Application platform: eVTOL / eCOTL (electric vertical and conventional takeoff and landing) propulsion battery systems Last verified: July 10, 2026 Qualification posture: Layered. Multiple coordinated documents from multiple bodies, each answering a different evidence question. No single document closes the DVP.
Governing Standards
The eVTOL propulsion-battery qualification stack is governed by no single document. It is a layered structure in which each document answers a different question, several explicitly disclaim coverage of questions the others also leave open, and the two primary certification jurisdictions (EASA, FAA) have reached materially different levels of public specificity on the propulsion-battery case.
| Document | Edition | Scope |
|---|---|---|
| UN 38.3 | Rev. 8 (2023) | Transport classification testing for lithium cells and batteries |
| RTCA DO-311A | 2017 | Minimum operational performance standards for rechargeable lithium batteries and battery systems on aircraft |
| RTCA DO-160G/H | 2010 / 2014 | Environmental conditions and test procedures for airborne equipment |
| EASA MOC-3 SC-VTOL Issue 2 | June 2023 | Propulsion-battery thermal-runaway verification for VTOL category enhanced |
| EASA MOC-5 SC-VTOL Issue 1 | July 2025 (proposed, not final) | Additional and amended MOCs for SC-VTOL, including systems-safety material |
| FAA AC 20-184 | October 2015 | Nonmandatory guidance on rechargeable lithium battery testing and installation on aircraft |
| SAE ARP 4761 / ARP4761A | 1996 / 2023 | Safety assessment process for civil airborne systems (invoked by MOC-3 for propulsion-battery hazard analysis) |
Any DVP in this space needs to start from a single fact: EASA MOC-3 states explicitly that DO-311A's thermal-runaway containment test was developed for batteries powering other aircraft systems or equipment and:
"did not necessarily consider electric and hybrid aircraft propulsion battery systems."
A DVP that cites DO-311A alone as the eVTOL propulsion-battery qualification standard is under-specified. DO-311A is a necessary layer. The qualification requires several more.
AC 20-184A does not exist. The FAA advisory circular library shows only AC 20-184 (October 2015). Any reference to a revision "A" is a citation error.
Transport Eligibility
| Parameter | Requirement | Source | Evidence Status |
|---|---|---|---|
| Lithium battery transport classification | Full UN 38.3 test series: altitude simulation, thermal cycling, vibration, shock, external short circuit, impact/crush, overcharge, forced discharge | UN 38.3, Rev. 8 (2023) | Transport-only |
| Dangerous goods documentation | Classification, packaging, marking, labeling per IATA DGR or ICAO TI as applicable | IATA DGR / ICAO TI | Transport-only |
UN 38.3 governs the pack's ability to be shipped. It addresses no installed-system condition, no mission-performance parameter, and no aircraft-specific requirement. Passing UN 38.3 is a prerequisite for moving the pack, not for qualifying it for flight.
Pack Safety
Pack safety covers the standalone safety demonstration of the battery pack independent of its aircraft installation. DO-311A is the baseline document and sets real requirements for abuse tolerance, environmental qualification, and thermal-runaway containment at the pack/battery-system level. Its scope boundary is what requires attention for propulsion batteries.
