Technical Interview 6 Flashcards
What does the abbreviation PAPI mean?
Precision Approach Path Indicator
Four lights in a single row
An aircraft is on the appropriate glide path when two of the lights are red and two are white. Three red lights indicate that the aircraft is below and four red lights indicate that the aircraft is well below the nominal flight path. Conversely, three white lights indicate that the aircraft is above and four white lights indicate that the aircraft is well above the flight path.
What frequency range and band is an NDB in?
The allocated frequencies for NDBs are 190 - 1,750 kHz
It transmits in the Low Frequency (LF) and Medium Frequency (MF) bands.
What can you tell about adiabatic lapse rates?
The rate at which the temperature of a parcel of air rises or falls with height is known as the “adiabatic lapse rate”. The value of the adiabatic lapse rate is dependent on the moisture content of the air.
The Environmental Lapse Rate (ELR) is according to ISA 2°C per 1000 feet increasing altitude.
If unsaturated air (that is, air at less than 100% humidity) is forced to rise or descend within the atmosphere, the temperature of the air parcel changes at a rate of 3°C per 1 000 feet. This is known as the “Dry Adiabatic Lapse Rate”.
If the air is saturated (that is, if the relative humidity of the air is 100%), the rate of change of temperature with height is lower than when the air is unsaturated. The “Saturated Adiabatic Lapse Rate” is 1.5°C per 1000 feet. However, the Saturated Adiabatic Lapse Rate (SALR) is not actually constant, but it varies from 1.2°C per 1 000 feet, close to the Earth’s surface, to 2.8°C per 1 000 feet in the upper atmosphere.
If you only have a compass, which is easier to navigate along: a line of longitude or a line of latitude?
A line of latitude.
Why would someone fly a Rhumb Line track?
A rhumb line is a line on the surface of the Earth which cuts all the meridians at thesameangle, that means that track is constant, which is easier to navigate. The disadvantage however it that is not normally the shortest distance between two points, except in The Equator, which is both a great circle and a rhumb line.
What is DA?
The altitude or height in the Precision Approach or approach with vertical guidance at which a Missed Approach must be initiated if the required visual reference to continue the approach has not been established.
What is a Great Circle?
A line of shortest distance between two points on a sphere.
Can you go through DA or MDA?
The altitude or height in the Precision Approach or approach with vertical guidance at which a Missed Approach must be initiated if the required visual reference to continue the approach has not been established.
The MDA/H is a specific altitude/height below which descent must not be made without the required visual references.
What is an NDB?
The Non Directional Beacon (NDB) is a ground based transmitter which transmits vertically polarised radio signals, in all directions, in the Low Frequency (LF) and Medium Frequency (MF) bands.
When an aircraft’s Automatic Direction Finding (ADF) is tuned to an NDB’s frequency, the direction of the NDB will be indicated.
When a radio beacon is used in conjunction with the Instrument Landing System markers, it is called a Compass Locator. Locators are low powered NDBs often installed on an ILS approach. They are co-located with Outer and Middle Marker.
How accurate are NDB’s?
NDB’s have to be within +/- 5 degrees.
What is an isobar?
A line on a meteorologic chart that joins places of equal sea level pressure.
Why is an NDB powered so that it only has a range between 15-25 miles?
These are low powered NDBs (locators), often installed on an ILS approach, co-located with Outer and Middle Marker and used as an aid for approach procedures.
En route NDBs. These have a range of 50nm or more, and where serving oceanic areas may have ranges of several hundred miles. They are used for homing, holding, en route and airways navigation.
NDB’s can suffer from a lot of errors.
What is the typical range of an NDB?
Low powered NDBs (locators) used for airfield or runway approach procedures normally have ranges of 10 to 25nm
En route NDBs can have a range of 50nm or more
Range for an NDB can be calculated with:
2√power output in Watts = Range (Land)
3√ power output in Watts = Range (Water)
What is departure?
Departure is the distance between two meridians along a specified parallel of latitude, usually in nautical miles.
Departure is maximum at the equator where 1° Change of Longitude (Ch. Long) equals 60’ of arc of a Great Circle.
Departure is zero at both poles because the meridians converge at these two points.
Departure (nm) = Ch.Long (min) × cos.lat
What is convergency?
Convergency is the angle of inclination between two meridians measured at a given latitude and is equal to the difference between the great circle directions measured at each meridian.
Convergency = Change in Longitude x Sine Mean Latitude
