Ep. 243: How Far Off Course CAN You Get on an Approach?

[@aviatortrevor]

That group of buildings is just past WEVPU, which is at 1100' MSL. That particular building is about ~360' MSL. The tallest building in that area is ~470' MSL. Technically, you'd be allowed to dive-bomb to the MDA (720' MSL) after WEVPU (1100' MSL), but if you were following the 3.04 degree glideslope, you'd arrive at MDA somewhere between Theodore Roosevelt Island and the Arlington Memorial Bridge. Realistically, if you weren't maneuvering wildly, you'd be around 900-1000' MSL when passing over that ~360' MSL building. In order to hit that particular building, you'd need to go 360' below MDA. I mapped the approach waypoints in foreflight and looked at the aerial map, and also used google earth to piece all that info together. Also some trigonometry to approximate where a plane would be if they were flying the 3.04 degree glideslope (I know this approach doesn't have glideslope guidance, but the IAP shows a 3.04 degree glideslope to hit each altitude along the way). Also, nit-picking here, but in the video you mention the hypothetical of being right-of-course, but your HSI graphic shows you left of course =P

[@aviatortrevor]

A 3 story building is 360 feet high??? If each story was 10 feet, that would be 36 floors. 15 feet per floor is probably a better estimate. That would be 24 floors. I did some research. That building is the "CEB Waterview" building at 1919 N. Lynn Street, Arlington VA 22209. I counted stories, and at most it would be about 26 stories. At 10 feet per story, that would be 260 feet tall (less than my number). I couldn't find much through google, but one site claimed it was 390 feet tall. Add the elevation to that, and you've got maybe 410-440' MSL. The sectional chart shows the tallest obstruction in that area is 470' MSL, and the CEB building is not the tallest building in that bunch. The original number of 360 feet I got from google earth, which displays elevations of terrain and building structures if you point your mouse at the right spot.

[@mytech6779]

The required clearance(buffer) and the shape of the obstacle clearance surfaces are strongly dependent on the type of approach and leg of the approach.

[@ryfle6012]

That’s a really really good point.

[@scottfranco1962]

Wow awesome example.

[@NikkoMamallo]

Great info! Having a bit of fun with your closing screen? ;) Wouldn't the pilot of an aerobatics plane be wearing a parachute to avoid exploding such as this guy?

[@hangyeolpark2304]

If LDA's off set is more than 30 degree from runway extended center line, still we can use straight in minimum?

[@mytech6779]

There will be no straight in minimum if it is not approved for a straight in landing.