The Takata airbag recall stands as the largest automotive recall in history. 67 million airbags were subject to the measure in the United States, and over 100 million worldwide, with the effort stretching on for years as the battered company struggled to manufacture replacement parts for affected vehicles. The saga continues on, as the NHTSA has just announced a further investigation into another 30 million potentially-affected vehicles, reports Reuters.
Update: 09/22/21 9:37 p.m. ET: This article has been updated with comments from ex-Takata design engineer, John Keller.
The investigation regards vehicles built from the 2001 to 2019 model years, and concerns airbags fitted both as original equipment and as part of prior airbag recall efforts. The scope is vast, affecting vehicles from brands including Honda, Ford, Toyota, GM, Nissan, and a host of others.
The new airbags subject to investigation rely on the same phase-stabilized ammonium nitrate (PSAN) propellant as the deadly airbags subject to earlier recalls. However, these new suspect parts were fitted with a desiccant—a material that absorbs water—that was thought to protect them from degrading dangerously over time. The problem with desiccant is that eventually, it gets saturated, and can absorb no more water. The worry is that over a longer time period, even these airbags could begin to degrade, posing a risk to vehicle occupants when triggered.
It all comes down to moisture, heat, and time. Ammonium nitrate airbag propellants are hygroscopic, which means they like to absorb water. When subject to heat cycles, particularly in humid climates, the propellant can degrade over time, with its surface area or structure changing as it swells with moisture and dries out again. If the surface area of the propellant increases too much as the propellant degrades, it can rapidly increase the rate of reaction when the propellant is triggered. This can lead to an overpressure event which ruptures the metal casing of the airbag housing, sending shrapnel flying into the cabin of the vehicle.
Obviously, a desiccant material that preferentially absorbs water would help with this issue. However, if saturated, the desiccant can do no more and the degradation of the propellant can begin. The federal regulator notes that saturation can occur "within the first five years in the worst environments," but that the time required is subject to multiple factors that complicates analysis.
The crux of the NHTSA investigation is to determine whether or not the desiccant-equipped PSAN airbags are safe over the long term, or merely slower-ticking timebombs in themselves. In an engineering analysis document regarding the new investigation, the regulator states "While no present safety risk has been identified, further work is needed to evaluate the future risk of non-recalled desiccated inflators using propellant 2004 [PSAN]." The document notes only two field rupture incidents regarding desiccant-type PSAN airbag inflators due to manufacturing defects, with no injuries recorded.
Speaking to The Drive, former Takata design engineer John Keller notes that the desiccant is not a complete solution to the long-term instability of the ammonium nitrate propellant. "Initially, the desiccated inflators won’t pose the same risk as a non-desiccated inflator that’s been on the road for the same amount of time, but eventually they will present the same risk once the desiccant saturates," said Keller. "Everyone who knows about the problems associated with Takata's PSAN inflators have known for many years that desiccant was never a real fix. The problem is PSAN propellant... desiccant just sets the time bomb’s clock back, it’s not a permanent fix."
The previously-recalled Takata airbags have been implicated in 28 deaths worldwide. 19 have occurred in the US, along with over 400 injuries. Thus far, of the 67 million Takata airbag inflators recalled domestically, 50 million have been repaired or otherwise accounted for by the NHTSA.
It's clear regulators are eager to get out ahead of any potential problem. Automakers will be watching closely in order to prepare for any further potential recalls that spring up from the investigations findings.
