Welcome To Our Maintenance Q&A's, & FAQ's Section

Mod Squad in the 1990s

Including Tips About The Proper Care and Feeding Of Mooneys.
(As Well As Commonly Asked Questions about our Mooney Maintenance Modification organization)

QUESTION) Why doesn't my local mechanic like working on Mooneys?

ANSWER) Remember, even though Mooneys are perhaps used or flown more frequently by their owners far more than the less efficient brand B, P, Or C's, at some 7,000 in the U.S., there simply aren't as many of them around as the others. Compare this figure to 18,000 V tails, well over 30,000 Cherokee series Pipers and who knows how many Cessna's. While many local mechanics will never like to admit it, but they simply don't work on nearly as many of them as the other designs. Human nature being what it is, most A&P's feel that if they annual or work on two, three or four a year they know Mooneys. That simply isn't the case. Also, there isn't as much room behind the engine between the accessory case and the firewall on M20's as there is on most other brands. That is where most usual A&P type work is done. So, combined with the tight spaces, and not working on nearly as many, most A&P's simply aren't understandably as experienced or enthusiastic. To put some humor to it, our guys only work on Mooneys, so maybe, they don't know any better.

QUESTION) I would like your shop to do my work, but after all, you are hundreds (maybe over a thousand) miles away. It doesn't seem that practical.

ANSWER) Facts are, Florida is one of, if not THE most favorite fly-in destination in the U.S for pilots! We offer more for you to do than anyplace. Think about that. Our area of beautiful semi-tropical SW Florida vacation-land (or mini-vacation-land) offers miles of gorgeous beaches, fabulous golf courses, great fishing & water sports, picturesque up- scale shopping areas, fantastic seafood eateries, and more World Class attractions (Disney, MGM, Busch Gardens, Sea World, etc.) within a hour or two driving than anyplace in the U.S. We gladly offer free hotel, B&B, and rental car reservation service and discount Disney and Busch Garden tickets to our clients. On top of that, as a courtesy we commonly drop owners off in Orlando, the Keys, or most anyplace in Florida, while we do our magic on their Mooneys. If you can't stay to enjoy the sunshine while we work, we even offer free* aircraft retrieval (pick up and delivery) for major maintenance items and/or mods, to and from your local location.

QUESTION) My local mechanic seems to do OK on Mooneys. Is it really that important to have a specialty shop like yours do ALL my maintenance?

ANSWER) Due to our shear volume, we probably inspect more Mooneys than anybody else in the U.S. Unfortunately, many of these have rarely seen the inside of a truly Mooney experienced shop. It shows! Many times a mechanic who truly knows where and what to look for, can stop a problem before it gets to the expensive replacement un-airworthy stage, or worse. Also, the average Mooney owner has no idea how many poor (sometimes dangerous) repairs an inexperienced mechanic can make simply because he doesn't know better, or has the proper factory tools and/or manuals. Human nature being what it is, many mechanics simply won't ask or know where to get proper information either! Remember, most men do not like to ask directions, and sadly the same phenomena applies to A&P's on occasion. Never let any shop touch your Mooney w/out the proper factory tools and the appropriate official Mooney Service Manuals etc.

QUESTION) AlL right, just how often should an expert Mooney shop check my Mooney?

ANSWER) Experience shows that it is best when you bring us your Mooney once a year, if not twice a year for (besides an annual), a 50-100 hr check if you find yourself in the neighborhood. If not, we strongly, repeat strongly recommend you bring it to us at least every other year for an annual inspection. We find that pending an engine set-up on turbos, gear problems, or re-adjustment of any flight or gear component, most Mooneys can survive every other annual at generic shops. Much longer than that and it shows. The problem is that generic mechanics simply can't be expected to know where and to what they should be looking for when probing for abnormal wear and tear. If you compare hundreds of Mooneys to each other, like our technicians do, then abnormalities become clearly evident.

QUESTION) What are some of the most common problems you find that other shops mis or never seem to catch?

ANSWER) Most shops are (of course) competent on aircraft they are familiar with or work on daily. We find they do not catch many of the persistent or problems SB's which are important because they can't know where to always look. We also find they don't know where the most likely spots exist for corrosion along the bottom spar cap (for example) and the lower longerons in the wings. The 4130 tubular rust is another problem as is the gear pre- load settings and wear on the nose gear truss (and trunnion) as also is the landing gear bungies. Amazingly, you would be surprised as to how many shops don't have a full set of Mooney Service Manuals and/or factory rigging tools but are still doing M20 inspections.

