Source: https://www.federalregister.gov/documents/2019/05/08/2019-09398/special-conditions-embraer-model-emb-550-airplanes-flight-envelope-protection-normal-load-factor-g
Timestamp: 2019-05-22 08:41:15
Document Index: 663070494

Matched Legal Cases: ['art 25', '§\u200921', 'art 34', 'art 36', '§\u200925', '§\u200925', '§\u200925', '§\u200925']

Federal Register :: Special Conditions: Embraer Model EMB-550 Airplanes; Flight Envelope Protection: Normal Load Factor (g) Limiting
Special Conditions: Embraer Model EMB-550 Airplanes; Flight Envelope Protection: Normal Load Factor (g) Limiting
A Rule by the Federal Aviation Administration on 05/08/2019
84 FR 20021
Special Conditions No. 25-520A-SC
https://www.federalregister.gov/d/2019-09398 https://www.federalregister.gov/d/2019-09398
These amended special conditions are issued for Embraer Model EMB-550 airplanes. This airplane will have novel or unusual design features when compared to the state of technology envisioned in the airworthiness standards for transport category airplanes. This design feature is associated with an electronic flight control system that prevents the pilot from inadvertently or intentionally exceeding the positive or negative airplane limit load factor. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. These special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards.
On August 9, 2016, Embraer applied for a change to Type Certificate No. TC00062IB to include additional flexibility to the normal load factor limit on the Embraer Model EMB-550 airplane, by requesting an amendment to the existing Embraer Model EMB-550 Special Conditions No. 25-520-SC as a result of harmonization efforts in the Flight Test Harmonization Working Group (FTHWG). The Embraer Model EMB-550 airplane, currently approved under Type Certificate No. TC00062IB, is a twin-engine, transport category airplane with a maximum takeoff weight of 42,857 pounds. The Embraer Model EMB-550 has a maximum seating capacity of 12 passengers.
Under the provisions of title 14, Code of Federal Regulations (14 CFR) 21.101, Embraer must show that the Embraer Model EMB-550 airplane, as changed, continues to meet the applicable provisions of the regulations listed in Type Certificate No. TC00062IB or the applicable regulations in effect on the date of application for the change, except for earlier amendments as agreed upon by the FAA.
If the Administrator finds that the applicable airworthiness regulations (i.e., 14 CFR part 25) do not contain adequate or appropriate safety standards for the Embraer Model EMB-550 airplane because of a novel or unusual design feature, special conditions are prescribed under the provisions of § 21.16.
In addition to the applicable airworthiness regulations and special conditions, the Embraer Model EMB-550 airplane must comply with the fuel vent and exhaust emission requirements of 14 CFR part 34 and the noise certification requirements of 14 CFR part 36.Start Printed Page 20022
The Embraer Model EMB-550 airplane will incorporate the following novel or unusual design features:
The Embraer Model EMB-550 airplane flight control system design incorporates normal load factor limiting on a full-time basis that will prevent the pilot from inadvertently or intentionally exceeding the positive or negative airplane limit load factor. This feature is considered novel and unusual in that the current regulations do not provide standards for maneuverability and controllability evaluations for such systems.
The normal load factor limit on the Embraer Model EMB-550 airplane is unique in that traditional airplanes with conventional flight control systems (mechanical linkages) are limited in the pitch axis only by the elevator surface area and deflection limit. The elevator control power is normally derived for adequate controllability and the maneuverability at the most critical longitudinal pitching moment. The result is that traditional airplanes have a significant portion of the flight envelope where maneuverability in excess of limit structural design values is possible. The Embraer Model EMB-550 airplane because of the normal load factor limit does not have this excess maneuverability.
As a result of harmonization efforts with other civil aviation authorities through the Flight Test Harmonization Working Group (FTHWG) and Embraer's request to incorporate them into Special Conditions No. 25-520-SC, the FAA is including additional flexibility in maneuverability limits by amending the existing Embraer Model EMB-550 airplane Special Conditions No. 25-520-SC. This additional flexibility allows for reduced maneuverability limits beyond Vmo/Mmo. The existing special conditions are otherwise unchanged.
The FAA issued Notice of Proposed Special Conditions No. 25-19-01-SC for the Embraer Model EMB-550 airplane, which was published in the Federal Register on April 8, 2019 (84 FR 13838). The FAA received a response from one commenter, while generally supporting the new technology requested a thorough review of the system reliability and failure modes. The comment is already addressed in § 25.1309, Equipment, systems, and installations.
As discussed above, these special conditions are applicable to the Embraer Model EMB-550 airplane. Should Embraer apply at a later date for a change to the type certificate to include another model incorporating the same novel or unusual design feature, these special conditions would apply to that model as well.
Under standard practice, the effective date of final special conditions would be 30 days after the date of publication in the Federal Register. However, as the certification date for the Embraer Model EMB-550 airplane is imminent, the FAA finds that good cause exists to make these special conditions effective upon publication.
1. To meet the intent of adequate maneuverability and controllability required by § 25.143(a), and in addition to the requirements of § 25.143(a) and in the absence of other limiting factors, the following special conditions are based on § 25.333(b):
[FR Doc. 2019-09398 Filed 5-7-19; 8:45 am]