The steep decline in global air traffic caused by the COVID-19 pandemic and resulting recession has led to a weakening in aircraft values. For Turk Hava Yollari A.O. (Turkish Airlines; THY), the loan-to-values ratio (LTV) of the B777-300ERs collateralized against its 2015-1 enhanced equipment trust certificates (EETCs) have now deteriorated to levels that no longer support the collateral credit that we currently assign. Therefore, we lowered our issue-level rating on Turkish Airlines' 2015-1 certificate by one notch to 'B+(sf)' from 'BB-(sf)'. Health and safety factors. Based in Istanbul, Turkish Airlines flies to more countries and international destinations (318 in 2019) than any other carrier in the world. The airline was the 10th largest globally in 2019, after carrying 74 million