Bits and Pieces
Aircraft Inspection Techniques for Homebuilders - Part 6
By Bill Evans, President - EAA Chapter 266, EAA 794228
Drawing All the Details Together
Those who have followed this series through the first five parts have learned that aircraft inspection consists of hundreds - even thousands - of details.
If you follow the accident surveys, you will see the same thing. There is no one cause, nor even a few common causes. In practice, by the time an item repeats for you, 25 years may have gone by.
Our challenge in inspection is to inspect everything. (He must have said that 10 times!)
There may be one or two professionals who can remember 25 snags. The rest of us need to jot them down. If our little snag recording system that I'll describe is very good, then it will be of far greater value and use to us than it took to create it. Everything we do here is done with future benefit in mind.
Defect Cards: The Advantages
Defect cards are just that: lined 3 x 5 index cards. Buy a pack of 100. Each snag goes on one card. Writing defects down prevents omissions. Buy 8-1/2 x 11 card stock, too.
- For each card, you need to place a tag or sticker at the location of the snag. The tag has the same number (e.g. 001) as the snag card.
- On these cards we gather all the information into one place.
- If desired, you can clip photos, or even print photos, on the back.
- These cards allow you to organize your work by:
- area (wing)
- skill (sheet metal)
- priority (the snag that grounds your plane has the highest priority)
- parts availability (you order parts by priority to fly rather than desirability)
- time required to repair (lengthy work needs to be started earlier than short tasks).
- Parts needed for each task will be recorded on the defect card for that task.
- Whenever needed, you can add more information to any defect card.
- Repair schemes and maintenance manual references are also listed on these cards. This avoids duplicate searches for information.
- Once you know the repair and parts required, you can determine the tools required. Given some notice, other homebuilders may agree to loan you specialized tools, or even better, help with the repair.
- Repair scheme: Record on the defect card in simple terms what was done to effect each repair.
- Why all this information? At the end of your annual inspection, you will be expected to record this work in the aircraft's journey logbook. Transport Canada requires it.
- Why not? Your defect cards have made it easy. Example: Right wing main spar Number xxxx replaced as per AC 43-13, Pages x-x2, and wing drawing XXX, using sheet metal tool kit.
Now you are legal, and you have left a paper trail should it be needed. In the airlines, the investigators have many ways to find the root causes of failures and accidents. Aviation safety has improved over the decades, because each time there is a failure, there are the means to find and eliminate it.
What are the means you provide to find and eliminate failures in homebuilt aircraft? Entering all your repairs in the logbook goes a long way.
If a repair is such that its details will not go on one card, then draw lines on an 8.5 x 11 sheet of card stock and use it as a defect card. No, don't record many similar snags on these sheets. You will defeat the purpose of your records.
Make a list - Take another sheet of card stock, line it, and record the title of each of your defect cards. Then tape the sheet to your tool box. List one item per line. You also add that ATA 100 code to identify system, area, and defect card number. (More on this later.) Should a defect card be lost, you still have a reference to the snag and can reproduce it.
The defect cards can be organized into groups for:
- ordering parts
- finding repair documents
- locating tools
- logbook entry
- skilled help needed.
These defect cards can be re-sorted into "parts available" stacks, so you know at a glance which work may be started.
It is not unusual for Transport Canada inspectors to visit airports. They may well ask to see the documents for your most recent annual inspection. If you have kept a completed annual inspection form and your defect cards, they are proof you have done an inspection and the repairs associated with it. (By golly, you'll be able to paralyze them with documents!)
The defect card needs a little explanation. Everything written on the card is done in block letters.
- The DATE (written) is in the top left corner.
- The defect card ATA reference is at the top right corner.
(Recently we inspected two homebuilt aircraft for the firewall-forward installation. One owner noticed that we inspect by ATA system and subsystem and requested that we include that information in this series. The series would have concluded with this installment, but we will go on to cover that material next time since it is requested.)
- Title - The subject of the defect card is written below the date.
- Description - The description of the snag is written down but should be condensed.
- Limits - If there are known flight limits, they should be stated here.
- Repair instruction - The repair to be accomplished is stated here.
- Documents - It is necessary for whoever works on an aircraft to show the drawing, manual reference, or modification which is used.
- Parts - The parts used are recorded here. If the parts list is long, record it on the reverse side.
- Tools - The tools, or instruments needed, are recorded here so that you may organize their purchase, rental, or loan.
- Rectification - It may seem to you that repair instruction and rectification should be the same, and they might be. However, good intentions and reality may differ. In this space, you record what was actually done. This is the heart of your paper trail. It may save others in the future.
- Details of the work, parts, documents, and test equipment are recorded here.
- Signature and date: This may be optional, but if someone else is paid for the work, record it.
We note that this article has focused on inspecting homebuilt aircraft structures. Admittedly we have diverged into aircraft systems whenever we felt it was needed.
We may restart this subject with a more thorough treatment of aircraft systems proper; that is to say ATA 21 Pressurization and Air Conditioning to ATA 80 Engine Starting.
- Our purpose in this series has been to help reduce the accidents among homebuilt aircraft.
- In our years in aviation since 1966, we have not found any book, document, or article which shows you how to inspect an aircraft. They all deal with the air regulations.
- This article is our work. It is intended for the education of Bits and Pieces Canadian readers.
- Do not copy, store, reproduce, or transmit the article without our express written consent. E-mail the editor for contact information.
- We provide no guarantee, promise, or warranty, stated or implied, for this article series or the results of your inspection, even if you follow these instructions perfectly.
- In this country, the regulatory agency states (and has testified) that the sole responsibility for the inspection of an aircraft lies with the person inspecting the aircraft. (If you are reading this from a country other than Canada, read your regulations.)
- Some nations require an AME or A&P mechanic or approved inspector to inspect homebuilt aircraft. You need to know that for your aircraft.
- There's virtually a limitless number of myths regarding aircraft maintenance. Some things that ordinary people state are entirely wrong or false. Call your agency and ask.
- The depth of inspection that you perform on your aircraft will impact your future. Be thorough and you will be sure your impact will be positive.
- Take your time. When in doubt, get the advice or help from a professional.
When this series of articles began, we said that if you perform an exhaustive inspection and follow up on the needed repairs, you can know with some degree of confidence that your aircraft will reach its destination. Finally, you and your passengers will land in the same conditions as you departed.
This knowledge of your aircraft will also enable you to perform your flight planning with the same confidence. You should and will know as much about your particular aircraft as your mechanic, perhaps more. I believe that is worth the work of an aircraft inspection as described above.