how to estimate the number of take-offs in the heathrow airport each day

Hi Youjie!

You can do either top-down or bottom-up here.

Top-Down

Population of London/Surrounding areas residents...subset of which would be flying in/out

PLUS population of daily visitors (business / tourist)

# passengers per plan

Viola...# planes required per day...cut that in half to get take-offs only

Bottom-up

When you've been to a large airport, how many takeoffs have you see on the board at one time?

How many per hour?

How many peak hours per day?

How many non-peak hours per day and what % of peak would this be?

Is Heathrow probably larger or smaller than this sample airport (multiple by that factor)

And again, voila!

There are certainly many ways how to estimate this. The most intuitive that comes to my mind is calculating total capacity:

• Heathrow has 2 runways - you might remember the public discussions around the permits for a 3rd one. This tells you (a) the number, and (b) that the 2 runways operate at capacity
• Calculate the max capacity based on 2 runways and one flight every x minutes. You might remember sitting in a plane, waiting for take off and seeing one plane after the other in line for the run way -> so assume one flight every 2 minutes
• This gives you 30 flights per hour and runway in 24 hours, or a total of 1440 flights. You might reduce that number by assuming a slightly longer time between take offs between midnight and 6am or so. Maybe half the density during that time, so reduce the number by 1/8th. This gives you 1260.

Googling wha the actual number is (although of course irrelevant, because it's about the approach, not the result): ~1300. So the estimation was pretty close ;)

Hey, why not post your structure & approach and coaches can comment. 

Hello!

THERE IS A CASE SOLVED FOR YOU :)

Have a look at this free case I did for the PrepL library,:

https://www.preplounge.com/en/management-consulting-cases/candidate-led-usual-style/intermediate/covid-19-impact-on-heathrow-airport-197

You have the answer step by step

Hope you find it useful!