Sometimes its called due diligence. Some brokers consider it research or homework. To most would-be buyers, its little more than paging through a stack of records and notations that may, at times, be incomprehensible.
Whatever you call it, an exhaustive review of an airplanes logbooks is the only way you have to separate the sellers tall claims and promises from reality. This should be obvious.
Yet time and again, anxious buyers gloss over this task or skip it entirely. Nine times out of 10, theyre lucky; no undue surprises develop. But more than a few owners could have avoided buying uneconomic wrecks if theyd just examined the logs more carefully and asked a few questions.
And there’s another dimension to logbooks : If you own your airplane, you can review the logs in as much detail as you like and I can tell you by personal experience, you might be surprised at what you find.
Many owners think theyre flying pristine, damage-free airplanes but the logbooks say otherwise. When you sell, its better to know about that damage before negotiations start than to find out about it from a savvy would-be buyer who found something in your logs that you missed.
As a broker specializing in expensive Cessna twins, buyers essentially hire me to find the skeletons buried in the logbook closet and over the years Ive developed some methods and tricks to find the expensive surprises before the new owner takes delivery.
For this article, Im going to assume that youve found an airplane you want to buy and a purchase agreement has been made, contingent upon a clean pre-buy inspection. Obviously, as a buyer, you or your mechanic wont always be able to delve into the level of detail Ill describe here. Its not practical. But Ill give you chapter and verse on what I do; do as much as you can. Above all, the half-hour gloss over logbook review is asking for trouble.
Make an Offer
When should the logbook research take place? Usually its done as part of the formal pre-purchase inspection, but not always. Often, a broker has traveled to see an aircraft and perhaps fly it and a logbook review will be done prior to the first purchase offer. This is especially true when buying at a distance, when significant travel and transportation costs are involved.
The logbook review may unearth minor problems that can be quickly solved to the buyers satisfaction or it may reveal big trouble that will encourage the buyer to move on to another prospect.
Like running a checklist, there are a few pre-start items to consider. First, obtain the serial number, the model and serial numbers of the engine(s) and propeller(s) and, if possible, the model and serials of key accessories and equipment.
Next, do an AD search for all of these items; airframe, engines, propellers and accessories. Several sources provide AD information. (For a detailed review see Aviation Consumer, January 1997.) You can order reports over the phone and have them delivered in a day or two.
These reports list all ADs issued for the type of aircraft and accessory and theyll identify which ADs apply to the subject aircraft. Many shops have AD services in paper, microfiche or CD-ROM format. Although this is a tedious method, it can be just as accurate. But…theyre only as accurate as the mechanic is diligent.
Further, get a list of Service Bulletins issued by the aircraft manufacturer, engine and propeller manufacturer and, if possible, any special reports from the aircraft manufacturer. For example, Cessna never dreamed that its twins would be in routine operation 30 or more years after they were built. To support these aircraft, Cessna has introduced a Continued Airworthiness Program for both the 300- and 400-series piston twins. These publications list ADs, Service Bulletins and other information, such as time component changes.
Chain of Title
I also suggest that you purchase a chain of title. This is available from any aircraft title and escrow firm for about $40. A title chain shows all locations where the aircraft has lived. This can be helpful when the detailed reading starts.
You should also order all FAA Form 337s that have been filed with the FAA. The title firm can supply these along with the title chain. They can be mailed, faxed or sent by overnight courier. There are basically two types of 337s: Positive and negative. The good ones are aircraft modifications and improvements such as avionics additions, improved brake systems, air conditioning and the like. The bad ones are 337s that describe serious repaired damage.
I often see reference to Form 337s that arent to be found anywhere in the aircraft records. Getting the list is worthwhile. And don’t be surprised if there are no 337s at all. Thats not unusual for some models.
you’ll need some simple tools: I carry a box of standard and jumbo paper clips, Post-it notes, colored stick-on flags, several colors of highlighters, a calculator, a magnifying glass, staple remover, a stapler, tape and a couple of writing tablets.
Photocopier access is nice to have. A three-ring loose-leaf notebook with a dozen divider tabs is a good addition, too. Begin by organizing everything supplied by the seller. Often the logbook system may have changed from the small size books to the three-ring ADlog System or RAM-style system. Organize the airframe, engine and propeller logs and check each logs beginning and ending entry. Do they sequence? Are you missing anything even before starting to read? Next, organize any STCs, Form 337s, current and all superceded weight and balance forms, factory equipment lists, invoices, colored maintenance tags, equipment manuals and any other item that seems important.
I like to organize these items into airframe, engine, propeller and accessory stacks. When appropriate, organize them in chronological order. Set aside junk documents and handle everything with care; these documents don’t belong to you. Yet.
Create titles at the top of several pages in your notebook. Title several pages airframe, title a couple of pages for each engine and component and each propeller/governor, a page for 337s, STCs, fuel tanks/fuel system, landing gear, electrical , de-ice, paint, interior, weight and balance. Depending on the aircrafts age, hours, maintenance history and just the recordkeeping style for various shops, a mid- 1970s aircraft may have three or perhaps four airframe logbooks. I always start with airframe logbook number one.
First, I suggest that you identify in the logbooks each user ownership change listed on the chain of title. This usually means a change in the maintenance facility. Look at dates, shop name changes, style of entries. Post-It notes and colored flags work great for this. Gear your reading speed down to super slo-mo. Read every entry slowly. Before reading each entry, note the date change and hour change. Does it make sense? Does it seem normal?
