Key Points

• APU use is limited – only allowed 10 minutes before TSAT, and only after towing.
• GPU reliability is shaky – some units failed or had to be replaced during operations.
• Heat may be damaging systems – OPSGROUP member reports of aircraft experiencing electrical failures, suspected to be caused by overheating while waiting without APU or proper cooling.

Recent reports from OPSGROUP members highlight growing concerns over the strict APU restrictions at LFMN/Nice.

Like many French airports, LFMN restricts APU use – aiming to cut noise and emissions. But as summer peaks on the Riviera, enforcement remains rigid despite the operational challenges this creates in high heat.

Beyond hot cabins, new concerns have emerged: potential electrical damage linked to the airport’s fixed ground power units (GPUs). Reports submitted to the airport remain unanswered. Here’s what we know so far.

A Little Context

Private jet flights at LFMN primarily use the ‘Kilo Apron.’ This is the designated parking area for BizAv close to FBO facilities.

The rules for APU usage are found under the airport briefing in the French AIP. Specific guidelines apply to the Kilo Apron:

• Arriving flights must stop on a designated line labelled ‘STOP ENGINE AND APU.’ From there towing to your parking spot is mandatory.

• Departing flights must be towed to start-up stands fitted with 400Hz/28v ground power units, along with air. APU usage is limited to 10mins prior to TSAT (Target Start-up Approval Time).

Exemptions are very limited. You either need to be operating a medivac, state or cargo flight (carrying temperature sensitive payload). Or if the plug isn’t compatible with your aircraft.

Recent Member Reports

Here are three recent member reports received from OPSGROUP members there.

Report 1:

After towing to Stand 35, the crew connected to the fixed GPU. CAS messages flickered, followed by complete electrical failure and aircraft blackout. Despite heatwave conditions and an overheated crew, APU start was denied. A portable GPU was brought in – but it was dead. When permission to start the APU was finally granted, it was too late: navigation and communication systems had already failed. The aircraft departed under MEL and required expensive repairs at the next stop. The ramp agent advised us to file a report, which we did. According to them, this wasn’t the first time such an event had happened.

Report 2:

Another crew experienced a similar issue. One of two FMS units failed after GPU connection. While the cause wasn’t immediately clear, the symptoms matched those described in the earlier report. The unit was removed for repair.

Report 3:

The GPU caused a fault on our GVII upon disconnect. Our FA that understands French overheard ground personnel stating “it’s too hot” in reference to the GPU. Surface temp at time was 24C so it was the equipment. Had to shut down aircraft to dark and restart to clear fault and get a new CTOT 40 mins later.

Potential GPU Issues

While we can’t confirm the GPUs are the direct cause, it’s plausible. Aircraft systems are sensitive, and power issues — including frequency drift, incorrect voltage, poor grounding, or surges — can trigger serious failures.

Heat may be a compounding factor. Ground air units often underperform in high temperatures, especially if hoses are blocked or airflow is weak. Aircraft may exceed thermal limits before crews can start APUs or get adequate air.

The GPUs themselves may also struggle in heat – output may sag or drift, or thermal protection systems may shut them down.

All of this increases operational risk – especially when APU use is restricted with no flexibility for safety.

And, despite being mandatory, GPU usage at LFMN comes with a charge.

If you’re going to enforce the rules on APU usage in summer there needs to be some flexibility for the operational safety of multi-million dollar aircraft and their crews. Quiet airports are great, but it’s easy to forget we are customers. In fact, Nice is the second busiest airport for business aviation in France, second only to Paris Le Bourget.

Mitigators

Following an alert issued to the group regarding these reports, another member (also a fully qualified pilot and aircraft engineer) got in touch with some practical advice to operators.

Here is what he had to say:

I thought it would be prudent to post some operational hints and tips to avoid problems like this event in the future. Not just with LFMN, but with any hot weather destination with restricted APU use (i.e. most  of Europe).

Most biz jet hydraulic pumps demand very high KVA from the GPU’s – avoid/delay applying hydraulic power to test systems and parking brake until APU start is approved.

Keep all the shades/sun shields drawn until packs are available.

Dim all the display units in the cockpit until air conditioning is available.

Open cargo and main door to allow air flow throughout the cabin. Small fans can run off the GFI plugs.

Open gear doors on some models as the exhaust for the avionic cooling fans use the wheel wells as the exit point.

Has this happened to you here, there, or elsewhere?

Please get in touch with us via blog@ops.group. We’d love to hear from you.

