Originally Posted by
westhawk
Black of night doesn't count.
The Office of the Chief Counsel has a different opinion.
See para 5 in the opinion given to Joseph P Carr on 7 Nov 1984 by John H Cassady, Assistant Chief Counsel, Regulations & Enforcement Division.
To answer your first question, actual instrument conditions may
occur in the case you described, a moonless night over the ocean
with no discernible horizon, if use of the instruments is
necessary to maintain adequate control over the aircraft. The
determination as to whether flight by reference to instruments is
necessary is somewhat subjective, and based in part on the sound
judgement of the pilot. Note that, under Section 61.51(b)(3),
the pilot must log the conditions of the flight. The log should
include the reasons for determining that the flight was under
actual instrument conditions in case the pilot later would be
called on to prove that the actual instrument flight time logged
was legitimate.
Archived as Legal Interpretation # 84-29 in a set of Chief Counsel opinions on logging time available here:
http://www.offhand.org/amb/pic-time.txt