Modern fighter jets carry little weaponry. Between stealth, drag, costs and rules of engagement, here is the technical and operational analysis.
In summary
Latest-generation fighter jets do not take off with a ‘wall of fire’ but with calibrated loads. The logic is not symbolic economy, but efficiency. First, stealth requires weapons to be carried in the cargo hold, which mechanically limits the available volume. Secondly, each additional bomb or missile degrades drag and performance: range, ceiling, acceleration, combat capability. Rules of engagement require positive identification and control of collateral effects: two accurate guided munitions are better than ten approximate ballasts. Planning is based on probability of hit and damage models; the exact number of munitions per target is calculated. In-flight refuelling and tankers also dictate load/fuel profiles. Finally, the unit cost of weapons (ranging from tens of thousands to over a million euros) and the rate of resupply limit payload. A ‘light’ aircraft fires faster, goes further, remains discreet and strikes accurately.
The operational framework and mission logic
An operational flight is not a show of force; it is an optimisation. Before each mission, the staff draws up a list of objectives with priority levels, threat environment, time window and evaluation criteria. From there, the weaponry is sized as accurately as possible. Two parameters dominate: the number of realistic targets to engage and the useful presence time in the area. On a typical air-to-ground strike, multi-role fighters often carry two guided bombs (e.g., two 454 kg bombs) or four small low-drag bombs (four 113 kg bombs), plus two to four air-to-air missiles for self-protection. This ‘small’ payload is sufficient in most scenarios, as the effectiveness of sensors and ISR support improves target assignment: fewer weapons, better employed.
Modern planning relies on networked ‘kill chains’: off-board designation by drones, surveillance aircraft, satellites. The aircraft fires at the optimal moment, from the axis and distance imposed by the guidance system (GPS/INS, laser, imaging) to maximise the probability of hitting the target. In contested airspace, carrying a light load shortens exposure time and facilitates escape. In a combined raid, the ammunition portfolio is distributed among the aircraft: some ensure the suppression of defences (anti-radar missiles), others maintain air superiority (long-range AAM), and others deliver the payloads to fixed targets. Each aircraft takes off with ‘just what it needs’.
Base and theatre constraints also matter. In hot and humid climates, or from a short runway, maximum payload cannot be achieved without significantly reducing fuel. A full-weight take-off reduces safety margins and initial climb. Air forces therefore prefer to conserve fuel and sensors, even if it means carrying fewer weapons, and rely on mid-flight refuelling. This philosophy improves mission success more than a ‘Christmas tree’ full of pylons.
Stealth, drag and flight performance
Stealth dictates geometry and therefore payload. A fighter with an internal bay maintains a low radar cross-section as long as the hatches remain closed. This is compatible with 2 to 6 compact air-to-air missiles or 2 907 kg bombs in central bays, but not with twelve external pylons. Opening the bays increases the radar signature by an order of magnitude or more, depending on the shapes and mounts. Stealth aircraft therefore favour ‘clean’ configurations with 4 to 6 missiles or 2 heavy bombs internally, even though the airframe could theoretically carry much more.
For non-stealth aircraft or those in ‘beast’ mode (bays + pylons), each hardpoint adds parasitic drag and wake. A 160 kg missile on the upper surface penalises cruising speed and climb rate; a 454 kg bomb under the wing widens the transonic envelope and increases fuel consumption by several hundred kilograms on a 1,500 km mission. With a package of four bombs and two pendulum tanks (2 × 1,150 litres), the effective range can be reduced by more than 20% depending on altitude and profile. The figures vary depending on the airframe and the aerodynamics of the loads, but the trend is consistent: more external armament means less range and less agility.
Heating and thermal load must also be taken into account. At supersonic speeds, some loads generate skin temperatures in excess of 120°C. Their integrity imposes limits on speed and load factor. In combat, this reduces the instantaneous turn angle and the ability to sustain 7–9 g. A light fighter, with two missiles on the wingtips and nothing else, retains its ‘nervousness’ and energy. The trade-off is clear: surviving and returning with unfired ammunition is better than going down after a first drop. Payload is performance traded for firepower. But military leaders buy performance first.
The lethality of guided munitions and effects-based planning
Since the rise of guided munitions (GPS/INS, laser, IR), the equation ‘more weapons = more results’ has changed. A 227 kg low-drag bomb with low CEP (circular error probable less than 5–10 m) can destroy a light command post or mast radar with a single impact. A 454 kg bomb can neutralise a standard aircraft hangar. For hardened targets, two weapons fired in sequence (delay/detonation) are often sufficient. Another multiplier effect: four small guided bombs (e.g. 4 × 113 kg) can deal with four ‘soft’ targets in a single pass, with a moderate aerodynamic load compared to two heavy bombs.
