Hello Guys/Gals, I've been noticing, and replying to A LOT, of posts, stating Phantom flying weird, ect., after crash or hard landing! Or any other unknown reason? So I'm posting this to try to help. IF you have crashed or experienced a hard landing, and your phantom is not acting right afterwards, Please follow these steps first, BEFORE YOU TRY TO FLY AGAIN! Ok, It is ALWAYS good to hook your phantom to PC ASSISTANT, to run Recalibration procedures. 1) ( this is up to you ) OPEN phantom shell, inspect for: A) loose/broken connections B) Broken components ( like GPS module, ect ) C) broken solder joints D) foreign debris ( dirt, dust, grass ect ) E) anything weird? 2) once convinced all is ok on the inside, hook phantom To PC assistant software. 3) check your MOD VALUES ( compass, accelerometer, and gyroscope ) A) gyroscope SHOULD BE ( 0.0 - 1.5 ) B) accelerometer SHOULD BE ( .98 - 1.02 ) C) compass SHOULD BE ( 700 - 2250 ) IF ANY MOD VALUES ARE OFF: 4) perform a ADVANCED IMU CALIBRATION! 5) power cycle phantom while still hooked to PC assistant Perform a Tx calibration, power cycle again, recheck all bars Are centered 6) take a quick look at all settings ( sometimes it reverts back to default ) Just make sure setting have not changed. 7) turn off everything , unhook from assistant, Go outside do a FRESH COMPASS CALIBRATION . She should be good as new! Hope this helps! Take care, fly safe!