Why a Three-City Itinerary Is Not Three One-Way Quotes

Three separate one-way quotes for London to Nice, Nice to Geneva and Geneva to London will usually add up to about £11,500 more, on flying time alone, than the single trip they describe. The gap comes from arithmetic rather than greed: each one-way price assumes the aircraft flies home empty afterwards, so every sector carries its own return leg.

Take a Bombardier Challenger 350 based at Le Bourget (LFPB). The client wants Farnborough (EGLF) to Nice (LFMN), three nights on the Riviera, Nice to Geneva (LSGG), one night in Geneva, then home to Farnborough. The three paid sectors total 4.3 block hours: 1.8, 1.1 and 1.4. Quoted separately, with an empty return assumed on each, the same trip is billed as 8.6 hours.

A villiersOS-style agent model works from the other end. It treats the trip as a chain of sectors, some paid for by the client and some not, and asks which empty sectors the itinerary genuinely needs. Here the answer is two: Le Bourget to Farnborough at the start and Farnborough back to Le Bourget at the end, 0.9 hours each. Total flying is 6.1 block hours, not 8.6.

That dependency is the heart of multi-leg charter pricing: the cost of any one sector depends on where the aircraft has just been and where it must be next. A quote built as a chain makes every link visible, so a broker can inspect each one before trusting the sum.

The Challenger 350 suits this routing. It carries up to nine passengers in a cabin 7 ft 2 in wide and 6 ft high, with a range of 3,200 nm, which covers every sector here with fuel to spare. The Cessna Citation Latitude, with a 6 ft 5 in cabin width and a 2,700 nm range, is the obvious alternative, and the model prices it alongside.

Costing Each Sector: Block Time, Fuel Uplift and Airport Charges Leg by Leg

Each sector gets its own sheet, and the first line is block time, measured from off-blocks to on-blocks rather than wheels-up to wheels-down. Taxi time at Nice in July can add 10 to 15 minutes to a sector, and seasonal winds move Farnborough to Nice by 5 to 8 minutes either way. The model uses the filed-route estimate and carries a stated tolerance.

Pricing a charter itinerary leg by leg, at an operator rate of £4,600 per block hour, gives this:

• EGLF to LFMN, 1.8 hours: £8,280
• LFMN to LSGG, 1.1 hours: £5,060
• LSGG to EGLF, 1.4 hours: £6,440
• LFPB to EGLF positioning, 0.9 hours: £4,140
• EGLF to LFPB ferry, 0.9 hours: £4,140

That is £28,060 in block time before anything else is added.

Fuel is priced separately, at the point where it is bought. The Challenger 350 burns roughly 850 kg an hour, about 1,060 litres, so 6.1 hours consume around 6,500 litres. Uplift prices at Farnborough, Nice and Geneva can differ by 20 to 30 per cent, so the model decides where to fill the tanks rather than assuming each sector refuels at its departure airport. At an average £0.95 per litre, fuel comes to about £6,100.

Airport charges are the third column. Landing, parking and handling across the airports on this trip come to roughly £4,200, with Nice the heaviest in peak season. Each charge is attached to a specific leg and date, because a Saturday arrival at LSGG can carry a different handling tariff from a Tuesday one.

Nothing at this stage is clever. It is a set of small sums, each traceable to a rate card, a fuel price or a published tariff, and each open to a broker's simple question: why this figure for that airport?

The Seams Between Legs: Positioning, Ferry Flights and Waiting Time Versus Night-Stops

The expensive decisions in this itinerary sit between the flights rather than in them. Start with positioning. The aircraft is at Le Bourget and the passengers are at Farnborough, so someone pays for 0.9 hours of empty flying at each end: £8,280 in block time before fuel.

If an operator has a Challenger 350 already at Farnborough, both legs disappear. If an aircraft is returning to base anyway, the operator may discount the empty leg, and the model records that as a negotiable line rather than a fixed one.

Now the three nights in Nice. The aircraft has two options. It can wait: three crew night-stops at about £800 for two pilots, plus roughly £3,000 in standby charges and parking, giving £5,400. Or it can ferry home and return, 1.5 hours each way between LFMN and LFPB. That is 3.0 hours, £13,800 in block time, plus about £3,000 in fuel before extra landing charges. Ferrying costs more than three times as much as waiting.

Waiting does not always win. Crew duty limits, maintenance windows and scarce parking at Nice in peak weeks can reverse the result. A stay of one to three nights almost always favours waiting; once it stretches towards a week, an operator may prefer to send the aircraft home to fly other work, and the model should price that choice and state who carries the risk.

Duty time is the second seam. A crew's flying duty period is capped, and a late departure from Geneva followed by a long ferry can run past it, forcing an extra night-stop the client never asked for. The model checks duty hours at each handover, so that cost surfaces in the quote instead of on the invoice.

What Happens to the Quote When One Leg Changes: Live Re-Pricing Across the Whole Itinerary

Suppose the client swaps Geneva for Zurich (LSZH) the evening before sign-off. A calculator that adds three rows would change one row. A chain changes several.

Nice to Zurich is a longer sector, 1.3 hours against 1.1, and Zurich to Farnborough runs 1.6 hours against 1.4. That adds 0.4 block hours, £1,840 at the same rate, plus about 400 litres of fuel, roughly £400. Zurich's landing and handling tariffs replace Geneva's. The positioning legs are untouched, but every figure after Nice has moved.

A date change costs more than an airport change. Bring the Nice departure forward by a day and the Geneva night-stop shifts, the crew's rest period resets, the standby charge at Nice drops by a day and the one at Geneva grows. If the new arrival time pushes the final sector past the crew's duty limit, the model inserts a night-stop. That is a cost on a leg that was never edited, caused by an edit upstream of it.

Pricing a multi-sector trip live therefore means carrying state forward. Each sector inherits the aircraft's position, fuel on board, crew duty hours and date from the one before. Change a link and everything downstream is recomputed, and the broker sees a delta of about £2,500 for the Zurich swap, itemised by the lines that moved.

The broker can then answer the client on the same call. Without that chain, the usual alternative is to phone the operator, wait for a revised sheet, and quote a figure that is already stale by the time it is read out.

From Calculation to Quote: Margin, Operator Availability and the Figure a Broker Can Actually Send

A figure of £45,560 is the operator cost of this trip, not yet a quote. It is made up of £28,060 in block time, £6,100 in fuel, £4,200 in airport charges, £3,200 for four crew nights and £4,000 for standby and parking.

Margin comes next. Broker margins on itineraries of this kind commonly sit between 8 and 15 per cent. At 10 per cent the model adds £4,556, for a send price of about £50,100.

The margin is not applied as a flat percentage across the sheet. Positioning and standby lines are where a client is most likely to push back, so the model shows the broker how much room each line has before the total falls below the agreed floor.

Availability turns the sheet into something sendable. The model prices only aircraft that can be where the trip begins. A Challenger 350 at Le Bourget carries the £8,280 of positioning described above, while a Citation Latitude already at Farnborough removes that empty flying before its own hourly rate is applied. The lowest hourly rate seldom produces the lowest trip cost.

The output carries conditions as well as a number: a validity window, the fuel price assumed, and the lines most likely to move, such as Nice parking and Geneva handling. A broker can send it knowing which parts are firm.

The same chain-of-sectors architecture could run a multi-stop yacht itinerary, where berths, fuel docks and crew changes play the part of airports. villiersOS does not operate there today, but the principle of checking each link before summing them applies equally. Every figure on the sheet can be challenged by the broker, and that is what makes the total safe to send.