1. ADF & NDB's Flashcards
What is the ADF Formula?
H +- A = T (The HAT Trick)
What frequency range does the NDB operate in?
200-400 kHz
Is the range of an NDB better or worse over water?
Better
Is the range of an NDB better or worse over mountain terrain or dry sandy country?
Dry sandy Country is better
Where can you find the range of NDBs?
ERSA
What is the range of the NDB below?
What is different about this NDB?
- The range varries dependant on the direction you are approaching from
- 30nm but reduced to 15 nm in sections
The range of the NDB is consistent over water or over terrain?
Over water
The range of the NDB relative to aircraft height is highly variable over water or over terrain?
Over Terrain
Which NDB are you as a pilot expected to use?
The closest NDB in range
Do NDBs have increased or reduced range at night?
Reduced range at night
What is the “Thunderstorm Effect”
- Radio signals generated by thunderstorms affecting the net signal received by the ADF receiver.
- This causes major interference with NDB signals
When does mountain effect on NDB decrease?
This effect decreases with increased height
What is coastal refraction in relation to the NDB?
When there is an abrupt change in the medium i.e ocean to ground the radio wave can bend
Using the HAT trick:
HDG:220°
ADF:010°
What is the TMG?
230°
FPT = 090°
HDG=085°
ADF=176°
Find
TMG
TE
Drift
TMG=081°
TE=9°
Drift=4°L
Present HDG = 110°
ADF Indictaion= 350°
FPT = 115°
Intercept Angle = 60°
FIND
HDG Required to intercept =
ADF indication once intercepted =
HDG Required to intercept = 055°
ADF at intercept = 060°
Present HDG = 300°
ADF Indictaion= 195°
FPT = 330°
Intercept Angle = 60°
FIND
HDG Required to intercept =
ADF indication once intercepted =
HDG Required to intercept = 030°
ADF at intercept = 120°
Present HDG = 175°
ADF Indictaion= 190°
FPT = 200°
Intercept Angle = 30°
FIND
HDG Required to intercept =
ADF indication once intercepted =
HDG Required to intercept = 230°
ADF at intercept =135°
What is the formula for 1-in-60 Radio Nav
a=60d/D
What is the formula to calculate nm for a NULL procedure?
mins flown x GS / Degrees of change
What is the formula to calculate mins to intercept NDB for a NULL procedure?
mins flown x GS / Degrees of change = Miles to NDB
THEN
Take adjust NM to GS to get mins
TRUE/FALSE: The NDB is a signal that is transmitted in equal strengths in all directions?
TRUE
What is the formula for a wave?
A VHF frequency of 124MHz has a wavelength of what?
2.42m
You Are flying from Hamilton Island to Cairns. What is the rated coverage for Townsville
170nm ( you are obviously flying over water from Hamilton island)
If a right crosswind is present and a pilot maintains 000° on the ADF towards the NDB: what will occur to the aircraft in regards to flight path?
The aircraft will take longer as it will now fly a curved path to the NDB and arrive into the wind.
Why do some NDBs have reduced coverage at night?
The radio waves are reflected by the ionosphere at night
What is a positive fix defined as?
(hint AIP ENR 1.1)
- Passage over RADIO Nav
- The intersection of 2 or more not less than 45°
- If using 2 NDBs must be within 30nm
If using 2 NDBs to gain a positive fix what range must they both be in?
30nm
When using Radio Nav equipment you must make an allowance of tracking errors of how many degrees?
(AIP ENR 1.1)
9°
Which is faster?
Ground waves
Sky Waves
Ground waves
(sky waves bounce off the atmosphere and then must travel further at the same speed.