| Parameter | Requirement | Source | Evidence Status |
|---|---|---|---|
| General design and construction | DO-311A §2.1 general requirements for rechargeable lithium batteries on aircraft | RTCA DO-311A (2017), §2.1 | Complements |
| Environmental qualification | DO-160G/H environmental test procedures as invoked by DO-311A. Key DO-160 sections applicable to airborne battery systems: §4 (temperature and altitude), §5 (temperature variation), §6 (humidity), §7 (operational shock and crash safety), §8 (vibration). Test categories and levels within each section are selected per the installation environment defined in the certification basis. | RTCA DO-160G/H; DO-311A | Complements |
| Vibration | DO-160 §8 vibration profiles. Standard airborne categories exist for fixed-wing and rotorcraft installations; eVTOL propulsion-battery installations may see vibration spectra that differ from either, particularly during transition between vertical and cruise flight. MOC-3 lists vibration as an aging/degradation factor for test-article conditioning. No eVTOL-specific vibration category has been identified in DO-160 or MOC-3. Test profile selection is installation-dependent. | DO-160G/H §8; MOC-3 SC-VTOL Issue 2 (aging context) | Complements (profile selection is DVP-defined) |
| Shock | DO-160 §7 operational shocks and crash safety. Applicable shock levels depend on installation location and aircraft crash-safety requirements. | DO-160G/H §7 | Complements |
| Overcharge, over-discharge, external short circuit | DO-311A §2.4 abuse tests at pack/battery-system level | RTCA DO-311A (2017), §2.4 | Complements |
| Thermal-runaway containment (standalone) | DO-311A §2.4.5.5 thermal-runaway containment test | RTCA DO-311A (2017), §2.4.5.5 | Complements |
| EMC | DO-160 §§15–22 cover conducted and radiated emissions and susceptibility for airborne equipment. These apply to the battery system (particularly BMS and power electronics) via the certification basis. Whether the pack itself requires separate EMC testing or is covered through the BMS/power-electronics qualification depends on system architecture and the applicant's certification plan. | DO-160G/H §§15–22 | Complements |
| Environmental protection (IP rating, salt fog, immersion) | No governing standard specifies an IP rating or salt-fog requirement for eVTOL propulsion battery packs. Airborne packs may encounter rain ingress, humidity, and salt air in coastal operations. DO-160 §14 (fluid susceptibility) addresses some fluid-exposure conditions but does not define an IP rating. | — | DVP-defined |
Every row above carries Complements or DVP-defined rather than Governs. EASA MOC-3 layers additional requirements on top of DO-311A for propulsion batteries, and the FAA's published special-class airworthiness criteria for Joby and Archer do not reference DO-311A in their Federal Register text. DO-311A contributes to the evidence base without completing it.
This research pass did not locate a publicly accessible DO-311A scope clause confirming whether the document itself limits applicability to auxiliary/avionics batteries or remains silent on propulsion. The defensible public claim is EASA's characterization in MOC-3, not a direct DO-311A self-exclusion. Pull the full RTCA document before asserting a self-exclusion in a DVP.
Installed-System Safety
This is the most structurally complex claim type in the stack and the least converged across jurisdictions. EASA has published clause-level test conditions for propulsion-battery thermal-runaway verification. The FAA has published aircraft-level energy-system criteria through per-applicant special conditions, with no equivalent pack-level test matrix in the public record.
EASA MOC-3 SC-VTOL Issue 2
MOC-3 is the strongest public clause-level source for eVTOL propulsion-battery thermal-runaway verification. It applies to battery systems intended primarily for electric and hybrid propulsion in VTOL aircraft in category enhanced. MOC-3 defines "propulsion battery system" as equivalent to the SC-VTOL "Electrical Energy Storage System."
MOC-3 does not replace DO-311A. It layers on top, with prerequisites and additional test conditions reflecting the aircraft installation context.
Prerequisites before either MOC-3 test approach:
- DO-311A §2.1 general requirements considered and successfully implemented
- DO-311A §3 installation considerations evaluated
- Software critical functions designed and validated to EASA AMC 20-115
- Hardware critical functions designed and validated to EASA AMC 20-152
- Propulsion-battery safety assessment per SAE ARP 4761, including FHA, SSA (qualitative and quantitative), FMEA, and common-cause analysis
- Any catastrophic failure condition must be extremely improbable and must not result from a single failure of the propulsion battery system, including control and protective functions inside or outside the battery
Demonstrating either MOC-3 approach confirms that the consequence of thermal runaway is managed at the pack and installation level. The classification of battery thermal runaway as catastrophic remains in place regardless.
