Evidence for the Safety- Capacity Trade-Off in the Air Transportation System

Transcription

1 Evidence for the Safety- Capacity Trade-Off in the Air Transportation System G. L. Donohue R. C. Haynie D. Wang J. F. Shortle Dept. of Systems Engineering & Operations Research George Mason University Fairfax, VA

2 Research Questions Is there a safety-capacity trade-off? What happens to safety during periods of high utilization? Safety More Safe 1.2 (Departures / Hull Loss) Less Safe0 Low Capacity (Departures / Year) Hypothesized Curve High

3 Outline Data collection process Results from data collection Further analysis Conclusions

4 Wake Vortex Separation Standards Small Small 4 Nm Large 5 Nm 6 Nm 4 Nm 5 Nm Large B757 Heavy Small 5 Nm 4 Nm Heavy Large Small > 255,000 lbs 41,000 lbs to 255,000 lbs < 41,000 lbs Heavy

5 Atlanta Airport 2 Runways Arrivals 2 Runways Departures 50 Arrivals / Hr / RW Max 72 Seconds between Arrivals 3.1% Operations Delayed (> 15 min) Total Operations, VMC, (per 15 min) T O T A L S C H E D U L E D O P E R A T I O N S A N D C U R R E N T O P T I M U M R A T E B O U N D A R I E S Schedule Facility Est. Model Est. Airport Capacity Benchmark Report, FAA, 2001.

6 Haynie, R.C Ph.D. Dissertation, George Mason University. Data Collection, Atlanta Observation Point Renaissance Hotel One Hartsfield Centre Parkway Atlanta, GA Runway 26 Runway 27 ATL Airport

7 Data Collection Process Threshold Airplane i Airplane i+1 Runway Aircraft Type Threshold Leave Runway Heavy 10:23:14 10:24:04 Large 10:24:28 10:25:13 Large 10:26:16 10:27:12 Small 10:28:32 10:29: Haynie, R.C Ph.D. Dissertation, George Mason University.

8 Data Manipulation Runway Occupancy Time (RTI) 45 sec Aircraft Type Threshold Leave Runway Heavy 10:23:14 10:24:04 Large 10:24:28 10:25:13 Large 10:26:16 10:27:12 Small 10:28:32 10:29: sec 77 sec = +31 sec Relative Inter-Arrival Time Inter-Arrival Time Wake Vortex Separation Standard Large following Large (3 Nm) (3 Nm / (140 knots / 3600 sec/hr))

9 Data Collection Summary Airport Days Observations Weather Atlanta (ATL) VMC LaGuardia (LGA) VMC / IMC Baltimore (BWI) IMC Haynie, R.C Ph.D. Dissertation, George Mason University.

10 Results Atlanta Runway 27 Collection Day #1, VMC Relative Inter-Arrival Time Target Observation # (3.3 hours collection time) Haynie, R.C Ph.D. Dissertation, George Mason University. Total Observations: 103 Arrivals / Hr: 31

11 Results Atlanta Runway 27 All Collection Days, VMC Lost Safety Lost Capacity 80 # Occurrences Relative Inter-arrival Time (sec) Haynie, R.C Ph.D. Dissertation, George Mason University.

12 ATL Summary 20 Perfect WVSS Adherence Value = 0 # Occurrences Relative Inter-Arrival Time (sec) D1P1 36 Arr/Hr D1P1 39 Arr/Hr D2/P2 39 Arr/Hr Haynie, R.C Ph.D. Dissertation, George Mason University. Bin size: 20 seconds

13 Results LaGuardia Collection Day #2, VMC Relative Inter-Arrival Time Target Observation # (5 hours collection time) Haynie, R.C Ph.D. Dissertation, George Mason University. Total Observations: 169 Arrivals / Hr: 33.8

14 Results Relative Inter-Arrival Time Target LaGuardia Collection Day #3, IMC Observation # (3.7 hours collection time) Haynie, R.C Ph.D. Dissertation, George Mason University. Total Observations: 126 Arrivals / Hr: 34

15 Comparison of Airports Aircraft Per Runway Per Hour LGA in VMC LGA in IMC ATL in VMC ATL in VMC Inter-Arrival Time (sec) Haynie, R.C Ph.D. Dissertation, George Mason University.

16 LGA & BWI Comparison 10 Target LaGuardia VMC / IMC (4 periods, Arrivals / Hr) Baltimore IMC (18.7 Arrivals / Hr) Observations VFR 33.8 Arr/Hr IFR 34 Arr/Hr VFR 30.9 Arr/Hr VFR 27 Arr/Hr IFR 18.7 Arr/Hr Relative Inter-Arrival Time (sec) Haynie, R.C Ph.D. Dissertation, George Mason University.

17 15 Min Arrival Rates Atlanta Airport Collection Day #1, VMC 15 min averages Arrivals per 15 min 11:15am 1:15pm 6:45pm 8:00am 10:30am 1:00pm 3:30pm 6:00pm Individual Flight Data Average: 31 / hr

18 Arrival Rates Frequency Inter-Arrival Times During Busy 15-min Intervals (> 31 arrivals / hr) Inter-Arrival Time (sec) Frequency Inter-Arrival Times During Light 15-min Intervals (< 31 arrivals / hr) Inter-Arrival Time (sec)

19 Safety / Capacity Relationship 120 ATL, DCA, LGA Historical Reports # Reports Filed NMAC RWY Inc Legal Sep Percent Capacity Used Haynie, R.C Ph.D. Dissertation, George Mason University.

20 Summary Inter-arrival times indicate frequent loss of WV separation Shape of inter-arrival distributions similar For different airports For IMC / VMC Some evidence for decline in safety for higher arrival rates Small data set (~ 1,500 points) more needed Data can be used as input to more sophisticated safety models (TOPAZ)

21 Backup Slides Backup Slides

22 Average Approach Speeds Aircraft Type Small Large B757 Heavy Avg. Approach Speed 130 knots 140 knots 140 knots 145 knots

23 ATL Arrival - Departure IMC 120 ASPM - April Instrument Approaches Arrivals per Hour ,90 Calculated IMC Capacity Reduced Rate (ATL) Departures per Hour

24 Modeling Implications Typical Modeling Approach Safety is a constraint (Maximum rate through node in network) Capacity is metric of interest Queueing Constraints (Minimum Times Between Operations) New Approach Safety is a function of capacity / demand