There are two ways to look at an aircraft's accounts, and they lead to opposite decisions.
The basic arithmetic
Operating costs split in two:
Variable. Fuel, hourly maintenance, landing fees. They only exist if it flies.
Fixed. Insurance, hangar, depreciation, certification fees, salaried crew. They exist anyway.
The consequence is direct, and many small operators do not keep it front of mind: every hour the aircraft sits, the fixed cost is spread over fewer flown hours.
An aircraft flying a hundred hours a year carries the same insurance as one flying four hundred. The first one's fixed cost per hour is four times higher.
Put the other way round, which is how it usually hurts: an aircraft flying half of what was planned has double the fixed cost per hour, and no quote reflects that.
Why that changes which flights to accept
Look only at the rate and a cheap flight looks bad.
Look at the fixed cost and a flight covering its variables and contributing something to the fixed is better than not flying — provided it does not displace a better one or compromise maintenance.
That is the useful criterion: the question is not "is this rate good?", it is "does this flight displace another, or fill a gap?"
A Tuesday gap in low season displaces nothing. A Saturday in Easter week does — and there the answer reverses.
Where the gaps actually are
Repositioning legs. If your aircraft has to fly San José to Palmar Sur empty to collect, those 76.3 nautical miles are paid for regardless. Selling them wholly or partly turns a cost into revenue.
Returns. A flight to Drake Bay from San José is 83.5 nautical miles out and the same back. If the return runs empty, half the operation does not produce.
Short connecting legs. Guápiles–Tortuguero is 26.9 nautical miles: a hop that rarely justifies its own departure, but which costs very little to add to an existing rotation. Three of those in a day is a very different account from one long return.
What this calculation does not say
It is worth being honest about the limits:
Maintenance is not linear. More hours is more wear and more cycles, and some costs that look fixed are in fact stepped by hours or by calendar, whichever comes first.
Crew has limits. Flying more means planning rest and, past a point, more pilots. That converts one fixed cost into a larger fixed cost.
And a rate that is too low teaches the market. Filling gaps at clearance prices works for a season; if it becomes the norm, the client stops paying the normal rate. The damage does not show in the quarter it happens, but in the next one.
The short criterion
Do not cut your rate: fill your gaps. They are different things, and only the second improves margin.
A repositioning leg sold at half rate is not a half-price rate: it is a cost that was going to exist anyway, partly covered. Operators we bring on evidence current certification, insurance and fleet documentation before receiving a first assignment.
Frequently asked questions
Which costs run while the aircraft sits?
Insurance, hangar, depreciation, certification fees and salaried crew.
Should I accept a cheap flight?
If it covers its variables, contributes to the fixed and does not displace a better one, yes. The question is gap or displacement.
Where are the usual gaps?
Repositioning legs, empty returns and short connecting hops between rotations.
Does the criterion hold in high season?
Not the same. On an Easter Saturday any cheap flight displaces a better one, and the answer reverses.
What is the risk of filling gaps cheaply?
That it stops being the exception. If it becomes the norm, the market stops paying the normal rate.
Does it help decide which flights to accept?
Yes. Variables plus fixed cost per hour give the real floor: below that, a flight destroys value however reasonable the invoice looks.
What is the short criterion?
Do not cut the rate, fill the gaps. Only the second improves margin.
Let's talk
Operators we bring on evidence current certification, insurance and fleet documentation before receiving a first assignment.
See also: Routes with no road access · How private charter pricing works · What decides your aircraft · All destinations · How to chain routes and eliminate empty legs · Single-aircraft operator · The metrics every operator should track · Costa Rica has two calendars · How to price without giving away margin · For aircraft operators · Listing your aircraft · Incremental revenue math · Buying an aircraft: the thesis