A free event feels like it shouldn't need any admin. There's no ticket to sell, no money to take and no box office. Put the date out, open the gate and see who turns up.
That works until the day you run out of bacon rolls at half past ten, or forty aircraft arrive at a strip with room for fifteen, or the speaker you booked for the club night looks out at six people in a room set for sixty. An RSVP doesn't stop any of that on its own, but it gives you a number to plan with, which is a lot better than a guess.
This guide is about why it's worth asking people to RSVP, and how to get a useful number out of it. If you want to know what Events.Aero's free RSVPs actually do, that's on the free RSVPs page.
What a headcount changes
Most of the decisions you make before a free event depend on how many people you expect.
Food and drink. Whoever is doing the catering, whether that's the clubhouse kitchen, a burger van or volunteers with a gas ring, needs to know how much to buy. Too little and people leave hungry. Too much and the club eats the cost.
Parking. Cars need a field, and someone has to decide which field and how many marshals to put on it. At a fly-in you also need space on the ground for every aircraft that arrives, away from the runway and the taxiway, with room to get them out again.
People to help. Marshals, someone on the radio, someone at the gate, someone making tea. Volunteers give up their day; it's easier to ask for the right number if you can tell them roughly how busy it will be.
Safety and space. A hangar, a clubhouse or a lecture room only holds so many people. If you're likely to go over, you want to know before the day, not when people are already standing in the doorway.
Your own confidence. If almost nobody has said they're coming a week out, you still have time to do something about it: put up more posters, post in the local flying groups, ring round the neighbouring clubs.
Fly-ins need it most
A fly-in has two audiences: people who drive in and pilots who fly in. The pilots are the ones you most need to hear from in advance.
Knowing who is flying in, in what, and from where, lets you plan aircraft parking, decide whether you need someone on the radio all day, and get in touch if the weather or the runway forces a change of plan. Events.Aero asks pilots who RSVP to a fly-in for their aircraft registration and type and where they're departing from, and you can set a limit on aircraft spaces separately from the overall number.
An RSVP is not prior permission to land. If your airfield is PPR, say so in your listing and say how to get it. Our guide to PPR explains what pilots will expect from you.
"But people don't turn up to free things"
That's true, and it's the strongest argument against relying on RSVPs. When people haven't paid, some of them change their minds, and they rarely tell you. Eventbrite's guide to free events quotes organisers outside aviation who plan for anything from a quarter to half of registered guests not coming. Those are their figures, from conferences, networking and recruitment events, not ours; we'll publish what we see once we have enough RSVPs to say something useful.
So don't treat the RSVP count as the number of people who will come. Treat it as a signal you can read:
- A trend over time. If last year's open day had 80 RSVPs and roughly 120 people, and this year you have 150 RSVPs at the same point, you know it's going to be busier.
- A floor for things you can't run out of. If 30 pilots say they're flying in, plan parking for at least 30 aircraft.
- A contact list. Everyone who RSVPs has given an email address you can use if the event changes.
How to get a better number
A few habits make the count more honest.
Make it easy to say no. If it's easy to cancel, people are more likely to cancel rather than just not come. Every Events.Aero RSVP confirmation email has a link to cancel, which frees the place for someone else.
Ask for groups, not individuals. A family of four is one decision. Let people RSVP for their whole party, so your count is people, not emails.
Confirm by email. A confirmed email address means a real person who meant it. Events.Aero asks guests to confirm from their inbox before they appear on your list.
Set a limit if space is the problem. If the room holds 60, set the limit to 60 and RSVPs close when it's full. People who missed out know before they travel, not when they arrive.
Keep the list somewhere you can use it. On the day, you'll want to look up a name, count the aircraft, or hand the gate team a printed list. Your guest list is in your organiser dashboard, and you can download it as a CSV.
Tell people what they're committing to. "RSVP so we know how many bacon rolls to order" gets a better response than a bare form. People are more willing to reply when they can see why you're asking.
When you might not bother
Not every free event needs RSVPs. A walk-up open hangar at a large museum, a seafront display with no gate, or a regular Sunday where the café is open anyway: none of those change much with a headcount. If nothing you'd do differently depends on the number, skip it and keep the listing simple.
The test is easy. Write down what you'd change if twice as many people came, or half as many. If the answer is "nothing", you don't need RSVPs. If it's "the catering, the parking and the number of marshals", you do.
Setting it up
You can list your event on Events.Aero for free and turn on RSVPs as part of the listing, with a limit if you need one. Our team checks every listing before it goes live. Once it's live, there's a free A4 poster with a QR code you can print for the clubhouse noticeboard, so people who see it can RSVP from their phone.
Sources and further reading
- Eventbrite, How to manage attendance at free events, published 13 April 2021 (organisers' no-show figures quoted above).
- UK Civil Aviation Authority, CAP 1988: Safety guidance for air rallies, fly-ins, air races/contests and charity events, version 1, 20 May 2026 (planning guidance for fly-in organisers).