This study evaluates the authenticity, verifiability, and alignment of Voluntary Carbon Offset (VCO) claims made by eighteen European airlines, aligning them with proposed EU regulations specifically targeting greenwashing practices. Our analysis focuses on four key components within VCO programs: measurement, integrity, significance, and alignment. Our findings reveal that European airlines are engaging in greenwashing practices in their VCO programs. The most compelling evidence lies in the insignificance and misalignment of these programs, indicating they are implemented without substantial impact on the airlines' mitigation efforts and are not integrated into their strategies. It is essential to clarify that this research does not delve into the intent behind greenwashing practices but rather aims to shed light on the potential for consumer misperception resulting from such practices. Despite some important limitations, the Greenwashing Directive represents a significant step towards enhancing transparency within the environmental sector, aligning closely with established academic frameworks.