Perth Airport has given itself a "C minus" for the state of the airport which has had the most sustained growth for a capital city airport in Australia.
In the past five years, the number of passengers using the main terminals has leapt 44 per cent to 12.6 million for the year to June 30.
Plane movements jumped the same percentage to 142,000.
Airport chief executive Brad Geatches admitted yesterday "we deserve the flak" because the experience at the airport was very poor in peak periods.
"International arrivals is the worst experience of all," Mr Geatches said. "We rate our customer service as C in peak periods but much better at other times."
The Australian Competition and Consumer Commission rates the service at Perth Airport as "good", which Mr Geatches says is "hard to believe".
But he said a vastly better service was only months away.
"The $750 million we are investing will see As all round," he said.
"The terminal developments we have under way will make a dramatic difference. The new regional domestic terminal, which opens early next year, is looking great."
Called Terminal 2, it will service regional airlines such as Skywest, Alliance and Tiger.
The building, which will be light and airy, will be finished early in December for about six weeks of testing.
International passengers will see big changes within a year when the new arrivals area at the western end of the international terminal opens.
However, Mr Geatches is still concerned that Federal Government border protection agency cuts will lead to restricted staffing levels.
"We are building a state-of-the-art facility but staffing issues are unclear," he said.
A new A380 gate is being fast-tracked to be ready in 12 months for plans to cater for the giant 490-seat plane in Perth as part of the airport's expansion plan with Qantas.
The final expansion phase at the new international terminal (T1), the new Virgin domestic pier and the international departures upgrade will be ready by mid 2014.