April 12

Notice of proposed special conditions

FR Doc 05-7320

Docket no. NM305

Flight systems safety

Monday, April 18, the A380 completed its nose-up test, whereby the aircraft was taken on the takeoff roll to nose-up and then slowed to a stop.

Airbus A380, a new double-deck airliner with a capacity of 550 passengers, has a target date for type certification of Jan. 2006.

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. These design features include side stick controllers, a body landing gear in addition to conventional wing and nose landing gears, electronic flight control systems, and flight envelope protection. These proposed special conditions pertain to the effects of such novel or unusual design features, such as their effects on the structural performance of the airplane.

Finally, the proposed special conditions pertain to novel or unusual design features, such as the effects of high intensity radiated fields (HIRF), or of operations without normal electrical power.

(ASW comments: it is not known at this time what special conditions will be required for Boeing's new B787, which is about a year behind the Airbus effort; the original B777 had eight special conditions; the prevalence of special conditions show the extent to which certification standards are not keeping pace with the technological times.)

Comments due by May 27.

Special conditions for the A380 are very similar, the announcement says, to those requested and granted for the A340, and are based on standardized requirements developed by the Aviation Rulemaking Advisory Committee (ARAC). The European Aviation Safety Agency was represented on the ARAC, therefore the requirements have been harmonized.

Additional special conditions will be issued on the A380 covering:

• Fire protection.
• Emergency evacuation.
• Emergency exit arrangement (e.g., outside viewing).
• Escape system inflation systems.
• Escape systems installed in non-pressurized compartments.
• Ground turning loads.
• Crashworthiness.
• Flotation and ditching.
• Gust requirements.
• Transient engine failure loads.
• Airplane jacking loads.
• Landing gear pivoting loads.
• Design roll maneuvers.
• Extendable length escape systems.

In the meantime, Airbus is requesting the following special conditions (refer to the special conditions for full details):

1. Dynamic braking. Loads arising from maximum braking must be defined and accounted for.

2. Interaction of systems and structures. Unless shown to be extremely improbable (1 x 10^-9), the airplane must be designed to handle any forced structural vibration resulting from failure of the flight control system.

3. Limit pilot forces. For all components between and including the handle and its control stops, nose up or down (pitch) 200 lb., and nose right or left (roll) 100 lb.

4. Side stick controllers. It must be shown that the temporary and maximum force levels are suitable for both normal and non-normal conditions. Moreover, coupling of the left and right controllers must "provide for corrective and/or overriding control inputs from either pilot."

5. Dive speed definition. 20 seconds after initiating the upset, manual recovery is made at a load factor of 1.5 G.

6. Electronic flight control system. The airplane must be shown to have suitable static lateral, directional, and longitudinal stability in any condition normally encountered in service.

7. Electronic flight control system, control surface awareness. Indications must be provided when flight control surfaces are coming so close to their limits that return to safe flight requires a specific crew action.

8. Electronic flight control system, handling qualities. The pilot-rated handling qualities must be adequate.

9. Flight envelope protection. Onset characteristics of each envelope protection feature must be smooth and not conflict with the pilot's ability to change the airplane's flight path, speed or altitude.

10. Flight envelope protection, normal load factor limiting. The positive limit load factor must not be less that 2.5 G, and the negative must be equal to or more than minus 1.0 G.

11. Flight envelope protection, high speed limiting. Must not impede normal attainment of speeds up to the overspeed warning.

12. Flight envelope protection, pitch and roll. The pitch and roll limiting functions must not restrict or prevent attaining roll angles up to 65 degrees or pitch attitude necessary for emergency maneuvering.

13. Flight envelope protection, high incidence protection and alpha-floor protection (alpha-floor is a system that automatically increases thrust when the angle of attack reaches a certain value). It must not be possible to enter a stall during pilot induced maneuvers.

14. High intensity radiated fields (HIRF) protection. Each critical electronic system must not be adversely affected by HIRF. A critical function is one whose failure would prevent continued safe flight and landing.

15. Operation without normal electrical power. Demonstrate that the airplane can continue safe flight and landing with inoperative normal engine and auxiliary power unit (APU) electrical power.

April 13

Airworthiness directive (AD), issued by Australia's Civil Aviation Safety Authority (CASA).

AD/IAI-W/28

6/2005

DM

Electrical system safety

Israeli Aircraft Industries Model 1124 and 1124A Westwind series airplanes.

This directive requires a one time inspection of the wiring harnesses together with the installation of protection and, if necessary, repairs or rework of the harnesses.

AD becomes effective on April 20. Comply within 50 hours time in service.

The Israeli Civil Aviation Authority (CAA) has received a report of an in-flight fire caused by electrical shorts in the wires due to chafing.

See http://www.casa.gov.au/airworth/airwd/Adfiles/over/iai-w/IAI-W-028.pdf