75 votes
Accepted

Explaining a "Great Circle Route" to young Civil Air Patrol cadets

I would recommend that you don't introduce the term first and then try to explain it verbally, but demonstrate it in an interactive, hands-on practical way instead. Bring a globe, a flat map, and a ...
Michael Hall's user avatar
  • 25.7k
49 votes
Accepted

What is significant about the number 8069 ft?

Apparently you aren't the only person who wondered this; the FAA actually has it in an FAQ: What is the significance of a runway 8069 feet in length and why are two different aerodrome symbols used ...
Pondlife's user avatar
  • 71.7k
35 votes

What does the "DO NOT USE FOR NAVIGATION" indication mean?

Unless it's an obsoleted procedure chart, it usually means that it's not complete. The example you show has only the features pertinent to that approach, and its missing (for clarity) the features ...
Toby Speight's user avatar
  • 1,087
29 votes

What does the "DO NOT USE FOR NAVIGATION" indication mean?

When an aviation chart is marked with "DO NOT USE FOR NAVIGATION", it means that ... umm ... it should not be used for navigation. The question is why it should not be, because it appears that the ...
Farhan's user avatar
  • 29.4k
26 votes
Accepted

What does "MERMA" mean on the Los Angeles TAC chart?

MERMA is an aviation waypoint Waypoints used in aviation are given five-letter names. These names are meant to be pronounceable or have a mnemonic value, so that they may easily be conveyed by ...
Jamiec's user avatar
  • 32.8k
24 votes

What do these white on red words indicate on a London Heathrow taxiway chart?

They are named holding points; this allows them to say things like "taxi to RABIT" rather than "taxiway Bravo, hold short of taxiway Charlie". This saves a lot of time for ground controllers at busy, ...
StephenS's user avatar
  • 27.7k
23 votes

What does the "T" on sectional charts mean in reference to airspace altitude?

T is used to signify that the top of Class C airspace that lies under Class B is the bottom surface of that airspace. This is important when the Class C segment lies under multiple layers of Class B, ...
Pilothead's user avatar
  • 20k
19 votes
Accepted

What does 00 mean on a sectional below the airport runway information?

That is the elevation and length of the longest co-located water runway. Elevation of 00, and runway length 5000 feet. This information is found on page 16 in the current Aeronautical Chart Users ...
Jimmy's user avatar
  • 2,829
18 votes
Accepted

While only RL will be sufficient at night for the aircraft to take off, both RL and RCLM are required to take off during the day. Isn't it illogical?

To me it makes perfect sense if you consider that at night there is high contrast between darkness and the lights. It is easy to make out the runway edge lights through the fog under darkness, so the ...
DeltaLima's user avatar
  • 83.1k
17 votes

What is "(CFMCC)" on an ILS approach chart?

A point shown in parentheses like this is called a Computer Navigation Fix (CNF). If it didn't fall right at the end of the runway, it would be marked with a small X. It's defined in the legend on ...
fooot's user avatar
  • 72.8k
17 votes

What organisation owns intersection names?

The allocation of waypoint names is actually handled by each country's individual aviation authority. This means that there are actually duplicates in different countries or regions. The ICAO has made ...
HiddenWindshield's user avatar
17 votes

Explaining a "Great Circle Route" to young Civil Air Patrol cadets

What would be an easily understood explanation of a "Great Circle Route" The interest for great circle navigation is a great circle arc between two points is the shortest route between ...
mins's user avatar
  • 71.8k
16 votes

How precisely are airspace borders defined?

The boundaries are defined more precisely than the chart can show. What you see on the chart is a visual representation of the text published in JO 7400.9Z (or the most recent version of it): AWP ...
Pondlife's user avatar
  • 71.7k
14 votes

What is the reason for this route while flying from USA over Cuba?

There are two large warning areas there, W-465 A and B. Both are active "intermittently" up to 70,000ft. It seems likely that the route was taken to avoid those areas.
Pondlife's user avatar
  • 71.7k
14 votes
Accepted

What does the T in RVR-T stand for?

From page 5-1-7, contractions in the AIM: RVRT . . . . . . . . . RVR Touchdown The full list is: RVR . . . . . . . . . . Runway Visual Range RVRM . . . . . . . . RVR Midpoint RVRR . . . . ....
Lnafziger's user avatar
  • 58.8k
14 votes
Accepted

How many airport charts do airline pilots have in the cockpit?

In the 1990s I flew for two 747 carriers, the first primarily a freight carrier and the second primarily a passenger carrier. Both used Jeppesen for their airway manuals, and both supplied each pilot ...
Terry's user avatar
  • 39.1k
14 votes

What does the "T" on sectional charts mean in reference to airspace altitude?

You can start many "what does this thing on an FAA chart mean" questions with the FAA's Aeronautical Chart User's Guide. It doesn't go into a deep explanation, but does show it as an ...
BowlOfRed's user avatar
  • 5,561
14 votes
Accepted

Where are the "Admitted Aircraft symbols" on Jeppesen VFR aerodrome charts defined?

With the help of Bianfable's answer I took it upon myself to email Jeppesen to get the correct answer.
wbeard52's user avatar
  • 12.6k
14 votes
Accepted

What is an "Alternate Airway"?

I found an old definition in the All-Weather Flight Manual published by the US Navy in 1957: Alternate Airways Alternate airways are occasionally used for lateral separation when traffic conditions ...
Bianfable's user avatar
  • 55.5k
14 votes
Accepted

What does the letter "H" on the upper side of ADANA word and mean?

Customers have stated "We noticed an 'H' symbol next to an airspace fix/navaid in the SID/STAR chart planview. Explain what this means?" The "H" symbol serves as an indicator for ...
Michael Harvey's user avatar
14 votes
Accepted

What is "Accident" on a VFR sectional?

What is "Accident" on a VFR sectional? It is simply the name of the town. (Wikipedia link)
quiet flyer's user avatar
  • 22.2k
13 votes
Accepted

Why publish an unusable airway?

Short answer: only part of the airway is unusable, and even then it's usable with GPS. Your image shows V522 between FAILS intersection and the ERI VOR but you have to look at the full airway, which ...
Pondlife's user avatar
  • 71.7k
13 votes
Accepted

What's a metering fix?

Definitions from this page. Metering: A method of time-regulating arrival traffic flow into a terminal area so as not to exceed a predetermined terminal acceptance rate. Metering airport: Airport ...
mins's user avatar
  • 71.8k
13 votes
Accepted

Does the large 6-pointed star on a sectional warn of dangerous radar facility?

There are two stars: The large multi-pointed Star (6 pointed in this case) is described in the Aeronautical Chart User’s Guide as an indicator of High Energy Radiation Areas. The Precision ...
Dean F.'s user avatar
  • 16.5k
13 votes

What organisation owns intersection names?

As already said in HiddenWindshield's answer, the five letter intersection codes do not have to be unique worldwide. I thought it might be interesting to see how many times these codes are actually ...
Bianfable's user avatar
  • 55.5k

Only top scored, non community-wiki answers of a minimum length are eligible