Spaced Repetition for Pilots

Updated July 2026 · by Jeff, pilot and builder of Zeekin Around

Spaced repetition is the most evidence-backed way to retain FAA knowledge: you retrieve each fact from memory on expanding intervals, right before you'd forget it. Without review, about two-thirds of what you learn is gone within 24 hours — and a checkride tests what you remember months after ground school, not the week you crammed.

How fast do pilots actually forget?

The forgetting curve is one of the oldest replicated results in psychology. Ebbinghaus measured it in 1885 — roughly two-thirds of newly learned material lost within a day — and a modern replication confirmed the same curve across intervals from 20 minutes to 31 days (Murre & Dros 2015, PLOS ONE). Aviation knowledge is no exception: hypoxia symptoms, airspace cloud clearances, and 91.213(d) all decay on the same schedule unless something brings them back.

What does the research say about how to study?

Two techniques stand clear of the rest, and they are exactly the two spaced repetition combines:

• Retrieval practice. In the classic test-enhanced learning experiment, students who repeatedly recalled a passage retained 61% a week later versus 40% for students who repeatedly reread it — about half again as much retained, from testing instead of rereading (Roediger & Karpicke 2006).
• Distributed practice. A Psychological Bulletin meta-analysis of 317 experiments found spaced study reliably beats massed study, and that the ideal gap between reviews grows as the retention target grows (Cepeda et al. 2006) — which is what interval scheduling automates.
• Of ten popular study techniques reviewed for Psychological Science in the Public Interest, only these two — practice testing and distributed practice — earned the top "high utility" rating. Rereading and highlighting ranked low (Dunlosky et al. 2013).

This is FAA doctrine too: the Aviation Instructor's Handbook (FAA-H-8083-9) teaches that learning sticks when it is retrieved, spaced, and applied — not reread. And in the highest-stakes adjacent field, medical students using daily spaced-repetition flashcards had a Step 1 board failure rate of 2.8% versus 10.9% for non-users in one cohort study (Medical Science Educator 2023).

What is FSRS?

FSRS (Free Spaced Repetition Scheduler) is an open-source, machine-learned scheduler that models your memory of each card and predicts when you'll forget it. On the public benchmark of roughly 350 million real reviews across nearly 10,000 learners' collections, FSRS predicted recall more accurately than the older SM-2 algorithm for 99.6% of collections — which is why Anki made it the default scheduler for new collections. In practice, better predictions mean reviews land right before you'd forget: typically fewer reviews for the same retention.

Does any pilot test prep actually use spaced repetition?

As of July 2026, none of the major FAA test-prep products — Sheppard Air, Gleim, Sporty's, King Schools, ASA Prepware, Boldmethod, or Pilot Institute — schedule reviews on forgetting-curve intervals. Several offer "adaptive" sessions or flashcard apps that resurface missed questions, which helps, but that is error tracking, not memory modeling. The full comparison is here. Zeekin Around's flashcards are scheduled by FSRS and organized per ACS task, so what you retain maps one-to-one onto what the examiner is required to test.

How do I use it alongside my ground school?

Spaced repetition is a retention layer, not a curriculum — keep your ground school. Learn a topic in Sporty's, King, Gleim, Pilot Institute, or with your CFI, then let the scheduler hold onto it: clear your due-card queue daily (ten minutes is enough), and the material you learned in month one is still there for the checkride in month six. Start with the free study sessions or read how to study for the private pilot written.

Sources: Murre & Dros, PLOS ONE (2015) · Roediger & Karpicke, Psychological Science (2006) · Cepeda et al., Psychological Bulletin (2006) · Dunlosky et al., PSPI (2013) · open-spaced-repetition/srs-benchmark · FAA-H-8083-9. Product claims checked against each vendor's site, July 2026.