Preliminary Analysis of the Impact of Miles-in-Trail (MIT) Restrictions on NAS Flight Operations

Transcription

1 Preliminary Analysis of the Impact of Miles-in-Trail (MIT) Restrictions on NAS Flight Operations Tim Myers Mark Klopfenstein Jon Mintzer Gretchen Wilmouth Ved Sud FAA/ATO-R A I R T R A F F I C O R G A N I Z A T I O N

2 2 Simple Example of MIT Impact

3 3 Simple Example of MIT Impact

4 4 Simple Example of MIT Impact

5 5 Simple Example of MIT Impact

6 Simple Example of MIT Impact Size of red dot proportional to delay relative to current route 6

7 Simple Example of MIT Impact Size of red dot proportional to delay relative to current route 7

8 Simple Example of MIT Impact Size of red dot proportional to delay relative to current route 8

9 Simple Example of MIT Impact Size of red dot proportional to delay relative to current route 9

10 10 Simple Example of MIT Impact

11 Simple Example of MIT Impact Cumulative delay = 1.4 minutes 11

12 National Traffic Management Log NTML deployed nationally on December 17, 2003 Records the implementation of various traffic management initiatives (TMIs) including Miles-In-Trail (MIT) restrictions Data manually entered using computer-based entry forms Only electronic source of MIT information May have numerous log entries per MIT restriction Proposal from the originating facility Approvals Modifications Not integrated with the Traffic Management System (ETMS) 12

13 MIT Restriction Characteristics /1/04 5/8/04 Daily Count 5/15/04 5/22/ /29/04 Mean = % 30% 20% 10% 0% Magnitude Required Spacing (mi) (nmi) 13 Top 10 Reasons Feb-04 May-04 VOL: ENRT SCTR 32% 31% VOL: Arrival Demand 27% 30% VOL: ARPT 13% 7% VOL: EnRoute Center 5% 6% WX: Low Ceiling/Visibility 5% 2% TM Initiatives:MIT/MINIT:VOL:Terminal 3% 2% WX: Wind 2% - RWY: CONST 2% 2% WX: TSTMS 2% 10% VOL: Complexity 2% 2% TM Initiatives:MIT/MINIT:VOL:Enroute - 1% 25% 20% 15% 10% 5% 0% Duration MIT Duration (mins)

14 Flight to MIT Matching Challenge Inconsistent Terminology Variations used to denote no exclusions NO NONE NORM NORMAL NORMAL EXCL NORMAL EXCLUSIONS NORML NORMX NRM NRML NRML EXCL Flight level Altitude Data Accuracy ETMS altitude Processed altitude 0 23:55 0:05 0:15 0:25 0:35 0:45 0:55 1:05 1: :55 0:05 0:15 0:25 0:35 0:45 0:55 1:05 1:15 Time Conflicting NTML parameters: DTW-bound traffic DTW ZOB Crossing from ZOB into ZID ZID 14

15 Flights per MIT Number of restrictions 2,000 1,500 1, % of restrictions involved 0-4 flights 59% of restrictions involved 0-9 flights Restriction involving zero flights: 22:15 to 23:15 ZDC ZOB PIT arrivals Jets only NASELEMENT = GRV/HGR PIT ZOB Zero flights flew near GRV or HGR R=10 nmi or more ZDC Flights per restriction 15

16 Flights Subject to Multiple MITs MIT Restrictions Encountered per Flight (May 1-14, 2004) Flights matching Flights with multiple multiple MITs restriction points MIT restrictions Number encountered MITs / Restriction per flight Points count 1 % count 2 % 1 42, % 45, % 2 10, % 9, % 3 2, % 1, % % % % 8 0.0% more % 0 0.0% Total 56, % 56, % 16

17 Measuring En Route Delay Vectoring and Directs: d = Δ t ( 1 cosθ ) θ X X Amendments: airspeed Old route New route Airspeed controls: Filed airspeed DELAY Airspeed not measured below FL260 Type of delay detected Avg. minutes per flight Pct. tot. abs. delay Vectoring % Directs % Amendments % Airspeed Controls % time

18 En Route Delays and MITs 0.3 Non-restricted flights Mean = 1.1 min. Std. = 11.4 min. Restricted flights Mean = 2.8 min. Std. = 10.0 min. Fraction of flights or less or more Airborne delay (minutes per flight) 18 Data Source: Flights involved in en route and arrival MITs on May 1-14, 2004 and the non-restricted flights between the same city pairs

19 Examining Spacing Spacing during a 20-miles-in-trail restriction Distance to NASELEMENT (nmi) Excess spacing Flight departs from PIT Placed behind bank of flights 15:40 15:50 16:00 16:10 16:20 16:30 Time (Z) Time 19

20 Excessive Spacing Distribution of Extra Spacing Distribution of Potentially Avoidable Extra Spacing 600 Number of flights Actual Required Spacing (nmi) Number of flights Actual Required Spacing (nmi) (Capped by max airborne delay) 20 Data Source: Restrictions >= 10-miles-in-trail on 2/5/2004

21 MIT Impact on GDPs Arrival Count Arrival Compliance (mins) En Route Delay (mins) Total Percent (Actual - Controlled) arrival time Total Airborne Delay Airport Date Flights Restricted Restricted Unrestricted Restricted Unrestricted ATL 5/17/ % PHL 5/17/ % SFO 2/2/ % ATL 5/18/ % PHL 5/18/ % DFW 5/18/ % SFO 5/17/ % LGA 2/3/ % ORD 5/17/ % PHX 2/8/ % EWR 2/3/ % IAD 5/18/ % ORD 2/5/ % EWR 2/6/ % DFW 5/18/ % EWR 5/17/ % The GDPs examined had arrival compliance problems that were not (fully) attributable to poor departure compliance and had MIT restrictions controlling some of the GDP controlled flights.

22 Conclusions & Next Steps Conclusions Developed methods for identifying flights involved in MITs based on NTML and ETMS data 32% of the May 1-14, 2004 MITs involved fewer than 5 flights, suggesting that these MITs may not have been needed In our limited data set, MITs do not appear to have a major impact on en route delay, actual en route spacing, or GDP arrival compliance Next Steps Investigate departure delays linked to MITs Propose specific improvements to NTML that will improve data quality that will benefit future analyses Identify those regular restrictions that are not needed due to insufficient demand that can potentially be eliminated 22