Drafted — not technically validated
Record revision 1 · The 3/9 line, the bubble, pursuit curves, corner airspeed and the yo-yos and scissors of basic fighter maneuvers.
Definitions are quoted or closely paraphrased from the source named with each word. Meanings change between editions and theatres; the brief and the current publications take precedence.
The words of the fight
These are the words of basic fighter maneuvers (BFM), one aircraft against another within visual range: the geometry of who is offensive, the pursuit curves, turn performance and the three-dimensional maneuvers. They are defined from the Navy’s T-45 training instruction, which notes that the fundamental tactics and maneuvers of air combat have changed little in decades. [1] The yo-yos are defined from the Navy’s tactical formation text. [2]
Fighter communities in every service use these words, but the numbers quoted with them, such as a 410-knot corner airspeed or a 10,000-foot hard deck, are the T-45 syllabus’s. An aircraft’s own manual and the unit’s training rules give its figures. [1]
Radio calls used in the same fights, such as KNOCK-IT-OFF, BANDIT and TALLY, are in the brevity words.
21 terms
- 3/9 line
An imaginary line through an aircraft's wingtips, at right angles to its flight path (the “3 and 9 o'clock” line). Behind it is generally offensive.
Source: [1] CNATRA P-1289 (Rev. 01-16), p. 5-1
- Bubble
The turn an aircraft scribes at maximum performance. An aircraft cannot turn inside its own bubble, so an opponent inside it is, for the moment, safe from its nose.
The training instruction uses a typical 3,000-foot T-45 turn radius for the bubble. [1]
Source: [1] CNATRA P-1289 (Rev. 01-16), pp. 5-2–5-3, 5-22
- Control zone
A cone-like area 2,000 to 4,000 feet behind a maneuvering aircraft. An attacker who arrives there with range, angles and closure under control can stay there, and the defender can no longer deny the position.
Source: [1] CNATRA P-1289 (Rev. 01-16), p. 5-3
- Corner airspeed
The airspeed where the load limit and the lift limit meet. It gives the best instantaneous turn performance, but also the highest bleed rate.
In the T-45 it is 410 KIAS, bleeding about 8 knots per second in a maximum-performance pull. [1] See also corner speed in the flight terms.
Source: [1] CNATRA P-1289 (Rev. 01-16), pp. 4-3–4-4
- Energy excursion
The conscious sacrifice of airspeed for angles, accepted to take or deny a shot or turning room.
Source: [1] CNATRA P-1289 (Rev. 01-16), p. 5-7
- Fight's on
The call that starts a training engagement. Lead counts “3, 2, 1, fight's on” and the wingman echoes it.
Source: [1] CNATRA P-1289 (Rev. 01-16), p. 5-14
- Flat scissors
A slow-speed, high angle-of-attack radius fight that typically follows an in-close overshoot. Both aircraft fly a series of S turns, transferring airspeed into altitude, to reduce their travel downrange.
Source: [1] CNATRA P-1289 (Rev. 01-16), p. 5-13
- Hard deck
The training floor, at least 10,000 feet above ground level or 5,000 feet above an undercast, with a soft deck 5,000 feet above it.
Source: [1] CNATRA P-1289 (Rev. 01-16), p. 3-1
- High yo-yo
“A lag pursuit maneuver designed to reduce angle off and closure rate.” The attacker quarter-rolls away from the bandit's maneuvering plane and pulls the nose up, trading airspeed for altitude, then rolls back toward the bandit and pulls down into pursuit.
Source: [2] P-1218, p. 28
- Lag pursuit
Nose or lift vector behind the bandit, used to manage the range, angle and closure problem. Held too long, it can give away the offensive advantage.
Source: [1] CNATRA P-1289 (Rev. 01-16), p. 5-4
- Lead pursuit
Nose or lift vector in front of the bandit, used only to employ weapons or to close nose-to-tail distance, then followed by lag to reduce closure and angle off tail.
Source: [1] CNATRA P-1289 (Rev. 01-16), p. 5-4
- Low yo-yo
Pulling the nose down toward the inside of the bandit's turn and well in front of it (lead pursuit), then working it back up toward the bandit approaching weapons range. An option after overshooting the control zone, or when turn rate cannot bring the nose to bear.
The T-45 instruction warns against a low yo-yo to make up angles behind a nose-low bandit: it only loses the altitude advantage. [1]
Source: [2] P-1218, p. 27; [1] CNATRA P-1289 (Rev. 01-16), p. 5-25
- One-circle flow
A radius or nose-to-nose fight, in which the aircraft with the smaller turn radius has the advantage and turn rate matters little.
Source: [1] CNATRA P-1289 (Rev. 01-16), p. 5-6
- Plane of motion
The plane in which an aircraft's turn circle lies.
Source: [1] CNATRA P-1289 (Rev. 01-16), pp. 5-2–5-3
- Post
The centre of the turn circle an aircraft is actually scribing.
Source: [1] CNATRA P-1289 (Rev. 01-16), pp. 5-2–5-3
- Radial G
The combination of the load factor the pilot pulls and gravity, the total turn performance. With a constant pull in a loop, gravity fights the turn at the bottom and helps it at the top.
Source: [1] CNATRA P-1289 (Rev. 01-16), pp. 4-5–4-7
- Rolling scissors
A fight with both aircraft inside each other's bubble, rolling over the top of each other, neutral for as long as it lasts. Offensively, finding yourself in one means a mistake has been made.
Source: [1] CNATRA P-1289 (Rev. 01-16), pp. 5-18–5-21
- Split-S
A pure nose-low maneuver. Flown at maximum performance, a T-45 needs about 6,000 to 6,500 feet of altitude to complete one, and comes out faster than it went in.
Source: [1] CNATRA P-1289 (Rev. 01-16), pp. 4-6–4-7
- Target aspect
The angular difference between the bandit's nose and your aircraft.
Source: [1] CNATRA P-1289 (Rev. 01-16), pp. 5-7–5-8
- Terminate
A training call that temporarily stops the engagement for administrative reasons; lead restarts it.
Not the same as KNOCK-IT-OFF, which ends the engagement. [1]
Source: [1] CNATRA P-1289 (Rev. 01-16), p. 5-11
- Two-circle flow
A nose-to-tail rate or energy fight, in which the two turn circles are centred over different points. The angular advantage usually goes to the aircraft with the higher turn rate at its corner speed.
Source: [1] CNATRA P-1289 (Rev. 01-16), p. 5-6
Sources
- CNATRA P-1289 (Rev. 01-16), Flight Training Instruction, Basic Fighter Maneuvering (1v1), Section Engaged Maneuvering (2v1), T-45. Naval Air Training Command, Revision 3 of 7 January 2016, Change 1 of 3 March 2021. https://www.cnatra.navy.mil/local/docs/pat-pubs/P-1289.pdf (accessed 2026-10-24). Cleared for public release. Training rules pp. 3-1 to 3-3; aerodynamics pp. 4-1 to 4-8; offensive BFM pp. 5-1 to 5-25.
- P-1218, Tactical Formation, (11-98) Original. US Navy flight training publication (transcription hosted by Integrated Publishing). https://navyflightmanuals.tpub.com/P-1218/High-Yo-Yo-P-12180039-39.htm (accessed 2026-10-24). Low yo-yo p. 27, high yo-yo p. 28. The transcription carries no issuing command or distribution statement.