Glossary

In alphabetical order

A

AENOR

Spanish standardisation and certification association

Apu

“Auxiliar power unit”. Unit for the production of power independent to the aircraft.

C

Chap 2

Chapter of Annex 16 of the ICAO, where a classification is established for aircraft with must noisier engines.

D

dB (A)

Decibels in weighting A.

E

Equivalent continuous level

Noise level generated by any source, measured in decibels.

L

Leq(A) day

Continuous equivalent level corresponding to the daily period, from 07:00 to 22:59 h.

Leq(A) night

Continuous equivalent level corresponding to the nighttime, from 23:00 to 06:59 h.

Leq(A) plane

Equivalent Continuous Level that would have been generated were there not more noise than that produced by the planes in weighting A.

Leq(A) total

Equivalent Continuous Level generated by all sources of noise in weighting A.

N

NL

Noise level of each airline according to which it can plan its operations according to the aircraft noise certificate.

O

OACI

International Civil Aviation Organisation.

OFIMA

Environmental Information and Service Office.

P

Percentile L10

Statistical value representing the level in dB(A) that has been equalled or exceeded for 10% of the time.

Percentile L50

Statistical value representing the level in dB(A) that has been equalled or exceeded for 50% of the time.

Percentile L90

Statistical value representing the level in dB(A) that has been equalled or exceeded for 90% of the time.

S

SCVA

Visual and Acoustic Control System.

SIRMA

Noise and flight path monitoring system.

T

TMR

Noise monitoring terminal made up of a microphone and computer support.

W

Weighting A

Frequency filter similar to that perceived by the human ear.