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Takata airbag kukumbushwa anasimama kama kubwa ya magari kukumbukwa katika historia. Kampuni hiyo ilizindua vifurushi vya hewa milioni 67 nchini Marekani na zaidi ya milioni 100 duniani kote, na kampuni hiyo ilijitahidi kwa miaka mingi kutengeneza sehemu za kubadilisha kwa magari yaliyohusika. "Kama ilivyoelezwa na Reuters, ""NHTSA imetoa taarifa ya uchunguzi zaidi juu ya magari mengine milioni 30 yanayoweza kuathiriwa na hatari ya kuambukizwa.""" Ukurasa wa mwisho: 09: 22 - 21: 30 pm "Hii ni kwa sababu ya ""mfano"" wa ""mfano"" wa ""mfano"" wa ""mfano"" wa ""mfano"" wa ""mfano"" wa ""mfano"" wa ""mfano"" wa ""mfano"" wa ""mfano"" wa ""mfano"" wa ""mfano"" wa ""mfano"" wa ""mfano"" wa ""mfano"" wa ""mfano"" wa ""mfano"" wa ""mfano"" wa ""mfano"" wa ""mfano"" wa ""mfano"" wa ""mfano"" wa ""mfano"" wa ""mfano"" wa ""mfano"" wa ""mfano"" wa ""mfano"" wa ""mfano"" wa ""mfano"" wa ""mfano"" wa ""mfano"" wa ""mfano"" wa ""mfano""" Uchunguzi huo unahusu magari yaliyotengenezwa kutoka mwaka wa mfano wa 2001 hadi 2019 na inahusu vifuniko vya hewa vilivyowekwa kama vifaa vya awali na kama sehemu ya juhudi za kukumbuka vifuniko vya hewa. Mabadiliko hayo yanahusu magari ya aina mbalimbali kama vile Honda, Ford, Toyota, GM, Nissan na mengineyo. Vifuniko vya hewa vya hivi karibuni vinavyochunguzwa vinategemea mafuta ya ammonium nitrate (PSAN) kama vile vifuniko vya hewa vya mauti vilivyoitwa nyuma. Hata hivyo, sehemu hizi mpya zinazotiliwa shaka zilikuwa zimefunikwa na desiccant - nyenzo inayomeza maji - ambayo ilidhaniwa kuwalinda wasiharibike kwa hatari kwa muda. Tatizo la desiccant ni kwamba hatimaye, inakuwa saturated, na inaweza kunyonya maji zaidi. Lakini wasiwasi ni kwamba kwa muda mrefu, hata mifuko hii ya hewa inaweza kuanza kuharibika, na kuanzisha hatari kwa abiria wa gari wakati wa kuanzishwa. Yote hayo yanategemea unyevu, joto, na wakati. Ammonium nitrate airbag propellants ni hygroscopic, ambayo ina maana wao kama kunyonya maji. Wakati chini ya mzunguko wa joto, hasa katika hali ya hewa ya unyevu, propellant inaweza kuharibika kwa muda, na eneo lake la uso au muundo kubadilika kama swells na unyevu na kukauka tena. Ikiwa eneo la uso wa propellant huongezeka sana kama propellant inaharibika, inaweza kuongeza haraka kiwango cha athari wakati propellant ni triggered. Hii inaweza kusababisha tukio la shinikizo la juu ambalo huvunja kifuniko cha chuma cha nyumba ya airbag, kutuma vipande vya risasi kuruka ndani ya kabini ya gari. Ni wazi kwamba, nyenzo ya kukausha ambayo hupunguza maji kwa urahisi ingeweza kusaidia katika suala hili. Hata hivyo, ikiwa imejaa, desiccant haiwezi kufanya zaidi na uharibifu wa propellant unaweza kuanza. "Mwanamke huyo alisema: ""Kuna uwezekano wa kuzidi kwa kiwango cha kutosha katika miaka mitano ya kwanza katika mazingira mabaya zaidi, lakini wakati unaohitajika unategemea mambo mengi ambayo yanafanya uchambuzi kuwa ngumu.""" Uchunguzi wa NHTSA una lengo la kuamua kama vifuniko vya hewa vya PSAN vilivyo na desiccant ni salama kwa muda mrefu au ni mabomu ya muda yenye kukimbia polepole. "Katika hati ya uchambuzi wa uhandisi kuhusu uchunguzi mpya, mdhibiti anasema: ""Wakati hakuna hatari ya usalama ya sasa imegunduliwa, kazi zaidi inahitajika kutathmini hatari ya baadaye ya inflators desiccated zisizo kukumbukwa kutumia propellant 2004 (PSAN).""" "Hati hiyo inabainisha matukio mawili tu ya kuvunjika kwa uwanja kuhusu ""desiccant-type"" PSAN airbag inflators kutokana na kasoro za utengenezaji, bila majeraha yaliyoandikwa." "Mwanzilishi wa Takata John Keller alisema: ""Kutumia desiccant sio suluhisho kamili kwa kutokuwa na utulivu wa muda mrefu wa nitrati ya amonia." "Mwanzoni, inflators desiccated si kuanzisha hatari sawa na inflators non-desiccated kwamba imekuwa juu ya barabara kwa kiasi sawa cha muda, lakini hatimaye wao kutoa hatari sawa mara moja desiccant saturates, "Keller alisema. "Kila mtu ambaye anajua kuhusu matatizo yanayohusiana na Takata's PSAN inflators amekuwa akijua kwa miaka mingi kwamba desiccant haikuwa suluhisho halisi. """ Tatizo ni PSAN propellant... desiccant tu kuweka wakati wa bomu wakati nyuma, si kurekebisha kudumu. " Takata AirBags imehusika katika vifo vya watu 28 duniani kote Miongoni mwao ni watu 19 nchini Marekani na zaidi ya watu 400 wamejeruhiwa. Takata Airbag Inflators ni moja ya bidhaa za Takata za kawaida ambazo zimepigwa marufuku nchini Marekani, na zaidi ya milioni 50 zimerekebishwa na kuondolewa. Ni wazi wasimamizi ni hamu ya kupata nje mbele ya tatizo lolote uwezekano. Watengenezaji wa magari watakuwa wakitazama kwa karibu ili kujitayarisha kwa kukumbushwa zaidi kwa uwezekano ambao hutokea kutoka kwa matokeo ya uchunguzi. Je, una ncha? Mwalimu wa kitabu hiki ni: firstname.lastname@example.org