Pt. 36, App. A (1) XY represents the portion of the measured flight path that includes the noise time history relevant to the calculation of flyover and approach EPNL; XrYr represents the corresponding reference flight path. (2) The points Q0, Q1, Qn represent airplane positions on the measured flight path at time t0, t1 and tn respectively. Point Q1 is the point at which the noise was emitted and observed as one-third octave values SPL(i)1 at the noise measuring station K at time t1. Point Qr1 represents the corresponding position on the reference flight path for noise observed as SPL(i)r1 at the reference measuring station Kr at time tr1. Q1K and Qr1Kr are respectively the measured and reference noise propagation paths, which in each case form the angle q1 with their respective flight paths. Qr0 and Qrn are similarly the points on the reference flight path corresponding to Q0 and Qn on the measured flight path. Q0 and Qn are chosen so that between Qr0 and Qrn all values of PNLTr (computed as described in paragraphs A36.9.4.2.2 and A36.9.4.2.3) within 10 dB of the peak value are included. (b) The portions of the test flight path and the reference flight path described in para- graph (b)(1) and (2), and illustrated in Figure A36-11(a) and (b), include the noise time history that is relevant to the calculation of lateral EPNL. (1) In figure A36-11(a) XY represents the portion of the measured flight path that includes the noise time history that is relevant to the calculation of lateral EPNL; in figure A36-11(b), XrYr represents the corresponding portion of the reference flight path. (2) The points Q0, Q1 and Qn represent airplane positions on the measured flight path at time t0, t1 and tn respectively. Point Q1 is the point at which the noise was emitted and observed as one-third octave values SPL(i)1 at the noise measuring station K at time t1. The point Qr1 represents the corresponding position on the reference flight path for noise observed as SPL(i)r1 at the measuring station Kr at time tr1. Q1K and Qr1Kr are respectively the measured and reference noise propagation paths. Qr0 and Qrn are similarly the points on the reference flight path corresponding to Q0 and Qn on the measured flight path. 803 VerDate Sep<11>2014 12:50 Apr 30, 2019 Jkt 247046 PO 00000 Frm 00813 Fmt 8010 Sfmt 8002 Y:\SGML\247046.XXX 247046 ER08jy02.020 spaschal on DSK3GDR082PROD with CFR Federal Aviation Administration, DOT