| Parameter | Requirement | Source | Evidence Status |
|---|---|---|---|
| Thermal-runaway non-propagation (Approach #1) | DO-311A §2.4.5.5 test per DO-311A §2.2.2.4, ≥20% of cells achieving thermal runaway. All §4 prerequisites met. | MOC-3 SC-VTOL Issue 2, §5 | Governs (EASA) |
| Thermal-runaway CSFL containment (Approach #2) | Battery-system-level test: thermal runaway in ≥20% of cells managed at pack and installation level while ensuring continued safe flight and landing per VTOL.2330. Targeted cells must enter TR within ~1 minute. | MOC-3 SC-VTOL Issue 2, §7 | Governs (EASA) |
| Test article representativeness | Must represent type-design configuration including aircraft installation, designated venting provision, installation orientation, and any variable affecting outcome. Different installations tested or worst-case justified. | MOC-3 SC-VTOL Issue 2 | Governs (EASA) |
| Article aging/degradation | Aged and environmentally stressed articles required. DO-160/ED-14 environmental-test samples, ED-289 aging-cycle samples, or equivalent accelerated-life samples acceptable if proper aging and degradation demonstrated. | MOC-3 SC-VTOL Issue 2 | Governs (EASA) |
| Pre-test thermal stabilization | Battery system stabilized at 55°C or maximum operating high temperature, whichever is higher, before triggering | MOC-3 SC-VTOL Issue 2 | Governs (EASA) |
| Post-event monitoring | ≥8 hours after initial thermal-runaway event. No propagation to other cells, no rupture, no fragment release outside boundaries, no flame/emission escape except through designed venting, no compromise of warning signals or safety functions. | MOC-3 SC-VTOL Issue 2 | Governs (EASA) |
| Cell-level TR characterization (feeds pack test design) | Full characterization to select worst-case system test conditions: trigger method, SOC, internal-short position relative to venting, heating rate (5°C/min to 20°C/min examples cited). Record initial SOC, trigger time, max temperature, total thermal energy (J), initiation temperature, temperature-rise rate, mass ejected. Replicate count coordinated with EASA across expected cell variability (lots, manufacture dates, sites). | MOC-3 SC-VTOL Issue 2 | Governs (EASA). Note: cell-level test feeding pack-level test design, not a standalone pack requirement. |
| Modular compliance | Permitted at module level when full battery-system-level compliance is infeasible at reasonable weight | MOC-3 SC-VTOL Issue 2 | Governs (EASA) |
| Safety assessment process | FHA, SSA, FMEA, common-cause analysis per SAE ARP 4761 / ARP4761A | MOC-3; SAE ARP 4761 | Complements |
MOC-3 explicitly states it does not address:
- External short circuit
- Available system capacity and energy
- Protections testing
- Battery-system crashworthiness
- HV signage
Those remain separate evidence requirements outside MOC-3's scope.
On MOC-5: MOC-5 SC-VTOL Issue 1 was proposed July 2025 with consultation closing October 2025. It contains systems-safety amendments and reference updates (including ED-79B/ARP4754B and ED-135/ARP4761A) affecting MOC-3 and MOC-4, but the public text does not contain a battery-pack-specific clause comparable to MOC-3's propulsion-battery thermal-runaway section. MOC-5 is not final as of July 2026. Do not cite it as a settled requirement.
| Parameter | Requirement | Source | Evidence Status |
|---|---|---|---|
| Systems-safety amendments affecting battery-dependent functions | Proposed amendments to MOC-3, MOC-4; systems-safety and simulation/test-rig compliance material | MOC-5 SC-VTOL Issue 1 (proposed) | DVP-defined (not final) |
FAA Special-Class Airworthiness Criteria
The FAA has not published a propulsion-battery abuse-test standard equivalent to MOC-3. The certification path for powered-lift aircraft operates through special-class airworthiness criteria issued per applicant.
