ATPL General Navigation - Class 6: Distance.

Summary

In this informative aviation class, Grant explains the various units used to measure distances in the field. He clarifies the use of nautical miles for long distances, converting them to meters, kilometers, and feet, and highlights the 1852 meters equivalence of a nautical mile. The video also touches on the use of statute miles in the United States and the conversion between different units. Grant simplifies the concept with practical examples, such as runway dimensions and ILS approach diagrams, and shares a helpful trick for descent planning based on a three-degree slope, which equates to a thousand feet every three nautical miles.

Takeaways

• 🌐 Units in aviation for measuring distance can be confusing due to the variety used, but they are specific to the context, such as altitude in Europe often being measured in feet.
• 🚀 Long distances are typically measured in nautical miles, which are based on a minute change in latitude and equate to 1852 meters or 1.852 kilometers.
• 📏 The conversion between nautical miles and feet is 60.76 feet per nautical mile, and one meter equals 3.28 feet for conversions between meters and feet.
• 🔢 To convert nautical miles to kilometers, multiply the nautical miles by 1.852, and to convert to feet, multiply by 60.76 and then by 3.28.
• 🇺🇸 In the United States, the statute mile is also used for measuring distance, with one statute mile equaling 1.609 kilometers or 1609 meters.
• 📐 For short distances, measurements are generally in feet or meters, and the conversion between them is straightforward using the 1 meter to 3.28 feet ratio.
• ✈️ Runway dimensions and vertical heights, such as threshold elevation, are often given in feet for aviation purposes.
• 📊 The side view of an ILS approach illustrates the use of feet for vertical distances, with a common slope of three degrees equating to a descent of 1000 feet every three nautical miles.
• 🌁 Aviation visibility minima are given in both feet and meters/kilometers, indicating the required cloud base and visibility for different types of approaches.
• 📉 The three-degree slope trick is a helpful tool for descent planning in aircraft, simplifying the math for pilots when descending towards an airport.
• 📝 While the three-degree slope trick might not be on exams, it's a practical tip for pilots to ensure they are on the correct vertical path for landing.

Q & A

What is the main topic of the video class presented by Grant?

The main topic of the video class is the range of units used in aviation to describe various distances, with a focus on conversions between different units.

Why are specific units used for specific measurements in aviation?

Specific units are used for specific measurements in aviation to ensure accuracy and standardization in describing distances, which is crucial for safety and efficiency in flight operations.

What is the definition of a nautical mile according to the video?

A nautical mile is defined as one minute change in latitude and is equivalent to 1852 meters or 1.852 kilometers, and also equals 6076 feet.

How can you convert nautical miles to kilometers?

To convert nautical miles to kilometers, you multiply the number of nautical miles by 1.852, since one nautical mile is equal to 1.852 kilometers.

What is the conversion factor between meters and feet?

The conversion factor between meters and feet is that one meter equals 3.28 feet.

Can you provide an example of converting five nautical miles to kilometers and feet as shown in the video?

Yes, five nautical miles times 1.852 equals 9.26 kilometers. To convert to feet, you would multiply 9260 meters by 3.28 to get 30,372.8 feet.

What is a statute mile and how does it differ from a nautical mile?

A statute mile is a unit of distance used in the United States and is equal to 1.609 kilometers or 1609 meters. It differs from a nautical mile, which is longer and used primarily in aviation and marine navigation.

How are short distances typically measured in aviation?

Short distances in aviation are generally measured in feet or meters, using the conversion factor between the two as needed.

What is the significance of the three-degree slope in instrument approaches as mentioned in the video?

The three-degree slope is significant because it simplifies the mathematical calculations for pilots during flight, allowing them to estimate their descent profile easily. For every three nautical miles, the altitude should decrease by approximately one thousand feet.

Can you provide an example of how the three-degree slope is used for descent planning in the video?

