In aircraft fuelling, precision is not just a standard — it is a responsibility. Safe Nozzle Removal and What Must Be Verified First. Every aircraft that departs relies on the assurance that its fuel system was handled correctly, safely, and in accordance with global aviation standards and manufacturer specifications. A strong safety culture, rigorous verification practices, and comprehensive risk assessment form the foundation of safe operations in this high-risk environment.

One incorrect action can disrupt operations, create a spill, damage aircraft equipment, or trigger a fire hazard. Among all steps, nozzle removal is repeatedly identified in industry incident data as one of the highest-risk moments in the fuelling sequence. A premature disconnection — even by a few seconds — can result in spray, residual pressure release, environmental contamination, or harm to personnel.

This article summarizes the essential checks required before disconnecting the nozzle, supported by procedures and principles reinforced in aviation fuel-handling standards worldwide, such as JIG, NFPA 407, and EI guidelines. These safety protocols are crucial for ensuring regulatory compliance and maintaining a safe working environment.

Equipment Inspection Protocols

Nozzle Damage Assessment

A detailed nozzle inspection before each fuelling operation is a requirement in JIG, NFPA 407, and all major OEM manuals. This visual inspection is critical for assessing equipment performance. Even minor deterioration — such as worn collars, hardened seals, fatigued nozzle surfaces, or contaminated ports — can directly affect the nozzle’s sealing and automatic shutoff performance.

Any defect, even millimetres of wear, affects:

• sealing integrity
• accuracy of automatic shutoff
• bonding continuity
• stable fuel flow regulation
• safe and controlled disconnection

Across all safety regulations, the message is identical: A damaged nozzle must be removed from service immediately.

Hose Condition Verification

Hoses deteriorate gradually through pressure cycling, UV exposure, bending, twisting, abrasion, and handling stresses — all documented in EI, JIG, NFPA 407, and into-plane O&M manuals. Even small structural changes can become critical under pressure, compromising the hose’s structural integrity.

Defects that compromise hose safety include:

• Cracks or soft spots that weaken pressure integrity.
• Blisters or bubbles indicating internal breakdown and potential leaks.
• Cuts or abrasions that compromise reinforcement layers.
• Damaged couplings that affect sealing, bonding, and threading engagement.

A short, tactile, and visual hose inspection prevents failures that often occur during depressurisation or nozzle removal. Regular hydrostatic testing is also crucial for verifying hose integrity.

• Monthly Aviation Fueling Hose Testing Requirements

Latching Mechanism Verification

Underwing nozzles are engineered to mate precisely with MS24484-compliant aircraft adaptors. This system depends entirely on a secure, undamaged locking mechanism, which is an essential part of the fuel handling safety devices.

Wear in the locking lugs, collar teeth, or collar surfaces can lead to:

• insecure coupling
• seepage upon pressure increase
• misalignment affecting shutoff sensitivity
• difficulty during nozzle removal

Aircraft adaptors must also be free of damage, missing lugs, or contamination. Standards require fuelling operations to stop if adaptor defects are found, emphasizing the importance of mechanical component integrity.

System and Pressure Checks

System and Pressure Checks are highlighted across all global standards as mandatory before disconnection. Safe Nozzle Removal and What Must Be Verified First checks involve the use of calibrated gauges and monitoring systems to ensure safety. Residual pressure in hoses, deadman circuits, regulators, or hydrant lines can cause:

• sudden fuel spray
• hose recoil
• poppet snapping during removal
• strain on the aircraft adaptor
• operator injury

The system must be allowed to stabilise completely. Pressure relief valves play a crucial role in maintaining safe pressure levels. Pressure control systems and deadman control valves testing help identify potential issues before they escalate.

• The Critical Role of Pressure Gauges in Aviation Fuelling

What Really Happens Inside the Nozzle

Underwing nozzles rely on an HECV system with a spring-loaded piston assembly. When fuel increases, the Hose End Control Valve adjusts the flow restriction in response to increasing downstream pressure. The Hose End Control Valve modulates fuel flow to maintain pressure at or below a preset maximum, and collapses the poppet, closing it.” This system is a key component of overfill prevention measures and prevents overpressurization of the aircraft’s fuel system.

However, the “closing” means only one thing: the poppet has shut. It does NOT indicate that the system is depressurised.

According to the manufacturer’s manual and other operator guides, internal pressure remains until:

• the hose-end regulator relaxes
• system backpressure dissipates
• gauges return to a steady baseline
• hoses physically soften

Disconnecting too early releases this trapped pressure violently, highlighting the importance of proper testing procedures and adherence to safety protocols.

This is why every fuelling standard instructs operators to wait, observe, and confirm before removal.

What Operators Must Confirm

To ensure the system has fully equalised, the operator must verify:

• Pressure gauges show zero or safe residual pressure.
• The hose visibly relaxes, indicating no trapped pressure.
• Nozzle and regulator show no vibration, noise, or movement.
• The deadman system disengages smoothly without rebound.

These observations take only seconds — and prevent the majority of pressure-related incidents recorded in the industry. Proper operator training is essential to ensure these checks are performed consistently and correctly.

Putting It Into Practice: The Safe Post-Fuelling Check

A recommended “after fuelling” procedure, aligned with JIG, NFPA 407, and EI, includes the following safety inspection checklist:

1. Stop fuel flow

• Release deadman control and close delivery valves.
• Confirm fuel flow has ceased (no discharge, no flow indicator movement).

2. Verify the hose pressure has released

• Check pressure gauges showing zero or safe residual.
• Listen for hissing, feel for vibration, confirm hose relaxation.
• Feel the hose coupling for tension; it should be relaxed

3. Disconnect the nozzle

• Follow aircraft adaptor disconnection procedure.
• Replace dust caps on the aircraft adaptor.
• Secure and close the fuelling panel.

4. Remove bonding cable (last step)

• Only remove bonding after the nozzle and hose are fully disconnected and stowed, ensuring equipotential throughout.

5. Conduct a 360° walk-around

• Confirm equipment clearance, no leaks, no hoses left on the wing.
• Verify a safe departure path.
• Check for signs requiring spill response or secondary containment measures.

6. Complete documentation

• Log uplift, density (if required), and observations in maintenance logs.
• Record irregularities immediately.
• Ensure all compliance documentation is complete, including inspection records.

These steps must be reinforced through training and regularly audited to ensure operational consistency and environmental compliance.

• Ensuring Safe Aircraft Refuelling: A Guide to Prevent Fuel Incidents
• Bonding Cables in Aviation Fuelling

Conclusion: Safety Is Secured in the Final Seconds

Safe Nozzle Removal and What Must Be Verified First may take only a moment, but it reflects the sum of every safety barrier embedded throughout the fuelling process. When operators verify equipment condition, inspect hoses, confirm latch security, and ensure full pressure release, they eliminate the root causes behind most fuelling incidents. These controls are not procedural extras — they are essential protective systems that safeguard aircraft, personnel, fuel quality, and operational continuity.

Aviation fuelling ends safely when discipline is applied precisely at the moment where many accidents begin. By embedding these verifications into every operation, fuelling teams strengthen their safety culture, comply with global standards, and demonstrate the professional excellence that keeps the industry moving.

To further enhance safety, regular safety briefings should be conducted, and emergency procedures should be reviewed and practiced. The use of appropriate personal protective equipment (PPE) must also be emphasized as a critical component of fuel handling safety.

By prioritizing these safety measures and maintaining rigorous inspection procedures, the aviation industry can continue to uphold its commitment to safety and efficiency in fuel handling operations.