# Emergency Shut-Down

To "Fine-Tune" or "adjust" the hydrogen burn-rate still further to obtain maximum engine performance, non-combustible gases from the engine exhaust system is meter mixed with the **Fuel-Cell Gases** under control means, as illustrated in Figure 5.

<p class="callout info">The engine provides the non-combustible gases on demand since **Ambient Air** is used firing the **Gas Combustion Process**.</p>

[![image-1711428480735.47.58.png](https://stanslegacy.com/uploads/images/gallery/2024-03/scaled-1680-/QmsxrcodIkfPZNKh-image-1711428480735-47-58.png)](https://stanslegacy.com/uploads/images/gallery/2024-03/QmsxrcodIkfPZNKh-image-1711428480735-47-58.png)