The aerospace industry and its careers

Prairiewind Aerospace is a small company in Wichita, Kansas, with an ambitious plan. Its 60 engineers, technicians and business staff are designing the Tern, a nine-passenger commuter aircraft with a hybrid-electric powertrain. A battery pack and two electric motors drive the propellers, and a small turbine generator recharges the pack in flight and extends the range. The target market is short regional routes such as Wichita to Denver, about 680 km, where today's aircraft are old, fuel-hungry and expensive to run. Alongside the Tern, the company builds a 24 kg cargo drone called the Skiff for delivering parts and medical supplies, and it supplies wing structures to larger manufacturers to pay the bills while the Tern is certified.

Through this course we follow four people at the company. Élise Fournier is the chief engineer. Marcus Webb leads the structures group. Sam Littlechild is a test pilot and flight test engineer. Arjun Mehta is a second-year engineering student on a co-op work term, and like you he is meeting most of these ideas for the first time. Each lesson takes one part of the Tern or Skiff program and uses it to introduce a branch of aerospace engineering: the atmosphere, aerodynamics, propulsion, structures, stability, performance, spaceflight, unmanned aircraft, regulation and design. Later courses in the program go deep into each branch. This one shows how they fit together.

What the aerospace industry makes

Aerospace covers everything that flies in the atmosphere (aeronautics) and everything that operates beyond it (astronautics). The industry is usually divided into a few large segments. Commercial aviation builds airliners, regional aircraft and the engines and systems inside them. Business and general aviation builds business jets, piston and turboprop aircraft for training, private flying, charter and bush operations. Rotorcraft covers helicopters and, increasingly, vertical-lift aircraft with many rotors. Defense builds military aircraft, missiles and their support systems. Space builds launch vehicles, satellites, spacecraft and the ground systems that control them. A fast-growing segment builds drones of every size, from 250 g camera drones to cargo aircraft weighing hundreds of kilograms.

Beneath the aircraft makers sits a long supply chain. Tier 1 suppliers build major systems such as landing gear, avionics suites, wings or engines. Tier 2 and Tier 3 suppliers make components and parts: machined fittings, wiring harnesses, composite panels, fasteners, sensors. After an aircraft is delivered, the maintenance, repair and overhaul (MRO) sector keeps it flying for 25 to 40 years. MRO is a huge employer in its own right, because every aircraft needs inspections, engine overhauls, component repairs and modifications throughout its life. Airlines, airports, air navigation service providers and regulators complete the system.

The United States has the world's largest aerospace industry. It builds airliners, business jets, general aviation aircraft, military aircraft, helicopters, engines and avionics, and it dominates launch services and satellite manufacturing. Wichita calls itself the air capital of the world: it hosts large plants building business jets, general aviation aircraft and fuselage sections for airliners, along with a university research institute that tests aircraft structures. Other major clusters are in Washington, California, Texas, Florida, Connecticut and Georgia. NASA leads civil aeronautics and space research, and commercial companies now carry out much of the launch and spacecraft work that NASA once did itself.

The industry runs on long cycles. A new airliner takes ten years or more from first sketch to first delivery and may stay in production for 30 years. A small company like Prairiewind Aerospace hopes to certify the Tern in about six years. Cash is tight during development because money flows out for years before any aircraft is sold. That is why many aerospace start-ups also do contract work, as Prairiewind Aerospace does with wing structures, and why partnerships with established suppliers matter so much.

Why aerospace engineering is different

Every branch of engineering balances performance, cost and safety. Aerospace engineering is distinctive because weight matters so much. An extra kilogram of structure on the Tern means a kilogram less of passengers or fuel on every flight for decades. An extra kilogram on a launch vehicle's upper stage can cost tens of kilograms of propellant at lift-off. So aerospace engineers work with smaller safety margins than, say, bridge designers, and they compensate with rigorous analysis, testing, inspection and quality control. A building might use a factor of safety of two or three on its loads; aircraft structures are typically designed for 1.5 times the largest load expected in service, and every assumption behind that number is checked.

Safety is the second defining feature. Commercial aviation is one of the safest ways to travel, and that record was built by learning from every accident. Each failure is investigated, the cause is published, and the lessons go into design standards, maintenance programs and pilot training. An aerospace engineer's work is reviewed by colleagues, by the company's own airworthiness office and by the regulator before an aircraft carries passengers. Lesson 11 describes that process.

The third feature is integration. An aircraft is a system of systems: aerodynamics, structures, propulsion, flight controls, electrical power, hydraulics, avionics, cabin systems and software must all work together, and a change to one affects the others. Making the Tern's battery pack 50 kg heavier, for example, raises the wing loading and the stall speed, which lengthens the take-off run, which may push the design over a runway-length requirement, which in turn might call for bigger flaps. Engineers who understand how the pieces connect are especially valuable.

Careers in aerospace

Aerospace employs engineers from almost every discipline. Aerospace and mechanical engineers work in aerodynamics, structures, propulsion and design. Electrical and computer engineers design power systems, avionics, sensors and flight software. Materials and chemical engineers develop alloys, composites, coatings and propellants. Manufacturing and industrial engineers plan production lines and tooling. Software engineers write flight control laws and ground-station software. Systems engineers manage requirements, interfaces and verification across the whole aircraft. Many roles combine engineering with business: program management, supplier quality, customer support and certification.

