Page 1 of 1

Boston 4R Approach Question

Posted: Mon Mar 30, 2015 5:22 pm
by 33lspotter
Probably a dumb question, but it's been bugging me and I figured I'd ask: how close does the wing or landing gear of, say, a 747 on final for 4R get to the nearest Massport cranes?

Last year, coming back from LHR on BA213, operated by 744 G-CIVF, I videotaped our approach and landing to Runway 4R; yes, I know I clearly positioned the camera the wrong way.  

When I was watching the video again, I noticed that we came what seemed awfully close to the Massport cranes—it almost seemed like the landing gear would hit the crane. And while it's obvious that we didn't make contact with the crane, I wondered if there is some kind of regulation for how close planes can be to the cranes. Furthermore, I can't imagine the cranes would have been placed in a spot where the aircraft would be at risk on approach from 4R or departure from 22L/22R (I haven't seen many planes land runway 4L.) Can anyone shed insight?

[Edited 2015-03-30 10:25:12]

RE: Boston 4R Approach Question

Posted: Mon Mar 30, 2015 5:26 pm
by alphaomega
Simple, they fly the published approach and no issues.

Massport does monitor the ship height of vessels passing in and out of the port, which can restrict or hold arrivals to 4R similar to a draw bridge, but thats the only real restriction.

RE: Boston 4R Approach Question

Posted: Mon Mar 30, 2015 5:53 pm
by Cactus105
Quoting alphaomega (Reply 1):
Simple, they fly the published approach and no issues.

Yep. If you take a peek at The ILS for 4R @ BOS, it is apparent that the Glideslope crosses said crane in between MILTT and the Middle Marker (MM). I also took a peek at google earth, and measured from the threshold to the shipping yard, and its around 1 mile. This specific Glide slope is 3.0 Degrees, which is standard. A general rule of thumb is 333' of descent per Mile for this angle. So as an estimate, the aircraft is somewhere in the neighborhood of 300-350 feet above the ground (or water) at this point in the approach.

http://155.178.201.160/d-tpp/1503/00058IL4R.PDF

RE: Boston 4R Approach Question

Posted: Mon Mar 30, 2015 6:21 pm
by 33lspotter
Very cool. Thank you both for your insight.