1. Biography for William Swan
Chief Economist, Seabury-Airline Planning Group. AGIFORS Senior Fellow. ATRG Senior Fellow. Retired Chief Economist for Boeing Commercial Aircraft Previous to Boeing, worked at American Airlines in Operations Research and Strategic Planning and United Airlines in Research and Development. Areas of work included Yield Management, Fleet Planning, Aircraft Routing, and Crew Scheduling. Also worked for Hull Trading, a major market maker in stock index options, and on the staff at MIT’s Flight Transportation Lab. Education: Master’s, Engineer’s Degree, and Ph. D. at MIT. Bachelor of Science in Aeronautical Engineering at Princeton. Likes dogs and dark beer.
I am an economist. Everyone thinks an economist can predict the stock market. If I could do that I would be so rich I could own Boeing Aircraft Company. Instead, it is the other way around.
Scott Adams

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

3. Noise Per Seat Lowest for Small Airplanes

4. Noise Per Seat Lowest for Small Airplanes This 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?

5. Movement Mix at Airports
Take 1% of the world’s scheduled passenger jet departures Think 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.

6. Apply Stage 3 Departure Loudness

7. Total Noise Combines Loudness and Frequency Noise 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 worse more frequent is worse moving from 50 to 60 per hour not as bad as from 10 to 20 adds 10 dB for night operations
Ns is Number of departures of airplane size s epnl is the single-event noise level (with 10 added for night)

8. Noise Per Departure is Change in Total Noise 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

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

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

11. Consequences Are Surprising Intuitions 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 departures smaller airplanes
Frequency caps will increase total noise:
unless air travel is curtailed dramatically

12. Simple Measurements Do Not Reduce Noise But 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

13. Can Institutions Work to Reduce Noise
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?