I'm well-aware of who has responsibility for what when accepting a Visual Approach and what my own is under FAA rules. Instrument flying 101. Thanks though
, I've been aware of them for about 40 years or so. Not sure if this this is your first foray into them because...,
I hate to break it to you, but I'm not incorrect, let alone glaringly, because (from your own source)
https://www.faa.gov/air_traffic/publ...section_7.html.
The generic Visual approach rule you referenced assumes the Visual approach clearance is received with no accompanying or further speed restriction issued by ATC. Speed-control restrictions are, as already mentioned, commonly re-stated/issued at SFO at the time Clearance for these 28 Visuals are issued. This restatement of a restriction is no different than for any Instrument approach when ATC desires or needs to retain positive control of spacing since issuance of any approach Clearance, Instrument or Visual, automatically cancels any previously assigned speed restriction.
Ignoring the effect that restating the speed restriction has on the Visual approach clearance when issued is not unlike ignoring that there is such a thing as a conditional clearance. For the purpose of clearing up your misunderstanding, it's not an unimportant detail.
Because details matter, ATC can and does restate/issue a speed assignment with the Visual approach clearance and it essentially becomes part of that Visual approach clearance,
so the generic rule you reference does not invalidate the restated/issued speed restriction (as it does a previously-assigned one). And, for the same reason ATC restates a speed restriction for an Instrument approach Clearance when they want to retain positive control for spacing, ATC does the same when issuing a Visual approach clearance; to retain positive control of spacing.
The only difference between a Visual and Instrument approach as far as Speed control and wake is what happens within 5 miles of the runway. But the subject is creating space to plug LH into the stream and the gap ATC needs to create for wake, not something that happens within 5 miles on any approach.
But, since you keep making your assumptions and hate my Manifestos, I'll assume you enjoy your own sources, so here's an excerpt from yours in the link above. Note, especially, points #9 and #10..
So yes, ATC does require one to fly a speed so restates the restriction when issuing the Clearance in order to retain positive control for required or desired spacing. SFO does it, as per the reasons in bold, and they are not alone in doing so. They also restate speed restrictions during Visual approaches at JFK, DCA, LGA...pretty much anywhere Charted Visual approaches are conducted and for the same reason. This shouldn't come as a shock to anyone except those who refuse to believe it's not a highly unsafe, free-for-all up there with pilots jockeying for position all over the sky just because "Visual" appeared in the Approach Procedure. No, it's pretty organised, controlled, and happens hundreds of time every day where Charted Visual Procedure are in use.
On the issue of "maintain visual separation" again, excerpts from your source... https://www.faa.gov/air_traffic/publ...section_4.html
The "maintain visual separation" instruction for pilot-applied visual separation is necessary if ATC wants to have aircraft positioned 750' apart side-by-side in pairs tracking the charted Visual inbound courses. While tracking those Visual inbound courses the aircraft targets on Controller's display with touch/merge, so pilot-applied visual separation becomes necessary in order to conduct them in that manner.
If ATC decides to alternately stagger aircraft with sufficient in-trail spacing during the Visuals (which does happen during off-peak hours), there is no need for the pilots to accept and confirm they will "maintain visual separation" when positive speed control is retained and ATC provides the approved separation.
The "maintain visual separation" instruction has nothing to do with the pilot jockeying his own speed to manage the in-trail spacing between himself and the aircraft miles ahead already spaced for wake turbulence by ATC. The Controller, by restating a speed restriction issued in conjunction with the Visual Clearance, is already providing-for and maintaining the wake turbulence spacing under positive control for as long as the positive speed control is valid, That's how they do it at SFO during the paired Visuals. Please don't keep repeating how something theoretically works, or can't work, until you've done sone ride-alongs in the cockpit to see how they work the Procedures.
What ATC is unable to do is see or provide for is lateral separation between the closely-spaced (750') paired aircraft, abeam each other with a slight stagger. If pilots are flying the Charted Visuals correctly, established on the inbound courses, the lateral separation will be there because that's how the Visuals are constructed. One is straight in, the other is Offset. The pilot only need to visually ensure and maintain the separation that flying to procedure establishes. Again, nobody has gets a clearance to eyeball and fly formation with anyone. The clearance is to fly a Charted Visual Procedure that has electronic lateral guidance and fly them at the ATC-assigned speeds until within 5 miles.
The excerpt directs a Controller "Do not permit an aircraft to overtake another aircraft when wake turbulence separation is required". The Controller can only prevent what he/she can clearly determine on the display, and the only way to prevent an aircraft from overtaking is through speed control. The Controller can see and prevent this for the pairs in-trail of other pairs, but the controller cannot see that the slight stagger between the aircraft that make up each pair, where pilot applied visual separation is, is being maintained. If a high-side aircraft in a pair overtakes the other and pulls ahead far enough, wake can become an issue. Therefore, the instruction.