Dreaming about a plane crash, especially while feeling calm, can be quite intriguing. Generally, plane crashes in dreams can symbolize feelings of loss of control, fear of failure, or anxiety about a significant change in your life. However, your calmness during this dream suggests a few possible interpretations:

1. Acceptance of Change: You may be experiencing a significant transition or change in your life, and your calmness indicates that you are accepting this change rather than resisting it.
2. Inner Peace: It could also reflect a sense of inner peace or confidence despite chaotic or challenging situations. You might feel equipped to handle whatever difficulties come your way.
3. Letting Go of Fear: If you have had fears or anxieties associated with flying or change, this dream could signify that you are overcoming those fears and learning to embrace the unknown.

To gain further insights, consider what is happening in your waking life. Are there any changes or challenges you are facing? Reflecting on your feelings and thoughts related to those situations can help you understand the significance of this dream more deeply.