"Gary Drescher" wrote

Look at 61.109 (Private Pilots, Aeronautical Experience). According to
61.109a2, you need "3 hours of night flight training in a
single-engine airplane that includes--(i) one cross-country flight of
over 100 nautical miles total distance". "Training" refers to dual
flights, so your night solo doesn't count. But any dual cross-country
flight of 100nm total distance does count. There is no straigh-line
distance requirement.

Notice the reference to "solo flight training" also in 61.109. It
would appear that "flight training" is not limited to dual flights.

Section 61.109: Aeronautical experience.
(a) For an airplane single-engine rating. Except as provided in paragraph
(k) of this section, a person who applies for a private pilot certificate
with an airplane category and single-engine class rating must log at least
40 hours of flight time that includes at least 20 hours of flight training
from an authorized instructor and 10 hours of solo flight training in the
areas of operation listed in §61.107(b)(1) of this part, and the training
must include at least—

Bob Moore