# How to Fix FPV Drone Yaw Washout and Instability During Punch-Outs
You punch the throttle, the quad rockets upward — and suddenly it spins uncontrollably on the yaw axis. You didn’t touch the yaw stick, but your drone acts like it has a mind of its own. This is **yaw washout**, and it’s one of the most frustrating FPV handling issues. The good news: it’s fixable, and this guide shows you exactly how.
## What Is Yaw Washout?
Yaw washout happens when a quadcopter loses yaw authority during high-throttle maneuvers. The flight controller commands the motors to spin faster for more lift — but some motors hit their RPM limit before others, creating a torque imbalance that the PID controller can’t correct. The result: uncontrolled yaw rotation that stops only when you lower the throttle.
## Root Causes of Yaw Washout
| Cause | Mechanism | How to Diagnose |
|—|—|—|
| **Motor saturation** | One or more motors hit 100% output at full throttle, leaving no headroom for yaw correction | Blackbox log: motor traces flatline at 100% |
| **Underpowered motors** | Motors lack the torque to both lift and stabilize at high RPM | Happens consistently at specific throttle levels |
| **Insufficient PIDs on yaw** | Yaw P-term is too low, D-term is too low, or yaw I-term can’t accumulate fast enough | Gentle yaw authority, washout at lower throttle than expected |
| **Propeller stall** | Props lose aerodynamic efficiency at high angles of attack during punch-outs | Often accompanied by increased noise in gyro traces |
| **Battery sag** | Voltage drops below what’s needed for full motor RPM | Telemetry shows voltage <3.5V/cell during punch-out |
| **Frame resonance** | Vibrations saturate the gyro, causing the FC to make bad corrections | Visible in gyro_scaled traces as noise spikes |
## Step-by-Step Fix
### Step 1: Eliminate Hardware Issues First
Before touching any software settings, verify:
- **All motors spin freely** by hand — no grinding, binding, or magnet damage
- **Props are tight** — a slipping prop nut causes sudden torque changes
- **Motor screws aren't touching windings** — use the right length screws
- **All four ESCs output equal power** — test with the Motors tab at 50% throttle
### Step 2: Check Motor Output in Blackbox
Record a flight where you intentionally punch out and trigger the washout. Open the log:
1. Look at the **motor traces** (motors 1-4). If any trace hits 100% during the punch-out, you have motor saturation.
2. Look at the **gyro traces**. If yaw gyro spikes occur at the exact moment of washout, the FC is losing control authority.
3. Check **RC command**. Confirm you're not accidentally inputting yaw (it happens more than pilots admit).
### Step 3: Increase Yaw PID Authority
If motors aren't saturated, your yaw PID tune needs strengthening:
```
# CLI commands to increase yaw authority
set p_yaw = 100 # Increase from default ~90. Range: 70-130
set i_yaw = 120 # Increase from default ~100. Boosts holding power
set d_yaw = 0 # Yaw D should almost always be 0
save
```
Test fly and increase incrementally. If the quad feels "nervous" on yaw (twitchy), back off the P-term.
### Step 4: Enable Anti-Gravity and Throttle Boost
```bash
set anti_gravity_gain = 3500 # Default 1000. Increases I-term gain at high throttle
set iterm_relax = RPY # Prevents I-term windup during fast maneuvers
set iterm_relax_cutoff = 15 # Frequency cutoff for I-term relaxation
save
```
Anti-gravity temporarily amplifies the I-term when throttle changes rapidly — exactly what you need during punch-outs.
### Step 5: Dynamic Idle (RPM Filtering)
Betaflight 4.3+ supports dynamic idle, which keeps motors spinning even at zero throttle. This maintains yaw authority during inverted maneuvers and punch-outs:
```
set dyn_idle_min_rpm = 35 # Minimum idle RPM percentage
set dyn_idle_p_gain = 50 # How aggressively it maintains idle
set dyn_idle_d_gain = 50
save
```
### Step 6: Check Your Motor/Prop Combination
If you're running high-pitch props on low-torque motors, upgrade:
| Problem | Motor Solution | Prop Solution |
|---|---|---|
| Yaw washout on 5" with 2306 1700KV | Upgrade to 2306 1900KV or 2207 | Switch to lower pitch (4.3 → 4.0) |
| Yaw washout on 3" with 1404 3800KV | Upgrade to 1408 3600KV | Try 3-blade instead of 4-blade |
| Yaw washout on 7" long range | Upgrade to 2807+ size | Reduce prop pitch |
### Step 7: Enable Yaw D-Min (Betaflight 4.5+)
The latest Betaflight versions include D-Min for yaw, which dynamically adjusts D-term based on stick movement speed:
```
set yaw_d_min_gain = 30 # Start conservative
set yaw_d_min_advance = 50
save
```
## Not Yaw Washout? Check These Instead
Sometimes what feels like yaw washout is actually something else:
- **I-term windup on yaw**: The quad holds a constant slow yaw after a fast maneuver. Lower `i_yaw` slightly.
- **Frame twist**: A cracked arm or loose standoff flexes under load, changing thrust vectors mid-flight.
- **Gyro noise at full throttle**: Add a notch filter or lower the RPM filter harmonics if noise spikes appear in blackbox.
## Recommended Hardware
Persistent yaw washout despite tuning usually points to underpowered motors. Check out the high-torque motor selection at [UAVModel](https://uavmodel.com) for motors that deliver the headroom you need for clean, controlled punch-outs.
## Watch: Fixing Yaw Washout in Betaflight
## Summary
Yaw washout is caused by motor saturation, insufficient yaw PIDs, or poor motor/prop pairing. Start by checking for motor saturation in blackbox, then increase yaw P and I gains, enable anti-gravity, and try dynamic idle. If tuning doesn’t fix it, your motors are likely underpowered for your prop and weight combination — upgrade to a higher torque motor.
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