What is the difference between mandatory and advisory requirements?
A requirement binds you because of where it comes from — law, contract or condition — not just because it is written in a standard.
Mandatory requirements are those made binding by regulation (for example national rules that implement ICAO Standards) or by contract or condition that names a document. Recommended items use should, and advisory material is guidance, notes and manuals.
The same document can be either. A standard that is voluntary on its own becomes mandatory once a regulation adopts it, a contract names it or a funding or certification condition requires it. Check the source of the obligation first, then the strength word in the clause.
- Find the source. Which regulation, contract or condition makes this document apply?
- Check it is called up. Is the exact document and edition named?
- Read the strength word. Shall, should or may.
- Classify it. Mandatory, recommended or advisory, and note it in the matrix.
- Route departures. Seek formal approval before not meeting a mandatory item.
Must be met. A departure needs a formal, recorded approval from whoever has the authority.
Guides good practice. Not binding on its own, but may be expected, so record reasons for not following it.
Frequently Asked Questions
Q1Can I ignore a requirement that says should?
Not casually. A should clause is a recommendation, not a requirement, but a regulator or client may still expect it to be met. Aim to meet it, and if you do not, record the reason so the decision can be reviewed.
Q2Are FAA advisory circulars mandatory?
Advisory circulars are advisory in general. They become binding where a funding condition, a certification requirement or a contract requires them. Check which applies to your project before treating one as optional or mandatory.
Q3Are IEC and Indian Standards mandatory?
Not on their own. They are voluntary until a regulation adopts them or a contract names them. Once a document is called up, the clauses it marks as requirements become mandatory for that project.
Q4Does ICAO bind an airport directly?
ICAO Standards bind its member States rather than individual airports, and States put them into national regulation. A State that cannot comply with a Standard is expected to notify ICAO of the difference. Recommended Practices and guidance manuals do not carry the same obligation.
Q5What if I cannot meet a mandatory requirement?
Do not work around it quietly. Raise it with the specifier or regulator, seek a formal approval for the departure, and record it as an agreed deviation in the compliance matrix with the approval reference.
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