when my aircraft had been upgraded by hhr to the glass cockpit standard , a new radar altimeter had been fitted , along with the upgraded communications and gps-aided navigational suite , so in theory my aircraft had one of the most up-to-date cockpits in the aviation industry , although it was surrounded by a geriatric fifty year old airframe , but it had still been four hundred and ninety-five feet out , exactly , at sea level , but not throughout its entire range .