How Aviation Expert Witnesses Get Excluded Under Daubert — and How to Survive the Cross

Daubert is not a medicine problem. Under Kumho Tire and the 2023 amendment to Federal Rule of Evidence 702, the trial court's gatekeeping applies to every form of specialized testimony — aviation included. A 20-year study of 2,842 challenges to non-medical experts found that roughly half of those opinions were excluded or partially excluded, and the single most-cited reason was “unreliable methodology.”

The exclusion rarely happens in a written motion alone. It is built, piece by piece, in the deposition cross-examination — where opposing counsel walks a aviation expert into conceding scope, methodology, or an assumption that unravels the whole opinion. Here are the three traps, and how a prepared expert answers each one.

The three ways aviation experts lose ground

Scope: testifying outside your lane

The cross-examiner's question sounds simple:

You opine the pilot was negligent — but you've never flown this specific aircraft type, correct?

Why it works: The type-rating scope attack. Anchor to the FARs, the data, and the standards you can speak to.

A stronger answer: “My opinions rest on the FARs and accepted airmanship standards plus the recorded flight data; I disclosed where type-specific experience does and doesn't bear on the analysis.”

Methodology: the reliability attack

The cross-examiner's question sounds simple:

Your reconstruction relied on the recorded data — but the aircraft wasn't equipped with a full flight-data recorder, was it?

Why it works: Methodology / data completeness. State what data you had and the limits of reconstruction without a full FDR.

A stronger answer: “Correct. I reconstructed from the available avionics, radar, and ATC data and stated the resolution limits where a full FDR was not present.”

Assumptions: the one premise that sinks the opinion

The cross-examiner's question sounds simple:

You assume the weather briefing was the one the pilot actually received — but you don't have proof of what was transmitted, do you?

Why it works: The information-received assumption. Tie it to records; flag what you can't confirm.

A stronger answer: “I relied on the documented briefing records and flagged where I could not confirm exactly what the pilot received, bounding that part of the opinion.”

How to prepare for the cross before you're sworn in

Every one of those traps is defeatable — but not by reading your report one more time. The experts who survive the cross have done three things:

• Rehearsed the cross-examination out loud, repeatedly, against a realistic examiner — so the scope concession, the methodology defense, and the assumption hedge are second nature.
• Mastered the record, so that when counsel asks them to recall the one line buried in thousands of pages of the flight data, maintenance logs, and FARs, they can produce it in seconds rather than fumble.
• Stress-tested the report against FRE 702 — finding the reliability gaps before opposing counsel does.

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