No-Go Criteria and Defense Questions

A mission plan is not mature until the team can explain when not to execute it.

No-go criteria are not pessimism. They are pre-decided boundaries that stop pressure, excitement, schedule, or sunk effort from changing the standard at the worst possible moment.

A no-go criterion must be observable

Weak criterion:

Do not fly if conditions are bad.

Stronger criterion:

Do not proceed if current weather evidence exceeds the approved project threshold, if required site control cannot be maintained, or if the airspace/authority check cannot be verified from a current official source.

The stronger version names evidence and conditions.

Build criteria by layer

Authority and site

Possible classroom planning criteria:

• required official-source verification is unavailable or conflicting;
• site permission/operating boundary cannot be established;
• a temporary or local condition invalidates the proposed area;
• the plan depends on an assumption that must be verified first.

Weather and environment

Examples:

• wind, visibility, precipitation, temperature, or other conditions exceed the approved aircraft/team planning boundary;
• safe launch/recovery geometry is not available;
• uncontrolled people or hazards enter the planned area.

Aircraft and energy

Examples:

• inspection identifies damage or unclear airworthiness;
• required payload configuration is not verified;
• endurance evidence does not support mission time plus required reserve/margin;
• a critical sensor or control function fails readiness checks.

Data/product

Examples:

• the required product cannot be produced with the available sensor/viewpoint;
• capture quality cannot meet the project acceptance test;
• file, calibration, or traceability problems make the evidence unreliable.

A no-go criterion can protect the product as well as physical safety.

Stop rules need owners

A criterion without decision authority can fail under pressure.

For each no-go rule, identify:

• who notices the evidence;
• who calls the stop in the classroom workflow;
• what artifact records the decision;
• what has to change before reconsideration.

Example:

Again: project roles model disciplined teamwork. Real operational authority belongs to the applicable qualified operator and regulatory framework.

Defense questions should attack assumptions

A weak presentation rehearses only friendly questions.

A technical defense prepares for questions such as:

• Which claim in your plan has the weakest evidence?
• What single change would force the largest redesign?
• Why does the stakeholder need this product instead of a simpler one?
• Where is your mission using an assumption instead of a measurement?
• What evidence would make you reject the selected aircraft concept?
• How does the plan recover if one required image is unusable?
• Which rule or operating condition must be re-checked immediately before a real operation?
• What does your mapping or imagery product not prove?
• Which control has the largest residual risk?
• Who owns the stop decision when schedule pressure is high?

These questions are useful because they expose the architecture of the plan.

Worked defense: “We have a geofence, so the route is safe”

Reviewer:

Why is the geofence enough?

Weak answer:

Because the drone cannot leave the area.

Stronger answer:

The geofence is one control against a boundary excursion, but the plan does not treat it as a safety guarantee. The boundary must be configured correctly, position estimates must be credible, the route still has to avoid people and obstacles, and recovery logic must remain valid. The residual risk stays in the register.

The stronger answer does not defend the feature. It defends the reasoning.

Write the stop card

Create a one-page no-go card containing your most important criteria. Organize it by:

• authority/site;
• weather/environment;
• aircraft/energy;
• control/sensing;
• product/data quality.

For each condition, include the evidence source and the required response.

Then write answers to five defense questions, including at least two that challenge assumptions or limitations.

Final test

If a reviewer asks, “What would make you walk away from this mission after two weeks of work?” your team should have a technical answer immediately.

That answer is part of being ready.