In short, this brings the US inline with the ICAO, in classifying heavy aircraft as greater than 300,000lbs MTOW.
So this means that all B757s, including those B752s modified to exceed the old 250,000lb MTOW, and the B753 are now all classified as large aircraft. The same separation standards still apply. So this will mean that you shouldn’t see any more heavy B757s flying around, let alone ATC asking ‘are you heavy today or not’ in their attempts to apply the right separation.
If you’re referring to the accident that killed the founder of In-n-Out, no.
The same separation standards apply to all B757s, not just one set for normal B752s, and another set for heavy B752s and B753s. So as far as wake turbulence separation goes, it is now all the same, and still gets the same cautions. They are just raising the MTOW limit to fall in line with ICAO standards, instead of having the B752 be on the cusp of it, while heavy B752s and B752s exceed the limit.
The separation is still there. What varied was that it was 4 miles for a B752, and 5 miles for a Heavy B752 or Heavy B753, because they exceeded the 255,000lb MTOW. Now that they raised the threshhold to 300,000MTOW, there is no longer that disparity, causing ATC to ask if they are heavy or not. the B757 is now in its own weight class, as far as separation goes.
because of the ambiguity, it was either 4 miles or 5 miles, depending on if the B757 was heavy. ATC wouldn’t know that if they were or not, so they had to ask. Now that it is raised to 300,000lbs, That ambuity is gone. It is 4 miles for a large or heavy aircraft behind a B757 regardless, and 5 miles if you are a small aircraft.
It’s not Nav Canada that defines the weight categories; it’s Transport Canada (the feds).
I’ll get the weights after my break (you think I remember by heart??!!!)
Ok… here we go:
Light: 15,000lbs or less
Medium: greater than 15,000lbs and less than 300,000lbs
Heavy: 300,000lbs or more.
There are also different radar wake separation standards:
Behind A380: A380 4 miles, Heavy 6 miles, Medium 7 miles, Light 8 miles.
Behind Heavy: A380 4 miles, Heavy 4 miles, Medium 5 mile, Light 6 miles.
Behind Medium: Light 4 miles, Medium or heavier, whatever sector minimum is (down to 2.5 miles in certain Terminal areas).