N737ER wrote:In addition to everything that atcsundevil mentioned in his post (
viewtopic.php?f=3&t=1456155&start=50#p22695325), I'll dive into the Airport Arrival Rate (AAR) for DCA, and a notorious East Coast airport: EWR.
DCA using Rwy 1 the AAR (Airport Acceptance Rate) ranges from 36 (VMC>2000/3) to 30 (Low IMC). DCA Runway 19 AAR ranges from 32 (VMC>2000/3) to 26 (Low IMC)
EWR using 4L/22R for departures and 4R/22L for Arrivals the AAR ranges from 40 (VMC >2000/3) to as low as 26 (Low IMC)
*I'm not getting into the weeds on the special configurations that EWR can run such as arriving Rwy 11 Land and Hold Short of 4L/22R (only adds 8 to the rate and only used in VMC<2000/3 conditions).
EWR, an airport with two parallel runways spaced 950' apart that are used with departures on the inner runway, and arrivals on the outer, can only accept 4-8 more arrivals per hour during good weather, and the same number of arrivals during adverse IMC as the current DCA. If and only *IF* a new runway was to be built there would only likely be an increase in the arrival rate during good weather days. There is not enough of a gain during all weather conditions to warrant spending at least half a billion dollars on a new runway.
Limited Airspace aside, the residents in Rosslyn and up the Potomac towards the American Legion bridge would fight this bitterly from the start. These people complained of noise increases when the new RNAV procedures were put in place years ago. In fact groups in Arlington, Montgomery County, and DC are
*STILL* complaining about noise from DCA's flightpaths (
https://www.msn.com/en-us/news/us/arlin ... r-BB1aNdiW). Note that DCA already has noise regulations for operations between 2200 and 0659 (
https://www.flyreagan.com/dca/dca-reaga ... noise-rule)
Personally I think any benefit that could arise from a parallel 1/19, is likely already acheived with the occasional arrival/departure on 15/33 (I've seen A319s and smaller both arrive and depart 15). If MWAA is going to spend $500m to $1b on something, it should be replacing C/D at IAD, not a new runway at DCA.
Oh good, someone showed up who actually knows what they're talking about. I'm in a center and I normally try to stay in my lane
at least it sounds like I was on the right track. Even if an efficiency gain were worth the expense, and if it managed to clear the very high hurdles the environmental studies would pose, any longtime DC resident would know that there ain't no way the NIMBYs will let it happen. There is a literal army of high powered lawyers that live on DCA's doorstep, and they will litigate another runway into oblivion.
N737ER wrote:
IAD absolutely needs this runway, and I believe it is likely to happen within the decade. I'm sure you're aware, but others may not be — 12/30 is a pretty vital runway at IAD. It gets regular daily use, but several times a year, ops are restricted to the crosswind due to weather conditions. It always seems to happen during the afternoon arrival push, forcing all departures and arrivals onto the crosswind (usually 30). Needless to say, it's a freaking mess when that happens. It's the same kind of mess the handful of times each year when DCA can only operate with the RNAV RNP to 19. Most RJs don't have RNP, so more often then not, it's indefinite holding followed by a diversion. A second crosswind at IAD would be enough of an efficiency and operational gain to be worth the expense, even if the total number of ops running from IAD doesn't necessarily translate to the airport needing five runways.
blockski wrote:It's true that the crosswinds do get some use at DCA, but 'extensively' is a stretch. The DCA noise report has some data from 2019 (page 8):
https://www.flyreagan.com/sites/default ... report.pdf The crosswinds (15/33 and 4/22) were used for a total of 6% of all arrivals (the vast majority of which happened on 33) and 7.1% of all departures (again, the vast majority of which use 15/33)
Definitely. I said in my last post that DCA is effectively a single runway airport, and this is why. I honestly wonder why they even keep the other two. I'm sure there's a reason, but it seems like a big maintenance expense for fairly limited use.
EssentialBusDC wrote:Especially compared to Dulles. (With Potomac Control and Center contributing both positively and negatively)
I'll assume only positive stuff for the Center side? If not, I have holding instructions, advise when ready to copy
IADCA wrote:And if you wanted to more cheaply spend money and time on landfill for runway space at DCA, you could extend 15/33 to allow more mainline takeoffs on 15. Not that it can't be done at present - one of my most memorable takeoffs was a 752 on DCA-DEN from 15, which is 5,200ish feet - but even a few hundred feet would make a difference.
But as you said, there are better places to spend the money.
Landfill into the Potomac to extend 15/33 wouldn't be possible. The Potomac is actually pretty narrow through there, and the environmental impacts would absolutely prevent it from happening. The river moves with a hell of a lot of force through there, and narrowing it would only make things more extreme. I'm also not 100% sure, but I don't think runways can be built new or lengthened so as to require an EMAS. I believe an EMAS pad is retrofit only, so it can't be relied upon to aid in lengthening the runway. If something ever did happen, the FAA would be big time sued.