Manual Pump (Yellow Hand Pump)

The Yellow hydraulic system is the only one of the three with a manual (hand-operated) pump. It exists for one specific operational case: opening the cargo doors when no electrical power is available on the aircraft. Beyond that case, the hand pump has no flight-deck role and no in-flight use.

This article covers the pump's location, the design of the removable handle (stored separately from the pump body for safety reasons), the engineering parameters of the axial-piston pump itself, and the architectural reasoning behind why this single mechanical-effort path exists on Yellow and nowhere else.

1. Why Yellow has a hand pump

The hand pump supports a use case that is unique to Yellow:

• Cargo doors are powered by the Yellow hydraulic system. On the ground, when AC electrical power is available, the Yellow electric pump pressurises the system and drives the cargo doors.
• If AC power is unavailable (no ground power, no APU, batteries depleted) — for example, on a remote-station turnaround or an aircraft in maintenance hibernation — the electric pump cannot run.
• Cargo loading must still be possible. The hand pump provides the alternate path: human effort, applied through a removable handle, drives the axial-piston pump, which pressurises Yellow enough to actuate the cargo door mechanisms.

Green and Blue have no equivalent operational case. Their consumers do not include any function that must be available with all electrical sources lost on the ground. No hand pump on Green; no hand pump on Blue.

2. Where it is, and where the handle is

┌──────────────────────────────────┐         ┌──────────────────────────────────┐
│   Yellow ground service panel    │         │   Green ground service panel     │
│                                  │         │                                  │
│   ┌─────────────────────────┐    │         │   ┌─────────────────────────┐    │
│   │  Hand pump body 7155JE  │    │         │   │  Removable handle       │    │
│   │   (axial-piston)        │    │         │   │   • 525 mm long         │    │
│   │   - Splined pivot       │    │         │   │   • Splits into 2 pcs   │    │
│   │   - Built-in check      │    │         │   │   • Splined fitting     │    │
│   │     valve and relief    │    │         │   └─────────────────────────┘    │
│   └─────────────────────────┘    │         │                                  │
│           ▲                      │         │  (handle is also used for other  │
│           │                      │         │   manual pumps on this panel,    │
│           │ Handle inserted here │         │   e.g., manual filling pumps)    │
│           │ when in use          │         │                                  │
│           │                      │         └──────────────────────────────────┘
└──────────────────────────────────┘

The pump body is on the Yellow ground service panel. The removable handle is stored on the Green ground service panel. The deliberate separation has two purposes:

• Prevents inadvertent operation. A handle stored at the pump would invite use during unrelated work in the same area. Separating handle and pump body requires a deliberate two-step retrieval, eliminating accidental pressurisation.
• Centralises handle storage. The Green ground service panel hosts other manual-pump interfaces (manual fuelling pumps and similar items). A single panel for all hand tools simplifies maintenance inventory and pre-flight checking — if any handle is missing, it is missing from the same location.

The same handle can connect to different splined fittings on different manual pumps. It is a shared tool, not a pump-specific one.

3. The pump itself

Designator: 7155JE. Type: axial-piston. The same architecture as the piston sections of the EDPs and electric pumps, but in a manually-driven format with a single piston cylinder driven via crank from the handle pivot.

Performance:

The 196 bar nominal is below the system normal of 206 bar (3000 psi) used by the EDPs and electric pumps. This is intentional — the hand pump's purpose is to pressurise the cargo-door circuit to an actionable pressure, not to bring the full system to flight-normal. The 196 bar is enough to operate cargo doors at appropriate speed and force.

The 234 bar relief setting protects against over-pressure during vigorous handle operation. The reseat at 220 bar provides hysteresis so the relief does not flicker open and closed at the boundary.

The > 10 cm³ per cycle displacement gives a sense of scale. Opening a cargo door requires moving a non-trivial fluid volume through the door actuator; the operator may need many handle cycles to complete the operation. The pump is sized to make the work physically feasible without being unnecessarily efficient at the expense of compactness.

