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  • Why Tivat Airport Has a Bird Problem — And Why It’s Getting Worse

    Why Tivat Airport Has a Bird Problem — And Why It’s Getting Worse

    On July 24, 2026, Tivat Airport (TIV) ground to a halt. For over three hours — from 07:40 to 11:00 local time — no aircraft could land. Air Serbia, Air Montenegro, easyJet, Turkish Airlines, Eurowings, Israir, FlyOne and Norwegian Air Shuttle were all forced to divert to Podgorica, Tirana, Brindisi, Rome and Bari. Airport authorities cited an “unprecedented concentration of birds on the runway.”

    It wasn’t a one-off. Bird-related incidents at Tivat have been climbing steadily: confirmed bird strikes rose from around 5 in 2023 to 17 in 2024, while total bird-related airspace events rose from 26 to 38 over the same period. Recent years have seen strikes on an EasyJet A320 (June 2024) and a SmartLynx A320 (2023), among others. The trend line points in one direction — and the causes are not mysterious.

    A wetland the airport can’t touch

    Tivat’s runway sits on reclaimed coastal land in the Grbalj valley, at the edge of the Bay of Kotor, with the runway threshold just 88 meters from the shoreline. Immediately adjacent is Solila, a roughly 150-hectare former salt-pan wetland that has been a protected nature reserve since 2007 and a Ramsar-listed Wetland of International Importance since 2013. It hosts more than 100 bird species — flamingos, herons, cormorants, egrets, birds of prey — and serves as a resting point on the Adriatic migratory flyway between Africa and northern/eastern Europe.

    This is a structural, largely irreducible constraint. Solila is legally protected; the airport cannot disperse, drain, or disturb it the way it might a patch of unprotected scrubland. Coastal wetland and flight path were always going to overlap here.

    An illegal landfill the airport absolutely can touch

    The more troubling factor is different in kind. It has been identified as an illegal dump directly adjacent to the airport, on land owned by the company Montepranzo Bokaprodukt but used by the municipal utility Komunalno Tivat. Estimates put the volume at more than 5,000 cubic meters of waste, much of it organic — precisely the kind of food source that draws large, persistent gull and scavenger-bird flocks onto an active runway.

    The site reportedly began under a temporary business agreement permitting limited transfer of waste pending a permanent municipal disposal location. That agreement has since lapsed, according to the landowner, yet dumping has continued. Montepranzo Bokaprodukt has formally notified the Tivat municipality, Montenegro’s Ministry of Ecology, Sustainable Development and Development of the North, the Ministry of Tourism and Transport, the Civil Aviation Agency, the Environmental Protection Agency, Airports of Montenegro, and environmental inspectors. Montenegro’s flight control agency has separately flagged the safety risk to the relevant authorities.

    Unlike Solila, this is not a conservation trade-off — it’s a jurisdictional and enforcement gap between a private landowner, a municipal utility, and multiple state bodies, all of whom appear to have been warned before the July 24 shutdown.

    Already on the official record

    This isn’t a hazard that caught anyone by surprise on paper. Montenegro’s Aeronautical Information Publication (AIP), in the AD 2.LYTV aerodrome section, carries a standing caution:

    “Maintain a careful look-out on APCH and DEP because of mountainous area close to AD. Birds in vicinity of AD.”

    Jeppesen charts for LYTV carry the same warning in shorthand, printed directly on the airport diagram: “Birds in vicinity of apt.” This is a permanent aerodrome remark, not a one-off NOTAM — every crew flying into Tivat is briefed on it as a matter of course, and has been for years.

    Two different problems, one runway

    Map showing Tivat Airport with Solila to the southwest and the reported landfill site to the southeast
    Tivat Airport (TIV): Solila nature reserve sits southwest of the runway, by the coast; the reported waste site sits southeast, adjacent to the road toward Kotor — flanking the approach/departure path from both sides.

    The result is that Tivat effectively has two bird-attractant systems stacked on top of each other at the exact moment traffic is at its seasonal peak — 2024 passenger numbers were up 32.5% year-on-year, and summer accounts for roughly 80% of annual volume. Airports of Montenegro says it applies radar-based detection and standard dispersal measures, but detection and dispersal can only do so much against a food source sitting a few hundred meters from the threshold.

    Solila will remain a fixture of Tivat’s operating environment; that trade-off is the price of a genuinely scenic, biodiverse coastline. The landfill is the part of this story that has a straightforward fix — if the responsible authorities act on the warnings already on file.

    Sources: Aviation Herald, Ground News, Investitor.me, Skala Radio, Portal Analitika, Grokipedia, Tivat Tourism Organisation, natureforpeople.org, Montenegro AIP (AD 2.LYTV), Jeppesen LYTV charts, public NOTAM records.

