Chasing ADs

There are more of them than ever and more ways to track them down. Adlog is the value leader; ATP the most complete.

by Jonathan Spencer

Are you an active or a passive aircraft owner when it comes to maintenance? Do you turn your airplane over to your mechanic each year for its annual and accept his word that all the airworthiness directives and service bulletins are complied with? Or do you track them yourself?

There are good reasons for investigating or at least understanding the ADs that apply to your airplane. More than a handful of models have recurring ADs that may come due between annuals. Chances are good that if you review the ADs and compare them to your logs, you’ll find one youre not in compliance with.

The most compelling time to review ADs is when youre shopping for another airplane or about to have a pre-buy done. In concert with the pre-buy inspection, you’ll be a better informed buyer if you know the types AD history. In fact, you might decide against an airplane type based purely on ADs.

Not surprisingly, there are lots of AD and maintenance subscription services out there, but most are aimed at the mechanic. No surprise there, either.

Every A&P or IA needs to have AD resources at his fingertips and most need it for a full range of light aircraft. (These services are also available for Boeing-sized airplanes, but we wont worry about that for this article). Aircraft owners arent required to track any of this, although many do and most are only interested in the paperwork for their specific airplane. But the buck stops with the owner when it comes to making sure all ADs are complied with before an airplane is flown.

Pay or Free?
The first question is why does anyone need a paid service? After all, the government distributes all of this stuff for free, right? Well, yes, but that distribution leaves out a few features. Here are a few of the things the paid services will tell you they do to earn the cost of the service:

Corrections – The AD listings from the FAA contain errors. Most are minor but there are a few biggies. They eventually get corrected in the official versions, but the paid AD services claim they catch errors and fix them long before the FAA catches up.

Convenience – Most of the services will send a new CD every two weeks, coinciding with the FAAs biweekly AD update period. The CDs contain the complete AD database, so you simply throw away the previous weeks CD and youre up to date.

Access to manufacturers data – Many ADs reference the manufacturers service bulletins or service letters. The FAA simply gives you the number of the SB or SE, leaving you to dig up the manufacturers information yourself. It turns out there’s a good reason for this: many of the manufacturers sell their service bulletins rather than publish them for free.

Cessna, for example, charges $11 per service bulletin. Many (but not all) of the services provide the manufacturers data, often with a hot link from the AD citation. Some provide a set of service bulletins. Others only provide the SBs referenced from ADs. And a few don’t provide them at all.

Four Ways
Four delivery systems are available for AD subscriptions: the Web, microfiche, CD-ROM and paper. None of the services provide all four and each has its advantages and disadvantages.

Web-based dissemination is the up-and-coming delivery mechanism, but its not really a mature system yet. Most of the services are talking about Web delivery but only a couple claim to have it now. Since mailing costs are a big part of the cost of the other methods, Web delivery promises to be less-expensive. Nonetheless, set-up costs are not insignificant, so its not clear that the Web will be as cost-effective as promised, at least in the beginning.

Microfiche is still a big part of the market. Try as they might to convert everyone to CD, the services have found that many mechanics are used to microfiche and have no intention of changing. And while you might think that CDs should be cheaper than microfiche, the opposite is true. Digitizing costs are the alleged culprit in keeping CD prices higher. Microfiche is a photo process. CD-ROM is the most popular medium today. CDs are small, easy to mail, and ubiquitous. And each CD update contains the complete database. You simply throw away the old one, put in the new one and you have up-to-date data.

Many of the services package additional data with the AD service. ATP-considered by many to be the Cadillac of AD services-includes Type Certificates, STCs, international regulatory information, FARs, the AIM, Advisory Circulars and FAA forms. And many also provide a mechanism for building a compliance record for individual aircraft, with forms that can be filled in and saved, something that should be attractive to owners who want precise, up-to-snuff logbooks. Because of this tendency to pile on data, requiring multiple CDs, some services are also offering subscriptions on DVD rather than CD.

