Regulation Details Flashcards
What is 14 CFR 25.301 Loads?
Strength requirements in terms of limit & ultimate loads (where ult = limit * factor). If loads cause deflections w/ significant load redistribution, must take into account. These are applied loads.
What is 14 CFR 25.303 Factor of Safety?
1.5 factor must be applied to limit loads. Intended to cover inadvertent in-service loads, as-built part thicknesses, and structural deflections above limit loads.
What is 14 CRF 25.305 Strength and Deformation?
At limit load, no detrimental permanent deformation allowed. Structure must support ultimate loading for 3 seconds (except dynamic loads) – must account for deformation, vibration and buffeting.
What is 25.307 Proof of Structure?
Must test critical load cases; may use analysis if experience says the method is reliable. Appropriate material correction factors must be added.
What is 21.17 Designation of Applicable Regulations?
Aircraft must meet regulations effective at date of application (or approved special conditions). Application valid for 5 years for transport category A/C. Can request extension.
What is 21.31 Type Design?
Engineering definition of product. Includes all drawings and specs necessary to define configuration. Includes info on dimensions, materials & processes needed to define structural strength., Includes airworthiness limitations as well as other data to determine airworthiness such as noise characteristics, fuel venting and exhaust emissions. Chapter 5 of ALS
What is 25.393 Loads Parallel to Hinge Line?
Control surfaces & support hinge brackets must be designed for inertia loads acting parallel to hinge line.
What is 25.562 Emergency Landing Loads?
Specifies seat requirements, G loading requirements. Purpose: protect occupants, prevent fuel tank/line or other explosive hazard, keep emergency exits viable.
What is 25.571 Damage Tolerance and Fatigue?
Must show that catastrophic failure due to fatigue, corrosion, manufacturing defects or accidental damage will be avoided during operational life of A/C. Must account for typical loading spectrum, and environmental conditions. LOV established via test to demonstrate that widespread fatigue damage will not occur.
What are the 25.571 Residual Strength Load cases?
o Limit roll, yaw & gust conditions
o Limit symmetric & asymmetric maneuver
o For pressurized cabins, (normal operating delta P + external aero pressure + above flight conditions), or (max normal operating delta P * 1.15 standalone) whichever is worse
o For landing gear, limit ground loading conditions
What are the 25.571 discrete source damage sources (with get-home loads)
o 4lb bird strike
o Uncontained fan blade impact
o Uncontained engine failure
o Uncontained high energy rotating machine failure
What is 25.601 General (Design and Construction)?
No known bad detail, based on experience or test.
What is 25.603 Materials?
The suitability and durability of materials based on experience or test. Must have approved specifications. Must take into account environmental considerations.
What is 25.605 Fabrication Methods?
Use approved specifications. New methods must be substantiated by test.
What is 25.607 Fasteners?
Critical removable fasteners (loss of would result in loss of A/C) must have 2 locking mechanisms.
Must take into account environmental considerations.
Any nut in a rotating joint must have 1 non-friction locking mechanism.