  • The End of Leaded Avgas: What Will Replace 100LL

    The End of Leaded Avgas: What Will Replace 100LL

    A general aviation piston aircraft, the type of aircraft affected by the 100LL-to-unleaded avgas transition

    For nearly a century, piston-engine aircraft have run on leaded fuel. That era is now closing. Driven by an EPA finding that lead emissions from aviation gasoline endanger public health, the FAA and industry have committed to eliminating leaded avgas for U.S. piston aircraft by the end of 2030 (2032 in Alaska). Three unleaded fuels are now racing toward that deadline, each taking a different path to market.

    Why 100LL Has to Go

    100LL (“low lead”) is the last widely used leaded transportation fuel in the United States. Tetraethyl lead is added to prevent engine knock in high-compression piston engines, but it’s also a potent neurotoxin, especially harmful to children living near general aviation airports. In 2023 the EPA formally determined that lead emissions from piston aircraft endanger public health, triggering a legal requirement for the FAA to move the fleet to unleaded fuel. The public-private EAGLE initiative (Eliminate Aviation Gasoline Lead Emissions) was formed to coordinate that transition without grounding the roughly 170,000 piston aircraft that depend on 100-octane fuel.

    The Three Contenders

    GAMI G100UL. Developed by General Aviation Modifications Inc. over more than a decade, G100UL was the first fuel to receive a broad FAA-approved model list Supplemental Type Certificate, in September 2022, covering nearly all spark-ignition piston aircraft engines. GAMI markets it as a true drop-in replacement requiring no engine modifications, only placarding. It has matched or exceeded 100LL’s detonation protection in FAA-observed testing and began reaching airports in late 2024. Its main controversy: GAMI has declined to pursue an ASTM International production specification, the industry-standard process other fuel makers use, which has made some distributors and insurers cautious about handling it.

    Swift Fuels 100R. Swift took the opposite route, earning an ASTM production specification (D8603) for its 100-octane unleaded fuel. As of mid-2026, 100R has FAA certification via STC for more than 1,200 engine models, with airframe approvals continuing to expand, and it’s already sold commercially in the U.S. and parts of Europe. Swift also produces UL94, a lower-octane unleaded fuel that has been commercially available since 2016 but only suits engines that don’t need full 100-octane performance, around two-thirds of the piston fleet.

    LyondellBasell/VP Racing UL100E. This candidate is going through the FAA’s own Piston Aviation Fuels Initiative (PAFI) rather than the STC route, aiming for a fleet-wide authorization rather than aircraft-by-aircraft approval. It passed a critical 150-hour engine durability test and remains in FAA evaluation.

    What’s Actually in the Tank

    100LL is a blend of alkylate and other high-octane hydrocarbons (isooctane, toluene, xylene) with tetraethyl lead (TEL) added as the antiknock agent — currently capped at 2.12 grams of TEL per gallon, half the level of the older 100/130 grade it replaced. The unleaded contenders swap that lead out for different octane-boosting chemistry:

    FuelOctaneBase compositionAntiknock/octane boosterDensity (lb/gal)Production standard
    100LL100/130Alkylate + aromatic hydrocarbons (toluene, xylene)Tetraethyl lead, 2.12 g/gal~6.0ASTM D910
    G100UL100High-octane alkylate baseAromatic amine (m-toluidine, ~3–4.5%) + trimethylbenzene~6.2–6.3GAMI proprietary spec (no ASTM)
    Swift 100R100Alkylate baseRenewable oxygenatesNot yet publishedASTM D8603
    Swift UL9494Alkylate base, water-white (uncolored)Non-lead, non-aromatic-amine formulation5.9ASTM D7547
    LyondellBasell/VP UL100E100Alkylate baseProprietary (undisclosed)Under FAA testingPursuing FAA fleet authorization

    What’s Different About Flying on Unleaded

    A general aviation piston aircraft on the ramp

    Early operational experience has surfaced a few things pilots and mechanics are watching:

      The Road to 2030

      The FAA released a draft four-phase transition plan for public comment in January 2026: establishing and comparing approved fuels, letting the market gain experience, a national rollout, and finally the Alaska transition in 2032. California has already passed its own law banning the sale of leaded avgas from January 1, 2031, timed to fall one day after the federal deadline, and other states are watching closely.

      Cost remains a sticking point. Unleaded fuels have generally sold at a premium over 100LL, sometimes $1–2 more per gallon, and airports need separate, dedicated fuel systems if they stock more than one grade at once. Supporters argue the price gap will close as production scales and that lower maintenance costs offset it; critics, including some pilot groups, argue the economics still favor sticking with 100LL as long as it’s legally available.

      Either way, the direction is set. Within the next few years, most general aviation aircraft in the U.S. will be filling up with something other than the fuel that’s powered them for eighty years.