In the video, it is explained that if a plane is at 35,000 feet and needs to descend to 2,000 feet, with a three-degree slope, they would need to start descending 99 nautical miles before the runway threshold to achieve a gentle slope towards landing.

What are the units used for measuring visibility and cloud base in the minima for instrument approaches shown in the video?

The units used for measuring visibility and cloud base in the minima for instrument approaches are feet for altitude and a combination of meters/kilometers for visibility.

Outlines

00:00

📏 Units of Distance in Aviation

In this segment, the instructor, Grant, introduces the topic of various units used to measure distances in aviation. He emphasizes the importance of understanding these units, especially since different regions may use different standards. The primary focus is on the conversion between nautical miles, feet, and meters. The instructor explains that in Europe, altitude is typically measured in feet. He provides a detailed example of converting five nautical miles into kilometers and feet, illustrating the process with mathematical calculations. Additionally, he touches on the use of statute miles in the United States and offers a conversion factor for nautical miles to statute miles. The segment aims to clarify the confusion surrounding these units and their conversions.

05:00

📐 Aviation Distance Conversions and Approach Slopes

This paragraph delves deeper into the specifics of vertical distance measurements in aviation, predominantly using feet. The instructor discusses the side view of an ILS (Instrument Landing System) approach, highlighting the importance of vertical distances in feet, such as the threshold elevation and the descent path. He introduces the concept of a 3-degree glide slope, which is a common angle for instrument approaches, facilitating easy calculations for pilots in flight. The instructor provides a practical example of descent planning using the 3-degree slope rule, explaining how to estimate the distance and altitude for a proper approach. He also mentions visibility minima requirements during approaches, given in both feet and meters/kilometers. The summary concludes with a set of key conversion factors: one nautical mile equals 1,852 meters or 6,076 feet, one statute mile equals 1.609 kilometers, and one meter equals 3.28 feet, encouraging students to memorize these for ease of conversion.

Keywords

💡Nautical Mile

A nautical mile is a unit of distance used in aviation, maritime, and navigation. It is defined as one minute change in latitude, which is equivalent to 1852 meters or 1.852 kilometers. In the video, the nautical mile is used to measure long distances and is a key concept for understanding how distances are measured and converted in aviation. For example, the script mentions converting five nautical miles into kilometers and feet to illustrate the process.

💡Altitude

Altitude refers to the height of an object or point in relation to sea level or ground level. In aviation, altitude is commonly measured in feet, especially in Europe. The script discusses altitude in the context of runway dimensions and vertical distances, such as the threshold elevation being 24 feet, which is crucial for pilots to know for safe takeoffs and landings.

💡Conversion

Conversion in this context is the process of changing one unit of measurement to another. The video script provides several examples of conversions, such as from nautical miles to kilometers and feet, and from meters to feet using the conversion factor of 3.28 feet per meter. Conversions are essential for pilots to navigate and communicate effectively across different systems of measurement.

💡Statute Mile

A statute mile is a unit of distance used primarily in the United States and the United Kingdom. It is defined as 1.609 kilometers or 1609 meters. The script mentions the statute mile as an alternative to the nautical mile for measuring distances on land and provides a conversion factor to help pilots understand the relationship between different units of distance.

💡Runway Dimensions

Runway dimensions refer to the physical measurements of an airport's runway, including its length and width. In the script, an example is given of a runway in Pharaoh, Portugal, which is 2445 meters long by 45 meters wide. Understanding runway dimensions is critical for safe aircraft operations and for planning takeoff and landing procedures.

💡Vertical Distance

Vertical distance denotes the height or elevation above a reference point, typically sea level or the ground. The video script discusses vertical distances in terms of threshold elevation and descent paths for instrument landing systems (ILS). For instance, the ILS approach starts at 2000 feet and descends to the threshold elevation of 24 feet, illustrating the importance of vertical distance in aviation.

💡Instrument Approach

An instrument approach is a set of procedures that allow a pilot to descend and land an aircraft under conditions where visual cues are insufficient. The script describes an ILS approach, which includes a descent path with a 3-degree slope, starting at 2000 feet at six nautical miles from the runway. This approach is crucial for safe landings in low-visibility conditions.

