Date: 201306
Local time of day: 0601-1200
Location: BMG.Airport, IN
Weather elements / visibility: Rain; Thunderstorm
Light: Daylight
Reporter organization: Government
Reporter function: Local
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Other / Unknown
Anomaly: ATC Issue All Types
Detector: Person Air Traffic Control
Result: General None Reported / Taken
Contributing factors: ATC Equipment / Nav Facility / Buildings
Primary problem: ATC Equipment / Nav Facility / Buildings

Narrative: BMG Tower is a federal contract Tower. Over the last year the internal shades have been replaced in two steps. The first three shades are several times darker than the last three shades replaced. Because of the greater amount of light entering behind the shades facing west exposure; the shades are difficult at best to see through and at times aircraft in the pattern are invisible to the controllers requiring them to step to the back of the Tower to view through the back windows; or to raise the shades. When a shade is raised all other windows become difficult to see through until the shade is returned to its down position. Because of the difference in tint on the shades purchased at different times; the lightest of days causes some of the most intense problems. It is like sitting in a lighted room after dark; you can't see outside while the lights are on; however when you shut the lights off; you can see much more out the windows. It's that way in the Tower; when the sun is brightly shining so much light spills in behind the darkest shades making them difficult to see through and aircraft disappear as they turn or at any angle northwest or southwest of the Tower. Sometimes aircraft on upwind or final will be invisible if they get more than a mile from the numbers and this creates a dangerous situation. Recently a pilot flying a sport taildragger lost sight of the aircraft he was following when the student in the first aircraft flew a 3 mile upwind; the taildragger turned west to crosswind inside of the first aircraft; which was invisible from the Tower because of the shades and distance. The taildragger was instructed to continue turning east because the number one plane was not visible from the Tower; but known to be somewhere in the pattern. Luckily; the taildragger began his turn while still visible from the Tower or circumstances could have been tragic. Often during any day controllers have to raise the shades in order to see aircraft in the traffic pattern or to view an aircraft entering the pattern. Many times controllers are stretched to the back of the Tower looking through the lighter shades to see aircraft which are not visible through the darker shades. An accident or incident is inevitable especially with the distractions of trying to find a position in which my visibility is not blocked. This is a VFR Tower and sometimes it's difficult to impossible to see aircraft without having to take extra steps which include raising shades; moving to different parts of the Tower or both and asking aircraft where they are when you had them in sight seconds previously. This is not about the ability to see; it's about the shades being too dark and too light together. If all six shades were the same tint; darker or lighter there would be no problem but so much light spills behind the shades that it is difficult to see through the way the situation is now.




Synopsis: BMG Controller voiced concern regarding an unsafe working condition involving sun shades currently in the Tower Cab and the limited visibility encountered.