Wing Drone Delivery Noise: Australians complain, “It’s gone too far!”

Some res­i­dents from Logan, Bris­bane have had enough of Wing’s deliv­ery drones fly­ing over their homes, on occa­sions close to eighty times a day, reports Aus­tralian Chan­nel 9 pro­gram, ‘A Cur­rent Affair’. “They are very very noisy,” says one res­i­dent. “It’s gone too far!”

For exam­ple, Dan Ling has to put up with Wing’s drones fly­ing over his house, often eight times an hour, each day and every day. He describes the noise like that of “a swarm of mos­qui­toes.” Anoth­er res­i­dent says, “They sound like a fly stuck in your bed­room when try­ing to sleep”; a third describes them sound­ing “like a dentist’s drill.”

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Apart from being attacked by birds (!) the Wing’s drones vul­ner­a­bil­i­ty has always been its noise. The com­pa­ny is acute­ly sen­si­tive to the issue and why few if any of the company’s videos mar­ket­ing the deliv­ery ser­vice has the fly­ing sound incor­po­rat­ed. Instead, it is washed over by a music back­ground.

Just over a year ago, Wing was able to reduce the noise of its drones, but this is still not enough, it seems, for some res­i­dents liv­ing under a flight path.

Ling tells the cur­rent affairs reporter, “I feel annoyed as it actu­al­ly stress­es me some­times. You’re sort of chill­ing out after work­ing all day and you hear the buzzing noise like a very very loud mos­qui­to and it gets loud­er and loud­er.” He adds, “We feel like we’re pris­on­ers to this noise. We have to close the front door because you can hear it com­ing.”

Dan Ling

Drone deliv­ery ser­vices have been intro­duced in sub­urbs across Aus­tralia. In Logan alone, Wing has made over 75,000 deliv­er­ies this year from trans­port­ing fast food and drinks to small gro­cery items. 

How­ev­er, anoth­er res­i­dent, Dale Carter, who lives close by from Ling says he uses the ser­vice every day and loves it. “I don’t see much of a prob­lem. If you’ve got a busy road close by, you hear cars and trucks. It’s no dif­fer­ent.” Carter says he often places six or more orders a day, there­by being part­ly respon­si­ble for Ling’s tor­ment.

In a state­ment to ‘A Cur­rent Affair’, a Wing spokesper­son said it has only received a hand­ful of com­plaints through­out sev­er­al years of oper­a­tion. It reads, “While the num­ber of com­plaints is low, we take any com­mu­ni­ty feed­back about noise extreme­ly seri­ous­ly.”

It goes on, “Last year we intro­duced a qui­eter drone mod­el in the Logan com­mu­ni­ty, that almost halved the sound lev­el expe­ri­enced dur­ing over­flight, mak­ing it much qui­eter than oth­er typ­i­cal nois­es in a neigh­bour­hood such as a deliv­ery car or truck on the street, or a leaf blow­er or lawn­mow­er in a neigh­bour’s yard.”

Drone noise in Aus­tralia is reg­u­lat­ed by the fed­er­al gov­ern­men­t’s Infra­struc­ture and Trans­port Depart­ment. At present, Wing must oper­ate dur­ing spec­i­fied hours. “Many drone oper­a­tors, includ­ing Wing, require a noise approval under the reg­u­la­tions to fly,” a state­ment by the depart­ment said. It goes on, ”As drones become more pop­u­lar for com­mer­cial and recre­ation­al use, the gov­ern­ment recog­nis­es the issue of noise is becom­ing more impor­tant.”

Noise has always been a major issue for both the drone and eVTOL indus­tries. Like elec­tric cars, very low lev­els must become the gold stan­dard. A car­bon-free green envi­ron­ment should not attract noise pol­lu­tion. The two do not equate.

“Joby As Qui­et as a Con­ver­sa­tion” (image: Joby)

JoeBen Bevirt, founder and CEO of Joby Avi­a­tion, takes great pride that his eVTOL is “as qui­et as a con­ver­sa­tion” and sounds like “the gen­tle swish­ing of trees in a mild breeze” giv­en its less than 65 deci­bels (dBA) at a dis­tance of 330 ft. Guy Nor­ris, edi­tor of Avi­a­tion Week wrote, “The air­craft makes only a par­tial­ly per­cep­ti­ble sound that would almost cer­tain­ly be unde­tectable against every­day noise back­ground of an urban envi­ron­ment.”

Yet, deliv­ery drones have a prob­lem when fly­ing low over sub­urbs. Giv­en the close prox­im­i­ty and need to inter­act with the res­i­dents, they should be even qui­eter than eVTOLs where silence is almost gold­en.

