plus or minus 6° of the published radial.

3. The maximum difference between two indicators of a dual VOR system is 4° between the two indicated bearings to the VOR.a. The CDI needles should be centered and the indicated bearings checked rather than

setting to identical radials and looking at the CDI needles.

4. VOTs are available at a specified frequency at certain airports. The facility permits you to check the accuracy of your VOR receiver while you are on the ground.

a. The VOT transmits only the 360° radial in all directions.b. Tune the VOR receiver to the specified frequency, and turn the OBS (omnibearingselector) to select an omnibearing course of either 0° or 180°.

1) The CDI needle should be centered; if not, then center the needle.2) If 0°, the TO/FROM indicator should indicate FROM.3) If 180°, the TO/FROM indicator should indicate TO.4) The maximum error is plus or minus 4°.

c. When using an RMI, the head of the needle will indicate 180°.

5. When making a VOR receiver check with your airplane located on the designated groundcheckpoint, the designated radial should be set on the OBS.

a. The CDI must center within plus or minus 4° of that radial with a FROM indication.

Cessna 182

180 degs TO

VOR Accuracy ChecksEvery 90 days

Check Error Allowed Notes

Dual VOR +/-4deg

Single VOR in the Air +/-6deg

VOR Ground Check +/-4deg Set the radial as indicated

VOT Ground Check +/-4deg Rem 182180degs TO

3.5 VERY HIGH FREQUENCY OMNIDIRECTIONAL RANGE (VOR) STATION

1. When VORs are undergoing maintenance, the coded and/or voice identification is notbroadcast from the VOR.

2. DME/TACAN coded identification is transmitted one time for each three or four times the VOR identification is transmitted.

a. If the VOR is out of service, the DME identification will be transmitted about once every 30 seconds at 1350 Hz.

3. A full-scale (from the center position to either side of the dial) deflection of a VOR CDIindicates a 10° deviation from the course centerline.

a. About 10° to 12° of change of the OBS setting should deflect the CDI from the center to the last dot.

CDI: Course Deviation Indicator

OBS: Omni Bearing Selector

4. An (H) Class VORTAC facility has a range of 40 NM from 1,000 ft. AGL to 14,500 ft. AGL,and a range of 100 NM from 14,500 ft. AGL to 18,000 ft.a. To use (H) Class VORTAC facilities to define a direct route of flight at 17,000 ft. MSL,

the facilities should be no farther apart than 200 NM.b. Generally, for IFR operation off of established airways below 18,000 ft., VOR

navigational aids should be no more than 80 NM apart.

5. VOR station passage is indicated by a complete reversal of the TO/FROM indicator.c. If after station passage the CDI shows a 1/2-scale deflection and remains constant

for a period of time, you are flying away from the selected radial.

6. Airplane displacement from a course is approximately 200 ft. per dot per NM on VORs.a. At 30 NM out, one dot is 1 NM displacement; two dots, 2 NM.b. At 60 NM out, one dot is 2 NM displacement; two dots, 4 NM.

What is a radial?

RMI QuestionsRadio Magnetic Indicator

The Needle Points TO the StationThe Tail of the Needle Indicates the Bearing FROM the Station

Agenda

• ADF (Today)• VOR (Today and Wednesday)• RMI (Wednesday)• HIS (Wednesday)• DME (Wednesday)

Instrument Ground Training Module 3

Randy Schoephoersterwww.airtreknorth.com

instrument ground training module 3

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