633Pneumatic Deice Boots Turboprop Aircraft

The following discussion is based on comments by Eugene G. Hill the FAA's chief scientific advisor for environmental icing. Eugene Hill had 36 years experience with Boeing, including extensive work on icing certification. He had a significant role in developing the FAA's current icing strategy. Manufacturers of most turboprops and some small jets are reviewing their recommended de-ice boot operating procedures and, in some cases, rewriting them. The activity stems from the FAA's July 1999...

21Introduction

Piston engine induction system icing, commonly, but not completely accurately, referred to as 'carburettor icing' may occur even on warm days, particularly if they are humid, IT CAN BE SO SEVERE THAT, UNLESS CORRECT ACTION IS TAKEN, THE ENGINE MAY STOP. Induction system icing is more likely at low power setting such as those used during descent, holding, on the approach to a landing or during auto-rotation on a helicopter. Statistics continue to show an average of 10 occurrences, including 7...

162 Ice Secretion

The shape of the ice that forms and the amount of ice that accumulates primarily influence aerodynamic performance degradation while the amount of liquid water in the cloud and the duration of the exposure to icing primarily determine the quantity of ice collected. Cloud droplet size is generally a secondary consideration. Temperature can determine the amount of accretion if it is close to freezing, some of the intercepted water droplets blow off before they can freeze. Ice accretion shape is a...

153 Wing Tip Stalling

Normally, washout helps to ensure that the symmetric stall starts inboard, and spreads progressively, so that roll control is not lost. Greater ice accretion has probably occurred at the tip, leaving it more impaired aerodynamically than the inboard wing section. Stall, instead of starting inboard, may start at the tip. Because the tip section may have a sharper nose radius and probably has a shorter chord, it is a more efficient ice collector. As a result, ice accretion at the wing tip may be...

884 Program for Relief of Ice Drag Fuel Penalty in Critical Fuel Scenario

This program for ice drag fuel relief applies to the mid-Pacific routes between the U.S. mainland and Hawaii. This area is relatively free of icing. Data from the U.S. Marine Climatic Atlas indicates percentage frequency of icing in winter ranges from a high of 30 in Seattle, to 12 in Oakland, to 0 in Hawaii. The program has certain constraints. There is no relief granted in this program for the anti-ice penalty (use of) which is provided in the manufacturer's data (e.g., 6 fuel penalty for use...