4. Handle geometry — why 525 mm and why 58°

The handle is 525 mm long (about 50 cm) and articulates through a maximum of 58°. Both numbers are ergonomic.

• 525 mm provides mechanical leverage. The operator's effort at the end of the handle is multiplied through the lever arm to produce the torque required to drive the pump piston against the system pressure.
• 58° maximum angle is the operational range — beyond this, the geometry of the linkage either binds or loses efficiency. The handle is designed to be cycled within this arc, not beyond it.
• Two-piece construction allows the handle to fit into a tool storage area when separated. Assembly is straightforward and the assembled handle is rigid enough to transmit the operator's effort without flexing.

The cycle is straightforward: handle in, full pressure stroke; handle out, return stroke (with the check valve preserving pressure already produced); repeat. An operator working steadily can complete tens of cycles per minute, depending on system pressure as it builds.

5. The flow path

Hand pump 7155JE
       │
       ▼
[Internal check valve]      ← prevents backflow from system into pump
       │
       ▼
[Internal pressure-relief]  ← cracks at 234 bar, reseats at 220 bar
       │
       ▼
Yellow HP system manifold 5101JM3 (≈ 154–206 bar working range)
       │
       │
       ▼
Yellow main system pressure path
       │
       ▼
Cargo door actuator (primary use case)
       │
       (other Yellow consumers receive
        any incidental pressure produced,
        but the system is sized for the
        cargo door function specifically)

The pump output feeds the same Yellow manifold that normally sees electric-pump or EDP output. The cargo-door actuator is the principal consumer; in practice the flow rate is too low to drive other Yellow consumers meaningfully.

6. Operational protocols

The hand pump's use is documented in maintenance procedures, not in flight-crew operating procedures. The crew should be aware of three points:

• No in-flight use. The hand pump is a ground-only tool. In flight, the Yellow electric pump runs automatically on its triggers (Engine 2 failure with flaps deployed; cargo-door operation on the ground is not an in-flight condition). The hand pump has no flight-deck pushbutton, no ECAM indication, and no role in any abnormal procedure.
• Used only with AC unavailable. When AC is available, the electric pump performs the cargo-door operation. The hand pump is engaged only when electric-pump operation is not possible — typically a deliberate cold-and-dark configuration during scheduled maintenance, or a remote-station situation with no GPU and depleted batteries.
• Yellow leak-measurement valve closes automatically during cargo-door operation. This is the same interlock that applies to electric-pump cargo-door operation — the architecture isolates the Yellow primary flight controls during any cargo-door movement, preventing inadvertent surface motion. The interlock applies to both hand-pump and electric-pump cargo-door work.

7. Why no hand pump on Green or Blue

The reasoning is symmetric to why Yellow has one:

The architectural rule reflects what is genuinely needed, not what is theoretically possible. Adding hand pumps to Green and Blue would add weight, complexity, and maintenance burden for no operational case.

This is also why no flight-control function is connected to the hand pump. The hand pump cannot reasonably pressurise the system fast enough to drive flight-control surfaces; it is sized for the slow, high-displacement cargo-door demand. Anyone expecting "hand-pump backup for flight controls" is misreading the architecture — that role is filled by the RAT on Green, not by a hand pump anywhere.

8. What the pilot sees

The hand pump does not appear on:

• The ECAM HYD page
• Any ECAM caution or memo
• The overhead 29 panel
• Any abnormal procedure

The hand pump appears on:

• The Yellow ground service panel (the body)
• The Green ground service panel (the handle stored separately)
• Maintenance procedures and Aircraft Maintenance Manual cargo-door operation sections

For the crew, the pilot's relationship with the hand pump is awareness only: knowing that it exists, that it is on Yellow, that it serves cargo doors when AC is unavailable, and that it is a maintenance-side tool with no operational handling in the cockpit.

