There seems to be a lot of confusion or dissatisfaction around the “On Condition” use on NTCA in particular their engines.
The regulation in Part 44 already provides for on condition use beyond time/date limits. This provision is specific for private use of such NTCA, and does NOT apply to commercial i.e. Part 96 use, which includes training with NTCA.
We have noticed a lot of speculation, accusations, and misinterpretation of what this means and how to apply it, there is also a lot of serious lack of knowledge and understanding of the regulations that apply to our industry.
For this reason we held a number consultation meetings with industry to determine a set of guidelines to assist industry on how to comply with the existing regulation. This resulted in the RAC as a guidance document to clarify a series of checks/inspections that will not be invasive or excessively expensive to make a reasonable determination of the engine’s condition.
It should be clearly understood that the final decision and responsibility for the airworthiness of an NTCA used privately rests with the owner of the aircraft. The inspection listed cannot and does not guarantee the engine, rather that based on the inspections and history of the engine it reasonably appears to be in a good running or serviceable condition. If these inspections indicate adverse wear or out of spec results, then clearly the engine should repaired or overhauled accordingly. This responsibility rests with the owner, and that is why it only applies to private use.
Both Part 24.01.7(3) and Part 66.04.16(3) states that the inspection carried out by an AMO/AME or AP shall be of a conditional nature, and that they shall not be required to guarantee the airworthiness of the aircraft, and that the owner or operator of an NTCA shall at all times be responsible for the airworthiness of the aircraft. (not verbatim)
66.04.16(4) states that when the AP issues a release to service they shall be satisfied that the aircraft and it equipment are serviceable and that maintenance has been carried out in accordance with the regulations and maintenance schedule.
The AP/AMO will only perform the inspections and enter the details in the aircraft maintenance logbook, and may recommend the engine as serviceable or not serviceable, they are not guaranteeing its airworthiness. The owner must then decide if they are satisfied with the results of the inspections and decide to continue use, or overhaul the engine. The owner must also issue the release to service if used privately not the AP or AMO, thus the owner must be satisfied that the aircraft and it equipment is serviceable prior to issuing the release to service. If an AP or AMO in not satisfied to perform the inspections or sign out the necessary paperwork, this is their prerogative.
RAASA as the issuing authority may determine when renewing an ATF if the test results are acceptable or not, as the results and recommendation form the AP will suggest that the engine is still within reasonable condition and specification, if not then the conditions may be varied or no ATF will be issued where the results indicate an unsatisfactory condition.
Where an NTCA owner does not want to, or is not happy to comply with the guidance document’s series of inspections, they simply need to comply with the manufacturers recommendations in cases where the time/date limits have expired and overhaul the engine.
In the case of automotive engines clearly the requirements are those in the maintenance schedule.
In the end the regulation was drafted and intended to help NTCA and private use of such aircraft by permitting a less onerous demand on this part of industry without affecting safety standards, this however does not mean that no checks and balances apply, therefore this guidance document provides for less onerous checks and balances, but the onus is that of the owner, and diligence should prevail when deciding to overhaul the engine or to continue using it following the results of series of inspections.
I hope this perhaps clarifies the issue.
National Operations Manager