sentences:  By this point, the prototype had accumulated 500 flight hours, which included a five week-long marketing tour around America, have flown an average of 6.5 hours per day during this sojourn.While the company had forecast a wider market for trainer aircraft of roughly 5,000 aircraft over the following decade, it stated that it was aiming for an initial market share of 4 per cent (equivalent to 200 aircraft) due to the unorthodox nature of the Fantrainer.During 1983, the prototype was refitted, its seven-bladed ducted fan being substituted for a five-bladed production standard counterpart, while the cockpit was also improved; the changes reportedly enabled a significant noise reduction and superior external visibility.