# What are some aviation rules of thumb?

Some examples can be:

• Speed below a certain altitude
• Vertical Speed (VS) during take-off and landing
• Calculating when to start your descent (some kind of equation/formula) and more.

Please feel free to put your own as well, as you don’t have to just answer the examples above.

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For descent, I made and always use this.

Vertical speed varies for every aircraft and even aircraft type. So does air speed.

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When I said speed below a certain altitude, I meant to say a range (i.e., 210kts-240kts). Same for VS.

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You should check out these two links:

https://community.infiniteflight.com/c/tutorials/15

Everything you would need to know is in these two resources

VS during takeoff: usually you rotate to a set pitch, then lower nose at 1000 agl to accelerate to 250
VS during landing: follow the 3% glideslope. Should be a little bit more than 5x ground speed.

When landing always feel free to go around.

Aviate, navigate, communicate. i.e. if you are losing control, regain control first before replying to ATC.

This is the same reason I think the ATC menu need to be moved because it covers live instruments completely…

I shall steal such a relish

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Just a few I remember off the top of my head, which I use IRL, and in the sim too. I’ll add more if I remember more!

Takeoff/Climb Performance Rules of Thumb

1. The 50/70 Rule

If you haven’t reached 70% of your takeoff speed by the time you’ve covered 50% of the runway length, abort your takeoff!

2. The Density Altitude Rule

The density altitude at an airport changes by 120 feet for every degree in variation from standard temperature (ISA, which is 15ºC or 59ºF at sea level). Density altitude increases with increase in temperature, and decreases with a decrease in temperature.In a formula: Density altitude = Pressure Altitude + 120 (Outside Air Temp - Standard Air Temp)

3. The Standard Adiabatic Lapse Rate

Standard temperature (ISA), which is 15ºC or 59ºF at sea level, decreases by 2º for every 1000 feet in altitude.

4. The Climb Rate Rule or Ft/NM to Ft/Min Rule

When you have a climb gradient in feet per NM (as most SIDs do), to get it in feet per minute, which is a more accessible format, divide your groundspeed by 60 and multiply it by the given climb gradient in ft/NM. In a formula: FPM = (GS / 60) x FPNM

5. The Cruise Climb Speed Rule

The best cruise-climb speed is the difference between Vx (best angle of climb speed) and Vy (best rate of climb speed), which is then added to Vy. In a formula: Cruise Climb Speed = Vy + (Vx - Vy)

Enroute Flight Rules of Thumb

1. The 1 in 60 Rule

When you’re 60 NM out from a VOR tracking station 1º of offset = 1 NM (note: on a VOR, a full-scale deflection on either side = 10º so each dot = 2º)
So if you’re off track, you can find out by how much, assuming you have a constant heading. The formula is: (No. of degrees off course x Distance to station) / 60

2. Standard Rate Of Turn

To calculate a standard rate of turn, divide the airspeed by 10, then add half the result to the total number. In a formula:
Step 1: Airspeed / 10 = blahblah
Step 2: blahblah + 0.5blahblah = Standard ROT

Apologies, I hate using the ‘standard’ variables such as x, y, a, b etc.

Approach/Landing Rules of Thumb

1. The Top Of Descent Rule, or Rule of Three

Calculate a rough top-of-descent by the 3 to 1 rule. You travel 3 NM for every 1000 feet lost. In a simple formula: Top of Descent = (Altitude/1000) x 3

2. The 3º Glideslope Rule

To calculate a 3º glideslope, which comes in handy when you’re on an ILS approach, divide your groundspeed by 2 and add a 0 to the end of the result to get your vertical speed. For example, if your groundspeed is 130kts, 130/2 = 75, then add a zero, that’s 750 feet per minute. Bonus: an ILS is 4 times more sensitive than a VOR. So while a full scale deflection of the needle on a VOR indicates a 10º offset, on an ILS it’s 2.5º

3. The Gusty Approach Rule

If you’re flying a gusty approach, add half of the gust factor to your approach speed. If your approach speed is 145 KIAS and the winds are gusting 20 knots, keep your approach at 145 + (20/2) = 155 KIAS

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80% of this went right over my head, but wow you know your stuff. I am going to have to study a lot of this. Thank you!

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Seems pretty simple, but I don’t see it on the live servers enough: see and avoid.

14 CFR 91.113 states that “When weather conditions permit, regardless of whether an operation is conducted under[instrument flight rules or visual flight rules, vigilance shall be maintained by each person operating an aircraft so as to see and avoid other aircraft. When a rule of this section gives another aircraft the right-of-way, the pilot shall give way to that aircraft and may not pass over, under, or ahead of it unless well clear.”