When purchasing firefighting drones, how should I ask suppliers about the strength and stability of the landing gear?

In our years of analyzing crash data from fire scenes crash data ¹, we have seen too many expensive missions fail simply because the landing skids snapped upon touchdown. You cannot afford to lose a high-value payload to a structural weakness.

To ensure reliability, ask suppliers for the specific material composition, such as 7075 aluminum or carbon fiber, and request dynamic load test reports showing resistance to impacts of 2.5 times the drone's weight. Additionally, verify if the design includes shock-absorbing dampers and proven stability on uneven terrain.

Here is exactly how you can vet suppliers to ensure their landing gear meets the rigorous demands of firefighting operations firefighting operations ².

What specific materials should I look for to ensure the landing gear can handle heavy payloads?

When we source raw materials for our assembly line, we immediately reject standard plastics because they become brittle under the intense heat and stress of fire zones. Cheap materials are the primary cause of hardware failure in the field.

You must look for landing gear constructed from 7075 aviation-grade aluminum for maximum structural rigidity or high-modulus carbon fiber for an optimal strength-to-weight ratio. These materials resist deformation under heavy payloads of 100kg or more and maintain integrity even when exposed to the high ambient temperatures of a fire scene.

When you are communicating with a supplier, do not settle for generic terms like "metal" or "composite." The difference between success and failure often lies in the specific alloy or fiber grade used. In our engineering facility, we have found that standard consumer-grade materials simply warp when a drone carrying a heavy fire-extinguishing bomb lands on hot asphalt.

You need to ask for the specific grade of material. For aluminum, the industry standard for high-stress aviation parts is the 7000 series specifically 7075 ³, specifically 7075. This alloy contains zinc and is significantly stronger than the more common and cheaper 6061 aluminum often used in hobbyist drones. For carbon fiber, ask about the weave and thickness. A simple tube is not enough; it needs reinforced joints, often made from nylon composites or CNC-machined aluminum, to prevent cracking at connection points.

Material Properties Checklist

Firefighting drones operate in environments that would destroy standard equipment. The landing gear is the only separation between your expensive sensor payload and the ground. If the material softens due to heat or snaps due to cold brittleness, the camera gimbal is usually the first component to break.

Use the table below to compare the answers you receive from suppliers against industry best practices:

The Importance of Heat Deflection

Another critical aspect to discuss with your supplier is the Heat Deflection Temperature Heat Deflection Temperature ⁴ (HDT) of the landing gear. Firefighting drones often land on surfaces that have been heated by nearby flames. If the landing gear feet are made of low-quality rubber or plastic, they can melt or stick to the ground. We always recommend asking if the "feet" or skid pads are made from heat-resistant silicone or high-temp nylon to ensure the drone can take off again after a brief landing in a hot zone.

Which impact resistance tests should I request to verify the durability of the landing gear structure?

Our quality control team drops prototypes repeatedly from various heights because theoretical engineering data often fails to account for the chaotic reality of an emergency landing. A supplier who does not test physically is guessing, not engineering.

Request specific evidence of drop tests conducted from a height of at least one meter while the drone is fully loaded to its maximum takeoff weight. Also, ask for fatigue cycle reports that demonstrate the gear’s ability to withstand thousands of landing impacts and vibrations without developing stress fractures.

Requesting test data is the most effective way to filter out inexperienced suppliers. A reputable manufacturer will have these reports on hand. You want to see "real-world" durability, not just computer simulations (FEA models). While simulations are useful for design, physical destruction testing Fatigue Cycle Testing ⁵ confirms reliability.

The "Drop Test" Protocol

When we validate a new firefighting drone model, we perform a standard drop test. We load the drone to its Maximum Takeoff Weight (MTOW) Maximum Takeoff Weight ⁶, which includes the batteries, the thermal camera, and the payload (such as a fire extinguishing ball or liquid tank). We then drop it freely from a height of 1 to 3 meters onto a hard concrete surface.

You should ask the supplier:

1. "What was the drop height?" (Should be >1 meter).
2. "Was the drone at full weight?" (Empty tests are meaningless).
3. "Did the gear deform permanently?" (Elastic bending is fine; permanent bending is a failure).

Fatigue and Vibration Analysis

Impact is not the only enemy; vibration is a silent killer. Firefighting drones often have powerful motors that generate high-frequency vibrations high-frequency vibrations ⁷. Over time, this shakes screws loose and causes micro-cracks in metal and carbon fiber.

Ask the supplier if they perform Fatigue Cycle Testing. This involves a machine repeatedly pressing and releasing the landing gear thousands of times to simulate years of landings. If they cannot provide this data, ask if they use thread-locking fluids (like Loctite) and locking nuts on all landing gear hardware. In our experience, riveted joints are often more durable than screwed joints for fixed landing gear because they cannot vibrate loose.

Environmental Stress Screening

Finally, inquire about environmental testing. Firefighting drones face water from hoses, chemical retardants, and smoke particles.

• مقاومة التآكل: Ask if the aluminum parts are anodized. Anodizing creates a hard, protective layer that resists corrosion from water and chemicals.
• Joint Sealing: Ask if the joints where carbon fiber meets metal are sealed. Water ingress can freeze at high altitudes or cause internal corrosion over time.

How do I determine if the landing gear design offers sufficient shock absorption for rough terrain landings?

Uneven ground is the norm in wildfires, and we have learned from early field deployments that rigid landing gear often causes drones to tip over upon contact. Stability is just as important as strength.

