Interpretation ID: 6921
President and CEO
Magnascreen
265 Kappa Drive
Pittsburgh, PA 15238
Dear Dr. French:
This responds to your letter inquiring about a recent amendment to Safety Standard No. 111, Rearview Mirrors. (49 CFR 571.111) You explained that your company is developing electronically controlled dimmable (day/night) rearview mirrors for motor vehicles and requested that the agency assess your reading of section S11 of the standard. We are pleased to have this opportunity to interpret our standard for you.
By way of background information, the National Highway Traffic Safety Administration (NHTSA) does not provide approval of motor vehicles or motor vehicle equipment. Under the National Traffic and Motor Vehicle Safety Act, the manufacturer is responsible for certifying that its vehicles or equipment comply with applicable standards. The following letter represents our opinion based on the facts presented in your letter.
Safety Standard No. 111 specifies requirements for the performance and location of rearview mirrors. Section S11, which was recently amended to better address new mirror designs, specifies requirements for mirror construction. (See 56 FR 58513, November 20, 1991.) The section states in relevant part that:
All single reflectance mirrors shall have an average reflectance of at least 35 percent. If a mirror is capable of multiple reflectance levels, the minimum reflectance level in the day mode shall be at least 35 percent and the minimum reflectance level in the night mode shall be at least 4 percent. A multiple reflectance mirror shall either be equipped with a means for the driver to adjust the mirror to a reflectance level of at least 35 percent in the event of electrical failure, or achieve such reflectance level automatically in the event of electrical failure.
You asked whether an alternate power source can be used to achieve the specified fail-safe operation (i.e., adjusting the mirror to a reflectance level of at least 35 percent in the event of electrical failure). While your letter did not specify what you meant by "alternate power source," we assume that it means an electrical power source other than the one intended to normally operate the mirror. Examples of an alternate electrical power source include solar energy or a self-contained battery system.
We interpret the term "electrical failure," as used in section S11 of Standard No. 111, to include any type of electrical failure. This would include electrical failure related to an alternate power source as well as electrical failure related to the primary power source. Therefore, unless adjustment of the mirror to a reflectance level of at least 35 percent occurred even in situations where there was electrical failure related to the alternate power source, the alternate electrical source could not be used to provide the fail-safe operation required by section S11.
The preamble to the final rule amending Standard No. 111 explained that the agency wanted to assure that multiple reflectance mirrors are capable of providing adequate images at all times during the vehicle's operation, including electrical failure situations where the mirror is unpowered. The agency noted that situations can occur where the mirror would be unpowered even though the vehicle could be operational, citing connector faults and circuit board faults. See 56 FR 58515.
To comply with section S11 in situations where a mirror is unpowered as a result of electrical failure, a mirror would either have to default automatically to the high reflectance mode (as in the case of an opposite polarity fail-safe liquid crystal mirror described in the preamble) or be capable of being manually adjusted to the high reflectance mode. We do not have enough information about your proposed mirror to determine whether it would comply with the amendments in the case of electrical failure related to the alternate power source.
I hope this information is helpful. If you have any further questions about NHTSA's safety standards, please feel free to contact Marvin Shaw of my staff at this address or by telephone at (202) 366-2992.
Sincerely,
Paul Jackson Rice Chief Counsel Enclosure Ref: 111 d:3/26/92