Federal Register / Vol. 76, No. 61 / Wednesday, March 30, 2011 / Proposed Rules 17615 

Frequency or frequency band Subpart Class of station Remarks 

123.025 MHz ............. F, Q ........................................ MA2, AVW ............................. Helicopter air-to-air communications; Air traffic control 

operations. 

123.050 MHz ............. G, L, Q ................................... MA, FAU, MOU, AVW ........... Unicom at airports with no control tower; Aeronautical 

utility stations. 

123.075 MHz ............. G, L, Q ................................... MA, FAU, MOU, AVW ........... Unicom at airports with no control tower; Aeronautical 

utility stations. 

* * * * * * * 

123.300 MHz ............. K, Q ....................................... MA, FAS, AVW 

* * * * * * * 

123.500 MHz ............. K, Q ....................................... MA, FAS, AVW 

* * * * * * * 

4. Section 87.483 is added under 

Subpart Q to read as follows: 

§ 87.483 Audio visual warning systems. 

An audio visual warning system 

(AVWS) is a radar-based obstacle 

avoidance system. AVWS activates 

obstruction lighting and transmits VHF 

audible warnings to alert pilots of 

potential collisions with land-based 

obstructions. The continuously 

operating radar calculates the location, 

direction and groundspeed of nearby 

aircraft that enter one of two warning 

zones reasonably established by the 

licensee. As aircraft enter the first 

warning zone, the AVWS activates 

obstruction lighting. If the aircraft 

continues toward the obstacle and 

enters the second warning zone, the 

VHF radio transmits an audible warning 

describing the obstacle. 

(a) Radio determination (radar) 

frequencies. Frequencies authorized 

under § 87.475(b)(7) of this part are 

available for use by an AVWS. The 

frequency coordination requirements in 

§ 87.475(a) of this part apply. 

(b) VHF audible warning frequencies. 

Frequencies authorized under 

§ 87.187(j), § 87.217(a), § 87.241(b) and 

§ 87.323(b) (excluding 121.950 MHz) of 

this part are available for use by an 

AVWS. Multiple frequencies may be 

authorized for an individual station, 

depending on need and the use of 

frequencies assigned in the vicinity of a 

proposed AVWS facility. Use of these 

frequencies is subject to the following 

limitations: 

(1) The output power shall not 

exceed¥3 dBm watts for each frequency 

authorized. 

(2) The antenna used in transmitting 

the audible warnings must be omni 

directional with a maximum gain equal 

to or lower than a half-wave centerfed 

dipole above 30 degree elevation, and a 

maximum gain of +5 dBi from 

horizontal up to 30 degrees elevation. 

(3) The audible warning shall not 

exceed two seconds in duration. No 

more than six audible warnings may be 

transmitted in a single warning cycle, 

which shall not exceed 12 seconds in 

duration. An interval of at lest twenty 

seconds must occur between transmit 

cycles. 

* * * * * 

[FR Doc. 2011–7382 Filed 3–29–11; 8:45 am] 

BILLING CODE 6712–01–P 

DEPARTMENT OF TRANSPORTATION 

Pipeline and Hazardous Materials 

Safety Administration 

Federal Motor Carrier Safety 

Administration 

49 CFR Parts 177 and 392 

[Docket Numbers PHMSA–2010–0319 

(HM–255) & FMCSA–2006–25660] 

RIN 2137–AE69 & 2126–AB04 

Highway-Rail Grade Crossing; Safe 

Clearance 

AGENCY: Pipeline and Hazardous 

Materials Safety Administration 

(PHMSA), and Federal Motor Carrier 

Safety Administration (FMCSA), U.S. 

Department of Transportation (DOT). 

ACTION: Notice of proposed rulemaking 

(NPRM); reopening of comment period. 

SUMMARY: On March 1, 2011, the 

Commercial Vehicle Safety Alliance 

(CVSA) requested that PHMSA and 

FMCSA extend the comment period for 

the Highway-Rail Grade Crossing; Safe 

Clearance Notice of Proposed 

Rulemaking, which was published on 

January 28, 2011, by 60 days. CVSA 

believes the extension is necessary to 

gain feedback from its members who 

will be attending the CVSA Spring 

Workshop Meeting from April 11–14, 

2011. This notice reopens the public 

comment period for the NPRM from 

March 29, 2011, to April 29, 2011. 

DATES: Comments on the NPRM are due 

by April 29, 2011. 

FOR FURTHER INFORMATION CONTACT: At 

FMCSA: Mr. Thomas Yager, Driver and 

Carrier Operations; or MCPSD@dot.gov. 

Telephone (202) 366–4325. Office hours 

are from 7:45 a.m. to 4:15 p.m., e.t., 

Monday through Friday, except Federal 

holidays. At PHMSA: Mr. Ben Supko, 

Office of Hazardous Materials 

Standards, (202) 366–8553, Pipeline and 

Hazardous Materials Safety 

Administration, U.S. Department of 

Transportation, 1200 New Jersey 

Avenue, SE., Washington, DC 20590 

0001. 

SUPPLEMENTARY INFORMATION: 

On March 1, 2011, the Commercial 

Vehicle Safety Alliance (CVSA) 

requested that PHMSA and FMCSA 

extend the comment period for the 

Highway-Rail Grade Crossing; Safe 

Clearance Notice of Proposed 

Rulemaking, which was published on 

January 28, 2011 (76 FR 5120), by 60 

days. CVSA believes the extension is 

necessary to gain feedback from its 

members who will be attending the 

CVSA Spring Workshop Meeting from 

April 11–14, 2011. 

PHMSA and FMCSA believe that 

other potential commenters to this 

rulemaking will benefit from an 

extension as well, and that 30 days is 

sufficient time to allow CVSA to gain 

feedback from its members during its 

Spring Workshop and prepare its 

comments. Accordingly, PHMSA and 

FMCSA reopens the comment period for 

all comments on the NPRM and its 

related documents to April 29, 2011. 

Issued in Washington, DC, on March 25, 

2011, under authority delegated in 49 CFR 

part 1. 

WReier-Aviles on DSKGBLS3C1PROD with PROPOSALS

17616 Federal Register / Vol. 76, No. 61 / Wednesday, March 30, 2011 / Proposed Rules 

By the Federal Motor Carrier Safety 

Administration. 

William Bronrott, 

Deputy Administrator. 

By the Pipeline and Hazardous Materials 

Safety Administration. 

Bizunesh Scott, 

Chief Counsel. 

[FR Doc. 2011–7554 Filed 3–28–11; 11:15 am] 

BILLING CODE 4910–EX–P 

WReier-Aviles on DSKGBLS3C1PROD with PROPOSALS