Hot Air Balloon Fuel Cylinders

by Peter von Moos, Senior Engineer-Domestic Regulations, Aircraft Certification Standards, Standards, Civil Aviation, Transport Canada

Attention hot air balloon owners, operators, and maintainers!

Did you know that the transport of propane to a hot air balloon launch site, or from a hot air balloon landing site, as well as filling a cylinder with propane for the purposes of such transportation are activities subject to the Transportation of Dangerous Goods Regulations (TDGR)?

Under the TDGR, the kind of cylinder that may be used for propane transport, and requirements for its filling and maintenance, are strictly prescribed. The TDGR requirements are in addition to the certification of the cylinders pursuant to the Canadian Aviation Regulations (CARs)511 and51 , and in accordance with Airworthiness Manual (AWM) Chapter531, the airworthiness standard for manned free balloons.

Recently, a Canadian balloon operator was fined for illegal land transport of balloon fuel cylinders that did not meet TDGR requirements. The operator was unaware that AWM531 compliance was not sufficient to transport and fill fuel cylinders.

Road, railway, ship or aircraft transport of balloon fuel in cylinders is an inherent characteristic of hot air balloon operations. However, balloon operators should be aware that compliance with AWM531 alone is NOT sufficient to permit the transportation, inspection, maintenance, and filling of the fuel cylinders outside their intended use as fuel storage during balloon flight. In the certification of aircraft, Transport Canada Civil Aviation (TCCA), just like other airworthiness authorities, is responsible only for the airworthiness aspects of an aircraft or any of its installed components. It is the user's responsibility to meet any additional requirements, e.g. the operating regulations, and in the case of hot air balloons, the TDGR requirements for the surface transportation of propane.

Balloon owners and operators should verify that they satisfy the requirements of the TDGR for surface transport of propane, including the requirements pertaining to the cylinders used for that purpose.

The TDGR require that cylinders manufactured after 1992, and used to transport compressed gas must comply with, and be certified to, the Canadian Standards Association (CSA) Standard CAN/CSAB339. Such cylinders can be recognized by their stamp markings, which begin with the letters "TC." Requirements for periodic reinspection are included within Standard CAN/CSAB339. Cylinder use, including pre-fill and post-fill inspection, and limits on the degree of filling, are specified in a companion Standard, CAN/CSAB340. These standards may be purchased from the CSA, while the Transportation of Dangerous Goods Act,1992 (TDG Act) and TDGR may be viewed on the Transport Canada Web site.

If your current cylinders do not comply with the TDGR, i.e. have no "TC" stamp markings, you may apply for a permit for equivalent level of safety under the TDGR. The Transport Canada Transportation of Dangerous Goods Directorate may, through such a permit, allow existing non-conforming hot air balloon cylinders to continue to be used during a phase-out period of specified duration. A permit may be granted to members of an association or to an individual. It is important to realize that such a permit applies only to the cylinders, and does not relieve the holder from their obligation to have a balloon configuration that conforms to the approved type design.

For more information on applying for a permit of equivalent level of safety, see Part 1 of the TDGR at the following Web address:

You may submit an application for a permit along with supporting rationale and documentation, by mail, fax, or e-mail to:

Director, Regulatory Affairs
Tower C (ASDD)
Place de Ville, 330 Sparks St.
Ottawa ON K1A 0N9

Fax: 613-993-5925

If not covered under a permit, non-conforming cylinders may not be used for the transport of compressed gas within the scope of the TDGR.

CL-215 Water Door Up-Lock Actuators: The SDR is for Your Benefit

by Rob Adamchuk, Civil Aviation Safety Inspector, Aircraft Maintenance and Manufacturing, Prairie and Northern Region, Civil Aviation, Transport Canada

Human factors training teaches us that an aviation incident or accident typically involves more than one causal factor. The events are like layers of Swiss cheese in which the holes eventually line up, allowing the final margin of safety to be penetrated. This penetration permits the incident or accident to occur. A positive action by one person can disrupt the layers, block the holes, and stop the sequence of events. The filing of a service difficulty report (SDR) can be that one positive action.

Recently, an operator of CL-215 water bombers was involved in a scheduled C-check of one of their aircraft. The type certificate holder's recommendations do not call for a non-destructive testing (NDT) inspection of the water door up-lock actuators in this particular check. The actuators do, however, have a 5000-hr time between overhauls (TBO), which had not yet been reached. The operator contracted a local NDT-rated approved maintenance organization (AMO) to do the NDT inspection portions of the C-check. The NDT technician informed the operator that he had recently been contracted by another operator to inspect their water door up-lock actuators, and had found some actuator piston shaft defects. The operator immediately requested that the NDT technician check their actuators. The result was that defects were discovered in approximately 83 percent of the actuator shafts in their fleet. At this point, the operator filed an SDR with Transport Canada.

In the course of a routine Transport Canada follow-up, several aspects of this SDR were revealed, some unexpected. Quite often, there are two cracks on each shaft at the chamfer between the body of the shaft and the threaded end. The two cracks are typically about 180° from each other. The type certificate holder's recommendations call for magnetic particle inspection (MPI). All of the NDT-rated AMO shops contacted stated that they do this type of inspection on these parts, but have also found, through experience, that the fluorescent liquid penetrant inspection (LPI) method gives a stronger and more positive indication of a defect in this part.

