Forced Air Technology

Added to the test was an air sleeve which was designed by FMC to give the forced air better direction when operating at lower speeds than those used with deicing fluid. The air sleeve consisted of "X" shaped aluminum, inserted into the forced air nozzle shaft.

The tests would validate whether the sleeve assists the air flow and more importantly, determine how much, if any, additional shearing it may cause to the fluid.

A temporary laboratory was set up on site and staffed by APS Aviation technicians. For testing the fluid samples, a Brookfield LV DV-1+ viscometer was used and all the fluids were stored in stainless steel totes in a controlled environment at 23-degrees Fahrenheit. In order to maintain testing consistency, all the fluid was sprayed at the same fixed angle and at a fixed distance between the nozzle and the wing. Viscosity of on-wing samples were measured by APS technicians immediately following the application.

After measuring the viscosity on the wing, APD technicians collected three samples from each fluid test. These included the fluid tote, on-wing with fluid applied without the air sleeve and on-wing with fluid applied with the air sleeve. The samples were taken to the APS onsite laboratory and analyzed by the Brookfield viscometer.

Test results concluded that the anti-ice fluid can be applied with forced air and is within the acceptable fluid degradation limits with or without the air sleeve.

In fact, the air sleeve equaled and even had less degradation in some cases when compared to tests without the air sleeve. Based on the results of the tests, the FAA issued bulletin number FSAT 05-02, which became effective on October 20, 2005, that addresses the use of forced air and forced air assistance with anti-ice fluid. The bulletin references the deicing equipment used in the test, the specific fluids used by brand name and charts which show the performance of these fluids (Clarient Safewing MP IV 2001, Kilfrost ABC-S, Octogon Max Flight 04) using FMC LMD-2000 and Tempest II deicing equipment.

The following statement was issued by the FAA. "Based on this information, operators using these two equipment models modified in the same manner as the test vehicles would be able to apply the listed Type IV anti-ice fluids using the forced air if they meet the lowest acceptable delivered viscosity values listed in the chart."

Through the determination of FedEx's Ron Thompson, along with the assistance of Clarient, Kilfrost, Octogon, Dow and FMC Technologies a new method to apply anti-icing fluid with existing technology that will save the airlines ground time and anti-icing fluid costs, was approved by the FAA. Though this procedure is currently limited to certain fluid types and deicing vehicles, it has laid the ground work for other manufacturers of deicing fluids and deicing vehicles who want to offer their customers forced air with anti-icing fluid in the future.