Normal Law and Pitch — Ground, Flight, Flare Modes and Load-Factor Demand

Normal law is the Airbus fly-by-wire heart: 3-axis control, full flight-envelope protection, and manoeuvre load alleviation. This article covers the pitch axis — the three modes (Ground, Flight, Flare), the defining load-factor demand law with auto trim, the handling technique it implies (minor corrections, hands-light), and how the flare is flown.

Flight control normal law provides: 3 Axis control, Flight envelope protection, Maneuver load alleviation... The normal law flight mode is a load factor demand law with auto trim and full flight envelope protection. — FCOM DSC-27-20-10-10 / -20

1. What Normal law is for

Per FCOM DSC-27-20-10-10, Normal law gives 3-axis control, flight-envelope protection and manoeuvre load alleviation. The FCOM is explicit about the philosophy:

Despite system protections, the PF must not deliberately exceed the normal flight envelope. In addition, these protections are not designed to be structural limit protections... Rather, they are designed to assist the PF in emergency and stressful situations, where only instinctive and rapid reactions will be effective.

[!warning]- Protections assist instinctive reaction — they are not a licence to exceed the envelope Read the FCOM's intent (DSC-27-20-10-10): protections let the PF pull full authority for best performance in extreme conditions and reduce the risk of over-stressing — but they are not structural-limit protections and the PF must not deliberately exceed the envelope. The design goal is an instinctive, immediate procedure (full back-stick to escape) that is safe to apply, not a system to fly against routinely. This matches the FCTM design principle that the crew can "exercise full authority by intuitive actions while eliminating the risks of overstress or overcontrol" (FCTM AOP-10).

The full protection suite — load factor limitation, pitch attitude protection, high-AOA protection, high-speed protection — is detailed in articles 06–09.

2. The three pitch modes

Ground mode

Per FCOM DSC-27-20-10-20, on ground pitch is a direct relationship between sidestick and elevator, without auto trim. The THS is automatically set 5° up (green band); before departure, once all three hydraulic systems are available, the PRIM sets the THS to the takeoff value computed from the ZFWCG and fuel distribution — once only, and the crew can override it. Rotation is flown in direct law with full authority. After lift-off, flight mode is progressively blended in; the reverse occurs after touchdown.

Flight mode — load-factor demand with auto trim

The normal law flight mode is a load factor demand law with auto trim and full flight envelope protection. In manual flight, it provides elevator and THS control from the sidestick controllers to achieve a load factor proportional to stick deflection, independent of speed. With the sidestick at neutral and the wings level, the system maintains 1 g in pitch corrected for pitch attitude.

Per FCOM DSC-27-20-10-20, in flight mode stick deflection commands a load factor, not an elevator position — and it is independent of speed. With the stick neutral and wings level, the system maintains 1 g corrected for pitch attitude. The consequences:

• no trimming with speed or configuration changes — pitch trim is automatic;
• in normal turns up to 33° bank, no pitch correction is needed once established;
• the pilot makes only minor path corrections, and releases the stick if sensing overcontrol.

[!warning]- A neutral stick holds the flight path — this is the Airbus pitch characteristic The single most important pilot fact: a centred sidestick commands 1 g corrected for pitch attitude, so the aircraft holds its flight path through speed and configuration changes with no pilot trimming (FCOM DSC-27-20-10-20). You fly trajectory, not attitude+trim. This is why a relaxed, hands-light technique works and over-controlling is the common error — and why on a manual approach the FCTM warns the crew to "avoid the temptation to make large inputs on the sidestick" because the aircraft, disconnected from a stabilised AP path, is already trimmed and stable (FCTM PR-NP-SOP-190).

Flare mode

Per FCOM DSC-27-20-10-20, when the aircraft passes 100 ft RA the THS is frozen and flight mode transitions to flare mode — essentially a direct stick-to-elevator relationship (damped by load-factor and pitch-rate feedback). At 50 ft a slight pitch-down elevator order is applied, so a gentle nose-up flare by the pilot is required.

[!note]- The flare is deliberately conventional — fly attitude, not airspeed (integrative synthesis) The 50 ft pitch-down order is intentional: it makes the aircraft need a normal nose-up flare input, restoring a conventional landing feel rather than holding 1 g into the ground (FCOM DSC-27-20-10-20). The FCTM landing technique reinforces this: at the flare "the pilot should not concentrate on the airspeed, but only on the attitude with external cues," with reinforced PM call-outs for excessive pitch attitude at landing (FCTM PR-NP-SOP). So both ends of the flight — takeoff rotation and landing flare — are flown in a quasi-direct relationship, with the protected load-factor-demand mode only in between.

3. Auto pitch trim — and when it freezes

Per FCOM DSC-27-20-10-20, pitch trim is automatic in manual and autopilot flight, but auto-trim freezes when:

• a manual trim order is made;
• radio height below 100 ft (for flare);
• load factor below 0.5 g;
• in high-speed protection.

