Cross-Exam: Professional pilot and licensed engineer put each other to the test

What separates a good teacher from a great one has less to do with what they know and more to do with how they make someone else understand it. Two of Teachable's most successful educators decided to find out the hard way.

Dan George (FAA Gold Seal CFI, founder of FlightInsight, and aviation instructor to 10,000+ students across 60+ countries) and Wasim Asghar (licensed Professional Engineer in the US and Canada, founder of Study For FE, and author of 8+ engineering exam prep books) sat down across from each other and agreed to teach a foundational concept from their own field to the other. Then they had to teach it back.

The result is the debut episode of Cross-Exam, a new Teachable series where two expert educators swap roles. What the teach-back reveals about learning, retention, and the gap between knowing and explaining is worth paying attention to.

Round 1: The physics behind flying airplanes

Dan opened with the lift equation: Lift = Coefficient of Lift x (1/2) x air density x velocity squared x wing surface area.

He walked through each variable, but kept coming back to velocity. Because it carries an exponent, small changes in airspeed affect lift far more than equivalent changes in any other factor.

Before getting into the equation though, Dan had to dismantle something first.

"If I slow the aircraft down, I can maintain my altitude by increasing angle of attack… I call this the Star Wars conception of how things fly. You point the ship in a certain direction and it just goes there at an angle." — Dan George, founder of FlightInsight

Naming the wrong model before replacing it is a teaching move that works better than most educators realize. 

Once the flawed assumption is on the table, students will let go of it. Before it is named, they hold onto it quietly and build misunderstandings on top.

Round 2: The core formula behind electrical engineering

Wasim covered Ohm's Law: V = I x R, voltage equals current times resistance.

Rather than define the variables abstractly, he built the whole thing around a water pipe. 

Voltage is the pressure difference between two ends. Current is the rate of flow. Resistance is whatever obstructs it.

"If there's dirt in here, if there are obstacles, rocks, pebbles, they're going to impede the flow of current." — Wasim Asghar, founder of Study For FE

From there, he went after the most persistent misconception in electrical safety: that voltage is what kills you.

It is actually current. 

Roughly 40 milliamps through the body is a guaranteed fatality. A coffee maker draws about 1,000 milliamps. The lethal threshold is two to five percent of what runs through a kitchen appliance.

"It's not the voltage that is dangerous. It's really the current." — Wasim Asghar, founder of Study For FE

A bird sitting on a 1,000-volt transmission line survives because the voltage difference across its two feet is zero.

For anyone building a course on a technical subject: definitions without physical anchors give learners nothing to hold onto. 

A concrete system they already understand gives the new concept traction.

What the best educators do differently

Both Dan and Wasim have taught their subjects hundreds of times. What this episode showed is how both of them have rebuilt their explanations around the most common misunderstandings rather than the most logical starting points.

Dan leads with the lift equation because it forces students to confront the variables that actually matter in the cockpit. Wasim leads with the water pipe because it replaces the assumption that voltage is dangerous with the fact that current is.

A 2008 study by Kornell and Bjork found that retrieval practice, having learners reconstruct material from memory rather than passively review it, produces significantly stronger retention than re-reading alone. Cross-Exam runs that experiment in real time.

Dan described what happens when he teaches the same material over and over.

"Every time I do it, it gets a little bit different. I can always rediscover some kind of a new insight or some new way of teaching." — Dan George, founder of FlightInsight

Dan built FlightInsight into a school with over 10,000 students by publishing twice a week, every week, for four years. His full creator case study gets into how that consistency turned into a real business.

Wasim built Study For FE on the same principle. His reframe that current determines electrical danger is the kind of correction that sticks because it runs counter to what most students walk in believing.

Watch the full episode

Dan and Wasim both teach on Teachable. Between them they have built course libraries that reach students in dozens of countries, in fields where getting the material wrong carries real consequences. 

Both of them became better teachers by treating their explanations as working documents rather than finished products.

Watch the full episode of Cross-Exam.

Want to know more about this episode’s guests?

Follow Dan George: YouTube | Website | Teachable School | Instagram | LinkedIn

Follow Wasim Asghar: YouTube | Website | LinkedIn

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