Aircraft Maintenance Questions And Answers

[Martha Weitz]

Aircraft Maintenance QuestionsReview the previously answered aircraft maintenance questions below. If you cannot find the answer to your question(s) there, then please feel free to submit your question(s) using the form below.

We'll do our best to answer your questions. The answers will be posted on your own question submission page. Your question submission page can then be viewed by others who may have the same or similar question.

So Uncle Bob just died and left me 3.14 million dollas. Or else I hit the lottery, or what have you. Whatever the case may be, I've decided that today is the day I buy myself an airplane. Harrison Ford has one and by God I want one too. This means that I need a mechanic.

We can assume that I don't already know any mechanics (For the purposes of the question, we can assume I soaked my home in Cristal, tossed flaming $100 bills at it until it burned down, and then moved to Beverly Hills, away from all the little people), so:

The key when selecting an aviation mechanic or shop to maintain your newly purchased plane is "time in type": You would not take a Cessna 172 to the United Airlines maintenance facility at JFK, not would you take an A380 to the local Cessna service center (even though it would be perfectly legal to do so).

If you're buying a new aircraft (of any type) the manufacturer will be able to recommend an authorized service center for you, and you'll probably want to use an authorized service center (especially for warranty work).

If you're buying a used aircraft you can still contact the manufacturer and ask about authorized service centers. They will usually be happy to give you a list of places near you that can work on your aircraft, and who are blessed by the factory to perform warranty service, complete mandatory service bulletins where the manufacturer is supplying parts / covering labor, etc.

For the most common single-engine piston aircraft (your typical Piper Cherokee, Cessna 172/182, etc.) you can almost certainly find a mechanic at your local general aviation airport - ask the FBO where you're storing the plane for recommendations or talk to other pilots on the ramp about who they use for maintenance.

For more esoteric aircraft (high-performance singles, twins, vintage/classic/warbirds, etc.) your best resource is often a type club (e.g. The American Bonanza Society for Beechcraft Bonanzas, or ICS for the Piper Comanche) - Google can help you track down a type club, and the members can help you find mechanics who have experience working on your particular airplane.
Type clubs are also a great source of other information (like where to find parts).

It's very, very easy to hire an aircraft mechanic. Drive to your local airport and explore the less-travelled roads beside the fence. You will find a number of maintenance facilities that can service anything from a Piper Cub to the Concorde. Walk in, say hello.

Small exception: major international hubs tend to be air carrier only. General aviation will be somewhere else, but any maintenance shop will know where the others are - it's a fairly small community.

Also note that uncle Bob's 3.14 million won't buy much. It will get you a really decent piston single or very light twin. Or a high-time turbine in need of some pricy maintenance. Remember that unlike a car, the sticker price on an aircraft is just the edge of the money pit. You make yourself a 5-year budget and spend no more than half on the actual aircraft. If you buy new you can shift it a bit as you won't need any unscheduled maintenance for a while but in the broad scheme of things aviation is not for the financially fainthearted.

I believe the best way to seek such a mechanic would be to ask the place you purchased your aircraft, asking the airfield you park your aircraft at or simply googling "Aircraft Mechanic in [insert location]".

Last night, I had to change planes at LAX because the United Airlines B737 that I was flying on had radio problems and thus could not fly over the ocean. One of the hi-frequency radios had problems, and the pilot said that both radios must function in order for the plane to fly over the ocean. So I flew on another B737 and arrived at Honolulu almost two hours late.

Do airlines keep "spare" planes at major airports in case problems with planes that are scheduled to fly happen? What is the procedure for getting a replacement plane? A plane could not be flown in at a moment's notice, obviously, because it could take hours for it to arrive.

In my experience, having permanent airplanes standing by as spares does not really happen. Based on historical data potential realtime spares, airplanes with potential availability on any given day, can be pinpointed for reschedule or delayed maintenance, should the need arise.

