The FAA  maintains all equipment required for aircraft operations at Quad Cities Intl. This site pictured above is located just behind the airport 1 mile on 72nd Street. This site houses all of the transmitters and receivers for not only the QC Airport, but also some Chicago Center frequency's, and some military freqs as well. Along with the Radar info for Quad Cities. This site has backup Diesel generators in the event of power failures. All radio and radar info is relayed from this site to the ATC Control tower with phone lines. As I recall the tower has Aux radio equipment in the tower in the event of some kind of failure. In the event of further failure the tower is also equipped with a multi colored light gun. This light gun, is a handheld unit that the controller can point at an aircraft and give commands to the pilot with different colored light signals. This light gun is seldom used, and most likely can not be used with Commercial aircraft.

Many years ago, I was flying a Piper Cub, this Cub did not have radios and I was cleared to land and take off at Moline, via light gun signals. 

The following are known frequency's at MLI

    Non FFA Frequency's at Moline

Other Frequency's of interest

A.C.A.R.S.

Click here to see a sample of ACARS transmission 

What is ACARS?
ACARS is an acronym for Aircraft Communications Addressing and Reporting System. Until a decade ago, almost all radio links between the ground and commercial aircraft used voice communications. The expansion in air traffic generated the need for a faster and more efficient system for handling communications. The result was ACARS, a digital data link system designed to utilize existing ground station and aircraft radio equipment, and enhance air-ground-air communications.

The Messages
The ACARS frequencies carry a lot of traffic between aircraft and ground stations. The types of information in the ACARS transmissions varies widely. It can range from simple arrival/departure reports, to lengthy aircraft computer downlinks of navigation, engine, and performance data. Messages also include: Weather observations, flight plans, navigation positions, aircraft and engine performance data, arrival/departure/delay reports, equipment malfunction reports, crew reports, connecting gate lists

ACARS Signals
For ham radio operators and short-wave listeners, ACARS can be regarded as a commercial type of packet radio communication. The ACARS signal uses a 2400 bps message data bit stream to differentially AM modulate the transmitter carrier using 1200 and 2400 Hz tones. AM modulation is used, consistent with the historical use of AM voice mode on the aircraft bands since the early days of radio.

Click here to download a free working demo program that will allow you to receive ACARS with your sound card and a scanner........

Nearby radio navigation aids

  VOR radial/distance                 VOR name   Freq   Var
  -------------------  -----------------------  ------  ---
  MZVr033/9.6                    MOLINE VORTAC  114.40  05E
  CVAr180/15.6                DAVENPORT VORTAC  113.80  04E
  DDDr079/29.3               PORT CITY VOR/DME  116.50  01E
  GBGr351/30.8               GALESBURG VOR/DME  109.80  03E

  NDB name                    Hdg/Dist  Freq  Var  CW-ID
  --------------------------  --------  ----  ---  -------------------
  	CLINTON                     198/24.2   377Khz  01E  CWI  -.-. .-- ..
      KEWANEE                     300/28.8   245Khz  01E  EZI  . --.. ..
          WHITESIDE                   243/36.0   254Khz  01E  BOZ  -... --- --..
         MAQUOKETA                   162/37.7   386Khz  02E  OQW  --- --.- .--