23.1391 Minimum intensities in the horizontal plane of position lights No policy available as of June 30, 2001.
23.1393 Minimum intensities in any vertical plane of position lights No policy available as of June 30, 2001.
23.1395 Maximum intensities in overlapping beams of position lights No policy available as of June 30, 2001.
23.1397 Color specifications Original Issue and Subsequent See AC 20-74, Aircraft Position and Anticollision Light Measurements, for guidance on color measurements.
23.1399 Riding light No policy available as of June 30, 2001.
23.1401 Anticollision light system Original Issue and Subsequent If certification for night operation is requested, an anticollision light system, per this section, is required.
See AC 20-74, Aircraft Position and Anticollision Light Measurements, for guidance on anticollision light measurements.
The flash rate of supplemental lights does not have to be applied to the anticollision light flash rate, but these lights should be checked to verify there is no unsafe condition associated with their use.
Amendment 23-11 and Subsequent There is no restriction on mixing aviation red and aviation white anticollision lights on the same airplane. Likewise, there is no restriction on the ratio of red to white provided that the light displayed in any one direction is either aviation red or aviation white.
Some white supplementary lights have been presented for certification as anticollision lights.
The visible limit of such lights may converge at some point forward and aft of the airplane such that from this point to the airplane neither light is visible. The maximum allowable distance to such convergence is 1,200 feet.
The regulations (§ 23.1397) require that aviation white’s “X” coordinate be no less than
0.300 and no greater than 0.540 (International Civil Aviation Organization (ICAO) Annex 8 requirement). Xenon flash tubes can exceed the “X” limit for some energy levels (20 to 40 joule range). For the function of an anticollision light, an occasional excursion beyond the
0.300 limit would not adversely affect safety or the performance of the intended function.
We have been advised by the National Bureau of Standards (NBS) that the measurement accuracy of the “X” value of chromaticity coordinates includes an error tolerance of plus or minus 0.008. It was not envisioned that filtering would be required on Xenon flash tubes to meet the aviation white limits since the color can be effectively limited by capacitor circuitry to control the energy level of individual flashes. The maximum joules per flash should be such that the 0.300 will not be exceeded more than 68 percent of the time and 0.292 will not be exceeded 99.7 percent of the time (3 sigma), which includes the measurement error tolerance suggested by NBS.
SAFETY EQUIPMENT
23.1411 General No policy available as of June 30, 2001.
23.1413 Safety Belts and Harnesses [Removed] See guidance for Section 23.785 in this AC.
23.1415 Ditching equipment No policy available as of June 30, 2001.
23.1416 Pneumatic de-icer boot system Policy is available in AC 23.1419-2A.
23.1419 Ice protection The § 23.1419 guidance in this advisory circular is focused on the ice protection systems at the component and system level. For information pertaining to airplane performance and handling in icing conditions please refer to AC 23.1419-2A, Certification of Part 23 Airplanes for Flight In Icing Conditions, and AC 20-73, Aircraft Ice Protection.
Original Issue and Subsequent Icing Policy for Small Airplanes The Civil Air Regulations (CAR) 3 airplanes and 14 CFR part 23 airplanes with a certification basis preceding Amendment 23-14, are permitted to fly in known icing conditions if their Type Certificates do not include a prohibition against this operation. Some of these airplanes may be placarded against flight into known icing because they lack deice/anti-ice equipment specified in the type design data. Installation of equipment required for icing approval per type design data is justification for removing the placard. However, the part 91 and part 135 operating rules in icing have limitations for these aircraft.
If the above airplanes’ type design data prohibits flight into known icing, then these airplanes can be approved for flight into known icing only if compliance is shown to part 23, § 23.1419, Amendment 23-14, and subsequent.
Amendment 23-14 and Subsequent To certificate a single-engine airplane for flight in icing conditions, part 21, § 21.101 would require the same criteria to be applied as in VFR, IFR, Day and Night flight, which is to keep the airplane in the air and flying even if performance is compromised somewhat. This may require redundancy in ice protection system components to minimize hazards to the airplane in the event of a probable malfunction or failure.
There is no requirement or allowance for making adjustments in the icing certification program for the frequency of encountering icing conditions. A probability of one is to be used for encountering discrete environmental conditions such as instrument meteorological conditions. Icing conditions are environmental conditions, and an encounter frequency of less than one for compliance with §§ 23.1093 and 23.1419 is not appropriate.
Amendment 23-43 and Subsequent See AC's 23.1419-2, 23-143-1, 23-8 and 20-73.