The mission calculation uses the probability of hit (Pk) and the probability of neutralisation (Pn) according to the type of target. Damage models (lethal zone, fragmentation, penetration) and a context coefficient (weather, countermeasures, angle of attack) are applied. The result is a number of weapons per target: often 1, sometimes 2, rarely more. This results in a minimum payload of 2 to 4 air-to-ground weapons on interdiction missions. In air-to-air combat, long-range active radar-guided missiles have ranges of over 100 km. The initial shot forces the opponent to break off, and a second shot closes the door. Four well-managed ‘BVR’ missiles are enough to maintain a patrol, with 1-2 short-range missiles as backup.
Finally, sensor-effect synergy reduces waste. A ground-based laser designator, an ISR drone and a fighter can ‘share’ a target: the fighter does not need to carry half the arsenal if it knows that another vector can complete the effort. Real-time and data links replace overloaded bays.
Logistical support, costs and fleet availability
Each weapon has a cost and weighs on the chain. A GPS/INS-guided bomb costs tens of thousands of euros per unit. A modular imaging-guided bomb can exceed €200,000–300,000. A long-range air-to-air missile frequently exceeds €1,000,000 per unit. Multiply these costs by the number of aircraft in a raid, and you get millions of euros ‘suspended’ under the wings. However, any weapon that is not fired must be reconditioned, inspected and sometimes ‘recertified’. The arming/disarming cycles consume time and skilled labour, slow down the return of aircraft to service and increase the risk on the ground. Taking off with ‘what you need’ reduces this burden.
Fuel and tanker logistics impose other limitations. A typical fighter consumes several thousand kilograms of kerosene on a 2-3 hour sortie. Adding 1,000-2,000 kg of external weapons increases the fuel bill and sometimes requires a second refuelling rendezvous. However, tanker resources are scarce and must be planned in slots. Command staff therefore prefer to reserve fuel margins for the unexpected (diversions, waiting times, throttle adjustments) rather than for ammunition ‘just in case’. This is a form of operational insurance.
Maintaining the condition of the hardpoints and pylons is also important. Loading cycles generate structural fatigue. Fleets seek to preserve airframe life (expressed in hours and cycles) to avoid costly downtime. Fewer weapons means fewer penalising cycles and better long-term availability. Finally, ammunition supply is not instantaneous: some supply chains take months to deliver. Depleting a stockpile in a month of overuse means making yourself vulnerable for the future. Parsimony is not timidity, it is fleet management.
The human, legal and strategic factors
Modern rules of engagement require positive identification, proportionality and limitation of collateral effects. In practice, this translates into fewer, better documented shots, often validated by a legal officer. A pilot does not ‘empty’ his rails because a window opens: he waits for the legal green light, the right angle and sensor assurance. In this context, two weapons are often sufficient to deal with targets that meet the criteria. Travelling light also avoids the operational temptation of unnecessary ‘opportunity fire’.
The human factor weighs on the outcome. A heavy aircraft is more difficult to land in poor weather; it increases the landing distance, approach speed and the risk of running off the runway. In an emergency (breakdown, fire), a crew may have to jettison loads into the sea or uninhabited areas. Reducing the payload reduces the risk of unwanted jettisoning and emergency management. In densely populated areas, an emergency jettison creates a major political risk. Military leaders therefore prefer to limit the number of weapons on patrol, especially during QRA alerts or when maintaining a presence.
Strategically, the perceived abundance of weapons under the wings can send a signal of escalation. Many capitals choose visible but measured postures: minimally armed patrols, ready refuelling, pre-positioned additional ammunition. It is a question of controlling the tempo. Some theatres also impose saturated air corridors where deconfliction is critical: fewer weapons, less risk of fratricide, more flexibility in trajectories.
Finally, there is training. Forces prefer to reproduce in operations what they have validated in simulations and firing campaigns: limited but repeated combinations of weapons to reduce human error and speed up aircraft preparation. This standardisation favours batches of 2 to 4 specific munitions rather than exotic assortments. Ultimately, the aircraft takes off ‘light’ because it takes off ‘right’: discreet, manoeuvrable, connected and lethal on demand.
Live a unique fighter jet experience