Overdue Directive, 100-Hour Usage and a Propeller Overhaul
An AME at a small approved maintenance organisation is asked to inspect a retractable-gear single used by a flying club that also gives ab initio instruction for hire. The records show: the last annual/periodic inspection signed 11 months and 15 days ago; 87 hours flown since, 62 of them on instructional flights for hire; a recurring airworthiness directive on the engine oil cooler requiring inspection every 100 hours' time in service, last recorded at 1,240.6 hours total time, with no later entry, while the tachometer now reads 1,352.4; and a propeller overhaul called for by the manufacturer at 2,000 hours or six years, last performed six years and four months ago. The club president says the airplane 'is Part 91, so only the annual matters', wants the inspection signed off today for a weekend fly-in, and does not want the propeller touched until after the event.
1. Establish the status of each of the three items and state which of them makes the aircraft unairworthy right now.
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1. Annual/periodic inspection - signed 11 months 15 days ago, so it remains valid for roughly another 15 days. Today it is not the limiting item.
2. 100-hour inspection - the aircraft is used to give instruction for hire, so a 100-hour inspection is required. However, where the national rules follow the familiar pattern, an annual inspection may be substituted for the 100-hour inspection provided it was performed within the preceding 100 hours and no more than 100 hours have been flown since. Here 87 hours have been flown since the annual, so the annual covers the 100-hour requirement - until the annual itself lapses.
3. Recurring airworthiness directive - 1,352.4 minus 1,240.6 equals 111.8 hours since the last recorded compliance, against a 100-hour interval. The AD is 11.8 hours overdue. An overdue AD is an airworthiness defect: the aircraft may not be flown until it is complied with and recorded. Neither the annual nor the 100-hour substitution cures it.
4. Propeller overhaul - is it mandatory or recommended? Check whether the interval appears in the airworthiness limitations section of the type certificate or an AD, in which case it is mandatory, or only in the manufacturer's service information, in which case it may be a recommendation that the operator's own programme, lease or insurance still enforces. That determination must be made and written down.
Unairworthy now: item 3 alone. Everything else is a scheduling issue.
2. Who may sign the inspection and the directive compliance, and what entries are required?
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Authority to sign
- The periodic/annual inspection must be certified by a person holding the inspection authorisation, or by the appropriately rated and authorised AME under the national system, with the correct rating on the aircraft. A mechanic without that authorisation cannot approve the inspection, regardless of who did the work.
- The directive compliance may be certified by the appropriately rated person who performed and inspected the work under approved data; where the rules require an authorised inspector to return the aircraft to service, that signature must be present too.
Entries required
- The directive entry must state the AD number and revision, the method of compliance, the date, the total time and hours since last compliance, and the signature and authorisation number. 'AD complied with' alone is inadequate - it does not show what was done or how.
- The inspection entry must describe the inspection performed, the reference to the approved inspection programme, the list of discrepancies found and their correction, and the statement that the aircraft was approved for return to service.
- The propeller determination - mandatory or recommended - recorded with its basis.
- The 100-hour/annual substitution recorded so the next inspector can see why no separate 100-hour entry exists.
Signing today's inspection without correcting the AD would be a false certification, and the inspector who signs owns that record.
3. The club wants the fly-in and refuses the propeller work. What options and limits apply, and how do you close this out?
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Options
- Comply with the oil-cooler AD now. It is a 100-hour recurring inspection and is usually a short job; there is no acceptable reason to fly with it overdue. Once complied with and recorded, the AD barrier is gone.
- Perform the annual now rather than in 15 days, since it is due during the same period and the aircraft is already in the shop. That also refreshes the 100-hour substitution.
- The propeller: if the interval is in the airworthiness limitations section or an AD, it is mandatory and the aircraft cannot fly until it is done - no argument about a fly-in changes that. If it is only a manufacturer's recommendation, the operator may elect to defer it, but I would record their decision, the basis, and my advice in writing, and confirm whether the club's insurance or lease imposes its own limit.
- If a required item cannot be corrected on site, a special flight permit or ferry authorisation may be available for a flight to a repair facility, with operating limitations. A ferry permit is not a maintenance deferral and is not issued to allow a weekend trip.
Close-out Give the president a written summary: current status of each item, what must be done before flight, what can be deferred and on whose authority. Document the advice given and the decision made. Records must be available to the authority on request, and the conversation should survive the weekend.