Preflight checklist

A cell charged days earlier and left at full degrades, and a cell charged on the morning is a cell you are rushing.

A damaged lithium cell can ignite, sometimes minutes after the damage rather than at the moment of it. This is the item on this list with a consequence beyond losing a flight.

Storage that fills mid-flight stops logging silently. You get a partial flight and no warning at the time.

A flight day is not the day to discover what changed. If you must update, do a full bench dry run afterwards.

A receiver with a flat battery is a payload with no downlink.

Adding mass moves the centre of gravity, and where the payload sits decides which way. A rocket that flew well ten times before tells you nothing about how it flies with a pod on it.

Dry grass and a hot motor casing is a real combination, and a field fire ends a club's access to a site permanently. Not flying is always available to you.

It is their field and their call. It also means someone else knows there is a lithium cell in the airframe.

A blocked vent makes the barometer measure a sealed tube instead of the sky, and it produces confident nonsense rather than an obvious failure.

Anything that can move under your hand will move far harder under boost. Shake it and listen.

Transmitting into a disconnected or shorted antenna is bad for the radio and gives you no link.

Confirm the link on the table, where you can fix it, rather than at the pad, where you cannot.

A cold start takes far longer than a hot one, and the pad is not where you want to be waiting for it.

The simulation you trusted last night assumed a mass. This is the thirty seconds that confirms it was the right one.

An external pod is the most common thing to catch on a rail button or a launch lug.

Arming starts the pressure reference settling and the pre-arm ring buffer. Everything before this point is not being recorded.

You need to be able to tell from several metres whether it armed, because that is where you will be standing when you wonder.

The ground pressure reference is an average over a settling window. Arm it, then let it sit.

This is the last moment the payload is reachable. A reading of zero here means the reference took.

A bumped rocket during the settling window corrupts the reference.

The beacon pattern is easier to hear from a standing start than from the middle of a field with wind in your ears.

The fix you have is the one you have. Write it down rather than trusting the receiver to still be showing it later.

A landed rocket does not grant permission. Access to flying sites depends on landowners tolerating rocketry, and that tolerance is spent one field at a time.

Every minute armed is a minute of battery you may want next flight.

Impact damage to a lithium cell is not always visible immediately and is not always immediate in its consequences.

The flight you did not offload is the flight you lose when the next one fills the storage.