Originally Posted by
ND76
The reason it takes 37 minutes, as opposed to 20-25, is that the route from DCA to LGA is one big zig-zag. Assuming the flight takes off from south to north, the plane follows the Potomac River to the Beltway (American Legion Bridge), then turns right and flies to the Chesapeake Bay Bridge, then turns north up the bay, then turns right at the Chesapeake & Delaware Canal, then turns left at the Delaware River, flies overhead PHL and then to a point somewhere over central NJ near the Raritan River, then turns east, then enters the pattern to land at LGA, which could mean circling NYC to the northeast and then landing to the southwest.
While it may seem like we are headed for those landmarks, you're a little off on track over ground and it's not nearly as convoluted as that, though the common delaying vectors given by Washington Center and New York Approach may make it seem that way. In ATC/Pilot speak, what you are describing is PALEO V44 AGARD KORRY3. The KORRY3 arrival into LGA is the same arrival for all traffic destined for LGA coming from the south and southwest. The AGARD transition to the KORRY is a special "onramp" to the arrival pattern specifically to allow traffic departing the DC metro airports to merge into the flow with all the planes coming from ATL, CLT, FLL, MCO, etc.....In fact, in many cases, even when the weather is fine in LGA there are release times out of DCA that are predicated on finding a 'space' to join the flow of overhead traffic already on the KORRY.