One of the perennial troubles facing aircraft operators is regional interpretations of the FARs that differ with each other, along with the absence of definitive rulings from Washington. Its most recent form has appeared in the rules governing the clearing of an aircraft for flight during conditions in which frost has formed, or is likely to do so, on wings, props, certain external sensors and control surfaces. All pilots know — or should — that it's dangerous to fly with a frost coating, but when you get to what the rules say about how to defrost it and who is responsible . . . well, there's the rub.

BCA has been contacted by an operator who shares with two others in the same region a major problem in gaining approval of their proposed procedures for coping with frost. The operator has contacted large entities such as NetJets in the hope of viewing an existing approved procedure that would assist in formulating an acceptable plan, but to no avail. And our attempts to seek guidance from FAA headquarters have been met by silence. It seems as if the FAA is chary of potential controversy.

The operators in question have been informed by regional operations inspectors that they are required to have a Ground Deicing/Anti-icing Program as prescribed by 14 CFR 135.227 and 14 CFR 121.629. One of the operators has plowed through the pertinent chapters, verses and sub-verses in both Parts 121 and 135. They've also looked at Advisory Circulars and at Chapters 18 and 27 in FAA Order 8900.1, Volume 3.

That last document contains the clearest and most complete guidance for a Part 135 operator regarding the issues surrounding ground deicing and anti-icing programs. It states in Volume 3, Chapter 27, Section 1 a kind of overview:

“There are essential differences in the ground-deicing/anti-icing requirements of Title 14 of the Code of Federal Regulations (14 CFR) Parts 121, 125 and 135. For example, Part 121 requires a complete deicing/anti-icing program that includes the training and testing of all personnel involved in the ground-deicing/anti-icing process. On the other hand, Part 135 requires training and testing for pilots only. Additionally, if a Part 135 operator chooses to use personnel other than pilots to assist in the ground-deicing/anti-icing and verification process, then those individuals must receive adequate and appropriate training. Part 125 requires testing for pilots only; however, other personnel involved in the deicing/anti-icing process must receive adequate and appropriate training. Parts 125 and 135 operators have the option to elect to meet the deicing/anti-icing requirements of 14 CFR 121.629(c) and institute a full deicing/anti-icing program.”

In the last sentence, note “. . . have the option to elect to meet . . .” What seems to be happening is that operators affiliated with FBOs, who routinely provide deicing to transient aircraft and have trained ramp personnel who perform it, propose their procedures for approval as a deicing process. And that's where the trouble starts.

Later in Section 1, FAA Order 8900.1 states that, based on Part 135.227, pilot training is required based on Part 135.341 if the aircraft is going to take off when frost, ice or snow “may reasonably be expected to adhere to the airplane.” And Part 135.227 further requires a pre-takeoff contamination check. Section 2173 (of 8900.1) covers the rules that apply to Part 135 operators and refers back to the pertinent sections in Part 135. It makes clear that only pilot training and checking is required. And yet, instances are reported of inspectors who are requiring operators to limit the procedures only to the maintenance department. One operator reported an inspector said, “'If some glycol got squirted into the engine, you would call maintenance, so therefore it must be a maintenance function,' but if you extend that logic, flying the airplane becomes a maintenance function because a part might fail and the pilot would call maintenance.”

Section 2173 clarifies further the “important differences” between Parts 121 and 135. Besides limiting the responsibilities to pilots only for training and checking, it notes that unlike Part 121 operations, the tables that provide holdover times in frost and precip are advisory only. And it reminds once again that a pre-takeoff check is mandatory.

In Section 2174, the nature of the pre-takeoff check is laid out: A contamination check has to be done no more than 5 min. before the actual takeoff. It can be done inside or outside the aircraft either visually or by touching the surfaces, or both. And then comes the good part: “The operator's POI must approve the pre-takeoff contamination check procedures for each specific type of aircraft operated by the certificate holder.” Which is the problem here: The POI won't approve the procedure and advises, in the words of the operator, “We can either put it in a hangar or wait until the sun comes out and defrosts it.”

Section 1, 3-2175 says: If a Part 135 operators opts (no requirement, mind you, it's a choice) for the Part 121-style ground deicing/anti-icing program, the POI will issue OpSpec A023 to approve it. If the Part 135 operator decides not to use such a program, the POI should issue OpSpec A042m and will authorize a pre-takeoff contamination check in OpSpec A041 based on Part 135.227.

The training requirements fall under 3-2177, which says that if you are required to have an approved training program, you need to train your pilots and other participating personnel in the procedures for operating in ground icing conditions. If you use a Part 121-style plan using fluids, you have to train your pilots in the use of holdover time. It stipulates what the procedures include, communications “with all agencies involved” and the decision-making process, identification of types of contamination and problem areas on the airframe. Pilots and others participating must be trained in the “types and characteristics” of the fluids used.

And there's a note that warns, “It is important that flight crews do not use deicing/anti-icing fluids unless they have been trained in the characteristics and effects of these fluids on their operation.” Another requires that the training be “aircraft specific.” Yet another requires general manuals to spell out the operator's icing procedures. And those rules are covered again in later sections.

The operator concluded that based on their reading of the pertinent regs, they don't need a ground deicing or anti-icing program like the one in Part 121. They are authorized to use the pre-takeoff check and only the flight crews are responsible to make certain the airplane is free of contamination. If they remove the ice, it's up to them to decide on the method.

Pilots and flight crews from other Part 135 operations stop by the FBO affiliated with the charter operator in question, and those pilots say their company advises they can deice with anything so long as the aircraft is free of contamination at takeoff.

As things stand, the operators in this region are not allowed to remove ice from their airplanes using any method other than a heated hangar or sunshine. Ironically, the FBO has been, and continues, deicing transient aircraft with the approved fluids mixes, and apparently that is approved.

Jacqueline Rosser, the NATA's director of regulatory affairs, stated in an email, “I can offer some suggestions for handling the operator's situation, as this has come up before. Usually it is one of a few problems: Often it seems that the operator was issued the wrong OpSpec; that is, they were given the one that states they have an approved anti-/deice [i.e. Part 121-compliant] program instead of the one that says they will use the 5-min. pre-takeoff contamination check. Or, occasionally the inspector is unclear of what is required if the operator is using the 5-min. check for compliance purposes, but also has a program [not a Part 121 program] to use deicing fluid to clear the aircraft but still complies with the regulations via the 5-min. check. We've also heard of an inspector telling an operator using the 5-min. check that they were prohibited from using deicing fluid, which is incorrect.”

Rosser advises operators to discard OpSpec A023, which governs Part 121 procedures, and adopt instead OpSpec A041, which is appropriate to the Part 135 requirement: The flight crew is responsible to ensure the pertinent airframe surfaces are free of frost and ice within 5 min. of takeoff. “People who got it resolved did two things,” she says. “They had the right OpSpec, and they trained their pilots.”

Few would argue that the FAA is trying to impose Part 121 rules on Part 135 operators. They're different. Airlines operate into known facilities on a schedule, and they have facilities in place dedicated to deicing. Charter operators will fly customers to almost any airport, and a requirement that maintenance personnel are responsible for the ice removal and takeoff clearance would require one to be aboard every flight. A reading of the regs and guidance tells us that just because an operator goes the extra mile and uses fluids to deice it is not supposed incur an extra burden or penalty. Yet that's what seems to be happening.

Confused? Of course. How could anyone not be? It's any icy mess — call it slush. BCA