HelicoptersofDC is dedicated to bringing DC residents the most accurate and up-to-date information on what's overhead and to foster collaboration and education about helicopter identification and mission profiles. Last year's GAO report found that 96.3% of helicopter noise complaints to the MWAA from 2018-2021 were unattributed to any specific operator - this is why we feel it's important to educate the community on helicopter identification in addition to reporting what is happening currently and why.
I'd like to thank our Patreon supporters, their contributions cover server costs and allow me to invest in hardware to bring radio calls to the platform.
Many flight tracking sites like Flight Aware, Plane Finder and Radar Box remove flights as a paid service to the owner. Even ADSBExchange, which doesn't filter any flights, does not receive tracking information from most military helicopters due to the Code of Federal Regulations Title 14, Chapter I, Subchapter F rule 91.225 which makes an exemption to mandatory flight transponders for "sensitive government mission for national defense, homeland security, intelligence or law enforcement." This makes an enormous amount of helicopter flights over the NCR untraceable in any systematic way. As a result, we rely on user submitted photos and identification of helicopters in addition to a separate system that allows users to categorize helicopter radio calls to/from DCA tower.
All CopterSpotter reports are voluntarily submitted, and thus cannot be considered a measured random sample of the full population of like events. One thing that can be reasonably expected from Copterspotter data is that the number of reports received represents the lower measure of the true number of such events that are occurring.
A unique quality to Copterspotter data - unlike ADSB - is it inherently represents the helicopters that people notice. In other words: if a helicopter flies over a forest and no one is around to hear it, as far as CopterSpotter is concerned - it didn't happen. Another way of thinking about it: CopterSpotter is like the Nielsen ratings of DC helicopters: what helicopters D.C. residents are currently watching.
Another inherent bias to the system is the location of its users: it was my (all of our) hope that in 2021 our geographical range would expand, and so with it would CopterSpotter data. However user data seems to still be rooted near their homes for now, thankfully we have several contributors situated along major helicopter routes.
One bias we acknowledge is what we will call "rarity bias," or that someone would decline posting a medevac helicopter, for example, because it is too common and does not interest them. As a spotter, you can mitigate this bias by deciding whether you will post a CopterSpotter sighting before you see or attempt to photograph the helicopter.
Luckily the DC area is uniquely positioned to benefit from CopterSpotter data because:
1. The high proportion of military and government agency flights that are not reported on ADSB
2. Operators can be reasonably inferred by aircraft type. If a user can identify type based on blades on the primary rotor, landing gear and tail shape, we can infer the operator with a high degree of accuracy.
We want researchers and residents to have access to this data so we have made an anonymized copy of the 2021 data set, after corrections were made to types based on provided images, available for download in the CSV format here.
Most spots on a given day:
February 3rd: 96 spots
January 20th: 95 spots
April 19th: 94 spots
The leaderboard to the left shows our most active spotters, who collect 1 point for each spot and an additional point for attached media. Presently transcriptions of helicopter radio traffic are worth 2 points each.
Active users decreased proportional to unknown helicopter spots January through October.
2 Big Reports
One thing that appears in both reports is the phrase "helicopters are required to follow the helicopter routes and altitude restrictions
established and enforced by FAA" yet in the previous paragraph they acknowledge frequent deviation from these routes. What is not mentioned nor shown on their limited route chart is the use of "Zones" that cover the NCR.
Over a limited 2-month sample of the radio calls we collected from the last year, helicopters requested zones in 75 of 200 requests.
While we can't draw an apples-to-apples comparison between these two data sources it is valuable to look at the data the two agencies provided side-by-side. The DoD report notes the difference in detail:
"Government Accountability Office (GAO) Report GAO-21-200 counted 11,011 military helicopter flights within the NCR in 2019, including Department of Homeland Security flights, which is substantially lower than the 21,863 flights reported in CY 2020 by the Army, Marine Corps, and Air Force. However, it is important to note that GAO used available flight track data from FAA and limited its data collection to flights within 30 miles of Ronald Reagan Washington National Airport, which differs from the prescribed scope of this report."
Again, not an apples-to-apples comparison, but interesting to look at the proportional rates of our data compared to GAO, and we roughly fall in line with the ranking, though local law enforcement is relatively over-represented while air medical is relatively under represented in our data set. It's easy to infer why as local law enforcement is the most likely operator to fly circles over your neighborhood.
While we fit our data as best we can to their categories, the following conflicts arise with type designations:
The Air Force 1st Helicopter Squadron's primary mission is to be prepared to evacuate high-ranking personnel from the Capital area in the event of a national emergency. It also supports Washington D.C. area airlift for high-ranking Executive Branch, dignitaries, military leaders and other VIPs. The squadron also supports search and rescue missions. [Wikipedia]
The President's New Copter
from burning holes in The White House Lawn to *almost* ready for action
The Sikorsky VH92A has been slated to take over for the aging VH3D. Through various operational tests this year it has had numerous setbacks and we expect testing to continue through 2022.
2022 and Beyond
Currently a bot tweets helicopters with ADS-B transponders over the NCR every 10 minutes. One of my top goal is to build a more intricate system that looks at craft patterns and will de-prioritize flights that are circling or landed for example. The goal being to lower the frequency of automated tweets to make the account more attractive to Twitter power users.
We have been logging every photo to Roboflow (the founder is based in D.C.!) and intend to implement a computer vision model to include a "guess" at the helicopter ID when someone posts an unknown copter.
Since October we have been logging spotters' transcriptions of helicopter radio calls and will be thinking of a way to present this data next year.