Banner towing is a form of skywriting where a banner is towed or dragged behind an aircraft usually to advertise or mark an event. The banner produces a large amount of aerodynamic drag, and subsequently the towing aircraft ends up flying slowly.
Banners are usually of three types: Standard letters, aerial billboards and logo banners.
Standard Letters
These banners consist of a series of either 5ft or 7ft high letters connected together by joints and designed for interchangeability.
Using 7ft. letters has the advantage of greater readability over a long distance, but incur a large drag penalty on the towing aircraft. A typical light aircraft is able to tow 25 piece 7ft. letters
By using 5ft. letters, on the other hand you trade off readability for the ability of towing longer messages. Usually longer messages are about 35 pieces. Advantages of standard letters are readability over a large distance.
The letters being prefabricated means they can be made into messages with very short notice and can be changed easily after each flight. Just make sure your staff can spell correctly. It has happened that messages have been spelt incorrectly with resulting humour or worse, very angry clients.
Aerial billboards
Aerial billboards are a relatively new form of banner towing consisting of a large area of nylon cloth and are similar in weight to a spinnaker on a sailing boat. The blank canvas allows vivid pictures to be digitally printed. Helicopter billboards tend to be more square in shape to prevent the top corner sagging and becoming unreadable. Aircraft-towed billboards tend to be rectangular; usually 1m high to 3m long, with some 4m long, which are more popular with clients.
The main advantage of aerial billboards is their visual impact. The disadvantages of aerial billboards are that once painted or printed they cannot be changed as quickly or easily as standard letters. Additionally, they take considerably longer to produce and subsequently cost more.
Logo banners
This form of banner-towing combines aerial billboards with standard letters to produce a banner that incorporates both types, bringing the “blank canvas” of aerial billboards together with the flexibility of standard letters. Commonly, an intermediate-sized area of nylon cloth is placed at the front of a banner which is then followed by standard letters. Static banners can also be lighted up for night advertising. This technique is most often used to advertise a brand, but can also be used as a marriage proposal or party invitation.
Dynamic banners use animated signage, either lighted or not. Audio is also sometimes used in dynamic towing.
History of banner towing
Prior to World War II, aviation pioneer Arnold Sidney Butler, the owner and operator of Daniel Webster Airport (New Hampshire, USA) utilising his fleet of J3 Cubs, created banner towing and was credited with a number of inventions and aircraft modifications used to pick up and release banners.
At the start of World War II, the US government took over the airstrip for military training. Afterward, Butler moved his aircraft to Florida and formed Circle-A Aviation where he continued his banner towing business. Still today, many of his aircraft remain in service and can be seen in the skies over Miami and Hollywood.
Requirements
Balloons, skywriting, and banner towing are usually strategically located. Due to safety, privacy, and aesthetic reasons, the ability to perform aerial advertising is regulated by local and federal entities throughout the world.
You need at least a private pilot certificate to tow banners – sport and recreational pilots aren’t allowed to do it. Since most banner towing is paid work, in practice the pilot will have a commercial pilot certificate.
How to tow banners
On the ground the banner or billboard is folded up with a lead pole in front. A harness is attached to the lead pole. Then a pick up rope is attached to a loop of rope that is attached between two poles about five or six ft. off the ground.
The banner or billboard will be laid down upwind of the poles (with the tow rope fully extended), so that the pick takes place into the wind; the lower ground speed will help with timing and allow the banner or billboard to come off the ground more smoothly.
Helicopters have the advantage of flying more slowly than aircraft, providing a longer viewing time. Because of their upward lift, helicopters are able to pull several times larger banners than aircraft, and the banner can have a more extensive message, but again, the cost is greater.