The previous aiREFORM Post presented a sequence of eight arrivals from California to SeaTac [KSEA], during a half-hour window from 10:22 to 10:52 on Thursday May 12th. The sequence showed some very substantial enroute delays, mostly over Oregon. Well, it turns out the exact same series of arrivals had very similar (and again substantial) enroute delays on the very next day, during the time window 10:13 to 10:49 on Friday May 13th. Here is a JPEG compilation:
Here are the important points to be made, looking at these KSEA arrivals for both days:
- For all flights, with the exception of the enroute delays, the routes are incredibly direct … proving that the current system is fully capable of maximizing efficiency by minimizing distance flown. That is, we do NOT need any new technologies to accomplish direct flights.
- In the big picture, SeaTac is a relatively simple ATC example, in that it is remote (far northwest corner of the nation), far removed from saturated delay-prone hubs (mostly in the northeast), has no major complications related to other airports, and has a very simple triple-parallel runway configuration.
- Despite this simplicity, empirical evidence viewed online indicates ATC begins imposing enroute delays to KSEA arrivals, even in perfect clear weather, whenever the arrival rate gets to around 30-40 aircraft per hour or more.
- SeaTac’s problems relate entirely to its current use as a hub by Alaska, Delta, and Southwest. Delta is the new player, aggressively initiating a hub expansion in 2014. At KSEA, Delta’s growth is creating many periods each day, with arrival flurries that necessitate enroute delays and long, inefficient landing patterns (e.g., extended downwinds to 20-mile+ finals).
- That the problem is caused by too many arrivals is proven by looking at the arrival data, and comparing days of the week that are slowest against days of the week that are busiest. Routinely, Thursdays and Fridays are two of the busiest days, while Saturdays are nearly always the slowest day of the week. As presented in this pair of aiREFORM Posts, the eight flights are all delayed on both Thursday and Friday. Odds are, if you study the routes for any of these same eight scheduled flights as conducted on a Saturday, you will find that no enroute delays were issued … simply because ATC is working 10-20% fewer arrivals.
- To accommodate an industry preference for large hubs (which maximize airline profits), FAA’s approach in the past decade has become to serve only the airlines and at the expense of taxpayers/citizens. Coincident with the evolution of the NextGen program, FAA’s efforts have included a wholesale abandonment of procedures that mitigate environmental impacts, while also doing the following:
- maximizing flow rates in/out of the airport (the term used in the industry is ‘runway throughput’);
- removing all airport-specific noise mitigation procedures (some of these date back to the 1970s, and billions have been spent installing noise insulation reference these procedures);
- creating RNAV departure routes that minimize distances flown, by allowing the earliest possible turns, in some extreme cases immediately after taking off;
- creating RNAV arrival routes that minimize actions by both ATC and pilots, proceduralizing the arrival into a steady repetitive stream along a narrowly defined route with a steady descent rate; a key part of this strategy is to get pilots to let the autopilot fly the arrival;
- Logically, FAA could manage/avoid hub-related delays by simply regulating hub traffic levels, to ensure arrivals never exceed a sustainable arrival rate upper limit. But, FAA refuses to regulate this, apparently due to their desire to accommodate the industry.
- The Av-Gov complex (and, yes, that includes shills like Bill Shuster) is pitching NextGen, but the technology essentially already exists, and has been in use for decades. Nonetheless, and despite rational opposition, they continue to pitch this in order to spend billions padding the financial positions of Av-Gov players (which includes many FAA employees who retire early and collect pensions but supplement their retirements working in industry!), while also using ‘NextGen implementation’ as an excuse to implement noise-impactful new RNAV routes.
- These two aiREFORM Posts look at the impacts related to KSEA, but the exact same situation is ongoing (and even worse) at many other major airports, including KSFO, KPHX, KCLT, KBOS, KLGA, KORD, KDCA, and KJFK.
- We can have all the whiz-bang technology we can buy, but if we allow the major airlines to schedule even brief arrival flurries that exceed airport capacity (which is ultimately a function of runway configurations), we will see delays. And, these delays not only magnify the environmental impacts of aviation, but they also wipe out all efficiency improvements that are potentially realized with more direct RNAV routes.
- The agency is failing, and our elected officials are also failing us. They are too busy fundraising, abandoning their duty to serve constituents. Like FAA, Congress has become too beholden to money.