Steven P. McNicoll wrote:
wrote:

So did approach control screw up? I'm sure they had the last ATIS
report some 70 to 80 minutes old at the time of my request, and the
weather was good in that report.


If the tower had closed just fifteen minutes earlier approach may have
had a weather observation less than 30 minutes old.

Well, the tower doesn't issue a new ATIS (on the recording) just before
they leave, but I suppose they probably do make a weather report that
goes to FSS. I'm not sure if that ends up at the ARTCC or not. But
they are not there to issue a special observation after they leave,
which is when the fog rolled in.

So I'd guess that for this clearance to have been "proper" the weather
observers would have to still be there and ready to issue a special
regardless of how old the last scheduled observation was. But, from
the discussion so far, it appears that such a requirement is not
actually spelled out in the regs.



Interestingly, both the AIM and the 7110.65 say that a requirement for
ATC authorization of a contact approach is that "The reported ground
visibility is at least 1 statute mile."

But the AIM starts out by saying: "Pilots operating in accordance with
an IFR flight plan, provided they are clear of clouds and have at least
1 mile flight visibility and can reasonably expect to continue to the
destination airport in those conditions, may request ATC authorization
for a contact approach."


Well, a reported ground visibility of at leats one statute mile and a
flight visibility of at least one statute mile are not mutually
exclusive. While ground visibility can be determined quite accurately,
flight visibility is just a guess.

Yes, but I found it interesting that the AIM specifically says that a
pilot may request a contact approach (flight viz 1) in conditions
when the controller may not approve it (ground viz 1). I suppose
that wording is left over from the days when the controller had more
access to weather observations than the pilot?