9. Hand pump vs Yellow electric pump — comparison

The hand pump is the emergency backup for the Yellow electric pump (1JJ). Their roles, parameters, and use cases differ substantially:

Flow ratio: assuming the hand pump produces 10 cm³ per cycle at a ~1-cycle-per-second pace, the hand pump delivers approximately 10 cm³/s — versus the electric pump's **533 cm³/s** (32 L/min ≈ 533 cm³/s). The hand pump delivers approximately 2% of the electric pump's continuous flow.

The 2% figure makes clear that the hand pump is a back-of-the-line emergency tool, not a performance substitute. It exists to allow cargo doors to be operated when the electric pump cannot run — not to provide hydraulic capacity comparable to the electric pump.

10. The three-layer safety pressure design

The hand pump's pressure specifications form a three-layer safety envelope:

The 14 bar hysteresis between relief cracking (234) and reseat (220) prevents oscillation around the relief threshold during vigorous handle operation.

Operationally, the hand pump's target is 196 bar, which is just below the system normal of 206 bar (3000 psi) typical of EDP and electric pump output. The hand pump can pressurise the Yellow system to approximately normal operating pressure — adequate for cargo-door actuation, though delivered intermittently in pulses rather than as continuous flow.

11. The "in flight in certain configurations" boundary

AMM 29-23 includes a brief mention that the Yellow hand pump "can also be used in flight in certain configurations" — but does not specify which configurations. The detailed AMM chapters that might expand on this are not part of standard operator documentation.

Honest boundary note: the operator's documentation specifies the hand pump for ground use, with cargo-door operation when no electrical power is available. The "in flight" mention is not unpacked at pilot-operating-procedure level. Two plausible scenarios (interpretive, not directly documented):

• Maintenance post-flight transitional procedures — where the aircraft is being prepared for an unusual configuration before the next flight.
• Engineering test or specific abnormal scenarios — where a procedure might invoke the hand pump for a non-standard task.

For day-to-day pilot understanding, the hand pump is a ground-only tool, used by maintenance personnel for cargo-door operation when the electric pump cannot run. Attempts to use it in flight are not covered by routine procedures.

12. Maintenance tasks — deactivation only on leak

The hand pump has a small number of specific maintenance tasks, notable for a peculiar condition:

The "only if it leaks" condition is unusual. Most hydraulic components are deactivated on any fault. The architecture's reasoning, inferred from the limited triggering condition: the hand pump is rarely used (emergency only), so most fault modes do not require immediate deactivation. The pump can sit faulty in the assembly indefinitely without operational consequence — unless it is leaking, in which case the leak path threatens the Yellow system fluid integrity even without active pump operation.

For the pilot, the implication: a hand pump deferred for a non-leak fault may stay deferred until the next maintenance window. A leaking hand pump must be deactivated immediately to protect the Yellow system fluid.

13. Pilot's awareness — four practical points

Beyond the maintenance interface, the pilot's hand-pump-related awareness fits into four points:

1. In flight with dual engine failure and Yellow loss → do NOT think of the hand pump as a Yellow recovery option. The hand pump cannot be used in flight by the crew. The system architecture does not route the hand pump's pressure to consumers that would be needed in flight (see Hydraulic Generation Overview on the Yellow architecture).
2. At a remote station without GPU, cargo doors can still be opened. Maintenance retrieves the handle from the green panel, attaches it to the hand pump body at the yellow panel, and cycles it. This is a normal operational procedure, not an emergency.
3. Hand pump handle location is at the Green ground service panel. If a maintenance technician asks "where is the hand pump handle?" the answer is the Green panel — not the Yellow panel where the pump body sits.
4. Operating time estimate: opening a cargo door takes approximately 100 hand-pump cycles (based on ~10 cm³ per cycle and ~1 L of actuator displacement). At a pace of one cycle per second, that is approximately 100 seconds (1–2 minutes) of continuous hand-cranking. Actual time depends on the door's full hydraulic-volume requirements and the pump's effective per-cycle output under the load.

