EASA publishes world’s first proposal on assessment and limitation of noise generated by eVTOL aircraft

The Euro­pean Union Avi­a­tion Safe­ty Agency (EASA) has pub­lished the first pro­pos­al world-wide for the assess­ment of the noise gen­er­at­ed by air taxis, address­ing one of the top soci­etal con­cerns for eVTOL air­craft.

The Envi­ron­men­tal Pro­tec­tion Tech­ni­cal Spec­i­fi­ca­tions (EPTS) are applic­a­ble to air­craft pow­ered by mul­ti­ple, ver­ti­cal, non-tilt­ing, even­ly dis­trib­uted rotors.

The EPTS doc­u­ment defines har­monised noise assess­ment cri­te­ria that could be used in the type cer­ti­fi­ca­tion of this eVTOL-capa­ble air­craft with this type of design. The aim is to reach a high, uni­form lev­el of envi­ron­men­tal pro­tec­tion and to pre­vent sig­nif­i­cant harm­ful effects of noise on human health in the EU, as man­dat­ed by the EASA Basic Reg­u­la­tion. It includes the applic­a­ble noise tech­ni­cal spec­i­fi­ca­tions and pro­ce­dures as well as max­i­mum allow­able noise lev­els.

Patrick Ky, EASA’s Exec­u­tive Direc­tor, said: “When EASA con­duct­ed a Europe-wide sur­vey on Urban Air Mobil­i­ty in late 2021, noise was high­light­ed as one of the major con­cerns by par­tic­i­pants with respect to air taxis, along with envi­ron­men­tal con­cerns and over­all safe­ty. This pro­pos­al address­es those con­cerns, describ­ing ways to mea­sure the noise pro­duced and set­ting lim­its to ensure that the noise pol­lu­tion is not exces­sive.”  

The pro­posed spec­i­fi­ca­tions are intend­ed to fill a reg­u­la­to­ry gap and took the inter­na­tion­al­ly har­monised noise cer­ti­fi­ca­tion stan­dard applic­a­ble to heavy heli­copters as a start­ing point, to allow for a lev­el play­ing-field and com­pa­ra­bil­i­ty of tech­nol­o­gy.

The pro­ce­dures defined are adapt­ed to the char­ac­ter­is­tics of eVTOL air­craft where nec­es­sary. For exam­ple, as eVTOL are expect­ed to be qui­eter in cer­tain phas­es of flight there is a need to allow them to fly clos­er to the micro­phone in cer­tain flight phas­es to main­tain a min­i­mum sig­nal-to-noise qual­i­ty.

In addi­tion, a hov­er noise assess­ment has been devel­oped to aid the noise assess­ment of oper­a­tions in the vicin­i­ty of ver­ti­ports.

The max­i­mum allow­able noise lev­els are kept iden­ti­cal to those of the most recent heavy heli­copter lim­its from the Inter­na­tion­al Civ­il Avi­a­tion Organ­i­sa­tion (ICAO Annex 16, Vol­ume I, Chap­ter 8.4.2), while EASA col­lects more noise data from such designs through cer­ti­fi­ca­tion projects.

The EPTS doc­u­ment is open to pub­lic con­sul­ta­tion until June 15th, 2023. Com­ments can be sub­mit­ted through the Com­ment Response Tool on EASA’s web­site, by click­ing here.