So the sequence is: state your reasons, get approval before you do anything — Page 1, Lesson 9

I want to walk you through the tail end of the standard mass rules — this is the part that governs what happens when the published tables just aren't good enough for a particular operation. We're looking at paragraphs (g) through (j) of OPS 1.620, and these are the escape hatches and the safeguards built around them. Let's start with paragraph (g), because it's the big one. The standard mass values in Tables 1 to 3 are the default — they're what you use unless you have a reason not to. But if an operator wants to use standard mass values other than those contained in Tables 1 to 3, they can't just make that call on their own. They must advise the Authority — that's the aviation regulatory authority — of their reasons, and they must gain the Authority's approval in advance. So the sequence is: state your reasons, get approval before you do anything. But that's not all. The operator must also submit, for approval, a detailed weighing survey plan. This isn't a casual document — it's a formal plan describing how they're going to gather the data. And critically, they must apply the statistical analysis method given in Appendix 1 to OPS 1.620 (g). That appendix is the prescribed mathematical way to crunch the survey numbers — you can't just use any statistical approach you like; it has to be the one specified in that appendix. Now here's the flow: after the survey is conducted, the results go to the Authority for verification and approval. And once that approval is given, the revised standard mass values are only applicable to that operator. They don't become a general industry standard — they're operator-specific. And they can only be used in circumstances consistent with those under which the survey was conducted. So if the survey was done on a particular route, with a particular passenger demographic, in a particular season, you can't stretch those values to a different context. The conditions have to match. There's one more safeguard in (g), and it's a one-way ratchet: where revised standard masses exceed those in Tables 1 to 3, then such higher values must be used. So the operator can't revise downward to a lighter value that's below the table and then use that — if their survey shows people are heavier than the table assumes, they're stuck with the heavier number. It's a safety floor. Now paragraph (h) shifts to a different scenario — it's about specific flights, not whole operations. On any flight identified as carrying a significant number of passengers whose masses, including hand baggage, are expected to exceed the standard passenger mass, the operator must determine the actual mass of such passengers. And there are two acceptable methods: by weighing them, or by adding an adequate mass increment. So you either physically weigh those passengers, or you add a safety margin on top of the standard value to cover the expected excess. The key word is "adequate" — the increment has to be enough to cover the real excess. Paragraph (i) is the exact same logic, but applied to checked baggage instead of passengers. If standard mass values for checked baggage are used, and a significant number of passengers check in baggage that is expected to exceed the standard baggage mass, then the operator must determine the actual mass of such baggage — again, by weighing, or by adding an adequate mass increment. Same two options, same requirement. Finally, paragraph (j) is about communication and documentation. An operator shall ensure that a commander is advised when a non-standard method has been used for determining the mass of the load, and that this method is stated in the mass and balance documentation. So the commander — the pilot in command — has to be told, explicitly, that the load mass wasn't determined by the standard method, and the mass and balance documentation has to state what method was used. This is about the commander's right to know exactly what assumptions went into the numbers they're flying with. So the whole picture here is: the standard tables are the baseline, deviations are possible but tightly controlled — you need Authority approval in advance, a proper survey plan, the prescribed statistical method, and the results are locked to your operation and your conditions. And on top of that, for individual flights where you know certain passengers or baggage are heavy, you can't just ignore it — you weigh them or add an increment. And the commander always gets told when non-standard methods were used. That's the complete safeguard chain.