Technicians and technologists are just as important. Aircraft maintenance engineers (AMEs) in Canada and airframe and powerplant (A&P) mechanics in the United States hold licenses to sign for maintenance work. Avionics technicians, composite technicians, machinists, inspectors and test technicians build and maintain the aircraft. Pilots, air traffic controllers and dispatchers operate the system. Many engineers start their careers on the shop floor or in flight test and say it was the best way to learn how aircraft really work.

In the United States, a professional engineering license is less common in aerospace manufacturing than in civil engineering, because federal aviation rules, not state engineering laws, govern aircraft design approval. Instead, the FAA appoints experienced engineers as designated engineering representatives (DERs) or as members of a company's organization designation authorization (ODA) unit. These people approve certain technical data on the FAA's behalf. Becoming one takes years of experience and a strong record of compliance work.

The industry also depends on people who choose it as a long-term career. Experienced engineers retire every year, and companies of every size report difficulty hiring people who understand both the engineering and the regulations. Co-op terms like Arjun's are one of the main routes in: students who have worked in an aerospace company graduate with experience, references and a better sense of which branch they enjoy.

How a program makes money

Engineers make better decisions when they understand the economics behind them. An airline buying a commuter aircraft compares operating cost per seat-kilometer with the fares it can charge. The main cost groups are energy (fuel or electricity), crew, maintenance, ownership (the cost of buying or leasing the aircraft, plus insurance) and fees such as landing and navigation charges. A small change in fuel burn or maintenance hours, multiplied over thousands of flights a year, decides whether an aircraft sells.

Two measures are standard. Available seat-kilometers (ASK) is the number of seats multiplied by the distance flown. Revenue passenger-kilometers (RPK) counts only seats filled with paying passengers. Their ratio is the load factor. Dividing the cost of a trip by the ASK gives the cost per available seat-kilometer, or CASK, the number airlines use to compare aircraft. Small aircraft have a high CASK, because crew, fees and ownership costs are shared among few seats. That is the problem the Tern is trying to solve: lower energy and maintenance costs should make short routes viable that larger aircraft serve poorly.

# Seat-kilometer economics for a nine-seat commuter on a 650 km route
# Illustrative numbers for Prairiewind Aerospace's market study
route_km = 680
seats = 9
load_factor = 0.70          # fraction of seats filled on average
trips_per_day = 4           # one-way flights per aircraft per day
days_per_year = 300

block_hours = route_km / 380 + 0.4      # cruise at about 380 km/h plus taxi, climb and descent
costs = {
    "energy": 2.10 * route_km,          # fuel or electricity, per trip
    "crew": 450 * block_hours,
    "maintenance": 380 * block_hours,
    "ownership": 1.6e6 / (trips_per_day * days_per_year),  # yearly lease and insurance spread over trips
    "fees": 600,                       # landing, navigation and airport charges per trip
}
trip_cost = sum(costs.values())
ask = seats * route_km                 # available seat-kilometers per trip
rpk = ask * load_factor                # revenue passenger-kilometers per trip
print(f"Block time per trip: {block_hours:.2f} h")
for k, v in costs.items():
    print(f"  {k:<12}{v:10.0f}")
print(f"Trip cost: {trip_cost:.0f}")
print(f"Cost per available seat-km (CASK): {trip_cost/ask:.3f}")
print(f"Break-even fare per passenger: {trip_cost/(seats*load_factor):.0f}")

Block time per trip: 2.19 h
  energy            1428
  crew               985
  maintenance        832
  ownership         1333
  fees               600
Trip cost: 5179
Cost per available seat-km (CASK): 0.846
Break-even fare per passenger: 822

The program shows why ownership and crew costs dominate on short routes: they barely change with distance, so a short trip spreads them over few seat-kilometers. Try changing the load factor to 0.5 or the route to 300 km and watch the break-even fare climb. Real airline cost models are far more detailed, but they rest on exactly these ideas.

Environmental pressure and the next generation of aircraft

Aviation produces roughly 2 to 3 percent of global carbon dioxide emissions, and its share is expected to grow as other sectors cut emissions faster. Airlines and manufacturers have committed to net-zero carbon emissions by 2050 through more efficient aircraft, sustainable aviation fuels made from waste or captured carbon, better air traffic management, and new propulsion: battery-electric, hybrid-electric and hydrogen. Noise near airports and contrails at altitude are also concerns.

Battery-electric aircraft are limited by the low energy stored per kilogram of battery, as Lesson 5 shows, so they suit short flights and small aircraft. Hybrid-electric designs like the Tern use batteries for take-off and climb, when power demand is highest, and a fuel-burning generator for cruise. Hydrogen stores far more energy per kilogram than jet fuel but takes up much more volume, even as a cryogenic liquid. Each option changes the aircraft's shape, weight and systems, which is why this is an exciting time to enter the field.