QUESTION) Does your shop do engine work?

ANSWER) Our engine work is sent to one of the major nationwide engine re-builders such as Terry Capehart's Blue Max, (High Performance Aircraft Engines), Victor, Firewall Forward, Carter Aircraft Engines, and Zephyr Hills Aircraft. We are perhaps the leading installer of Blueprinted and/or High Performance Ported and Flow Balanced aircraft engines in the U.S. We commonly see 8-12% more HP out of our custom O/Hauls and experienced a much smoother running engine as well. In general, we believe that a custom blueprinted engine can actually be better than an off the shelf assembled OEM brand new.

QUESTION) Does your shop do interior and paint work?

ANSWER) Yes, we specialize in Award Winning Pearlesence and BaseCoat/ClearCoat finishes which have probably won more MAPA Awards than any other painting facility. Like many shops, we  generally sub-contract out full paint jobs to a local captive shop that we represent. We also offer the NASA inspired Feather Filed M20 wing contouring which has proven to add significantly to performance as per NASA tests.

QUESTION) Does your shop do avionics and autopilot work?

ANSWER) Yes, we specialize in Mooney avionics and A/Pilot installs and commonly install many factory prototypes of various deigns for various manufactures. Like most maintenance facilities, we typically sub-contract most of our avionics work as few like Mooney shops actually have an internal FAA avionics shop per se.  We do however, work closely with several local major avionics shops and we both supervise and coordinate this type work so as to be a one stop type shop with can offer state of the art GPS/MapCom installs which are OEM quality and virtually indistinguishable from factory new.

QUESTION) What is all this stuff I read about speed rigging Mooneys?

ANSWER) Speed Rigging can be very effective if your Mooney is out of rig or has been maladjusted, or if it has had any work done in which any control surfaces have been removed etc. It is not un-common to find nearly ½ of all the Mooneys we examine to be out of rig to some degree. Any out of rig condition deteriorates performance to some degree, and can detract from both safety and performance significantly.

QUESTION) What is the true stuff I keep hearing about the corrosion problem older Mooneys face?

ANSWER) True severe or serious 4130 fuselage tubular rust is somewhat rare, but if present can be catastrophically expensive; nearly to the point of totaling an older M20. What is becoming more common is spar cap and lower longeron corrosion within the Mooney wing assy. This is caused by rodent and/or bird infestation and possibly by natural causes especially in older airframes kept outdoors in high moisture areas and/or in industrial areas. This is most difficult to find during inspection and requires copious experience as to just where look what to look for. It is serious but can be contained and virtually eliminated by proper maintenance especially by fogging the aircraft with effective corrosion preventative products such as Corrosion X .

QUESTION) Why do so many Mooney owners seem to grimace when the conversation turns to fuel tank problems?

ANSWER) The vast majority of shops simply do not know how to deal with Mooney tanks: period, end of discussion! In our estimation, there are only a few (less than 10) shops in the U.S. where we would recommend you to take your Mooney for tank work. If an experienced shop has the proper tools and pressure testing equipment (usually shop fabricated), and Mooney Fuel Tanks Specialists (in fact, we call two of our guys; Fuel Tankologists) who are experienced with tanks, they are actually no problem. It is the almost total lack of expertise in the field nationwide which has given Mooney tanks a bad rap. Rarely do we have to actually completely strip and re-seal a fuel cell. Usually, we have the repair process down to a science and our repairs last as long as you own the Mooney; or longer. We can't warn you enough to only have someone look at your tanks who both wants to, and is vastly experienced (having a long track record) in successful repairs.

QUESTION) Does the Mooney landing gear require special maintenance?

ANSWER) Yes to a point. They do require that no one messes them up with bad adjustments concerning the pre-load adjustments. Unfortunately, far too many Mooneys we see have been subject of just that; improper pre-load adjustments and maintenance by shops which do not have the education and/or proper rigging tools.. This can be catastrophic and cause a gear collapse, no question. Also, few shops can recognize the need for shims in certain nose gear wear areas as well as diagnose out of tolerance bungies. This means that many times the gear is left to go too long and then when someone looks at it who knows what he is doing, it is too late and costly parts have to be replaced. Actually, if lubricated about twice a year (which the owner can do), the average Mooney gear can go years w/out any other maintenance or parts replacement whatsoever.

