22/07/2026
𝟓 𝐰𝐚𝐲𝐬 𝐩𝐫𝐞𝐥𝐢𝐦𝐢𝐧𝐚𝐫𝐲 𝐝𝐞𝐬𝐢𝐠𝐧 𝐚𝐧𝐝 𝐟𝐢𝐫𝐬𝐭-𝐨𝐫𝐝𝐞𝐫 𝐜𝐚𝐥𝐜𝐮𝐥𝐚𝐭𝐢𝐨𝐧𝐬 𝐜𝐫𝐞𝐚𝐭𝐞 𝐯𝐚𝐥𝐮𝐞 𝐢𝐧 𝐚𝐢𝐫𝐜𝐫𝐚𝐟𝐭 𝐝𝐞𝐯𝐞𝐥𝐨𝐩𝐦𝐞𝐧𝐭
𝟏. 𝐀𝐭 𝐭𝐡𝐞 𝐛𝐞𝐠𝐢𝐧𝐧𝐢𝐧𝐠 𝐨𝐟 𝐚 𝐩𝐫𝐨𝐣𝐞𝐜𝐭
They help compare concepts, estimate orders of magnitude, identify the main design drivers and risks, and align expectations before significant time and money are invested.
This reduces the number of surprises later in the development process and during flight testing.
𝟐. 𝐃𝐮𝐫𝐢𝐧𝐠 𝐟𝐥𝐢𝐠𝐡𝐭 𝐭𝐞𝐬𝐭𝐢𝐧𝐠
A quick calculation can help evaluate a planned change before the test, interpret the results afterward, or even support a decision in the field.
Sometimes, a notebook and a pencil are enough.
In other cases, a prepared Excel sheet or a simple code allows us to update the relevant parameters and understand the expected trend almost immediately.
𝟑. 𝐖𝐡𝐞𝐧 𝐫𝐞𝐯𝐢𝐞𝐰𝐢𝐧𝐠 𝐚𝐧 𝐞𝐱𝐢𝐬𝐭𝐢𝐧𝐠 𝐝𝐞𝐬𝐢𝐠𝐧
Some systems are developed quickly because the schedule does not allow for a complete preliminary-design process.
First-order tools allow us to step back, evaluate the existing configuration against its requirements, identify the main gaps, and define which changes should be investigated in greater depth.
𝟒. 𝐖𝐡𝐞𝐧 𝐞𝐯𝐚𝐥𝐮𝐚𝐭𝐢𝐧𝐠 𝐚𝐧 𝐞𝐱𝐢𝐬𝐭𝐢𝐧𝐠 𝐬𝐩𝐞𝐜𝐢𝐟𝐢𝐜𝐚𝐭𝐢𝐨𝐧
A few initial calculations can often reveal whether product claims are reasonable.
Maximum speed, endurance, payload, climb performance, or range can be sanity-checked using basic estimates of drag, propulsion, power, energy, and weight.
The purpose is not to reproduce the complete design, but to determine whether the numbers are physically consistent.
𝟓. 𝐁𝐞𝐟𝐨𝐫𝐞 𝐚𝐧𝐝 𝐚𝐥𝐨𝐧𝐠𝐬𝐢𝐝𝐞 𝐡𝐢𝐠𝐡-𝐟𝐢𝐝𝐞𝐥𝐢𝐭𝐲 𝐚𝐧𝐚𝐥𝐲𝐬𝐢𝐬
CFD, FEA, and other high-fidelity tools can provide more detailed and accurate predictions when the models, assumptions and inputs are correct.
But a detailed result is not automatically a reliable result.
First-order calculations help explain the relationships between the parameters, establish an independent baseline, identify unreasonable results, and ensure that the expensive tools are being used to answer the right questions.
High-fidelity analysis provides detail.
𝐅𝐢𝐫𝐬𝐭-𝐨𝐫𝐝𝐞𝐫 𝐞𝐧𝐠𝐢𝐧𝐞𝐞𝐫𝐢𝐧𝐠 𝐩𝐫𝐨𝐯𝐢𝐝𝐞𝐬 𝐝𝐢𝐫𝐞𝐜𝐭𝐢𝐨𝐧, 𝐮𝐧𝐝𝐞𝐫𝐬𝐭𝐚𝐧𝐝𝐢𝐧𝐠, 𝐚𝐧𝐝 𝐩𝐞𝐫𝐬𝐩𝐞𝐜𝐭𝐢𝐯𝐞.