      So Which One Wins?

      On raw head start, G100UL is ahead. It has the broadest FAA approval of any unleaded 100-octane fuel, an AML-STC covering nearly the entire spark-ignition piston fleet, over a decade of development, and it’s already being pumped at a growing number of U.S. airports. If the race were decided purely on “which fuel can go into the most airplanes today,” GAMI’s product is the clear leader.

      But certification breadth isn’t the same as industry buy-in, and that’s where the picture gets more complicated. G100UL’s refusal to pursue an ASTM International production specification has left it outside the standard that every other current aviation fuel, including 100LL itself, is built on. That’s fed real hesitation from airframe makers (Cirrus has declined to approve it over sealant concerns), from insurers, and from Swift Fuels, which won’t allow G100UL to be commingled with its own products. Reports of paint staining, fuel leaks, and elastomer damage since G100UL reached the field in late 2024 have also given distributors and FBOs reason to move cautiously.

      Swift Fuels’ 100R is the strongest challenger, and arguably the safer long-term bet. It’s the only 100-octane unleaded fuel with an ASTM production specification (D8603), the process the broader industry, OEMs, and regulators are accustomed to trusting. Its STC coverage is expanding fast (over 1,200 engine models by mid-2026, with airframe approvals following) and it’s already selling commercially in the U.S. and parts of Europe. Its lower-octane sibling, UL94, also has years of real-world dispensing history behind it, giving Swift an operational track record G100UL doesn’t have.

      LyondellBasell/VP Racing’s UL100E is the dark horse. It’s pursuing the FAA’s own fleet-authorization path rather than the STC route, which would in theory make it available to every aircraft without per-tail paperwork, but it’s still working through PAFI testing and is the furthest from market of the three.

      The most likely outcome isn’t a single winner but a split market: G100UL keeps its lead where it’s already established and distribution is in place, Swift’s 100R gradually gains share as ASTM backing wins over airports and insurers, and UL94 continues to serve the roughly two-thirds of the fleet that doesn’t need full 100-octane fuel. If one fuel does emerge as the de facto national standard by the 2030 deadline, industry momentum currently favors Swift’s ASTM-backed approach over G100UL’s technically-superior-but-unstandardized one, though GAMI’s head start and existing infrastructure mean that’s far from settled.

      Last updated: July 2026

      Frequently Asked Questions

      Is 100LL banned yet?
      No. 100LL remains legal and widely available in the U.S. The FAA’s EAGLE initiative targets elimination by the end of 2030 (2032 in Alaska), and California’s state ban takes effect January 1, 2031. No blanket federal ban is in effect today.

      What is G100UL?
      G100UL is a 100-octane unleaded avgas developed by GAMI. It holds the broadest FAA Supplemental Type Certificate of any unleaded avgas, covering nearly all spark-ignition piston aircraft engines, but it has not been submitted to ASTM International for a production specification.

      Can I mix unleaded avgas with 100LL?
      It depends on the fuel. G100UL can be freely mixed with 100LL in any approved aircraft. Mixing G100UL or 100LL with UL94, however, is restricted to aircraft already approved to use UL94 — check your aircraft’s specific fuel approvals before mixing.

      Which unleaded avgas is best for my aircraft?
      It depends on your engine’s octane requirement and which STCs are approved for your airframe/engine combination. Aircraft needing full 100-octane fuel can look at G100UL or Swift’s 100R; aircraft that can run on 94-octane or lower have more options, including Swift’s UL94.

      When will unleaded avgas be available at my airport?
      Availability varies widely by region and depends on local FBO decisions. GAMI and Swift both publish airport rollout maps on their websites, and the FAA’s draft transition plan outlines a phased national rollout through 2030.

    • What Really Happens When a Plane Loses a Window: Inside the Ryanair Decompression Scare

      What Really Happens When a Plane Loses a Window: Inside the Ryanair Decompression Scare

      A Ryanair Boeing 737-800
      Photo: Andrew Thomas from Shrewsbury, UK, via Wikimedia Commons, CC BY-SA 2.0 — EI-DCJ Boeing 737-8AS (cn 33564/1562) Ryanair, Birmingham Airport, June 2, 2012

      On Friday morning, a routine Ryanair departure from Thessaloniki to Memmingen, Germany, turned into a mid-air emergency that has reignited public fascination with one of aviation’s rarer and more frightening failure modes: sudden loss of cabin pressure.

      What happened aboard FR1879

      Flight FR1879 departed Thessaloniki at 6:12 a.m. local time on Friday, July 10, 2026. About eight to ten minutes into the climb, as the Boeing 737 operating for Ryanair (registered to sister carrier Malta Air) passed roughly 15,000–16,000 feet, it suffered an apparent engine problem. Debris — reportedly including a fan blade — struck the fuselage and shattered a cabin window. The sudden opening triggered an immediate pressure loss, and the passenger seated beside the window was pulled toward the gap, his head and shoulders briefly outside the aircraft.

