Per Diem Trick Torches Overtime Pay, Bleeds Aviation Staffing

A wage-and-hour suit landed against an aviation staffing firm this week, and the allegation is one that every mid-market HR lead should already have a runbook for. The claim, per HR Dive: the company restructured per diem payments in a way that allegedly held overtime compensation down. If you run payroll for a staffing operation, a contract-labor shop, or any firm that ships workers to job sites with travel allowances, this case is your Tuesday afternoon problem, not somebody else's quarterly newsletter trivia.

The trick is older than payroll software. Relabel a chunk of effective wages as per diem, exclude it from the regular rate, and the overtime multiplier shrinks. The DOL has been writing brief against this exact move for two decades. The reason it keeps showing up in lawsuits is the reason every old scam keeps showing up: the math works in the short term, the auditor does not show up for years, and the firm hopes the workers do not file.

The Deployment

The complaint targets Complete Aviation Services. Per the HR Dive write-up, plaintiffs allege the firm modified its per diem scheme in a way that allowed it to reduce overtime pay obligations. The legal frame is the Fair Labor Standards Act, which sets the baseline rule: overtime gets calculated against the regular rate of pay, and the regular rate must include all remuneration tied to work performed, with narrow exceptions.

Per diem, properly used, is a reimbursement for travel-related expenses an employee actually incurs. When it is genuinely tied to costs (lodging, meals on the road, incidentals), it sits outside the regular rate. When it scales with hours worked, fluctuates with the schedule, or quietly substitutes for what would otherwise be hourly wages, courts have repeatedly treated it as wages in disguise. the line the lawsuit alleges was crossed.

HR Dive notes that both federal courts and the DOL have flagged this category of conduct before. The agency issued opinion letters on the question. Circuit courts have ruled on it. The pattern is well-documented enough that any staffing-industry compliance lead should recognize the contours on first read.

Why It Matters

The interesting thing about this case is not that it happened. It is the timing.

We are eighteen months into wage-and-hour cases getting AI-assisted on the plaintiff side. Discovery firms now run pattern detection across years of payroll exports in hours, not weeks. The variance between an employee's stated hourly rate and their effective rate (total comp divided by total hours) is a single SQL query. If the variance is wide, and per diem is the bridge, the spreadsheet flags it before a human reads page one.

That changes the economics of this trick. Five years ago, a staffing firm could run a per diem-shaped wage scheme and reasonably expect that any individual worker filing pro se would not produce a clean enough damages model to attract a contingent-fee attorney. The damages were real but the unit economics of the case were marginal. Plaintiffs' firms now run those models in batch. The marginal case becomes a class.

the shift HR leads at staffing firms should be tracking. The move is not new. The detection is. And once detection is cheap, the back-pay math is the only thing that matters: regular FLSA cases get two years of lookback, willful violations get three, liquidated damages double the unpaid wages, and the firm pays the plaintiffs' attorney fees on top.

For an aviation staffing firm with hundreds of contractors moving through per diem cycles, the exposure compounds fast. A $5/hour effective underpayment, across 200 contractors, across 50 weeks of overtime-eligible hours per year, across three years, doubled for liquidated damages, lands north of $9M before fees. Whether or not Complete Aviation's specific numbers come out anywhere near that, the exposure for any firm running a similar scheme is in that neighborhood.

The other thing worth saying out loud: the DOL has been clear about this for so long that the "we relied on counsel's interpretation" defense gets thin. When the agency has issued opinion letters and circuit courts have ruled, the willfulness inquiry tilts uncomfortably for the defendant.

What Other Businesses Can Learn

If you run HR or payroll at a staffing firm, a contractor-heavy services business, or any operation that uses per diem as part of total comp, here is the practical work this week.

Run the variance analysis yourself. Pull twelve months of payroll. For every employee who took per diem, compute their stated hourly rate, their total comp (wages plus per diem) divided by total hours, and the delta. If the delta is more than trivial and per diem moves with hours rather than days-on-travel, you have your answer before opposing counsel runs the same query.

Audit the per diem trigger. Genuine per diem is paid because the employee was on the road, not because they worked. If your scheme pays per diem only on workdays, only on hours-worked, or scales the per diem amount up when overtime hours rise, you are not running per diem, you are running shadow wages. Restructure or accept the FLSA exposure.

Document the cost basis. The cleanest defense for per diem treatment is a documented, GSA-style cost rate (or a defensible internal equivalent) that ties the per diem amount to actual incurred travel expenses. If your finance team cannot produce that documentation, the IRS and the DOL will treat the payments as wages.

Buy AI payroll audit, or build the query. Vendors like Gusto, ADP, and Paychex now ship variance-detection inside their payroll suites. Mid-market players get the same query for under $200 a month on top of base payroll. For a 200-contractor staffing firm, that is the cheapest insurance you will ever buy. If you are running on legacy payroll without it, write the SQL yourself, the regular-rate calculation is forty lines.

Get the right opinion letter, in writing, before the next pay cycle. Wage-and-hour counsel reviewing your per diem structure costs four-figure dollars. Defending an FLSA collective action costs seven. The math is not subtle.

The DOL has been writing brief against this exact move for two decades. The reason it keeps showing up in lawsuits is the reason every old scam keeps showing up: the math works in the short term, the auditor does not show up for years, and the firm hopes the workers do not file.

The firms that get caught are not the ones with creative compensation theories. They are the ones whose theory was tested in 2009, lost in 2014, and got recycled in 2024 because nobody at the firm remembered the earlier ruling.

Looking Ahead

Watch the pleadings on this one. Two specific things to track. First, whether the plaintiffs allege willfulness, that pushes the lookback from two years to three and signals how cleanly the variance shows in the firm's own payroll data. Second, whether the case gets certified as a collective action under §216(b). Aviation staffing has natural class characteristics (similar job duties, similar pay structures, geographically distributed but contractually unified workforce) that tend to support certification.

The action item for every HR lead reading this: run your own variance query before the end of the quarter. If the number you get back surprises you, the number opposing counsel gets back will surprise you more.

Sources

• HR Dive, Aviation staffing company used 'per diem' scheme to avoid paying overtime, lawsuit says, accessed 2026-05-06