Global Index for CDG Noise

Note: This is a translation from French to English

CDG Noise Overall Index

Method of Calculation

A database of noise levels for each aircraft frequenting or likely to frequent the airport has been established from information furnished by the airlines. This database contains 5,100 separate aircraft registration numbers , of which 3,759 did operate at the airport in 1997.

The sound energy of each movement is calculated from the noise levels at "approach" (L_a) and at "flyover" (L_s)

Flyover energy = w_s = 10^Ls/10
Approach energy = w_a = 10^La/10

The overall index for the year 1998 is then defined as follows:

W_s and W_a representing the sums of the energies w_s and w_a of each movement.

Aircraft certified in dB(A) (helicopters, light airplanes...) and supersonic flights are not taken into account in the calculation.

Results for the Year 1997

	Movements	Reference Energy SI	Noise Certification Levels EPNdB
Arrivals - 24 hr	200,370	2129.99 x 10¹²	100.3
Departures - 24 hr	200,371	492.37 x 10¹²	93.9

Arrivals - Night	24,603	253.82 x 10¹²	100.1
Departures - Night	16,874	60.64 x 10¹²	95.6

Contribution of Chapter 2 aircraft

Movements Global Index

24 hr Index 11% 36%

Night Index 5% 15%