QUESTION) All facts given, what are the top three service problems you see in maintaining a Mooney?

ANSWER) Aside from the fact that you need to locate a true Mooney specialist to service your Mooney about once a year, there are about 8-12 common problems, but considering Mooneys over say, 10 years old I would list the following: 1) Landing Gear being significantly (dangerously) out of adjustment and/or nose gear truss and trunnion being worn beyond Service Manual Specs. 2) Fuel Tank seeps (especially in the wing root/cockpit areas) to the point of requiring service. 3) Poor engine compartment maintenance such as worn hoses, harness, exhaust systems etc. And if there is a 4th, it would be previously un-identified corrosion in a vital areas which if caught (and treated) soon enough isn't a big problem. Remember, corrosion is the Mooneys main enemy, not calendar time and especially not even excessive flight time. or total time.

QUESTION) Just how much flight time (total time) is excessive in a Mooney?

ANSWER) This is one of the most mis-understood fallacies of GA ownership, especially Mooney ownership. These things are built like a tank and can last nearly for ever if you maintain them and protect them from corrosion. Rocky Peters, former Head of Engineering at Mooney was quoted as saying that (providing it had good maintenance) he felt the M20 airframe was good for some 50,000 hrs ... ! For the most part, since the landing gear attach points are attached directly to the spar, the wing has been supporting 1G since the day it rolled off the assembly line and (if it could have feelings), it doesn't know if it is sitting on the ground or flying! Think of a Mooney as sort of a travel trailer RV. For example, rarely do you ever inquire mileage when purchasing a used travel trailer or 5th wheel. Aside from the engine/prop etc., there are about as many moving parts in a M20 airframe as a travel trailer being towed down the road and it actually doesn't wear out in normal flight. Heavy training and/or mis-use may be a slightly different situation, but for the most part total time really doesn't matter to a knowledgeable informed buyer. Conversely, how it was actually maintained should, however. Common sense prevails however, and a 8-10,000+ hr airframe may have some moveable or wearable parts (control rod ends etc.) needing replacement as apposed to a 2,000 tt airframe. But, for the most part, these parts designed to be economically and quickly replaced, are easily identifiable, and relatively inexpensive by themselves.

QUESTION) With all that said, what do you feel is the prime problem to look out for when buying or owning a Mooney long term?


Typical Spar Cap Corrosion Repair
Usually requires wing off to repair.

ANSWER) Despite several eye opening research articles in various widely respected aviation magazines (Aviation Consumer/Light Plane Maint. for examples) aluminum airframe corrosion is still one of the most commonly overlooked problems thus far in General Aviation's ageing fleet. Besides the problem of folks not keeping their Mooneys properly maintained, read; putting off (or simply not doing) MAC Service Manual recommendations, and thus having lots of important and even vital deferred maintenance problems, like most any aluminum airframe, structural airframe corrosion is by far the ageing Mooney airframe's main enemy. We are seeing far too many (otherwise preventable) spar cap and 4130 fuselage tubular corrosion problems. There is absolutely no excuse not to properly corrosion proof Mooney airframes. For nearly 8-10+ years now we have had the product(s) commonly available (ACF-50, BoShield T-9, & Corrosion X, for example), and the technology to prevent nearly most all types of GA airframe corrosion. It is a crying shame to see Mooneys deteriorate needlessly (especially those which sit outside lots) and not get protected via economical anti-corrosion proofing or fogging with some quality type of a corrosion preventative product.

Besides corrosion, it appears that most of the non-near new (i.e.: older or more experienced) of the M20 fleet simply has far too many paper annuals or marginal annual inspections, and/or just subsistence day to day airframe maintenance which largely is not performed by experienced Mooney mechanics in accordance with Mooneys Factory Service Manual using Factory Tools etc. The vast majority of the M20's we do pre-purchase inspections on are requiring far too many deferred maintenance items having to be rectified which should have been caught years or annuals prior.
Note: See our 36 Point Pre-Purchase Common Squawks Inspection Report in our Mooney Buyers Kit and/or Coy's Book (The Backwards Tales) for more exact details of what we refer to a The Deferred Maintenance Syndrome.