The aeroplane a dropzone flies

A tandem passenger sees the aeroplane for twenty minutes and usually remembers two things: that you sit on the floor, and that the door is enormous. Both come from the same place. A jump plane is a machine designed or rebuilt for one job — lift a dozen people four kilometres as fast as possible, let them out, and come back for the next load. Twenty times on a good day.

Why this is not an airliner

An airliner flies long and flat. A jump plane does the opposite: it works in a climb-and-descend cycle, over and over, at full load. That wears an engine and a landing gear differently from cruising, so it pays to fly a machine built around the cycle rather than adapted to it.

• A large sliding door that a dozen people leave through in as many seconds — that is what decides how close together the group lands.
• A cabin with no seats. You sit on the floor, facing backwards, because that is how people in harnesses and rigs actually fit.
• A climb measured in minutes rather than quarter-hours: every minute is fuel and one fewer lift in the day.
• Short take-off and landing, often from a surface that is not concrete.
• One turbine instead of two piston engines: a better power-to-weight ratio and simpler maintenance.

The lineage: a top-dresser on a hillside

One of the machines most often seen at dropzones worldwide, the New Zealand PAC 750XL, married the wing and engine of the PAC Cresco agricultural aircraft to a new and much larger fuselage. The Cresco is itself a turbine development of the Fletcher FU-24 — a fertiliser top-dresser built from the 1950s for short, rough strips on New Zealand hill country.

That is not a historical footnote. It is the explanation for why this shape works over a dropzone. An agricultural aeroplane spends its whole life doing what a jump plane does: taking off heavy from a short strip, climbing fast, dropping its load and coming down for the next one. The wing, the gear and the duty cycle were calculated for exactly that, long before anyone thought of carrying skydivers with it.

What that means in numbers

The 750XL prototype first flew in September 2001 and the type was fully certified in the United States in March 2004. It is powered by a Pratt & Whitney Canada PT6A-34 turbine rated at 750 shaft horsepower, which is where the name comes from. The manufacturer quotes a certified capacity of seventeen parachutists; in practice dropzones fly eleven to fourteen, because what decides the number is take-off weight with fuel rather than the seat count.

• A take-off run of roughly 220 metres and a landing roll of about 166 metres — grass-strip figures, not runway figures.
• A stall speed with flaps below 60 knots, under 110 km/h.
• Fixed landing gear with long-travel shock absorption, sized for hard arrivals on uneven ground.
• A climb to 4,000 metres in something like ten to thirteen minutes at full load.
• A descent after the drop at idle, on the order of a thousand metres a minute — down considerably faster than it went up.

Published figures for this class of aircraft disagree between sources, sometimes widely: performance certified at maximum weight is a different measurement from performance flown at a particular load. Where the sources disagree we give a range rather than pick the most impressive number.

A certification that actually means something

In 2012 the type was approved for single-engine commercial passenger transport under instrument flight rules, in line with ICAO Annex 6. That is an approval a single-turbine design has to earn separately, and it is the reason single-engine turboprops carry paying passengers at all in many countries.

The PT6 engine family itself has been in production since 1964 and has several hundred million flight hours behind it. The manufacturer quotes an in-flight shutdown rate on the order of one per several hundred thousand hours, among the lowest ever measured for an aircraft engine. The same turbine powers a great many machines, from crop dusters to transports.

The factory that nearly disappeared

The manufacturer's history is less orderly than the aeroplane's. The Hamilton works were formed by a merger in 1973, traded as Pacific Aerospace from 1982, and sold half their shares to a Chinese investor in 2016. In February 2021 the company declared insolvency and the court placed it in liquidation. Weeks later the assets were bought by a new owner — a company from the skydiving industry — and since November 2023 the works have traded as NZAero.

For a buyer that is not trivia. Continuity of technical support, parts availability and who holds the type certificate go into the valuation of an airframe exactly as engine hours do.

How one gets here from the other side of the world

A New Zealand machine bought by a European operator has somewhere over ten thousand nautical miles to cover. There are two ways: dismantle it into a container, or fly it. The second is often cheaper and faster, but it means crossing the Pacific and Asia in an aeroplane not built for the job.

There is a published Polish account of exactly that flight and it is worth knowing. A crew from a skydiving school in Nowy Targ brought a PAC 750XL from Hamilton to Poland in fourteen days: around ninety hours in the air, thirty-odd landings on the way, no ferry tanks, no autopilot, flown visually and only in daylight. The six-part diary ran on the aviation portal dlapilota.pl under the pilots' own names.

A ferry flight is a discipline of its own: overflight and landing permits across a dozen countries, legs planned around range, long-range communication over water, survival equipment, weather windows, and the knowledge that over an ocean a single-engine aeroplane has nowhere to divert. It is also, for ninety hours, simply cold and loud.

Before it wears its new registration

Buying an aeroplane is closer to buying a building than a car, and most of the work happens on paper. The order varies; the scope does not.

1. 01A pre-purchase inspection: airframe condition, corrosion, repair and damage history.
2. 02The paperwork: airframe, engine and propeller logbooks, the full set of airworthiness directives and service bulletins.
3. 03The engine: hours remaining to overhaul, maintenance history, hot-section inspection and borescope.
4. 04Deregistration from the seller's national register and an export certificate of airworthiness.
5. 05Registration with the national authority and the allocation of new marks.
6. 06Continuing airworthiness management under the European rules, with a contract with a maintenance organisation.
7. 07Customs clearance, import taxes and insurance.

Any one of those can add weeks, and several of them can end a deal. Which is why far more time usually passes between finding an aeroplane and its first lift than the ferry flight alone would suggest.

A day at the dropzone, from the aircraft's side

On jump run the pilot holds around 80 to 85 knots with half flap and maintains altitude. When the group leaves, the aeroplane loses several hundred kilograms from the back of the cabin in a few seconds and the nose drops slightly — expected, and designed for. Aircraft in this class carry the main gear aft of the centre of gravity, so the machine will not sit on its tail even when everyone has moved to the door.

Then comes the part the jumpers never see: door closed, descent at idle, landing, refuelling, the next load. A jump pilot flies more take-offs and landings in a single day than many airline pilots fly in a month.

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