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_18933037_3 (b_52_model VARCHAR, unit VARCHAR)

### Question ###
When 7th bw attached to 43rd sw is the unit what is the b-52 model?

### Accurate SQL ###

SELECT b_52_model FROM table_18933037_3 WHERE unit = "7th BW attached to 43rd SW"