Estimate the number of passengers arriving in SF airport every day.

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Estimate the number of passengers arriving in SF airport every day.

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Clarifying Questions:

By arriving people count we mean people arriving by flight specifically into SF airpoirt.

Equation:

# of people arriving = (# of planes arriving in SF x average capacity of each plane)

Assuming average capacity of each plane = 150 passengers

# of planes arriving in SF = # of planes arriving in SF during peak hours + # of planes arriving in SF during non peak hours

# of planes arriving in SF during peak hours = number of runways in SF x (average # planes during peak)

# of planes arriving in SF during non peak hours = number of runways in SF x (average # planes during non peak)

(average # planes during peak) --> assuming there is atleast a 5 min gap per plane landing ---> 60 mins / 5 --> 12 planes per hour x peak duration

(average # planes during non peak) --> assuming there is atleast a 15 min gap per plane landing ---> 60 mins / 15 --> 4 planes per hour x non peak duration

Peak duration 6 am - 10 pm --> 16 hours

Non Peak duration 6 am - 10 pm --> 8 hours

# of runways in SF airport = 2 (just remember seeing it from the sky :) )

# of planes arriving in SF = (2 x 12 x 16) + (2 x 4 x 8) --> ~450 planes in 24 hours

assuming every plane has a capacity of 200 passengers --> 450 planes x 200 passenger/plane --> 90000 passengers arrive in SF everyday

productmanager123 · Answer 2 · 2021-06-11T02:20:29+0000

Assumptions & Clarifications

Its a typical weekday. Not a holiday. Sometime in late Spring or early Fall so that its not tied to seasonal variations. For e.g, not during summer vacations, or spring break, winter break etc.

Equation

Passengers arriving = number of flights landing in SFO x avg number of people in a flight.

Number of flights landing = number of gates x number of flights landing per gate.

Number of gates = Number of terminals x number of gates per terminal

Terminals = I think 3 terminals.

Number of gates per terminal = 40 gates.

Total number of gates = 120.

Number of flights landing per gate dependent time of day, turn around time for flight to deboard and board passengers. Turn around time = 1hr.

7am - 11am: High. 100% gates open. No time wasted between flights within a gate. 1 flight per hr = 4 flights per gate. 120*4 = 480.

11am - 4pm: Medium: 75% gates open. 1 flight per hr = 5 flights per gate. Flights = 120 * 5 * 0.75 = 450.

4pm - 9pm: High. 100% gates open. 4 flights per gate. Flights = 120 *5 = 600.

9pm - 7am: Low. 20% gates open. 1 light every 2 hrs per gate. Flights = 10 * 0.2 * 0.5 * 120 = 120.

Total flights landed = 1750 flights.

Number of people per flight. Assume occupancy = 75%

Type of flights: Large: 400 people. 20%

Medium: 200 people. 50% flights. Here assume 20% of flights are stopping with a layover in SFO. So only 100 people will disembark.

100*0.1 + 200*0.4

Small: 80 people. 30% flights.

Avg number of people = 0.75 * (0.2*400 + 100*0.1 + 200*0.4 + 80*0.3) = 0.75*(80 + 90 + 24) = 0.75*200 = 150 people.

TOtal people landing = 150 * 1750 = 262K passengers landing. Seems ok.