Exterior Dry Wash at Ljubljana Jože Pučnik (LJLJ)

Why choose a dry wash over a wet wash at Ljubljana?

Water access on the apron is not always straightforward, and a wet wash requires containment, drainage approvals and often a tow to a remote stand. Dry wash eliminates those variables. Our technicians arrive with everything in hand luggage: aviation-grade waterless emulsions, microfibre bonnets, degreasing concentrate for the belly and gear bays. The aircraft stays on its assigned stand, GPU and airside escort already arranged by the handler.

The chemistry lifts contaminant without scratching; we work panel by panel, applying product, agitating gently and buffing to a streak-free finish. Bug residue on the radome and leading edges comes off with a dedicated solvent, and we degrease the nacelle interiors and wheel wells separately. Brightwork gets a light touch-up where oxidation has started. The result is an exterior that photographs well and, more importantly, sheds water cleanly until the next service cycle. For operators running a two- to four-week rotation, this is the maintenance cadence that keeps paint in good condition without the overhead of a full wash bay each time.

What changes at Ljubljana Jože Pučnik for the cleaning crew?

Ljubljana sits at 1,273 feet elevation, 26 kilometres from the city centre. The single runway — 12/30, 3,300 metres — handles everything from regional turboprops to the occasional widebody charter, and the airport operator, Fraport Slovenija, requires a PPR at least 24 hours before arrival for general-aviation aircraft. The General Aviation Centre has relocated into the main passenger terminal; its staff security checkpoint operates from 06:00 to 21:00 local, and outside those hours airside access routes through checkpoint R1 with advance notice to the Security Operations Center.

For a detailing crew, that means coordination begins the moment the slot is confirmed. We liaise with the handler to confirm stand assignment, GPU availability and escort timing. If the aircraft arrives late evening, we arrange Security Operations Center notification and ensure our airside passes are current. The apron is fully paved and well lit, but winter temperatures drop sharply after sunset, which thickens the waterless product and slows the buff. We adjust our technique accordingly: smaller working sections, more frequent product application, synthetic bonnets that hold up in the cold.

The General Aviation Centre offers cabin cleaning, de/anti-icing and water service; out-of-hours GA assistance is charged per started 30 minutes. We schedule our arrival to overlap with the handler's normal hours whenever possible, reducing the operator's ground-time costs and ensuring that any last-minute requests — a tech-log squawk, a pitot cover left in the cabin — are handled without waiting for an escort to cycle back through security.

How does the handler see a third-party detailing crew on the apron?

Handling agents present at the airport have their own workflows, and a detailing crew is one more variable on a stand already occupied by refuelling, catering and passenger movement. The handler's concern is safety, timing and liability: they need to know we hold valid airside passes, that our equipment will not obstruct a tug path or foul a jetway, and that we will not delay the next departure.

We brief the duty manager on arrival, confirm the aircraft's ETD and ask whether any maintenance is scheduled that might require access to panels we are cleaning. If deicing is expected later, we avoid applying any product to the wings that might interfere with holdover-time tables, even though our dry-wash emulsion is not a contaminant in the regulatory sense. The handler appreciates that we carry our own lighting, that we police our own rubbish and that we leave the stand in the condition we found it. Trust is built one turn at a time; after three or four visits, the ground crew knows our faces and the coordination becomes a quick radio call rather than a ten-minute briefing.

What does Central European weather do to an aircraft exterior?

Slovenia's continental climate brings warm summers and cold, damp winters. June through August, insects are prolific; a descent into Ljubljana after a low-level leg leaves the leading edges, nacelle lips and windscreen stippled with bug strike. The protein in insect remains is mildly acidic, and if left for more than a few days it etches through wax and begins to dull the clearcoat. A dry wash every two weeks during the summer keeps that residue from becoming a polish job.

Winter is a different problem. Road salt, de-icing fluid and airborne particulate settle on the belly and gear bays, and the cold slows evaporation, so the aircraft stays damp longer. Hydraulic weeps that would dry to a faint stain in July become streaked trails by December. We degrease the belly and wells with a pH-neutral concentrate that emulsifies oil without attacking seals or composite panels. The nacelle interiors — always a reservoir of soot and unburned fuel — get the same treatment. A clean belly is not only cosmetic; it makes the next pre-flight inspection easier and flags new leaks that might otherwise hide in the general grime.

How long does an exterior dry wash take at Ljubljana, and what drives the schedule?

A super-midsize jet — Challenger 350, Citation Latitude, Praetor 600 — takes three to four hours if the exterior is reasonably clean to start. A large-cabin or ultra-long-range type — Global 7500, Gulfstream G650, Falcon 8X — can stretch to seven or eight hours, especially if the belly has not been touched in months and the brightwork needs careful attention. We quote duration as a range because the variables are real: how much bug residue, how cold the apron, whether the handler can leave the aircraft on stand for the full window or needs it towed after two hours to make room for a scheduled arrival.

The operator's schedule drives ours. If the aircraft is overnighting and departing mid-morning, we start at first light and finish before the passengers arrive. If it is a quick turn — two-hour slot, crew rest, then outbound — we focus on the most visible areas: fuselage from the cheat line up, nacelles, windscreen and the cabin windows. The belly and gear bays can wait for the next overnight. That flexibility is the advantage of a dry wash: no hoses to rig, no wastewater to collect, no dependency on weather. We adapt to the turn, not the other way around.

Is dry wash suitable for an aircraft that has been sitting at Ljubljana through winter?

If the aircraft has been static for weeks, a dry wash is a good first step but not always sufficient on its own. A cold-soaked airframe collects condensation, and that moisture traps dust, pollen and particulate. The paint may look dull rather than dirty; that is often a sign that the hydrophobic layer has broken down and contaminant has bonded to the clearcoat. A dry wash will remove the loose material and restore some gloss, but if the surface feels rough to the touch even after cleaning, it will need a single-stage polish to cut through the oxidation and re-establish a smooth finish.

We assess the paint during the walk-around and advise the captain or chief pilot if we think a polish is the better option. For an aircraft returning to regular service after a winter layover, the usual sequence is: dry wash to remove the bulk contamination, then a polish within the next month to restore the protective layer, then back onto the two- to four-week dry-wash cycle. That approach keeps the paint in good condition without the cost of a full detail every time the aircraft moves.