Conversation so far:
What is the H-4 hercules?
HK-1 Hercules flying boat.
What was the use of the flying boat?
use during World War II to transport troops and equipment across the Atlantic as an alternative to seagoing troop transport ships that were vulnerable.
How much did the hercules cost to make?
CANNOTANSWER.
Was the hercules used for many missions?
The Hercules flew only once for one mile (1.6 km), and 70 feet (21 m) above the water, with Hughes at the controls, on November 2, 1947.
Did the boat have many critics?
Howard Hughes was summoned to testify before the Senate War Investigating Committee to explain why the H-4 development had been so troubled.
Did hughes win this battle?
Hughes turned the tables on his main interlocutor, Maine Senator Owen Brewster, and the hearings were widely interpreted as a Hughes victory.
Is there any other interesting aspects about the hercules?
On November 4, 2017, the 70th anniversary of the only flight of the H-4 Hercules was celebrated at the Evergreen Aviation & Space Museum.

Question: Was the anniversary well attended?
Self-contained rewrite: Was the Howard Hughes' H-4 Hercules anniversary well attended?