A huge increase in hours in a short time is suspicious. Check the math. You can crosscheck dates and hours between engine and airframe logs to confirm math errors or shed light on something that doesnt make sense.
As you read, note every AD that has been performed and check it against your AD search. Note the date, hours, method of compliance and any other comment from the entry. Do the same with service bulletins. If you see an entry that says See 337, the seller should have it or you should be able to find it in the 337s you ordered.
Its possible that the 337 may have never been sent to the FAA. I see that quite a lot. If the 337 refers to an STC, see if the STC paperwork is present and accounted for. Often, you’ll see a entry that refers to a change in weight and balance: See weight & bal dated Day/Month/Year. Check and read those, too.
Note and keep track of changes to the aircrafts empty weight and useful load on the page titled weight and balance. Often, the aircrafts current weight and balance is wrong and since thats a legal issue, reweighing may also become a negotiation item.
Note on the respective notebook page repairs and/or replacement of high-ticket component changes such as fuel cells, fuel pumps, de-ice boots, alternators, heater and air conditioning components. Were these items repaired or replaced? Are replaced components new, overhauled or serviceable units? This is a good time to record component serial numbers, if listed. These can be of value if one day a part needs replacement and you have to know its serial number.
A brief listing of events can also apply to ADs and SBs. Further, this listing of major maintenance items will often reveal a story or two about troublesome trends and these may be a predictor of future problems. Frequent part changes and required maintenance will stand out. Find out about it before buying the airplane.
Troublesome Trends
I often see items such as a particular fuel cell thats been a problem, an exhaust component that keeps cracking, electrical problems and so on. These items would obviously be looked at closely on an evaluation flight or formal pre-purchase inspection but, then again, without the logbook review, they could easily be overlooked. I suggest noting the date and hours at each annual inspection. Its easy to see periods of low utilization and periods of being out of annual. What was done to the aircraft after it was parked for a while? Was anything done?
When reviewing engine logbooks, confirm if the engine(s) is indeed factory remanufactured or factory overhauled or field overhauls. Confirm total hours since new besides hours since remanufacture or overhaul. If the seller is claiming the engine is still in warranty, what do the logs give as engine in-service date?
On a twin, was the left engine once the right engine? (It happens.) Damage history and repairs? Is the last overhaul shop still in business? Again, all STCs and 337s should be present. You can plot cylinder compressions, but be careful. Low compressions are not always bad news, especially in Continental engines. When reviewing propellers, its important to confirm hours since new and since overhaul. Both Hartzell and McCauley have had major propeller ADs in the last three years.
Several hours into this process, you’ll have a good feel for the airplane. I often know more about an aircraft that Ive reviewed than its owner or mechanic-even before flying it- simply because no one ever did a thorough logbook review. Should the deal proceed to an evaluation flight and pre-purchase inspection, the knowledge you’ll have gleaned from the logs may prove invaluable.
Sight Unseen
As a broker, I often have to do logbook reviews at a distance, before even seeing the airplane. Sometimes logbooks and records are photocopied, in part or entirely, and shipped to the person doing the review. For a very expensive airplane, this isn’t an unreasonable request, although it may be for an inexpensive single.
Under these circumstances, all shipped materials remain the property of the owner and are clearly on a timed loan to the buyer/researcher. They shouldnt be permanently marked by a prospective buyer any more than the originals would be. Photocopied logbooks and other records are generally not sent to a perspective buyer who is still kicking tires before getting serious about a particular airplane.
Shipping of logbook photocopies should occur only after an offer has been made and accepted, or in the opinion of the seller, if discussions are clearly in the ninth inning. That takes an educated ear to determine. However, a serious customer has the right to be supplied with key information about the aircrafts history in addition to the normal spec list with hours and equipment.
Ive prepared this article based upon my expertise in the twin Cessna market. A light single will likely require far less time to thoroughly research. But not always. An aircraft such as a Malibu represents a huge investment and it may have a long and checkered maintenance history.
Regardless of what type of aircraft youre researching, when you hear a mechanic or pilot say after a 20-minute logbook review that everything looks okay-or the opposite-count on this: That person really doesnt know enough about the airplane to make a reliable judgment one way or another. And youre depending on that judgment.
Ive often spent an entire day and part of an evening just reading logs. At times, my travel schedule required an all nighter in a hotel room. On a half-million dollar investment that can easily require additional thousands for post-sale maintenance, its a rather small investment in time.
As the general aviation fleet gets older and builds hours, the requirement to conduct comprehensive research grows. As a professional aircraft broker, I routinely hear from owners who didnt conduct in-depth research into the aircraft they purchased and then spent thousands getting the aircraft right. Im often asked, or expected, to try to recover these expenses when selling the aircraft. Its rarely possible.
So before you take title on a new airplane, make sure you-or someone you trust-has more than passing knowledge of the secrets hidden in the logbooks. Know what youre buying and know what you own.
Also With this Article
Click here to view the Logbook Checklist.
Click here to view “How ‘Bout No Logs At All?”
Click here to view the Title Chain/ 337 Sources.
-by Jerry Temple
Jerry Temple is a broker specializing in twin Cessnas. Contact him at 972-416-3140.