The FAA publishes on paper, but so does adlog (yes, the name is all lower-case in their logo), which is an intriguing, if low-tech, alternative that offers some interesting advantages and a couple of disadvantages. See the sidebar.

Pricing should not be a problem for most aircraft owners. If you need the complete system (updates every two weeks) it will cost in the vicinity of $500 to $600 a year for microfiche or CD.

But most owners don’t need updates that frequently and many of the services offer a monthly update for about $100 less. The only really established Web-based system, The Aviation Database from Aviation Datasource, Inc. is $399 for year for unlimited web-based access.

If you expect to be able to use these right out of the box, think again. Most of the services provide the data with the A&Ps perspective in mind. And that perspective may not be instantly usable for the pilot/owner. Heres an example: We own a 1977 Cessna Cardinal RG, known in the database as a 177RG. If you look in any of the AD libraries, you are first told to select from airframe, engine, propeller and appliance databases. Under each category, you have to select a manufacturer, sometimes a category and then a model number.

Almost everyone knows the name of the airframe they fly in, most can name the engine they fly behind and most could probably figure out the propeller. But how about the appliances? For example, we have a Bendix ignition switch. We didnt know that until we looked on the list of ADs on the Cardinal Flyers Website.

Sure enough, if we look through any of the databases under appliances/Bendix/switches, there’s an AD on Bendix ignition switches (76-07-02 for anyone interested). But it doesnt appear in the list for the airplane itself.

We called our mechanic and asked how he looked up the ADs for an aircraft in for an annual. Its pretty straightforward, he said. I just look under the manufacturer for the airframe, then the engine, then the prop. And then I look under appliances for all the items that I know have ADs against them. The italics are ours.

Mechanics survive by knowing their way around ADs, so this is no sweat for them. The rest of us, however, have a problem: the A&Ps brain doesnt come packaged with these AD services.

For the CD-based services, the way around this is to construct and save a profile of your aircraft.

Most of the services provide this feature. you’ll have to research every accessory that might have an AD listed against it-you might want to buy an hour of your mechanics time to help with this- but you’ll only have to do it once. After that, you can use the profile as the search basis for AD searches and it will find any that apply to the airframe, engine, prop and accessories youve identified.

Tdata provides the best solution to this problem; they include pre-formatted profiles for most popular aircraft. You can open the profile and make changes to it that apply to your aircraft, then save it for future use. But you still have to do a little research to see if the default accessories apply to your aircraft and then make changes where necessary.

The only other option we found is the adlog (paper) system. If you order the adlog system, one item they ask for is your aircraft serial number. The package comes with all the ADs that could apply to your serial-numbered aircraft, using your aircrafts TC and all STCs that apply to your aircraft as the basis. All the updates take that into account. In other words, they do the research for you for a low fee.

Whats Out There?
FAA ( Go to the FAAs home page, click on Regulations and Policies, then scroll down and click on Airworthiness Directives. Its all there and for free. You can sign onto an e-mail list to get e-mailed every time an Emergency AD is issued. No service bulletins or letters are offered and you are on your own for type-specific research knowledge. The site is generally up to date but weve seen more than a few ADs missing from the list.

Aero Flight Data (, 800-756-0650). Their Website claims to offer AD data via both internet and CD. But the site is hard to navigate, in our view, and they didnt return phone calls querying for more information. One of their competitors considers them not a serious contender. Internet access: $120/year. One-time CD plus Internet access: $150/year.

Aircraft Technical Publishers (, 800-227-4610). Considered the 800-pound gorilla by their competitors, ATP has the most complete offerings, the largest number of service bulletins (they have copyright agreements with many OEMs for maintenance data, ensuring that they get virtually everything, the largest staff and the highest prices. Subscription prices: monthly ADs and applicable SBs only are $395 first year/$345 each year thereafter; complete library with ADs, SBs, FAA forms and other FAA publications, issued bi-weekly for $895/$795.