In reality, often the "spare" as you called it, is an airplane that can be pulled from another trip with a subsequent replacement available causing less delay than the flight generating the need for the spare in the first place.

It is extremely costly to have "extra" airplanes standing by to replace an aircraft that may go out of service. Swapping aircraft is sometimes quite difficult because the type aircraft scheduled may not be available. An alternate aircraft (different type) poses difficulty because the crew that was going to fly the B737 you were scheduled on, could not fly a substitute Airbus, for example (they either would not be qualified or not current/legal to fly the different type at a moments notice).

The airline's SOC (Systems Operations Control) or similar has a difficult challenge on most occasions dealing with maintenance delays or cancellations. It is not uncommon for the flight to just be cancelled and have the passengers put on later flights. However, the airline's Operational management people are experienced at minimizing actual delays and maximizing aircraft utilization.

There are a lot of factors to this and flight planning has gotten much better over the past few decades so planes are rarely flown empty, moved for no reason, or just sitting around any more like they did in the past. The prevailing mentality is that an aircraft is only making money when it's flying, so keep it in the air as much as possible.

However the reality of airline operations requires aircraft to come in and out of service every so often for maintenance and routine checks. This creates a bit of wiggle room in the fleet, so while there are no spare aircraft per se, a fleet of sufficient size may have excess resources. The chances of getting a replacement aircraft are greatly increased if you are at an airport the airline considers a hub or an airport that has large maintenance facilities. Ultimately the demand is not always there to keep all planes in the air all the time so spare capacity is sometime driven by the nature of the business.

In your particular case it's also possible another aircraft was swapped in with the assumption the HF would be fixed fairly fast and thus capable of being dispatched for a flight in fairly short order filling the void it created.

These days it's often cheaper for an airline to cancel the flight, put everyone up in a hotel and book them on the next available flights to the destination. This will obviously be weighed by the airline prior to doing so, but it's a risk they know they have and one they are typically fairly prepared for.

HF radios are only used on transoceanic flights, so in that specific case, all the airline had to do was swap your plane for another one at LAX that had a working one but didn't need it, i.e. a continental flight. Ideally, that plane would be on the ground at LAX long enough for them to replace the radio there, but if not, they could prearrange to have it replaced later somewhere else, probably overnight.

More generally, as others have noted, airlines don't really keep spare planes around. However, many of the planes out of service for maintenance could be pressed into service if needed without too much hassle, especially at hubs like LAX, so there is some slack in practice.

My experience is on the Regional side but in that business spare aircraft are common with operators that have large fleets. There are two important metrics: Dispatch Reliability and Schedule Completion Rate.

An airline can have a fleet with at DR that is below 99%, sometimes well below, but by having spares they can achieve SCRs close to 100%, which is the critical metric overall. In many cases, especially if the fleet is large and well ammortized, it's worth the cost to keep spares.

An aircraft maintenance technician must be able to manage stress well. When a plane or helicopter arrives at an airport, it is the duty of the technician to thoroughly review and perform any needed maintenance on the aircraft before it takes off. As an aircraft maintenance technician, you will need to possess expertise within your line of work and carry out your duties regularly and reliably.

Explanation: This is an operational question which the interviewer will ask to determine how you go about performing the duties required for this position. The majority of questions you will be asked during an interview as an aircraft maintenance technician will be either operational or technical. The best way to respond to these types of questions is directly and concisely.

Question: Once you have completed the maintenance, what methods are used to inspect the work, certify the maintenance meets FAA standards, and verify the aircraft is ready for operation?

Explanation: This is another operational question related to the previous one. During an interview, any answer you provide to a question could elicit a follow-up question from the interviewer. Be prepared for this and keep your answers short so the interviewer has the opportunity to ask follow-up questions.

Explanation: This is another operational question in which the interviewer is seeking to understand how you go about performing the duties required by this job. As an experienced aircraft maintenance technician, you should be able to answer these types of questions quickly. Operational questions are often answered best by providing the interviewer with a step-by-step description of how you go about performing this task.

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