Dur­ing Wing’s Amer­i­can tri­als over Chris­tians­burg, Vir­ginia, start­ing in late 2019, a peer-reviewed study from Vir­ginia Tech showed that while 89 per­cent of respon­dents had used the ser­vice or planned to soon, major con­cerns includ­ed noise and pri­va­cy. Even so, three-quar­ters of those who said they were both­ered by the noise still liked the idea of the ser­vice.

One of the best known researchers into “noise-free” is for­mer NASA engi­neer, Mark Moore, and now co-founder of Ten­nessee-based start­up Whis­per Aero. At this year’s HAI Heli-Expo in Dal­las, Texas, the com­pa­ny dis­closed that its drone propul­sion is inaudi­ble from just 200’ away. A huge help for peo­ple like Dan Ling.

A pan­el dis­cus­sion on eVTOL acoustics at Heli-Expo 2022, orga­nized by the Ver­ti­cal Flight Soci­ety (VFS), fea­tured Juli­et Page of Blue Ridge Research and Con­sult­ing, Ben Gold­man of Archer Avi­a­tion, Mark Moore of Whis­per Aero (cen­tre), and Rex Alexan­der of Five-Alpha LLC. (image: VFS)

Dur­ing an Heli-Expo pan­el forum on eVTOL acoustics, organ­ised by the Ver­ti­cal Flight Soci­ety where Moore con­tributed, the impor­tance of how such craft would sound with­in its envi­ron­ment includ­ing the time of day it oper­ates was dis­cussed. For exam­ple, dur­ing rush hour a loud­er vehi­cle may blend more into the back­ground.

Ben Gold­man, acoustics man­ag­er at Archer, shared, as like Joby, that the noise emis­sions of its eVTOL craft has been a focal point for the com­pa­ny since the start. He com­ment­ed, “This is a crit­i­cal aspect of the vehi­cle design, in terms of inte­grat­ing it into the mar­ket. We’re slow­ly learn­ing how to quan­ti­fy pub­lic accep­tance and annoy­ance, but the ques­tion becomes how much is a per­cent, a dB, worth to its design? That’s been a chal­lenge in dri­ving the noise down as low as it can go while still being able to close the busi­ness case.”

He con­tin­ued, “Much con­sid­er­a­tion is put into mix­ing the noise sources in such a way that there are no dom­i­nant tones.” Adding, “We’re real­ly focused on try­ing to make this vehi­cle blend into the back­ground.” To become one with the envi­ron­ment is cer­tain­ly a noble goal.

Moore then stat­ed, Whis­per Aero’s mis­sion is “pro­pelling qui­et elec­tric tech­nolo­gies from fans to flight,” and that its elec­tric air­craft design was always intend­ed “to be a com­mu­ni­ty-friend­ly solu­tion.”

He observed the world is becom­ing increas­ing­ly urbanised and peo­ple are liv­ing and work­ing clos­er and clos­er togeth­er. Moore point­ed out, “For any exist­ing heli­port and small air­port where oper­a­tors are try­ing to fun­da­men­tal­ly change the nature of the oper­a­tions and go to scale, it requires a new lev­el of buy-in from the com­mu­ni­ty.” Adding, “We live in a future — espe­cial­ly in Europe — where noise will be bud­get­ed.”

So, an almost silent drone means a silent drone hub.

Ion Propul­sion (image: NASA)

One pow­er sys­tem could be ion propul­sion. Flori­da-based start­up, Unde­fined Tech­nolo­gies, recent­ly announced its Silent Ven­tus ion propul­sion eVTOL drone has cleared an essen­tial test flight.

With noise lev­els around 75 dBA, this is still no bet­ter than some eVTOLs, although the com­pa­ny claims that by next year, this should be reduced to being on par with Joby’s 65 dBA.

The pres­sure is on the drone indus­try to resolve its noise issue, espe­cial­ly when com­pa­nies like Man­na Drone Deliv­ery is expect­ing full com­mer­cial and BVLOS cer­ti­fi­ca­tion next year lead­ing to a major expan­sion in to Europe. Those liv­ing close to drone hubs or under busy flight paths are the ones who may com­plain. It is unlike­ly noise can be com­plete­ly erased, but the low­est pos­si­ble lev­el is required. Around 35 dBAs or less is fea­si­ble? Either that or find a way to cre­ate a sound that is pleas­ing and accept­able to the human ear. Mos­qui­toes, a swarm of bees or a den­tist drill are cer­tain­ly not.

Fas­ci­nat­ing Arti­cle on Drone Noise (a must read)

DRONE NOISE LEVELS

(Top Pic: Wing)