Aerospace manufacturing and aircraft maintenance (MRO) operations span some of the widest noise exposure ranges in American industry — from quiet avionics benches below 70 dBA to engine test cells generating 140+ dBA at test points. OSHA 29 CFR 1910.95 applies to aerospace manufacturing as general industry. MRO operations at airports are subject to the same 1910.95 requirements regardless of whether they are performed at an airline's maintenance base or an independent MRO facility. According to CDC/NIOSH, approximately 22 million U.S. workers are exposed to hazardous occupational noise annually.
Soundtrace delivers in-house audiometric testing and noise monitoring for aerospace & mro operations — ANSI S3.1-compliant, automated STS detection, and licensed audiologist review.
Noise Sources and TWA Ranges
| Equipment / Process | Typical Level | Typical 8-hr TWA | OSHA Status |
|---|---|---|---|
| Engine test cell (gas turbine) | 110–140 dBA | 100–115 dBA | Far exceeds PEL — double HPD required |
| Pneumatic riveting | 100–110 dBA | 95–105 dBA | Significantly exceeds PEL |
| Metal forming / stamping | 90–105 dBA | 88–98 dBA | At or above PEL |
| Composite cutting / routing | 90–100 dBA | 88–96 dBA | At or above action level; many exceed PEL |
| Run-up / power checks (MRO) | 130–160 dBA near engine | High dose rapidly | Extreme — distance and timing controls critical |
| Hangar general assembly | 80–92 dBA | 82–90 dBA | Monitor by work station |
| Avionics / electronics bench | 60–75 dBA | <80 dBA | Below action level |
OSHA 1910.95 Requirements
All aerospace & mro workers at or above the 85 dBA action level must be enrolled in the full six-element OSHA 1910.95 hearing conservation program. Workers above the 90 dBA PEL require documented engineering controls assessment. The most commonly cited violations across all industries are identical: late baseline audiograms, annual audiogram schedule failures, and inadequate HPD for actual exposure levels. See: audiometric testing for employers: complete guide and OSHA noise monitoring requirements.
| Violation Type | Frequency | Typical Penalty |
|---|---|---|
| Late or missing baseline audiograms | Very high — most common | $2,000–$7,000 |
| Annual audiogram schedule failures | High | $2,000–$7,000 |
| No noise monitoring (assumed below AL) | High | $1,000–$5,000 |
| No engineering controls assessment above PEL | Moderate | $3,000–$9,000 |
| Missing training records | High | $1,000–$4,000 |
Engine test cells and run-up areas
Engine test cells represent the highest occupational noise exposures in aerospace. Personnel in the test cell vicinity during turbine operation face extremely high noise levels even with hearing protection. The HCP for test cell workers must specifically address: noise monitoring during actual test conditions (not just facility surveys), dual HPD requirements verified by fit testing, and exclusion zones or time-limited entry protocols. Run-up and power check operations at MRO facilities require the same approach for line maintenance staff.
Riveting operations
Pneumatic riveting generates impact noise at 100–110 dBA that is both extremely loud and highly impulsive. Workers in close proximity to riveting operations — both the riveter and the bucking bar operator — face TWAs that significantly exceed the PEL. HPD that adequately attenuates these exposures must be confirmed by individual fit testing, not assumed from NRR labels.
Mixed-exposure aerospace campuses
Large aerospace manufacturing campuses include both extreme-noise environments (test cells, stamping) and quiet areas (cleanrooms, avionics assembly). Noise monitoring must characterize each job classification independently before determining HCP enrollment. Assuming sub-action-level exposure across an entire campus because some areas are quiet leads to citation exposure when workers in high-noise areas are excluded from the HCP.
Workers’ Compensation Defense
Occupational hearing loss WC claims in aerospace & mro follow the same pattern as other industries: claims arrive years after exposure begins, requiring complete audiometric records from hire to claim date for apportionment. A pre-employment baseline audiogram is the most critical single document — without it, the employer cannot demonstrate what hearing the worker had on day one. See: workers’ compensation for occupational hearing loss: 50-state guide.
Audiometric records must be retained for the duration of employment. Occupational health attorneys recommend 30 years beyond separation for long-tenure workers. Records held exclusively by a mobile van vendor are at risk if the vendor relationship ends. Cloud-based retention with documented chain of custody is the only reliable long-term solution.
In-house audiometric testing for aerospace & mro operations
Soundtrace delivers OSHA-compliant audiometric testing and noise monitoring for aerospace & mro employers — automated STS detection, 30-year cloud retention, and licensed audiologist supervision.
Get a Free Quote Book a demo →Frequently Asked Questions
Yes. OSHA 29 CFR 1910.95 applies as general industry. All workers with 8-hour TWA exposures at or above 85 dBA must be enrolled in the full six-element hearing conservation program. Workers above the 90 dBA PEL also require a documented engineering controls feasibility assessment.
Engine test cell (gas turbine) (110–140 dBA) and Pneumatic riveting (100–110 dBA) are typically the highest noise sources. Typical 8-hour TWAs for workers in these areas: 100–115 dBA and 95–105 dBA respectively. Both require enrolled workers, ANSI-compliant audiometric testing, and confirmed HPD adequacy.
OSHA requires audiometric records for the duration of employment. Occupational health attorneys recommend 30 years beyond separation for workers with long-tenure noise exposure histories, given the latency of occupational hearing loss WC claims.