Budget a Multi-Stop VFR Cross-Country

Most pilots plan cross-country routes backwards. They draw a straight line from their home base to their furthest destination, check their endurance midway along the track, and pick whichever aerodrome sits closest for a fuel uplift.

That approach is expensive. Across verified UK aerodromes in the Airfield Atlas directory, 100LL Avgas prices vary from £1.73 per litre at Old Sarum (EGLS) and £1.96 per litre at Netherthorpe (EGNF) to £2.45 per litre at Caernarfon (EGCK). Furthermore, select aerodromes waive landing fees entirely when you purchase fuel. Netherthorpe waives its £10.00 landing fee with a 40-litre fuel purchase, and Nottingham City (EGBN) waives its landing fee with 50 litres.

Structuring your multi-leg route to take advantage of low fuel prices and landing waivers consistently reduces total trip outlay.

Here is a worked three-leg VFR cross-country demonstrating fuel sequencing, legal reserve calculations, and the mathematical limit for off-track detours.

Sourced route: London / Midlands circuit

We examine a 230-nautical-mile touring circuit flown in a Piper PA-28-161 Warrior II:

• Aircraft Preset: Piper PA-28-161 (33.3 L/hr fuel burn, 110 kts cruise speed).
• Leg 1: Elstree (EGTR) to Sywell (EGBK) — 48 nm (0.44 hrs flight time)
• Leg 2: Sywell (EGBK) to Netherthorpe (EGNF) — 62 nm (0.56 hrs flight time)
• Leg 3: Netherthorpe (EGNF) to Sherburn-in-Elmet (EGCJ) to Elstree (EGTR) — 120 nm (1.09 hrs flight time)
• Total Track Distance: 230 nautical miles.
• Total Flight Time: 2.09 hours cruise + 0.41 hours taxi/climb/circuit = 2.50 logbook hours.

Leg	Route	Distance	Flight time
1	Elstree → Sywell	48 nm	0.44 hr
2	Sywell → Netherthorpe	62 nm	0.56 hr
3	Netherthorpe → Sherburn-in-Elmet → Elstree	120 nm	1.09 hr

Sourced fuel prices and landing fee schedule

Airfield	ICAO	100LL Avgas (Inc VAT)	PA-28 Landing Fee	Fuel Landing Waiver Threshold
Elstree (Home)	EGTR	Direct retail	Resident covered	N/A
Sywell	EGBK	£2.15 / L	£20.00	None
Netherthorpe	EGNF	£1.96 / L	£10.00	Waived with 40L fuel uplift
Sherburn-in-Elmet	EGCJ	£2.08 / L	£12.00	None

Sequencing uplifts: comparing two options

Strategy A: Buying fuel at Sywell (No waiver)

• Depart Elstree with 70 litres.
• Fly Leg 1 to Sywell (Burn 15 litres).
• Uplift 50 litres of 100LL at Sywell @ £2.15/L = £107.50.
• Pay Sywell PA-28 landing fee = £20.00.
• Fly Leg 2 to Netherthorpe (Burn 19 litres). Pay Netherthorpe £10.00 landing fee (no fuel bought).
• Fly Leg 3 back to Elstree.
• Total Fuel & Landing Fees Paid: £137.50.

Strategy B: Buying fuel at Netherthorpe (With waiver)

• Depart Elstree with 70 litres.
• Fly Leg 1 to Sywell for transit only. Pay Sywell £20.00 landing fee. Buy zero fuel.
• Fly Leg 2 to Netherthorpe. Uplift 50 litres of 100LL @ £1.96/L = £98.00.
• Netherthorpe landing fee (£10.00) is waived due to meeting the 40L threshold.
• Fly Leg 3 back to Elstree.
• Total Fuel & Landing Fees Paid: £20.00 (Sywell) + £98.00 (Netherthorpe fuel) = £118.00.

By sequencing the primary fuel uplift at Netherthorpe rather than Sywell, you save £19.50 on the identical flight plan (9.50 fuel savings + £10.00 waived landing fee).

VFR reserve fuel requirements

Under UK CAA standard VFR operating rules, an aircraft must land with no less than 45 minutes of final reserve fuel at normal cruising consumption, plus an en-route contingency allowance.

Taking the Sywell-to-Netherthorpe leg as the example (62 nm at 110 kts, 0.56 hr), a PA-28-161 burning 33.3 L/hr needs:

Component	Basis	Fuel
Trip fuel	0.56 hr × 33.3 L/hr	18.6 L
Contingency (10% of trip fuel)	wind/routing margin	1.9 L
Diversion fuel	15 nm alternate @ 110 kts	4.7 L
Final reserve	45 min at normal cruise, non-negotiable	25.0 L
Minimum fuel at engine start		50.2 L (~13.3 US gal)

In a PA-28-161 with 181 litres total capacity (144 litres usable to fuel tabs), filling to the tabs provides 4.3 hours of endurance, allowing you to fly the first leg with comfortable reserve margins before uplifting fuel at your discounted destination.

The mathematics of fuel detours

Diverting off track to save 12p per litre on fuel can easily cost more in extra engine time and landing fees than the value saved at the pump.

The cost of a detour is the extra flight time it burns, priced at fuel plus engine wear, against whatever it saves at the pump.

Take a planned direct track from Sywell to Sherburn-in-Elmet, with Netherthorpe sitting 18 nm off that line — a 36 nm round-trip detour to reach it. That's an extra 0.33 hours airborne (20 minutes), burning 11.0 litres. Netherthorpe's Avgas is 12p/L cheaper than Sherburn's (£1.96 vs £2.08), so uplifting 50 litres there saves £6.00 at the pump.

Against that £6.00 saving: 11.0 litres of extra fuel burned getting there (£21.56 at Netherthorpe's own price), plus £5.94 in engine wear reserve for the extra 0.33 hours — £27.50 in detour cost, even with Netherthorpe's landing fee waived. Diverting for this fuel saving alone loses £21.50.

The detour is only worth flying if one of three things is true: the fuel saving (litres uplifted × price difference) exceeds the hourly cost of the extra air time, the diversion airfield's fee waiver offsets the extra burn on its own, or the stop was already going to be your lunch break.

Use the Airfield Atlas route cost calculator to check distances, verified fuel prices, and landing fee waivers across alternative route legs.