Just a couple of issues to think about -
Fixed term accounts prevent weekly withdawls so no draw down.
Turkish Currency can be extremely volitile. 90% inflation isnt that long ago, the currency devalued substantially in the recent past and the inflation rate for this year was circa 10%. Present inflation rates are the best for 37 years, so, historically, it has a poor record for inflation.
There is a reason that Turkish Banks pay high interest - inflation and risk are large parts of that. This is why large corporations dont simply put all their money into a Turkish bank account !! It's just not that simple. If it where, it would be a nation of multi millionaires.
A common thread of financial advice is NOT to put all your earnings into Lira but to spread your bets as it where - have some in GBP, some in Lira. The economy in Turkey is seen as improving however, and inflation is presently decreasing.