1 / 14

Treatment of Flights in Stack Hours and Extensions

Treatment of Flights in Stack Hours and Extensions. Flights in Stack Hour. Stack hours - the hours after the GDP end time Flights scheduled to arrive AFTER the GDP end time are EXCLUDED and do NOT get slots Example: GDP from 1600-2059

ebony-donovan
Download Presentation

Treatment of Flights in Stack Hours and Extensions

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Treatment of Flights in Stack Hours and Extensions

  2. Flights in Stack Hour • Stack hours - the hours after the GDP end time • Flights scheduled to arrive AFTER the GDP end time are EXCLUDED and do NOT get slots • Example: GDP from 1600-2059 • Flight scheduled to arrive at 2059 will be delayed and issued a slot • Flights scheduled to arrive at 2100 or after will not receive a delay or a slot (not available for substitution) • Under simplified subs, airlines will be able to voluntarily control excluded flights in the stack hours to re-order flights (Thanks, Roger)

  3. Stack Hour AAR’s Effect on Extensions • FSM allocates slots in the stack hour based on the stack hour AAR • If the lower program rate is used (extension expected) • fewer slots will be allocated in each hour • additional delay may be incurred initially - unrecoverable delay if conditions improve • controlled flights will receive less additional delay in extensions • If the higher default AAR is used (extension not expected) • more slots will be allocated • less delay will be incurred initially • more delay will be received if there are extensions • Slots are “reserved” for excluded flights that would be exempt in the case of an extension

  4. BEFORE EXTENSION SFO 10/30/2000 - 6West Example At 2315, it was decided to run a pure extension from 0200-0359. The stack hours were set to the program rate (30). Due to the number of cancelled and excluded flights, few slots were left for the non-cancelled controlled flights to fill. The stack extended for five hours. (Since a pure extension was run, flights were not compressed into cancelled slots that were earlier than 0200.) AFTER EXTENSION

  5. Is There Something Better? SFO 10/30/2000 - 6West Example Setting the stack AAR to the default (60) keeps most of the stack in the two hours after the end of the program. This is a good option when the program is not expected to be extended again. For airports that tend to run programs all day long (LGA), this only postpones the delay flights will eventually obtain. HIGHER DEFAULT STACK AAR (PURE EXTENSION)

  6. BEFORE EXTENSION STL 7/28/2000 - ALL Example At 1654, it was decided to extend the program. With the end time currently at 2159, the spikes after the 2100 hour are normal. The cancelled flights were moved to the 0300 hour mostly as a result of substitution. At 1702, the program was extended to 29/0059, pushing a large number of cancelled flights into the 0100 hour and extending the stack for four hours. AFTER EXTENSION

  7. What Happened? • The cancelled slots showing up in the hour after the end of the program is not unusual in itself because cancelled flights will be compressed to the end of the program for all non-bridge-only carriers. • But then the question becomes, “Why weren’t the cancelled slots moved even later since there are so many controlled flights in the 0200 and 0300 hours?” • Looking at the analysis report from the revision revealed that although all of the cancelled flights were included in RBS, not all of the cancelled flights were included in the compression - Only open slots with slot times before the program end time are eligible for compression in RBS++

  8. How Do We Smooth Out Demand? • Compression only affects controlled flights so there would still be a spike of light green flights departing without EDCTs in the 0100 hour. • Extending the program until 0259 to include the cancelled flights and those not previously controlled would smooth out demand.

  9. STL 7/28/2000 - ALL Example Compression only moves the controlled flights, creating a spike in the 0100 hour. Extension includes flights not previously controlled as well as the cancelled flights. COMPRESSION WITH END TIME = 9999 EXTENSION WITH 0259 END TIME

  10. What Was Done STL 7/28/2000 - ALL Example At 1806, the GDP was extended until 29/0559

  11. Summary • The AAR for the stack hours should be decided based upon the expectations of the program. • If it appears that an extension will be necessary, keeping the stack AAR lower will help spread out the flights early on. • If it looks like the program may be cancelled early or not need to be extended, the higher default AAR is acceptable.

  12. Back-up Slides

More Related