Determine this by inspecting the gear for hydraulic dampers or heavy-duty spring systems integrated into the vertical struts. You should also verify that the landing skids have a wide footprint and a low center of gravity to prevent tipping when landing on slopes, gravel, or debris.

In the sterile environment of a factory floor, any drone can land smoothly. However, in a forest fire scenario or a post-disaster ruin, the ground is never flat. It is covered in rocks, tree branches, and hose lines. If the landing gear is completely rigid, the shock of hitting a rock with one leg transfers instantly to the drone's frame, confusing the flight controller's gyroscope (IMU). This can cause the drone to flip over—a catastrophic failure dynamic rollover ⁸ known as a "dynamic rollover."

Active vs. Passive Shock Absorption

You should scrutinize the mechanism used to absorb impact.

• Rigid Gear: The cheapest option. It relies entirely on the flex of the material (like the bending of a plastic leg). This is usually insufficient for heavy firefighting drones.
• Passive Spring Suspension: A metal spring inside the leg compresses upon impact. This is better, but without damping, it can cause the drone to "bounce" back up, leading to instability.
• Hydraulic/Pneumatic Damping: The gold standard. Similar to a car's shock absorber, it uses fluid or air to suppress the energy of the impact. It compresses but does not bounce back immediately.

Ask your supplier: "Does the landing gear feature rebound damping?" This feature prevents the dangerous "pogo stick" effect during a hard landing.

Stability Geometry: Skids vs. Legs

For firefighting applications, the geometry of the gear is crucial.

• Four Independent Legs: Good for uneven terrain if each leg has suspension, but higher risk of tipping if one leg sinks into soft mud or ash.
• Skids (Helicopter Style): Two long horizontal bars. These are generally superior for firefighting because they distribute the weight over a larger surface area. This prevents the drone from sinking into soft ground, mud, or deep ash layers.

Analyzing Ground Clearance

Don't forget to ask about what is happening between the landing gear. Firefighting drones often carry bulky payloads under the belly bulky payloads ⁹.

• Height Clearance: Ensure there is at least 15-20cm of clearance بعد the suspension is fully compressed. You do not want your expensive thermal camera smashing into a rock because the suspension was too soft.
• Width Clearance: The landing gear must be wider than the payload to protect it if the drone lands at an angle.

What questions should I ask about the maximum load-bearing capacity during emergency landings?

Emergency descents exert massive G-forces that far exceed the static weight of the drone, and our flight logs show that these force spikes are where structural failures usually occur. Buying based on static weight alone is dangerous.

Ask for the dynamic load rating specifically, confirming the gear can withstand 2.5 to 3 times the Maximum Takeoff Weight (MTOW) to account for rapid deceleration. Ensure this calculation includes the inertia of attached payloads, such as shifting liquid tanks or drop mechanisms, which add stress during impact.

Procurement managers often make the mistake of asking, "Can this gear support a 50kg drone?" The supplier says "Yes" because it can hold 50kg while sitting still (static load). However, when a drone descends quickly in an emergency—perhaps due to a low battery or incoming wind gusts—it might hit the ground at 3 meters per second. The force of that impact can momentarily multiply the weight of the drone.

The Math of Safety Margins

You need to act like an engineer when you ask these questions Safety Factor ¹⁰. You are looking for the Safety Factor.

• Static Load: The weight of the drone at rest (1G).
• Dynamic Load: The force exerted during impact (often 2G to 3G).

If your firefighting drone weighs 20kg fully loaded, the landing gear must be tested to withstand at least 50kg to 60kg of force without snapping. If the supplier has only tested it to 20kg, the gear will collapse during a hard landing.

Payload Inertia and Stress Shifts

Firefighting payloads present unique challenges. Liquids (like water or retardant) slosh around, and drop mechanisms (like fire balls) change the weight distribution instantly.

• Sloshing Loads: If you are carrying liquid, the momentum of the fluid continues downward even after the gear touches the ground. This "secondary impact" can break landing gear that was not designed for it.
• Lateral Stress: High winds in fire zones mean drones rarely land perfectly vertically. They often come in sideways. Ask the supplier about Lateral Load Ratings. Can the gear survive a sideways drag if the drone lands while drifting?

Dynamic Load Reference Table

Use this table to evaluate if the supplier's stated specs are safe for your specific operations.

By insisting on these dynamic ratings, you filter out suppliers who modify hobbyist frames for industrial use. You ensure that the equipment you buy is purpose-built for the harsh reality of firefighting.

الخاتمة

The landing gear is the foundation of your aerial operations; if it fails, the mission ends. By demanding specific material grades like 7075 aluminum, requiring proof of dynamic load testing up to 3x MTOW, and verifying shock-absorption capabilities, you ensure your fleet returns safely every time. Ask the hard questions now so your team doesn't face hard failures later.

الحواشي

1. Official source for aviation crash data and investigation statistics. ︎

2. US Forest Service guidance on Unmanned Aircraft Systems in firefighting. ︎

3. SAE International standard for 7075 aluminum alloy used in aerospace. ︎

4. Educational explanation of HDT in material science. ︎

5. ISO standard for fatigue testing of metallic materials. ︎

6. Official FAA definition and explanation of Maximum Takeoff Weight in aviation. ︎

7. Technical explanation of vibration measurement and its effects on mechanical structures. ︎

8. Research publication explaining the physics of dynamic rollover in aircraft. ︎

9. Technical specifications for a heavy-lift drone capable of carrying bulky payloads. ︎

10. Overview of safety factor principles in structural engineering. ︎