Not every duty is a flight. Standby and reserve are the states of waiting to be needed, and because waiting can be more or less restful, the rules treat them carefully and convert them into duty in specific ways.
This is general educational information, not operational, legal, or regulatory advice. Rules differ by authority and change over time. Always verify against current official sources and follow your operator's approved procedures.
What standby and reserve are
Standby, in the EASA framework, is a defined period during which a crew member is required by the operator to be available to receive an assignment for a flight, positioning, or other duty, without an intervening rest period, set out in ORO.FTL.225. EASA also defines a separate reserve in ORO.FTL.230, so under EASA standby and reserve are distinct statuses, not the same thing. In the FAA framework, reserve (14 CFR 117.21) is the status of being available to receive an assignment for a flight duty period. The terms do not map one-to-one across the two systems, so read each against the rules it belongs to; the shared idea is time spent ready rather than flying.
The reason the rules care is fatigue. An hour spent at the airport in uniform, expecting a call at any moment, is not the same as an hour at home where you might nap. So both systems distinguish the kinds of waiting and assign them to duty differently.
Standby under EASA
EASA ORO.FTL.225 sets out how standby works, and the headline distinction is between airport standby and other standby:
- Airport standby, where you must be present at the airport, counts in full as duty from its start. How much of it then counts towards the flight duty period is set by the operator's approved scheme, but the whole period is duty. It is effectively treated like working.
- Standby other than airport standby, typically at home or in suitable accommodation, is treated more leniently. A defined proportion of it counts towards cumulative duty under the operator's approved scheme, on the basis that you have a real chance to rest.
The rules also define how a standby that turns into a flight affects the flight duty period: how much of the standby is added, when the FDP clock starts, and whether a long standby before the call reduces the maximum FDP you are then allowed. The practical message is that being called late in a long standby is not the same as a fresh report, and can leave you with a smaller allowance.
Reserve under the FAA
FAA 14 CFR 117.21 handles reserve through two types:
- Short-call reserve has a defined reserve availability period (RAP), a window during which you can be contacted and assigned with relatively little notice. The length of that period is limited, and it is protected by the rest rules, because short notice means less certainty about sleep.
- Long-call reserve gives you more notice before a flight duty period can begin, so it is treated more like ordinary time off until the assignment lands.
The thread that runs through the FAA approach is notice: the less warning you get before flying, the more carefully the reserve has to be bounded, because the chance to be properly rested depends on knowing when you will be needed.
A worked example
A crew member is on home standby from 0600. Under EASA, only part of that standby counts towards their cumulative duty while they wait, reflecting the rest they could be getting. At 1100 they are called for a flight. From that point, the flight duty period rules apply, and depending on the scheme the standby already served can reduce the maximum FDP now available, so the day they can legally fly is shorter than if they had reported fresh at 1100. Under the FAA, a short-call reserve crew member would have a defined availability period and protected rest around it, with the assignment having to fit inside the duty and rest limits that apply to that reserve type. Different mechanisms, same intent: account honestly for how rested the waiting really left you.
From standby to a duty: a timeline
The abstract rules are easiest to see as a timeline. Take a crew member on home standby under the EASA scheme, and follow the clock.
- 0600. Standby begins at home. From here, a defined proportion of the standby time counts towards cumulative duty under the operator's approved scheme, on the basis that the crew member can rest while waiting.
- 1100. The operator calls with an assignment. This is the notification, and the time between report and the standby that preceded it is what the scheme uses to work out the effect on the flight duty period.
- 1200. The crew member reports at the airport for the flight. From here the flight duty period runs in the normal way, to the end of the last sector.
The key question the rules answer is how much of that 0600-to-1200 standby reduces the maximum FDP now available. The longer the standby ran before the call, the more it is treated as having eaten into the crew member's freshness, so a call late in a long standby leaves a shorter allowable duty than a fresh report at the same hour would. There is also usually a limit on the total of standby plus the subsequent FDP, so the two together cannot stretch indefinitely.
Under the FAA, a short-call reserve crew member is in a defined reserve availability period during which they can be assigned with limited notice, and that period and the rest around it are bounded by 14 CFR 117.21, so the assignment that lands has to fit inside the duty and rest limits that apply. The mechanisms differ, but the timeline tells the same story in both systems: the clock that matters started before the crew member ever reached the aircraft, and the time spent waiting is accounted for, not free.
Airport standby in practice
The contrast between the two kinds of standby is sharpest in a worked case. Two pilots both spend six hours on standby before a four-hour flight.
Pilot A is on airport standby, required to be at the airport the whole time. Under EASA ORO.FTL.225, that airport standby counts in full as duty and counts towards the flight duty period from its start. So by the time the flight begins, six hours of FDP have effectively already run, and the flight duty period is well advanced before the aircraft even moves, which sharply limits how long the subsequent flight can legally be.
Pilot B is on home standby for the same six hours. Only a defined proportion of that time counts towards cumulative duty, on the basis that rest was possible, and the flight duty period is calculated differently when the call comes, so Pilot B has more allowable duty left for the flight than Pilot A does.
Same six hours of waiting, same four-hour flight, and two quite different positions, because where you wait changes how the time is counted. The practical reading for anyone studying a roster is that an airport standby is close to working and should be treated as such when judging how much duty is left, while a home standby is more protected, with the exact proportions set by the operator's approved scheme. The FAA achieves a comparable result through its bounded reserve types under 14 CFR 117.21. The broader habit to build is to ask, first, which kind of waiting a standby is, because that single fact decides how much of the day is already spent before the flight is even assigned, and therefore how much flying the rules will still allow. A standby that looks like idle time on paper can, if it is airport standby, leave almost no room for the flight that follows, which is exactly the kind of surprise a pilot watching only flight hours can walk into.
Common pitfalls
- Treating all standby as equal. Airport standby counts as duty in full; home standby does not.
- Forgetting that standby eats into the FDP. A call late in a long standby can shorten the duty you are then allowed.
- Assuming reserve is time off. Short-call reserve is a bounded, protected duty state, not free time.
- Mixing the schemes. EASA standby and FAA reserve are different rules with different conversions.
- Ignoring the operator scheme. The approved scheme fills in the proportions and can be more restrictive than the baseline.
In Pilot EFB
Pilot EFB's flight time limitation calculator accounts for standby and reserve periods when it works out your duty, so a standby that converts into a flight is reflected in your totals rather than being lost. It is a planning and awareness aid built to help you see the picture, not a compliance system: how your standby or reserve converts to duty and what flight duty period you are then allowed is governed by your operator's approved scheme and the current regulation. Pilot EFB is not a certified Electronic Flight Bag. Saved roster data stays available offline; pulling a fresh roster needs a connection.