What is the minimum required capacity of a fuel tank sump for a rotorcraft?

The sump must have a capacity of not less than the greater of 0.10% of the tank capacity or 0.24 litres (0.05 Imperial gallon/one sixteenth US gallon).

How is the minimum sump capacity calculated for a fuel tank?

The minimum sump capacity is the greater of 0.10% of the tank capacity or 0.24 litres (0.05 Imperial gallon/one sixteenth US gallon).

Is there a requirement for the sump drain to permit complete drainage in flight?

No, the requirement states that the sump drain must allow complete drainage of the sump on the ground.

Does the regulation specify a minimum sump capacity for a fuel tank with a capacity of 100 litres?

Yes, for a 100-litre tank, the sump capacity must be at least 0.24 litres, because 0.10% of 100 litres is 0.10 litres, which is less than 0.24 litres.

CS 29.971 Fuel tank sump

Q: In what rotorcraft attitudes must the fuel tank sump capacity be effective?

The capacity must be effective with the rotorcraft in any normal attitude.

Q: Where must the fuel tank sump be located relative to the tank outlet opening?

The sump must be located so that the sump contents cannot escape through the tank outlet opening.

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CS 29.971 Fuel tank sump

ED Decision 2003/16/RM

(a) Each fuel tank must have a sump with a capacity of not less than the greater of:

(1) 0.10% of the tank capacity; or

(2) 0.24 litres (0.05 Imperial gallon/one sixteenth US gallon).

(b) The capacity prescribed in sub-paragraph (a) must be effective with the rotorcraft in any normal attitude, and must be located so that the sump contents cannot escape through the tank outlet opening.

(c) Each fuel tank must allow drainage of hazardous quantities of water from each part of the tank to the sump with the rotorcraft in any ground attitude to be expected in service.

(d) Each fuel tank sump must have a drain that allows complete drainage of the sump on the ground.

Details

Source-Title: CS 29.971 Fuel tank sump View latest amendments

Erulesid: ERULES-1963177438-5633 Compare versions

Domain: Initial airworthiness

Amendedby: Initial issue

Applicabilitydate: 14 November, 2003

Entryintoforcedate: 14 November, 2003

Regulatorysource: ED Decision 2003/16/RM Navigate

Regulatorysubject: CS-29

Typeofcontent: CS (Certification specification)

Origin: EASA

Category: EAR