Maintenance Items


Propeller blades should be removed when making a change to the configuration of ALTA Pro to prevent propeller strikes in the event of unintentional motor starts and should be replaced if they become damaged. Generally, a nick on the leading edge that is large enough to catch a fingernail indicates that the propeller should be replaced. If the blade composite structure becomes delaminated, the propeller should be replaced.

Freefly makes folding propeller assemblies available that include the blades and propeller hub fully assembled and factory balanced. They are available in clockwise and counterclockwise orientations.

Only use propellers supplied by Freefly on ALTA Pro. Use of third-party propellers can cause motor instability, overheating, and failure.

The folding propellers are installed on the motors with four M3×8 socket head bolts.

Always use a thread locking compound on the bolt threads that attach the propeller hub to the motor.

Odd numbered booms (1, 3, 5 and 7) use clockwise rotating propellers when looking from the top down, and even numbered booms (2, 4, 6 and 8) use counterclockwise rotating propellers.

Always check to ensure the correct propeller rotation direction and correct propeller prior to flight. Propellers that spin in the incorrect direction will cause ALTA Pro to be uncontrollable.

Replacing Propeller Bumpers

Under normal use, propeller bumpers (see exploded view figure on the next page) may split and fall out of the folding propeller assembly. Six spare bumpers are provided with the ALTA Pro. To replace the bumper, disassembly of the folding propeller is required.

Start by removing the M3 x 19 bolt and nylon nut. Pull off the upper prop adapter. The two bumpers are held in place by cylindrical features in the lower prop adapter. Replace the worn or split bumper.

To reassemble, follow the parts layout in the figure above. Note that there are two different types of washers, one made of nylon and the other made of PTFE. The nylon washer is smaller in width and thicker, and is installed between the nut or bolt head and the two prop adapters. The PTFE washer is wider and thinner and is installed between the prop blades and prop adapters.

Propeller blades are balanced and paired individually. Do not mix and match individual propeller blades when reassembling. Unbalanced propellers can affect flight performance.

Every 15 Flights

ALTA Pro is designed to be as low-maintenance as possible.

It is recommended to check ALTA 8’s fasteners regularly. This check should occur roughly after every 15 flights, depending upon the level of vibration ALTA 8 experiences in flight or during handling. To check ALTA 8’s fasteners, apply a tightening torque to each fastener on the chassis using the supplied hex drivers. The fasteners should not slip.

If a fastener does slip, tighten it using the methods described in the Fastener Installation section. Do not apply additional thread locking compound unless the fastener has repeatedly come loose.

Every 15 Flight Hours

The following items should be checked after every 15 hours of flight.

Fastener Tightness

Check the tightness of the following fasteners:

  • Motor mount bolts

  • Prop hub bolts

  • Prop bolts

  • Top and bottom chassis bolts

  • Closeout panel bolts

  • FPV camera mounting plate bolts

  • Accessory mounting plate bolts

  • GPS/Compass mounting bolts


Inspect the following items. Replace if worn.

  • Propeller blades

  • Prop bumpers

Hinge Latch Tightness

Check hinge latching tightness by closing the hinge. There should be a firm closing force and click. Adjust the tension by using a 1.5mm hex wrench on the set screw located under the hinge latch.

Replacement Of Parts

Spare or replacement parts are available for sale separately at Please refer to the store for a current listing of all available spare parts.

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