21-27-04 is equipment cooling exhaust fan norm/alt R/R. 21-27-02 is equipment cooling fan norm/ exhaust fan R/R. 700 models
All individual ATA chapters listed along the top – hover over numbers for drop down
21-27-04 is equipment cooling exhaust fan norm/alt R/R. 21-27-02 is equipment cooling fan norm/ exhaust fan R/R. 700 models