Farewell, Heavy B757.

[tyketto]

The FAA just put out a notice about the weight class defining the B757:

http://www.faa.gov/documentLibrary/media/Notice/N7110.525.pdf

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.

BL.

[wazzu90]

Yeah but, what about spacing behind a 757?

[tyketto]

@wazzu90

Yeah but, what about spacing behind a 757?

No change, except for what happened if anything followed a Heavy B757.

Large behind B757 was 4 miles. Large behind heavy B752s, B753s, and anything heavier was 5 miles.

Now, Large behind all B757s is 4 miles regardless.

All other separation minima still applies.

BL.

[nssd70]

I have never heard ATC at KDSM refer to any 757 as heavy,only 767,A300,and of course a 747.

Doug

[flyboy97222]

@nssd70

I have never heard ATC at KDSM refer to any 757 as heavy,only 767,A300,and of course a 747.

Doug

I’ve heard ATC ask if they are a heavy today- several times.

[azav8r]

@nssd70

I have never heard ATC at KDSM refer to any 757 as heavy,only 767,A300,and of course a 747.

Doug

UA and UPS 757’s aren’t categorized as “heavy” 757’s.

[wazzu90]

So we’re back to flipping Citations?

[tyketto]

@wazzu90

So we’re back to flipping Citations?

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.

BL.

[deef1999]

So, because it isn’t a “heavy” anymore, the 5 mile seperation isn’t needed?

Yeah, that makes sense.

[nssd70]

@azav8r

@nssd70

I have never heard ATC at KDSM refer to any 757 as heavy,only 767,A300,and of course a 747.

Doug

UA and UPS 757’s aren’t categorized as “heavy” 757’s./quote

Thanks,I didn’t know that.

Doug

[wazzu90]

@tyketto

@wazzu90

So we’re back to flipping Citations?

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.

BL.

I was thinking of the Citation at Billings. I think the In-N-Out related crash was a Westwind. But yes, they were both trailing a 757.

http://www.aopa.org/asf/asfarticles/sp9403.html

[ericvap]

I think there was also a IAI Westwind and 1 other (737?) a total of 4, that had loss of control in trail of 757 before they increased the distance.

[tyketto]

@deef1999

So, because it isn’t a “heavy” anymore, the 5 mile seperation isn’t needed?

Yeah, that makes sense.

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.

Before, it was this:

1.Heavy behind heavy- 4 miles.
2. Large/heavy behind B757- 4 miles.
3. Small behind B757- 5 miles.
4. Small/large behind heavy - 5 miles.

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.
BL.

[MrBurns]

In comparison, Canadian ATC (and Transport Canada) always listed the 757 as a medium aircraft when following, heavy when followed.

[tyketto]

@MrBurns

In comparison, Canadian ATC (and Transport Canada) always listed the 757 as a medium aircraft when following, heavy when followed.

Which brings up the question… how does NavCanada define a heavy aircraft? Are they going off of something that isn’t ICAO standard? If so, what is that criteria?

It’s that criteria that the FAA changed, eliminating the B757 as being anything heavy. The same separation standards apply…

BL.

[MrBurns]

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).