💡Visibility

Visibility in aviation refers to the distance at which an object can be clearly seen from a specific point. The script mentions visibility requirements for different types of approaches, such as having at least 750 meters of visibility or one kilometer, which is essential for ensuring safe operations and avoiding collisions.

💡Cloud Base

Cloud base is the lowest altitude at which clouds are present in the sky. In the context of the script, cloud base is an important factor for pilots during takeoff and landing, as it affects visibility and the decision to go around. The video provides examples of cloud base requirements, such as 200 feet for certain approaches.

💡Descent Planning

Descent planning is the process of calculating and executing a descent from cruising altitude to a lower altitude for landing or other purposes. The script introduces a 'trick' for descent planning, where a slope of 3 degrees equates to a descent of approximately 1000 feet for every three nautical miles. This method helps pilots plan their descent to achieve a smooth and safe landing.

Highlights

Introduction to the range of units used in aviation for measuring distances.

Specific units are used for measuring different things in aviation.

In Europe, altitude is measured in feet.

Exploration of conversions between different units of distance.

Long distances are typically measured in nautical miles.

A nautical mile is defined as one minute change in latitude.

Conversion rates: 1 nautical mile equals 1852 meters or 1.852 kilometers.

Conversion rates: 1 nautical mile equals 6076 feet.

Conversion between feet and meters using 1 meter equals 3.28 feet.

Example calculation: converting 5 nautical miles to kilometers and feet.

Statute miles are used in the United States for distance measurements.

Conversion: 1 statute mile equals 1.609 kilometers or 1609 meters.

Recommendation to remember a few key conversions for practical use.

Short distances are measured in feet or meters.

Example of runway dimensions given in meters.

Vertical heights are generally discussed in feet.

Illustration of vertical distances in an ILS approach diagram.

The 3-degree slope rule for instrument approaches simplifies calculations.

Practical application of the 3-degree slope for descent planning.

Summary of key conversions: 1 nautical mile, 1 statute mile, and 1 meter.

Transcripts

i would walk 500 miles and i would walk

800 kilometers more just to be the man

who walked 870 nautical miles to fall

down at your door

i'll do that that's funny

[Music]