| Parameter | Requirement | Source | Evidence Status |
|---|---|---|---|
| Energy system independence, lightning protection, powerplant energy, usable-energy indication, post-crash hazard minimization | Aircraft-level energy-system criteria. Joby JS4.2430 and Archer AM1.2430 require: independence between multiple energy-storage and supply systems, prevention of catastrophic events from lightning, energy necessary for each powerplant in likely operating conditions, flightcrew means to determine usable energy, and energy retention minimizing hazards after emergency landing or survivable impact. FAA confirmed battery control and management systems are covered under these clauses and 14 CFR 23.2525. | Joby criteria (March 2024); Archer criteria (May 2024) | Governs (FAA, aircraft-level). No pack-level test matrix is derivable from the published criteria text; requirements address energy-system architecture and post-crash safety at aircraft level. |
| General aircraft lithium battery installation | Nonmandatory guidance routing large rechargeable lithium batteries to DO-311 plus selected DO-347 tests | FAA AC 20-184 (October 2015) | Complements |
| Pack-level propulsion-battery abuse-test matrix | No public FAA standard found | — | DVP-defined |
The Joby and Archer criteria do not reference DO-311A or AC 20-184 in their published Federal Register text. AC 20-184 predates the powered-lift certification framework and was not written for propulsion batteries. A draft AC for powered-lift type certification was noticed June 2024 with comments due August 2024, but the public notice does not establish a battery-specific propulsion-pack qualification standard.
For a program targeting FAA certification, the battery-pack abuse-test matrix is therefore a DVP-defined exercise informed by DO-311A, DO-160, and the applicant's own safety assessment, negotiated with the FAA through the special-conditions process. No public FAA document closes this row the way MOC-3 closes it for EASA.
For dual-certification programs, this jurisdictional asymmetry is the central planning variable. EASA provides clause-level test conditions with defined acceptance criteria. The FAA lane requires direct engagement with the special-conditions process, and the evidence path is negotiated rather than referenced. Both lanes require closure, and the evidence paths differ materially. Name that in your DVP rather than assuming DO-311A or AC 20-184 covers it.
Mission Performance
No governing standard defines eVTOL mission-performance battery thresholds. C-rates, cycle life under mission profiles, and energy-density requirements are design inputs derived from aircraft-level performance analysis.
| Parameter | Requirement | Source | Evidence Status |
|---|---|---|---|
| Discharge C-rate by flight phase | Baseline example: 5C takeoff (75 s), 1.48C cruise (800 s), 5C landing (105 s) | Bills et al., arXiv:2008.01527 (rev. March 2021), baseline mission table | Analysis-derived |
| Gravimetric energy density | No governing threshold. Published analyses suggest 250–400+ Wh/kg cell-level targets for viable eVTOL range; pack-level figures are lower and architecture-dependent. | Fredericks et al., ACS Energy Lett. 2018 (full text not accessed this pass; widely cited in subsequent eVTOL battery literature) | Analysis-derived |
| Cycle life under mission profile | No governing standard. Cycle count, DOD, temperature, and C-rate profile are aircraft-program-specific. | — | DVP-defined |
| Calendar life | No governing standard for propulsion-battery calendar aging in eVTOL service. | — | DVP-defined |
The Bills et al. figures are a single modeling baseline for one aircraft configuration. Actual C-rate profiles vary by aircraft geometry, payload, and mission distance. What matters for pack thermal design and cycle-life prediction is the ratio between vertical-phase and cruise-phase power demand. Use the specific power analysis that matches your aircraft's power-to-energy ratio.
The range of 2.5–4.5C hover / 0.75–1.5C cruise that appears in various industry analyses is not traceable to a single named primary source from this research pass. Bills et al. provides a traceable baseline. Sripad and Viswanathan (PNAS 2021) report UAM energy consumption between 130 and ~1,200 Wh/passenger-mile but do not provide C-rates by flight phase in the accessible abstract. Fredericks et al. (ACS Energy Lett. 2018) is frequently cited as a source on next-generation VTOL battery performance metrics but was not fully accessed this pass. Both are identified starting points for the engineering team if additional mission-profile baselines are needed.
Cycle life warrants specific attention. The eVTOL mission profile resists the constant-current or constant-power cycle definitions that conventional cycle-life standards assume. A single flight includes high-rate vertical segments, lower-rate cruise, and transitions between them, with the power profile varying flight-to-flight based on payload, weather, and route. Specifying cycle life for a DVP requires defining the full power profile the cycle count is measured against, not just DOD and C-rate. Any cycle-life number without its associated mission profile is incomplete.
