Learn
Learn.
Videos, seminars, training resources, technical papers. The clearest way to understand OnSpeed is to hear it flying.
01 — Videos
The video library.
Pattern and approach
▶ Video
An inadvertent stall in the base turn at 800 feet AGL, from inside the cockpit. The buffet cue arrives later than the AOA tone; the recovery margin is narrower than seat-of-pants suggests.
▶ Video
A coordinated stall in the base turn, recoverable at low altitude. Pair with the skid case to see why rudder discipline is what determines whether you fly the airplane out or it departs.
▶ Video
Rudder in the direction of turn, opposite aileron, exceed critical AOA. The inside wing quits flying and the airplane spins. Likely non-recoverable below pattern altitude.
▶ Video
Pulling g to tighten a base-to-final turn drives AOA up with load factor. The tone reads 98% capacity while the airspeed gauge stays steady — there is no seat-of-pants cue that the wing is at the limit.
Maneuvering and energy
▶ Video
Long-form walkthrough of the aural logic in flight. Approach, climb, turn, and stall recovery cued entirely off the headset.
▶ Video
AOA stays constant in a steady turn; airspeed varies with bank and load factor. The tone holds steady through a turn that has the airspeed needle climbing well above pattern speeds.
▶ Video
Constant AOA across changing attitude and airspeed. On-speed is an AOA condition, not an airspeed condition — the same AOA flies at any pitch attitude.
Engine-out and turnbacks
▶ Video
Takeoff on speed, climb at L/Dmax, three-second startle delay after the prompt, flaps 40, fly on speed to touchdown. End-to-end demo of the turnback decision aid.
▶ Video
Representative turnbacks in the RV-4 with flaps 40 at idle to compensate for residual thrust. Shows what the technique buys you in altitude required for a 3-5 second startle delay.
▶ Video
An on-speed base turn and final approach using a Dynon percent-lift signal driving a tone generator. High pitch is slow, steady is on speed, beeping is fast.
▶ Video
The TLAR developer flying the same procedure in a different cockpit, with a Garmin AOA indexer in plain view. The technique transfers across instruments.
02 — Simulator
Hear OnSpeed in X-Plane today.
The plugin plays the same tones as the panel box. Free download, macOS / Linux / Windows, X-Plane 12.4 or newer. Take off in any aircraft, fly the pattern, hear the cue. Calibration uses X-Plane's alpha dataref — not a substitute for an in-aircraft calibration, but the closest thing to the real experience until your kit ships.
Plugin · Free
Download the latest `.xpl` for your platform from GitHub releases. Drop into `X-Plane/Resources/plugins/AOA-Tone-FlyOnSpeed/`. Install and calibration walkthrough at dev.flyonspeed.org.
03 — Seminars
Seminars and webinars.
NAFI · Apr 2025 · WINGS
Vac walks instructors through how the military "slow, on speed, fast" tone logic adapts to GA. The companion paper covers the physics, the indexer history, and why the cue helps reduce loss-of-control mishaps.
NAFI · Sep 2024 · WINGS
Vac and Jeff Brown's outbrief from two years of EAA Power Loss on Takeoff working group analysis. Mishap data, simulator results, flight-test findings, and what an honest assessment looks like before the throttle goes up.
EAA · Annual
The OnSpeed engineering prototype runs on the RedBird trainers in the EAA Pilot Proficiency Center. Five modes of operation, instructor-led, drop-in welcome at AirVenture. Forum stages 5 and 11 carry the AOA discussions across the week.
FAASafety · WINGS
FAASafety.gov seminar series. The talk pairs the Power Loss on Takeoff working group findings with the case for AOA cuing as a primary reference for approach and maneuvering.
EAA · 2021
Roughly 90 pilots flew a power-loss-on-takeoff scenario in a typical GA airplane. The data set drives the bank-angle, startle-time and altitude assumptions Vac and the EAA working group cite when discussing the impossible turn.
04 — Training
Training resources.
Syllabus
Built on FAA AC 90-109 with Van's factory references. Three tracks (Basic, Advanced, Combined), gradesheets, RV performance and weight-and-balance briefs. Vac maintains the document; Word and PowerPoint originals available for editing.
