Noise Per Seat or How to Increase Annoyance Without Really Trying

1. Noise Per Seat or How to Increase Annoyance Without Really Trying Bill Swan Economist BOEING Commercial Airplane Group Marketing

2. Noise Per Seat Lowest for Small Airplanes

3. Noise Per Seat Lowest for Small AirplanesThis is PER SEAT, not per departure • Bigger airplanes make more noise PER SEAT • not only is per departure noise higher, but so is per passenger noise • If you drive airports to fewer airplane movements per day • air travel moves to larger airplanes • total noise increases • This result is revolutionary counter-intuitive for many means limiting departures will increase noise reducing noise will mean using smaller airplanes & more departures Now, can we really explain how we got these numbers?

4. Movement Mix at Airports Take 1% of the world’s scheduled passenger jet departuresThink of it as Amsterdam’s Schiphol airport in size Short haul under 1600 kilometers; 3200 for widebodies. Night defined as after 2300 and before 0600.

5. Apply Stage 3 Departure Loudness

6. Total Noise Combines Loudness and FrequencyNoise is measure of Annoyance at one spot on the ground – one person listening • Day-Night Level (DNL) is total noise estimate: • one of several in common use imperfect but as sensible as any • DNL makes sense: • louder is worsemore frequent is worsemoving from 50 to 60 per hour not as bad as from 10 to 20adds 10 dB for night operations Ns is Number of departures of airplane size sepnl is the single-event noise level (with 10 added for night)

7. Noise Per Departure is Change in TotalNoise reduction for removing one departure • DNL value at start was 70.7 total for all movements on list • How much does total noise change for one departure? • Requires two DNL calculations and taking the difference

8. Noise Per Seat Divides by SeatsPer-seat measure is noise per passenger These are the values plotted on the original graph

9. Normalized Against Their Own Lowest Available,Actuals Show the Same Pattern

10. Consequences Are SurprisingIntuitions about departure frequency are misleading • Example: replace 2 departures at 125 seats with one at 250 seats: • total noise goes up 50% 5-days-a-week at 250 seats makes same noise as twice-daily at 125 large airplane/constant noise reduces air travel by 30% • Limits on departures will increase total noise: • if air travel is anywhere near original total seats • Noise reductions can be achieved by adding departures: accompanies with reductions in airplane sizes used • Reducing noise at airports will require: more departuressmaller airplanes • Frequency caps will increase total noise: unless air travel is curtailed dramatically

11. Simple Measurements Do Not Reduce NoiseBut simple things will • 83% of departures are narrow-body short-haul daytime: • they contribute only 28% of the departure noise based on being 3dB quieter than long-haul levels these will be eliminated first with departure limits • 1% of departures are wide-body long-haul night time: • they contribute 26% of the noise these will not be the first to be eliminated • Drastic departure-reduction plan: eliminate all below 125 seats, plus 60% of 125-seaters reduces departures from 446 to 266 OR • Reduce the wide-body sizes by one step (50 seats): requires 6 more operations per day for same seat total reduces noise the same as drastic departure-reduction plan

12. Can Institutions Work to Reduce Noise?Political constraints can limit travel while increasing noise • Noise per seat higher for larger aircraft. • Noise certification levels miss lower short-haul noise levels in actual use. • Measures that miss these two effects will not limit noise effectively. • Can institutions develop measures that will?