14. Cross-references

15. Documentation boundary

What the maintenance documentation specifies:

• The full physical design (axial-piston pump body, handle dimensions, splined pivot, check valve, relief valve thresholds, displacement per cycle).
• The location of the body and handle storage.
• The deactivation/re-activation tasks for the leak-condition exception.

What is not at crew level:

• Detailed disassembly / overhaul procedures (maintenance-side, AMM 29-23 detailed chapter).
• The relationship between hand pump cycles and specific door types (typical figures vary by aircraft configuration).
• Performance verification methodology for the hand pump as a system.

For the pilot, the documented level is more than sufficient — the hand pump is a maintenance-side tool with no in-flight role, and the awareness gained at the chapter level supports the rare occasion when ground service interaction requires the pilot to understand what is happening at the panels.

Self-test

[!note]- Q1. The aircraft is at a remote station with no ground power and depleted batteries. Ground personnel need to open the forward cargo door for loading. What hydraulic path is used?

The Yellow hand pump (7155JE). Ground personnel retrieve the handle from the Green ground service panel, attach it to the splined pivot on the hand pump body at the Yellow ground service panel, and cycle the handle through its 58° range to build Yellow pressure (nominally 196 bar). The cargo door actuator opens at the resulting pressure. The Yellow leak-measurement valve closes automatically during the operation to prevent any flight-control surface movement. The whole operation requires no electrical power on the aircraft.

[!note]- Q2. Why is the hand pump's handle stored at the Green ground service panel rather than next to the pump body at the Yellow panel?

Two reasons: prevention of inadvertent operation and centralised handle storage. A handle adjacent to the pump invites accidental use during unrelated maintenance work. Storing it at a different panel requires a deliberate two-step retrieval. The Green panel also hosts other manual pumps in the maintenance architecture (manual fuelling pumps, for example), and the handle is shared across them, so the Green panel is the natural single location for hand tools of this type. The design reflects an operational philosophy about how tools should be stored, not a structural constraint.

[!note]- Q3. The hand pump nominal pressure is 196 bar — below the system normal of 206 bar (3000 psi). Why not match the normal?

Because the hand pump's purpose is cargo-door operation, not full-system pressurisation. The cargo door actuators operate at the lower pressure adequately. Designing the hand pump for 206 bar would require either a much larger displacement per cycle (more piston volume) or a much higher operator effort (longer handle, higher torque). Either choice would make the hand pump physically harder to use without operational benefit, since the cargo doors do not require 206 bar to function. The 196 bar design is the engineering compromise between human effort and door-operation requirement.

[!note]- Q4. Is the hand pump usable in flight if all electrical sources fail?

No. The hand pump is a ground-only tool with no in-flight role. There is no cockpit access to it, no abnormal procedure references it, and Yellow's in-flight automatic backup is the electric pump (which requires AC supply). If all electrical sources fail in flight, Yellow's in-flight options are exhausted — Yellow goes unpressurised. The hand pump is not a flight-control reserve; it does not contribute to in-flight system recovery.

[!note]- Q5. The hand pump's pressure-relief valve cracks at 234 bar and reseats at 220 bar. Why is the reseat lower than the crack?

Standard hysteresis design. If crack and reseat were at the same pressure, the relief valve would oscillate open and closed at the boundary, producing pressure flutter and accelerated wear on the valve seat. The hysteresis ensures that once the relief opens, the pressure must drop a noticeable amount before the valve closes again, giving the system a clear "relief is active" or "relief is closed" state. The 14 bar window (234 − 220) is wide enough to suppress oscillation while narrow enough that the relief intervenes promptly when pressure overshoots.

References

Per FCOM DSC-29-10-20 (hand pump general role); AMM 29-23 (Yellow Auxiliary Hydraulic Power — hand pump 7155JE specifications, performance, handle dimensions, storage location); AMM 29-23 cargo-door interlock with the Yellow leak-measurement valve.

Independent study material, not an Airbus publication. Refer to current operator FCOM, FCTM, AMM, and QRH for operational use.