Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_name_84 ( laps INTEGER, grid VARCHAR, time_retired VARCHAR, manufacturer VARCHAR )

### Question ###
What is the average number of laps with an accident time/retired, aprilia manufacturer and a grid of 27?

### Accurate SQL ###

SELECT AVG(laps) FROM table_name_84 WHERE time_retired = "accident" AND manufacturer = "aprilia" AND grid = 27