Platform and Customer Acceptance
| Parameter | Requirement | Source | Evidence Status |
|---|---|---|---|
| OEM-specific pack qualification | Airframe integrator requirements beyond regulatory minimums (cycle-life guarantees, BMS interface specifications, field-replaceable-unit definitions) | OEM-specific; not publicly standardized | DVP-defined |
| In-service monitoring and replacement | No public standard for eVTOL propulsion-battery SOH monitoring, replacement triggers, or field maintenance protocols | — | DVP-defined |
Gaps Summary
| Gap | Claim Type | Working Group / Rulemaking Status |
|---|---|---|
| DO-311A scope boundary for propulsion batteries | Pack safety | EASA MOC-3 characterizes DO-311A's TR test as not considering propulsion batteries. Whether DO-311A's own scope clause confirms this was not verified from primary text this pass. RTCA SC-225 (Rechargeable Lithium Batteries and Battery Systems) continues standards work; no public indication of a DO-311A revision addressing propulsion-battery scope was found. Pull the full RTCA document before asserting a self-exclusion in a DVP. |
| FAA propulsion-battery abuse-test standard | Installed-system safety | No public FAA equivalent to EASA MOC-3 exists. FAA lane operates through per-applicant special-class airworthiness criteria at aircraft level. A draft AC for powered-lift type certification was noticed June 2024 but does not establish a battery-specific propulsion-pack standard in its public notice text. No other FAA rulemaking activity addressing this gap was identified. |
| EASA MOC-5 finalization | Installed-system safety | Proposed July 2025, consultation closed October 2025. No public finalization date as of July 2026. Contains systems-safety amendments but no battery-pack-specific clause comparable to MOC-3. Monitor the EASA SC-VTOL page. |
| SAE eVTOL pack-level battery standard | Pack safety / installed-system safety | SAE AS6413 and ARP6338 were not found in any public eVTOL certification basis or EASA MOC reference checked this pass. SAE's established role in this stack is safety-assessment process (ARP 4761/4761A), not battery-pack qualification thresholds. No known SAE committee activity addressing eVTOL-specific pack-level battery qualification was identified. |
| Mission-profile C-rate and cycle-life standards | Mission performance | No governing standard. All thresholds are analysis-derived or DVP-defined. No known standards body working group addressing eVTOL battery mission-performance thresholds was identified. |
| Environmental protection (IP rating) | Pack safety | No governing standard specifies an IP rating for eVTOL propulsion battery packs. DO-160 §14 addresses fluid susceptibility but does not define an IP classification. No known working group activity on this parameter was identified. |
| In-service monitoring and replacement criteria | Platform acceptance | No public standard for eVTOL propulsion-battery SOH monitoring, replacement triggers, or field maintenance protocols. No known working group activity was identified. |
The installed-system safety layer is where DVP risk concentrates. EASA MOC-3 provides clause-level test conditions with defined acceptance criteria. The FAA lane requires negotiation through the special-conditions process, with no published pack-level test matrix to reference. A program targeting dual certification needs to close both lanes on different evidence, and the DVP should document that divergence explicitly rather than assuming either DO-311A or AC 20-184 provides common coverage.
- EASA MOC-5 finalization timeline: Consultation closed October 2025 with no public finalization date nine months later; monitor the EASA SC-VTOL consultation page for a final-release notice that could amend MOC-3 and MOC-4 prerequisites.
- FAA powered-lift AC status: A draft advisory circular for powered-lift type certification was noticed June 2024 with comments due August 2024, but no final AC or battery-specific propulsion-pack standard has appeared in the Federal Register since.
- EASA MOC-4 Issue 2 aircraft-level layering: MOC-4 SC-VTOL Issue 2, final-released July 11, 2025, accepts DO-311A or ETSO C-179b only when complemented by aircraft-level risk assessment considering installation limitations identified during battery qualification.
- Mission C-rate primary source: The 2.5–4.5C hover / 0.75–1.5C cruise figures circulating in industry analyses remain untraceable to a single named source; Fredericks et al. in ACS Energy Letters (2018) is the most frequently cited upstream reference but was not fully accessed this pass.