Part number 215750098
Up-lock actuator, part number215750098

They all stated that they do the inspection twice: once with the recommended MPI method for initial indications, and then the second time with the LPI method for confirmation and fail-safe purposes. Even though the type certificate holder's recommendations call for a 5000-hr TBO for the up-lock actuator, some operators are overhauling, and NDT inspecting, their actuators annually. This is a significant reduction of time between overhauls. This would also suggest the operator evaluated the information, and modified their maintenance requirements to ensure the reliability of the parts involved, and thus, safety. Another aspect revealed was that some operators have been aware of the defect issue since about 2004, apparently having communicated the relevant information amongst themselves. Unfortunately, not all operators are equally aware. It appears to depend on who is on individual e-mail and telephone lists, rather than a national information system such as the SDR database.

The Transport Canada routine follow-up included checking the SDR national database. Including the most recent submission, only three SDRs regarding this part have been filed. The first two were in the early months of 2000. The relatively small number of reports in the database raises several questions. Is the type certificate holder aware of the actual rate of defects found in this part, and the average time in service? Are they aware of the different NDT processes being used in the field, and why they are used? The SDR reporting process would allow them to assess what is happening, evaluate the data, and take appropriate action, if necessary. Are all the operators of this aircraft type in Canada aware of the additional information? Unless another operator happened to inform them in some way, it is not likely. Is there a way a new or foreign operator can obtain this information in a readily-accessible fashion? Again, unless another operator happened to inform them in some way, it is not likely.

Part number 33130131
Shaft, part number 33130131, with a defect shown

It is logical to conclude that, at some point in time, an operator not having all the necessary information readily available to fully evaluate the maintenance requirements of their aircraft will experience an unexpected failure of the up-lock actuator shaft. If the failure occurs, in this case, during a high force-loaded part of the flight, such as takeoff, landing or while scooping water, the result may be catastrophic. If everyone shares information using the available process, which is the SDR database, then the information is available to everyone. That action of filing an SDR may close the holes in one or more layers of the Swiss cheese. If someone downplays or complains about filing an SDR, ask yourself one question: "is all the relevant information readily available to me?" The SDR is for everyone's benefit.

Inspection Levels Part 2: Detailed Inspection Please!

by John Tasseron, Civil Aviation Safety Inspector, Aircraft Evaluation, Standards, Civil Aviation, Transport Canada

This is the second of three articles on the topic of inspection levels.

This is the second article concerning aircraft maintenance inspection levels. The first covered the term "general visual inspection" (GVI). When discussing inspection levels, it must be remembered that the topic concerns how closely an item is inspected, which in turn translates into how small a defect or unsatisfactory condition we hope to find. The idea is to first assign an appropriate level of inspection to a task, and then prescribe an effective inspection interval.

The term detailed inspection has been assigned the acronym DET. This does not conform to the usual concept of using the first letter of each word of a term to derive the acronym, but has come into common usage through the Air Transport Association of America (ATA). Perhaps the intent was to differentiate between this term and the term daily inspection (DI). The problem is partially caused by the fact that the word "visual" has been deleted from the term. Had this been retained, DVI would have been the result. The definition of the term detailed inspection is as follows:

"An intensive examination of a specific item, installation or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at an intensity deemed appropriate. Inspection aids, such as mirrors, magnifying lenses, or other means, may be necessary. Surface cleaning and elaborate procedures may be required."

Some key words in this definition are intended to differentiate this level of inspection from that of the GVI. Let's look at these words more closely.

The word "intensive" alerts us to the fact that this inspection demands a higher level of scrutiny in order to find unsatisfactory conditions that are more difficult to detect. The emphasis has shifted from general inspection to detailed inspection. An assumption is made here that an intensive examination would only be possible by moving the eyeball closer to the surfaces to be inspected, and that the need for specifying a distance is therefore waived. Furthermore, the intensive examination is directed towards "a specific item" (note the singular). Since this is not the same as looking at a number of items, as is done during a GVI, the specific item to be inspected needs to be clearly identified as part of the inspection task. Supplemental lighting is specified as a "normal" requirement here, so one can assume that at least a flashlight should be available. The intent is to direct the light to a specific area so that smaller defects can be more easily detected. The reference made to "surface cleaning" relates to having to pay particular attention to the fact that the general cleaning carried out prior to the start of the inspection may not have been adequate to permit intensive examination of a small detail. Finally, the mention of "elaborate procedures" raises an awareness of a possible need to gain additional access by moving adjacent items, defuelling tanks, etc.

The definition for the term "detailed inspection" appears to be fairly concise and easy to understand, and has not been the subject of significant controversy. This is partly due to the fact that it is almost automatically compared to the definition of GVI because both terms are used frequently in large aircraft maintenance schedules. Note that the term lends itself to use in any maintenance schedule, as long as the corresponding definition is clearly explained. Since problems occur when a definition is chosen to describe a term not normally associated with it, or vice versa, it is best to maintain consistency in the applicability of ATA terms and their definitions, before using them in other maintenance schedules.

The final article will look at the highest inspection level, and how it sometimes creates controversy in the inspection level selection process.

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