CHAPTER 4. BANNER TOW SPECIAL PROVISIONS
The following is a suggested checklist. Its purpose is to help the banner tow operator better understand the importance of the pre and post flight inspection of the equipment used in banner towing. It is NOT intended to replace or supersede the current FAA approved Aircraft Flight Manual, Pilot Operating Handbook, or Rotorcraft Flight Manual for the aircraft being flown. No person may operate a civil aircraft without complying with the Abnormal/Emergency procedures.
a. If a safety link is used, the safety link should be closely checked following each flight. When a heavy load has been exerted on the safety link the ends of the link will bend out of their parallel position. High winds, excessive speeds, and extra large or extra long signs, may cause the load limits of the link to be exceeded.
b. Check the ends of the tow-lines, hook lines, and/or grapple lines frequently for wear. Examine the hemming of the letter fabric. If an edge is snagged or coming loose at the hem, repair it before the next flight.
c. Check the operation of the tow hitch.
d. A suitable shoulder harness should be installed.
e. Inspect the grapple hook for anything unsafe.
f. Check the banner layout assuring that nothing is twisted, and the towline at front of banner is in good condition.
g. Check the banner for any tangles or uncoupled fasteners.
h. Inspect the grapple line and assure that it is correctly coupled before takeoff.
i. Extend the main section of the towline along the flight path to minimize slack.
j. Attach the towline snap to the bridle ring on the mast assembly.
k. Inspect the towline for serviceable condition. It will usually start to deteriorate from the inside rope first. Small broken fibers will be visible extending through the outer strands, indicating an unsafe condition. There should not be any knots in the line. Knots weaken a towline.
DESCRIPTION OF SUGGESTED AIRPLANE FLIGHT MANEUVERS.
I. The Banner Pickup (All procedures should be adjusted for different aircraft performance).
a. After takeoff and the grapple hook is dropped, the pilot should visually inspect the grapple line and hook to ensure it did not become entangled in the tail section of the aircraft during deployment.
b. The airplane approaches the poles at 250 feet AGL at 1.6 times the airplane stall speed.
c. At the point where the down-line is initiated, the airplane is pitched down at a minimum of 5° and maximum of 15° angle while reducing the engine power to maintain proper airspeed.
NOTE: Where to initiate the down-line varies depending upon wind conditions.
d. At the point of the mast poles, full throttle should be selected to assure a safe climb-out. (If the banner should snag another banner or object on the ground, the pilot would have a better chance of reacting to this situation.)
e. Minimum airspeed through the pickup poles should be 1.6 times stall speed.
NOTE: The pilot should always fly to a point at pickup. This will allow the ground crew to give direction to the pilot after a missed attempt such as 10 feet forward or aft of the pilot’s established reference point.
f. Upon hooking the banner the airplane is climbed at a minimum speed of 1.2 times the stall speed and maximum engine power is applied.
g. Upon reaching 225 feet - 250 feet AGL, maintain proper forward momentum and altitude. Although the climb is stopped, the aircraft may remain in a nose-high attitude.
h. Full power and adequate airspeed are maintained until reaching 1,000 feet AGL.
II. The Banner Drop (All procedures should be adjusted for different aircraft performance).
a. The airplane approaches the designated drop zone at 300 feet AGL.
b. Upon reaching the drop zone full power is applied prior to releasing the banner and minimum airspeed should be 1.2 times stall speed. Full power should be maintained after the banner release handle is activated. This is a safety procedure in the event the banner does not release and snags an object. The pilot would then have power to assist in recovery. Caution should be exercised as to not exceed 1.5 times the stall speed of the aircraft.
c. Rotation is initiated prior to dropping the banner.
d. When the airplane is established on the up-line a delay of approximately 3 seconds is incorporated into the maneuver to allow the banner to reach its lowest altitude.
e. After the banner is released, the pilot should be prepared to hold the controls in position as the nose will pitch up because of the reduction of drag after banner release.
III. Description of Helicopter Flight Maneuvers.
IV. Oversize Banners Towed by Helicopters. Extremely large banners using long suspension ropes and heavily weighted bags for flight positioning require additional review. The operator should take into account the lowest point on the trailing banner when determining a helicopter’s correct flight altitude. For safety purposes, the altitude should be sufficient for the aircraft and trailing banner to comply with section 91.119(b)(c). Some banners may extend as much as 250 feet behind the aircraft.
Certain procedures for towing should be observed in addition to normal flight rules and safety measures. Tow at the lowest airspeed that provides adequate engine cooling, positive control, and a safe margin over stall. The drag of the banner increases in proportion to the square of an increase in speed; an increase in airspeed of 10% will produce a 20% increase in drag, requiring more power. Wear of the banner equipment will also be greater at the higher speeds.
During towing operations the engine must work harder than normal. Watch the airspeed indicator and work toward finding the best tow speed for the airplane. At towing speeds, a climb prop is more efficient than a cruise prop. Use the flattest pitch and largest prop diameter allowable for the engine and airplane. Slow flight may reduce engine cooling on some airplanes, with resultant cylinder head temperature increase, although oil temperatures may not be up significantly.
On some airplanes, a slight extension of flaps helps by effectively increasing the attack angle of the wings, allowing the nose to be a little lower for better visibility and engine cooling.
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