For ops at LFMN, if you identify a GPU issue (malfunction, incorrect configuration, electrical hazard, emissions), report it via your handling agent to the airport’s operations or safety department, or directly to Aéroports de la Côte d’Azur: +33 4 08 20 42 333, or via this contact form.

The summer peak is nearly upon us, and so too is the busiest season for BizAv at LFPB/Le Bourget.

Several upcoming events will see an influx of traffic to the airport including the French Open (May 19 – June 8), the Paris Air Show (June 16 – 22) and Paris Fashion Week (June 24 – 29).

While this isn’t a new change, if you’re heading into LFPB it’s a good time to remind yourself of the strict rules for APU usage lest you fall victim to some potentially large fines.

They’re not mucking around either – two groups are involved. The Air Transport Gendarmerie is responsible for monitoring APU usage at the airport and making sure operators follow the rules. If not, a group known (in English) as the Airport Nuisance Authority (ACNUSA) will get involved and issue fines.

In a recent year, ACNUSA imposed 334 fines for non-APU compliance across French airports. Their haul? €6.9 million – that’s an average of more than €20,000 per fine. This has been confirmed as accurate and current by a local handler. Both the operator and PIC can be held liable.

The French AIP (LFPB AD 2.21) has the full rules – but here’s what you need to know…

Know the time limits

Since 2023, the rules at Le Bourget have depended on whether your parking stands have ground facilities or not:

Departing Flights – APU use limited to 10 minutes prior to the EOBT if your stand is equipped with ground air and power, or 45 minutes on stands without these services.

Arriving Flights – APU use limited to 5 minutes after arrival if your stand is equipped with ground air and power, or 20 minutes on stands without these services.

There are limited exemptions to the rules, these include:

• Humanitarian and medical flights.
• Military aircraft.
• Aircraft carrying live animals, perishables, medical or cosmetic goods that require active air flow.
• The sake of flight safety (which specifically includes passenger, crew or handler health). For departing aircraft it’s worth noting it can take up to 30 mins to cool the cabin of a larger jet (such as a G650, or Falcon 8X) to comfortable temp when the ambient temp outside is more than 30 deg C (86 deg F).

For BizAv flights, determining whether or not the FBO is “equipped with ground air and power” is a slightly tricky business. One FBO reported the following:

We have some mobile GPUs, but not for every space. That creates two interpretations:

The first one: if we have a mobile GPU available, so it is 5 minutes on arrival and 10 minutes on departure; and if we don’t have it available, it is 20 minutes on arrival and 45 minutes on departure.

The second one: they consider that as we are not able to provide one GPU to each aircraft, we are in the 20 minutes on arrival and 45 minutes on departure category by default.

But as the second way is not an “official” one, it is only a tolerance, that’s why you might get different replies from the different FBOs about how the rules work here.

I need an exemption

This is at the PIC’s discretion, but you need to be able to justify it using one of the conditions above.

To do so, you’ll need to provide your agent with a declaration for the Gendarmerie that you intend to break the APU rules, and most importantly why.

Feedback from local agents

Here’s what handlers at Le Bourget had to say when we reached out to them directly.

• “…the airport authorities are very strict with the use of APU’s here. The authorities may fine you for failure to comply – we are able to provide a GPU at the request of the crew…”
• “…there are some unexpected and random inspections by the authorities, after which they write a report and impose a fine…”
• “…the use of the APUs is randomly controlled by the Gendarmerie here in LFPB. The maximum amount of the fine for APU infractions is 20,000€…”
• “…the Captain may only deviate from APU rules for safety reasons. Violation is heavily penalized by the ACNUSA agency, with fines generally exceeding €10,000!…”

Why the fuss anyway?

Two things – noise and pollution.

APU’s are noisy things – a typical one produces 113 decibels, an equivalent noise range to a power saw, jackhammer or even a rock concert. Le Bourget is noise sensitive and located in close proximity to residential areas.

Then there’s the dinosaurs we’re burning – carbon dioxide, nitrogen oxides and other nasties are ejected from our APU exhaust. Reducing runtime helps lower emissions and improves air quality near the field. In fact, here is a surprising statistic – approx. 30% of an airport’s carbon emissions come from aircraft on the ground (with APU use being a significant factor).

This is all in line with global and EU climate goals (such as Fit for 55 or the Paris Agreement). Agree or not, we have to play by the rules – or find ourselves paying a hefty price.

Have a report to share?

Have you been stung or know someone who has? Please share your story with us (as always, our reports are always de-identified). There are several thousand crew out there who will owe you a beer. You can reach us around the clock on news@ops.group.