And when AOA protection is active, the THS is limited between its setting at entry and 2° nose-down — further nose-up trim cannot be applied.

[!warning]- The trim freezes guard the protections (integrative synthesis) Each freeze has a reason: below 100 ft so the flare is hand-flown; below 0.5 g and in high-speed protection so the system does not trim the aircraft into a worse state; and in AOA protection the THS is blocked from adding nose-up so it cannot trim toward the stall. Auto-trim is suspended exactly where letting it run would fight a protection — and because the THS override means a manual wheel input always cancels the electronic trim, a deliberate manual trim also freezes the auto-trim.

4. Handling technique implications

Because the flight mode holds 1 g hands-off, the manual-flying technique is distinctive (FCTM PR-NP-SOP):

• make small inputs — the aircraft holds its path; large inputs cause the over-control the protections are designed to absorb but which still degrade the path;
• release the stick when sensing overcontrol — neutral returns to 1 g/path-hold;
• on AP disconnect for a manual landing, disconnect early enough to evaluate the drift before the flare, and avoid large corrections — the aircraft is already stable;
• in crosswind, do not eliminate the drift too early and do not duck under.

[!note]- The Airbus pitch law rewards a light hand (integrative synthesis) The whole point of load-factor demand + auto-trim is that the aircraft flies the trajectory for you — so the correct technique is the opposite of a conventional aircraft's continuous trimming and pressure-holding. The most common faults (FCTM) are over-controlling and trying to "fly the needles" with large inputs. A neutral stick and small corrections is not laziness — it is the designed technique.

5. Counterintuitive points

[!warning]- Stick commands g, not elevator — and not speed-stable In flight mode, deflection = load-factor demand independent of speed (FCOM DSC-27-20-10-20); the aircraft does not return to a trimmed speed, it holds the commanded path.

[!warning]- Rotation and flare are flown direct, not protected Ground mode rotation is direct law; flare is essentially direct with a 50 ft nose-down nudge (FCOM DSC-27-20-10-20) — the protected mode is only in between.

[!warning]- Fly attitude in the flare, and make small inputs throughout Concentrate on attitude (not airspeed) in the flare; avoid large sidestick inputs (FCTM PR-NP-SOP).

6. Self-test

[!note]- Q1. What does the sidestick command in flight mode, and what holds with it neutral? A load factor proportional to deflection, independent of speed; neutral stick + wings level holds 1 g corrected for pitch attitude (flight path held, no trimming).

[!note]- Q2. The three pitch modes and their character? Ground (direct stick-elevator, no auto trim, rotation in direct law), Flight (load-factor demand + auto trim + protections), Flare (THS frozen at 100 ft, quasi-direct, 50 ft pitch-down → manual flare).

[!note]- Q3. When does auto pitch trim freeze? Manual trim order, RA < 100 ft, load factor < 0.5 g, in high-speed protection; in AOA protection THS limited to 2° nose-down.

[!note]- Q4. The manual-flying technique the law implies? Small inputs, hands-light, release if overcontrolling; in the flare fly attitude not airspeed; on AP disconnect avoid large corrections (the aircraft is stable).

[!note]- Q5. How is the THS set for takeoff? Auto 5° up then, with 3 hydraulics, the takeoff value from ZFWCG + fuel (once, override-able by crew).

7. Key takeaways

References

• FCOM DSC-27-20-10-10 (Normal Law — General) — 3-axis control, flight-envelope protection, manoeuvre load alleviation; protections assist instinctive PF reaction, not structural-limit protections, PF must not deliberately exceed the envelope.
• FCOM DSC-27-20-10-20 (Normal Law — Pitch Control) — Ground mode (direct stick-elevator, no auto trim, THS 5° up then takeoff value from ZFWCG + fuel distribution, rotation in direct law); Flight mode (load-factor demand law, auto trim, full envelope protection, load factor proportional to stick independent of speed, neutral stick holds 1 g corrected for pitch attitude, no trimming with speed/config, 33° bank no pitch correction, release stick if overcontrol); Flare mode (THS frozen at 100 ft RA, essentially direct stick-to-elevator with load-factor/pitch-rate damping, 50 ft slight pitch-down requiring gentle nose-up flare); auto-trim freeze (manual trim, RA < 100 ft, load factor < 0.5 g, high-speed protection; AOA protection limits THS to 2° nose-down).
• FCTM PR-NP-SOP-190 (Approach / Landing) — at the flare concentrate on attitude not airspeed, reinforced PM call-outs for excessive pitch attitude; AP disconnect early enough to evaluate drift before flare, avoid large sidestick inputs (aircraft stable), do not eliminate drift too early/duck under.
• FCTM AOP-10 (Design Philosophy) — full authority via intuitive actions while eliminating overstress/overcontrol risk.

Independent study material, not an Airbus publication and not endorsed by the manufacturer. Always defer to the current operator FCOM, FCTM, and QRH for operational use.