You may be able to terminate your lease without penalty. All leases come with what's known as the "implied warranty of habitability." This is the legal obligation that the rental premises be fit for their intended purpose--in this case residence. Things that make it unhealthy or unsafe to reside there can violate this warranty.There is also what is known as the covenant of quiet enjoyment, or the requirement that the tenant be allowed to "enjoy" his/her rental without unreasonable interference by the landlord or other tenants.Storing jet fuel (which has safety and health issues) under your apartment can violate the implied warranty of habitability; having planes take off and land withing 20 feet of you all day and night would seem to violate the covenant of quiet enjoyment (noise) also the implied warranty of habitability (safety).These violations could provide grounds to terminate your lease without penalty and/or to seek monetary compensation (e.g. the cost tomove elsewhere). In addition, if the garage is not properly zoned for this commercial use and/or the proper permits have not been obained, it may be illegal for the helicopter tour company to operate out of it or in this neighborhood.Therefore, from what you write, you seem to have rights which you can vindidate. You should speak with a landlord-tenant attorney about your options.