      Passengers described a bang “like a tire bursting,” followed by screaming as oxygen masks dropped from the ceiling. Crucially, the man’s seatbelt was fastened, and it is widely credited — along with the grip of the person seated next to him — with keeping him from being pulled further out. The crew declared an emergency, flew a rapid descent, and returned the aircraft to Thessaloniki within minutes. One passenger was treated on the ground; everyone else continued their journey on a replacement aircraft.

      Greek and Irish aviation authorities, along with the US National Transportation Safety Board, are now investigating both the engine failure and the structural loss of the window.

      Explosive decompression: the physics in plain terms

      Diagram of rapid and explosive cabin decompression

      Aviation engineers actually distinguish between several categories of pressure loss, and the distinction matters enormously for what a passenger experiences:

      • Explosive decompression happens in under half a second, typically from a large structural failure (a blown door or major fuselage breach). The pressure differential equalizes almost instantly, producing a violent outward rush of air, a fog of condensation, and genuine risk of objects — and unsecured people — being ejected.
      • Rapid decompression takes a few seconds, as with a smaller opening like a window. Still forceful, still deafening, but marginally less instantaneous.
      • Slow decompression, from a failed seal or small crack, can go unnoticed for minutes without an alarm.

      A critical detail in Friday’s incident: it occurred shortly after takeoff, not at cruising altitude. Cabin pressure differential builds progressively as an aircraft climbs toward cruise (typically 35,000–40,000 feet), where the pressure difference between the cabin and outside air is at its maximum. At a few thousand feet, the differential is far smaller — which is almost certainly why the outcome here was survivable without irreversible injury, whereas the same failure at cruise altitude could produce far more severe forces, hypoxia risk, and a shorter window for the crew to act.

      Standard operating procedure: what the crew is trained to do

      Airline crews drill decompression scenarios regularly, and the sequence is standardized across manufacturers:

      1. Don oxygen masks immediately — pilots first, since impaired judgment at altitude can happen within seconds without supplemental oxygen.
      2. Initiate an emergency descent, generally to 10,000 feet or the nearest safe altitude above terrain, as fast as the aircraft safely allows — often exceeding 3,000 feet per minute.
      3. Declare an emergency (squawk 7700) and coordinate immediately with air traffic control for priority routing and, if needed, diversion.
      4. Secure the cabin: cabin crew, once masks are confirmed, assess injuries, check for secondary hazards (loose debris, fire risk), and prepare for landing.
      5. Land at the nearest suitable airport — in this case, a return to the departure airport rather than continuing toward Germany.

      By all accounts, the FR1879 crew executed this playbook closely: masks deployed, a fast descent, a return to Thessaloniki within minutes of departure.

      How real is the “held onto him” scenario?

      This is where physics gets more encouraging than the footage suggests. Full ejection of an adult through a standard passenger window is aerodynamically difficult: airline windows are roughly the size of a dinner plate — far smaller than the width of a person’s shoulders — so the opening itself limits how much of a body can pass through, and the force pulling outward drops off sharply once shoulders wedge against the frame. That’s consistent with reporting here: the passenger went out head-and-shoulders first and no further, aided by his seatbelt.

      There is a well-known precedent that makes the “someone held on” detail entirely credible: British Airways Flight 5390 in 1990, when a cockpit windscreen blew out at altitude and the captain was sucked halfway out of the aircraft, torso outside the fuselage, for over twenty minutes. He survived because a flight attendant grabbed his legs and physically held on until the crew could land — a case still taught in aviation safety training today. Compared to that scenario, Friday’s incident involved a smaller opening, lower altitude, and a seatbelt already in place, all of which make a fellow passenger successfully holding on considerably more plausible, not less.

      What investigators will be looking for

      Diagram of an uncontained engine failure

      Two separate threads will likely dominate the inquiry: why engine debris was able to depart the engine casing and strike the fuselage (a containment failure question, known in the industry as an uncontained engine failure), and why the window assembly failed as it did under that impact. Both feed into broader scrutiny of maintenance and manufacturing oversight that has followed Boeing 737 aircraft in recent years.

      For passengers, the practical takeaway hasn’t changed in decades: keep your seatbelt fastened whenever seated, even when the sign is off. In this incident, it may have made the difference between a terrifying scare and a fatality.

      This article is based on public reporting from CNN, Bloomberg, the Irish Times, and Greek broadcaster ERT, as investigations by Greek and international aviation authorities remain ongoing. Details may be updated as official findings are released.