Their ATP Navigator system, which provides ADs and almost every other maintenance publication you could think of, also includes Type Certificates, STCs, International regulatory information, FARs, the AIM, Advisory Circulars and FAA forms. It has a good user interface thats about to get an overhaul. Based on the demo shown to us, the new interface will be even better. They assured us that all current users will be upgraded free of charge.

Avantext (, 800-998-8857). Slightly awkward front end but once you get into the AD search, it works nicely. It asks you to select airframe, engine, prop and appliance components and as you do, you are building a profile. Then it finds all the applicable ADs and brings up a compliance component for building a compliance record. AD-only library for small aircraft: $450/year; AD and SB library for small aircraft: $650/year; AD and SB library for small and large aircraft: $1050/year.

Aviation Computer Media (, 800-824-5145). An aging system (the install program wouldnt accept Windows 95/98/ME/2K folder names but insisted on Windows 3.1 format). Its based on NextPages Folio publishing system, which is not as good a search engine as some later systems. Includes AD-related service bulletins/letters. $495 for a years subscription.

Aviation Database (, 800-952-8844). No, the URL is not a typo. Aviation DataSource decided that was easier to remember and chose that for their Web address rather than their own name. Just about everything else about this outfit is similarly quirky, but they are the only ones who can boast of a working online AD reference.

Once you get into the database, youre confronted with the same four categories (airframe, engine, prop, appliances) and a search on the applicable manufacturer brings up the appropriate ADs. But there’s no profile system, so you have to search for accessories one by one.

Service data is there but not yet complete. Type certificates and other data is also available. There’s also a free (available to the public) STC database. Just select your aircraft and it pops up a list of all the listed STCs for that aircraft. Also free is a list of daily AD activity, so you can check for ADs and emergency ADs issued in the last three weeks.

Perhaps most interesting feature is a non-subscribers AD search service. At the moment, this is done by e-mail, they do the search manually. But they are developing an automated version that will allow users to enter data about their aircraft and get an instant AD list. you’ll still need to identify all your appliances that might have ADs, but the information will be there instantly.

The current price for a single AD-only search is $29.95. A single search for ADs and all applicable service bulletins, in Word format ready to be annotated and saved for compliance purposes is $149. That price may change when the automated system comes up. The price for a full subscription, which allows unlimited Internet access, is $399/year.

Summit Aviation (, 800-328-6280). This product is generally considered to be the best regulatory aviation reference library available. Regulatory is industry-speak for government publications. In other words, no manufacturers data (service bulletins or letters). But if the government prints it and it applies to aviation, you’ll probably find it here.

Summits database uses a newer version of the Folio publishing system (compared to ACM), so searching is less flexible than some other systems. Individual CD: $79 plus $9 shipping and handling; semi-annual subscription: $99, plus $11.50 for shipping; monthly subscription: $396, plus $29 for shipping; bi-weekly subscription: $495 plus $49 shipping and handling.

Tdata (, 800-783-2827). Nice user interface with a really nice feature for aircraft owners – pre-formatted profiles for most popular models. Allows you to edit the profile and save it for future AD searches. Includes applicable service information. Subscriptions are bi-weekly: $549; monthly: $449.

For an owner wishing to keep positive track of ADs on just one airplane, adlog is clearly the best value, along with signing up for the FAAs emergency AD alert service by e-mail. Its free and you’ll see fewer e-mail alerts than you will junk spam.

For an owner doing serious pre-buy investigations on several types of airplanes, Aviation Databases pay-per-search is a good adjunct to the FAAs free site. It may very we’ll turn up things that the FAA site doesnt have.

For professional shops and A&Ps, Aircraft Technical Publishers seems to be the gold standard. Expensive, yes, but with the features those who deal in ADs for a living will need.

Also With This Article
“Adlog: Terrific Service, Bargain Price.”

-Jonathan Spencer is an Aviation Consumer contributing editor. He lives in the Boston area.