hi i'm grant and welcome to the sixth

class in the genome series today we're

going to be taking a look at the range

of units we use in aviation to describe

various distances

can be a bit confusing at first because

there are so many but generally specific

things are measured in specific

distances for example in europe we use

feet for altitude so this class is going

to be fairly short but it's basically

going to look at the conversions between

different units that are used for

measuring distance

as i said in the intro usually specific

things are measured in very specific

units so let's start with long distance

which is normally measured in nautical

miles

we established in the second class when

we looked at latitude and longitude

that a nautical mile is

one minute change in latitude

normally we don't think of distances as

degrees of latitude though so let's put

some numbers to it

one nautical mile

is 1852

meters

or 1.852 kilometers

and it also equals

60

76

feet

and we can convert between feet and

meters

using the conversion of one meter

equals 3.28

feet so let's just check

our conversions to see if they work i'm

going to pick i don't know five nautical

miles and i want the value in

kilometers and feet so

five

nautical miles

times by

one point eight five two because it's

185

uh

1850 meters or 1.852 kilometers and that

equals and that equals

9.26

kilometers

and then if we want to find the value in

feet

we would just use this conversion here

and it would be

9260

meters times by

3.28 to get into feet which gives us 30

372.8

feet and if we were then to divide this

number

by 60

076 feet we should get back to five

knock miles so let's just do that so we

have 30

372

divided by

60

76

equals

4.99 yeah let's call that five

so occasionally

in the states like the united states i

think they also use the statute mile for

distance

and if you need to then the conversion

for that

that is good to remember is one statute

mile

equals 1.609

kilometers or

1609

meters

you could also remember that there's a

conversion between knock miles and

statute miles but i would recommend just

remembering a few conversions so you get

to a common point and then convert from

there

and what i mean by that is

say i wanted those five nautical miles

from earlier

in

statute miles

i have one conversion in my head for

nautical miles which is 1852 meters well

i have two or 60 76 feet

i can convert it into meters

and then

know what that is in kilometers and i

can go back into statute miles

i already know that 3.28 feet are in a

meter and that 1.609 kilometers are in

statute mile in

every statute mile

so i can get to a statute mile by going

through meters and kilometers

if you find it easier just to remember

that

one statute mile

to one knock mile whatever that

conversion is then go for it but that's

just my personal recommendation

short distances are generally measured

in feet or meters

and using that same conversion that

we've seen before you can get between

the two

so

this is just an example of a chart into

a place called pharaoh which is in the

south of portugal that we go to often

and

this diagram here is runway dimensions

which are in meters

so you can see that it's

2445 meters long by 45 meters wide

and

when we're talking about vertical

heights we generally talk about feet

and the threshold elevation is 24 feet

and you can also see some

more examples of vertical distances

being measured in feet

so this

is the

side view of an ils approach coming in

and you can see that it starts at 2000

feet comes along and then at

six nautical miles because we're talking

horizontal distances

we start to go down and at four nautical

miles we've got to be 1350 feet

and then we keep going down

and then we get all the way to the

threshold elevation

which is at 24 feet

and that would be our zero nautical mile

mark

for

the ils

you can also see some more examples down

here these are our minima that we use

we've got to have at least these

categories of visibility

so you can see it's feet and then it's

in meters slash kilometers and then the

other one is in feet it gives you the

units here

so we need

a

cloud base this is

um of 200 feet that means the lowest

level of cloud essentially

and then we need at least 750 meters of

visibility or if you're doing this

slightly different type of approach you

need 310 cloud base and one kilometer

visibility and then this is our altitude

that we would descend down to before

deciding whether to

go around you can also see something

interesting about the vertical heights

on this kind of diagram

you can see that the

slope here

says three degrees three degrees is a

very common slope for

instrument approaches

and the reason behind it is because it

makes the maths quite easy

for us when we're in the air

you can see that as we go out to

six nautical miles it's 2000 feet

so or we could say that every three

knock miles it's a thousand feet it's

not exact but it is

pretty good estimation

so you can say that at roughly

three nautical miles to go we should be

a thousand feet

at six nautical miles we should be 2000

feet you can project it all the way back

up and you could say that for us to be

on profile as they call it like on the

correct sort of vertical path

and we're at

12

nautical miles away from the runway

we should be about 4 000 feet for it to

make sense so this is what we can use

for our like descent planning as well

that that three degrees

uh slope

every three nautical miles is a thousand

feet

we basically use that to plan when we're

going to start our descent from our

cruising altitude so say this was our

airport up faro

and we are at

we know we need to get down to that what

was it two thousand feet

it was two 000 feet here

and we're at

35 000 feet

we know that we have to change in height

by

33 000 feet and with a nice gentle slope

of three degrees which is roughly a

thousand feet for every three nautical

miles

for us to descend this thirty three

thousand feet we'll need three nautical

miles for every thousand feet of that we

would just multiply that by three and we

would find out that we needed to send

99 nautical miles before this point

and that point if you remember was at

six nautical miles

so if we

descend 105 nautical miles before the

runway threshold of faro

we should get a nice gentle slope in

towards landing

that won't come up in the hbl exams but

it's just a handy trick to know when

you're actually flying aircraft so as i

said nice short class there the only

real things to remember are these

conversions and that three degree

uh slope trick of

1000 feet is three nautical miles

although that won't come up in the exam

i don't think

so one nautical mile 180

1852 meters or 60 76 feet

one statute mile is 1.609 kilometers or

1 609

one meter is 3.28 feet

and convert between them as you see fit

[Music]