Introduction: The introduction of high-performance fighter aircraft has led to changes in operational warfare and to unprecedented acceleration forces that have a three-dimensional effect on the human body. One of the biggest problems is the overloading of the cervical muscles of fighter pilots. More than half of all fighter pilots already suffered from cervical or lumbar complaints, which often led to limited flight perfor-mance or even to flight bans and thus to flight cancellations. The aim of this thesis is to examine the already implemented program "Human Performance Enhancement HPE" (meanwhile renamed "Human Performance Optimization HPO") with the example of a model association by means of quasi-experimental, ex-post longitudinal analysis for its effectiveness. Methods: Various physical and mental variables are considered in three study groups. Experimental group (EG) 1 (Eurofighter pilots), EG 2 (Tornado pilots) and control group (KG) (soldiers) with 25 participants each are tested for their psycho-physical performance at three test points within one year. All training/therapy units within the framework of HPE are documented and categorized by the execution personnel. The most important hypotheses at a glance: (1) Physical and mental performance increases more strongly in fighter pilots than in non-pilots during the course of the examination depending on a treatment (HPE intervention program). (2) The factors cervical strength and training/therapy frequency HPE have a positi-ve influence on orthopedically induced flight downtimes and are predictors of these. Inferential statistical analyses are subject to a significance level of α = .05. Differences are checked by means of t-tests for combined and independent samples and variance analyses with repeated measurements on one factor are performed. Correlation analyses by Pearson and Spearman, as well as multiple linear regression analyses are applied. Relationships, differences and interaction effects are shown with effect sizes. Results: The EG differs from the KG neither at the beginning nor at the end of the investigation in one of the physical and psychological variables considered. The 2-factorial variance analyses with repeated measurements do not show a statistically significant main effect in any variable due to participation in interventions in the context of HPE. Correlation analyses between mental and physical performance parameters do not show statistically significant relationships. Multiple linear regressi-on analyses suggest that fuselage strength endurance and training/therapy frequency in HPE are the most influential predictors of flight downtime. This statistically signifi-cant model reveals 50 percent of the variance in flight downtime due to orthopedic limitations. The model suggests that an increase in the training/therapy frequency HPE of a pilot by 18.5 hours could avert economic damage amounting to 60,000 euros. Conclusions: The present study provides findings for the Federal Ministry of De-fence and all flying units of the German Armed Forces. The results indicate that immense economic damage to the Federal Republic of Germany can be avoided by participating in intervention within the framework of HPE. Human Performance Enhancement has a decisive influence on the operational readiness of fighter pilots by increasing their functional fitness and reducing flight downtimes due to orhtopedic reasons.