FAA · AC
The FAA's formal transition-training framework for experimental and unfamiliar types. Foundation for the RV syllabus above and the structure most type-clubs key off.
AOPA · Course
Generic but solid coverage of transition considerations. The EAB module is worth the time, especially for pilots picking up an already-flying experimental and skipping a builder's phase-1.
App · iOS
Jeff Brown's iPhone app. Computes "turn back possible" from POH numbers, then guides the maneuver in flight. Built to make pilots think through performance and options before pushing the throttle up — the in-flight cue is a bonus.
Reference
The team's curated reference shelf. NASA TN D-6210 (1971 GA AOA flight evaluation), the FAA Tech Center papers the firmware was built against, and a running set of AOA / energy-management resources Vac points new pilots at.
Handout
Vac's notes on flying the engine-out problem with AOA as the primary reference. L/Dmax glide, the math behind minimum-power AOA, and how the "slow / on speed / fast" cue collapses the cockpit workload during an actual emergency.
05 — Papers
Technical papers.
Paper · 2024
Vac and the FlyONSPEED team. Written for pilots by pilots: how the military adapted aural AOA cuing to improve handling precision, energy management and reduce loss of control. Embedded videos and illustrations throughout. NAFI MentorLIVE 91 companion paper, 2024.
Paper · 2021
Team-authored. System operation, the coefficient-of-pressure derivation, project history and flight-test results. The reference Vac points engineers and curious builders at when they want the full picture. See pages 202–204 for the cockpit-checklist treatment.
NAR · Rogers
Dr. David F. Rogers, NAR Associates. Optimal turn-back maneuver after engine failure during takeoff. The reference paper Vac and the EAA working group cite when discussing the math behind a 180 back to the runway.
AIAA · Jett
Brent W. Jett, full AIAA paper. The simulator experiment behind the turn-back-from-500-feet problem. Pairs with Rogers' work above; together they make up the peer-reviewed core of the impossible-turn discussion.
NAR · Rogers
Short how-to from Dr. Rogers. Where the L/Dmax-to-min-power AOA ratio comes from (1.73× in AOA, 0.76× in V) and why endurance glide and best-range glide aren't the same point. Vac cites it as the practical math reference for setpoint work.
FAA · TC18-7
FAA Tech Center. The physics of accurately measuring AOA from differential pressure, plus probe placement guidance. The paper that drove how OnSpeed normalizes alpha; flight test against this method shows ½° error at six G's and 20° of yaw.
FAA · TC18-19
FAA Tech Center. De-identified comparison of ten production AOA systems. The team treats this as a requirements document — every shortcoming the report flags became a thing OnSpeed had to solve.
FAA · Handbook
FAA. Chapter 4 covers energy management. Vac flags it as the canonical text on the relationship between throttle, AOA, gross weight and G load — the same content the OnSpeed tone logic operationalizes.
AOPA · GAJSC
AOPA-hosted. The advocacy report that Charlie Precourt's Sport Aviation column drew from. Recommendations on transition training, AOA cuing, and the structural changes the GA community needs to dent the LOC accident rate.
DTIC · 1976
Old military report on the aerodynamics of differential-pressure AOA systems and the engineering math behind the indexer-tone logic. Vac cites it for builders who want to understand the heritage that adapts directly to an RV.
06 — Books
Books on the shelf.
Book · 1944
Vac calls this the original case for flying the wing on AOA. "A step in the direction Wolfgang Langewiesche started marching when he wrote Stick and Rudder in 1944." The reason airspeed is treated as a surrogate for AOA in every subsequent OnSpeed discussion.
Book · Lowry
The bootstrap flight-test technique reference. Vac points builders here for working through static-source error and pitot-static plumbing on a fixed-pitch RV. Pairs with AC 90-89 and Kevin Horton's site for a complete phase-1 toolkit.
Book · Pytka
Vac's shelf reference for grass and unimproved-strip operations. Pairs with the UK CAA SafetySense leaflet on strip flying when the airplane is heading somewhere a paved-runway POH wasn't written for.
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