The Basics / Screwdrivers

What can I say about screw drivers? I have a Craftsman Ratcheting Magnetic for most jobs, a Short 3/8 flat blade for opening cowling and a Craftsman Ratcheting Off Set for hard to reach places. The largest selection I have that diversifies it all, is a Bag of Bits and Bit Holders that I can connect to any of the ratcheting handles to give me access to virtually any place.  This Bag contains various lengths and styles of bits as well as 1/4 inch square drive adapters for male and female to hex. This combination keeps my weight down and my tool bag uncluttered.

I also carry a precision screwdriver kit as well for electronic potentiometers  and relays.

The Basics / 1/4 Inch Drive Socket Set


The quarter inch socket set is the most necessary component in the Aircraft Mechanics tool set. When we begin using tools there are some that just fit our particular hand shape better than others. This is particularly true with the Quarter Inch Ratchet. When choosing a ratchet of any size buy a quality brand. Fine tooth ratchets are for tighter places but the finer teeth are less robust than the coarser teeth and may not take the torque that a course tooth ratchet of the same brand might. Swivel handles make excellent “speed” handles but become uncontrollable when paired with a universal socket. My fight line bag contains a fine tooth standard 1/4″ ratchet and a coarser tooth swivel handle 1/4″ ratchet which is my go to ratchet for almost every normal job. I have very big hands so the length of the swivel handle just fits better.

Quality tool truck brands are very expensive and you may not have access to any particular brand, but for me there are just certain tools that I can’t be without and I will search out a tool truck to obtain and maintain them. The two ratchets that I have linked to are on that list.

I also own some older Craftsman ratchets that are excellent but you have to scour flea markets, yard sales, estate sales etc. unless your grandpa left them to you to find these.Craftsman

Although I have not used them much, Gearwrench by APEX should be a very good alternative to the more expensive brands. They make a fine tooth close tolerance 1/4″ drive, also in a swivel head, that looks to be very usable.

1/4 Inch Drive Sockets

A full set of 1/4″ standard and deep 12 point sockets from 3/16″ up to at least 1/2″ is a must. Most good quality brands will do, but I search for US or German steel although some Oriental brands use quality steel as well.

A set of 1/4″ SAE 12 point universal sockets is also a must but if you can’t afford the entire set immediately, then the 5/16″ and 1/4″ will get you started. The Snap-On version is still the best on the market, though a few other brands are close.

Don’t forget the Bit Holder, some of the larger sets will include one, but with those you also get a bunch of items you will never use.


I have recently been using locking extensions. I wasn’t a big fan at first, but because my line bag is only 12″ long I have to use multiple extensions to get a bar over 12 inches and the locking mechanism adds security.

The Basics / Wrenches



Looking at the list lets group them together and try to touch the highlights.

The list calls for a standard SAE combination wrench set starting at 3/8 inch, which is woefully short of my most used list.

Missing are the small wrenches that are used on shoulder nuts on modern turbines and airframe alike. The ignition wrench set covers those sizes but unless you buy a high quality set they are not adequate for the job.

My line bag wrench set starts at 1/4 inch and I took out the 1 inch to save weight. I have added three Long Double Box End Wrenches; 1/4″-5/16″, 5/16″-11/32″ and 3/8″-7/16″.  A long 1/4″ box is an absolute necessity.

The next two on the list are an 1 1/8 inch and 1 1/4 inch combination wrench. I’m not sure why 1 1/4″ is required but the 1 1/8″ fits Oxygen / Nitrogen bottle regulator fittings. I don’t carry either in my line bag due to weight issues. Instead I rely on my “Ford” wrench or Knippex Pliers (more on that later). I used to carry an 1 1/8″ Service Wrench (Bonney) but someone decided they needed it more than I did. Although the Bonney wrench set is too heavy for my line bag I think they are a must for an aviation roll-away because they are narrower than most standard combination wrenches.

Next on the list is the ignition wrench set. I carry a cheap Craftsman set that I don’t use much and could be substituted with two individual wrenches; a 7/32″, 9/32″, but by the time I bought these two wrenches from Snap-On I could buy three or four of the Craftsman sets. I have had to update my wrenches with the addition of my Snap-On 1/4-5/16″ off set box wrench.

Next is a 10″ or 12″ Crescent wrench. Again, I’m not sure why these are necessary and they are far too heavy for my line bag. Instead I rely on my “Ford” wrench and Knippex Pliers. Some people prefer the “Boeing” wrench (Rigid Hex Wrench) but at nearly 12 pounds it is much too heavy for my line bag.

Finally although they are not spanner type wrenches the list calls for a set of Allen Wrenches. I find that not all allen wrench sets include the .050 size used on many instrument knobs. Buy a quality set and make sure it includes that size. Not mentioned are the Bristol wrenches that Gables Engineering uses on their audio selector panels. I still run across these occasionally.



The Basics / Diagonal Cutters

Lets Start Here with the Basics

Diagonal Cutter;

“Side” cutters are one of the most basic requirements but there are a  thousand different styles and brands, I have one pair of six inch side cutters in my line bag. I have seen techs with a drawer full; long handled, angle headed, flush cut , 8″, 6″, you name it they have it. I too am a tool collector but my budget doesn’t stand for frivolity. My shop box contains three pair of diagonal cutters, in 4 inch, 6 inch and 8 inch. The 4 inch pair are high quality (expensive little nippers) pointed flush cut pliers that I use to cut tape, wire shielding and insulation from aircraft wiring. The 8 inch pair are vintage vacuum grip metal handled Snap-On units that I use for larger cotter pins, while the six inch pair is my every day go to pair that I also have duplicated in my line bag. The most important thing about side cutters is that they cut (duh). To this end take a look at the latest offerings from Home Depot, Sears, and Harbor Freight. No, I mean take a really CLOSE look, do the cutting edges even touch? When I first started buying side cutters the test was could they cut paper. My Snap-on 8 inch pair could, even though the cutting edges looked almost blunt. They have remained sharp over the years because the cutting edges are so beefy.

I’m not saying you have to buy from the tool truck but do look closely at the cutting edge for whatever you buy.

TIP: The next time you have some left over PRC 890, or 1440 fuel tank sealant, or even faying sealant, put some inside the jaws of your side cutters. When it cures, use a razor bade to cut along the jaw line so they will open. Now you won’t have to chase that cotter pin cutting or safety wire pig tail across the ramp.

KNIPEX 70 01 110 Diagonal Cutters
are very good German steel that will last a life time.

What Works?

In today’s world of aviation there are many sub categories of aviation maintenance from General Aviation to Corporate Aviation to Commercial Aviation and then there are Helicopters, UAV’s and Lighter Than Air Craft. This is by no means a complete listing.

My experience is with Fixed Wing Aircraft, from single engine GA aircraft to Commercial heavy jets and the purpose of this blog is to discuss the various hand tools that I have used, and that I am aware of, with the hope that the reader, whether just out of A&P school or a seasoned veteran, can glean some useful information and hopefully some recommendations to build a usable tool kit.

Disclaimer: I will from time to time post links on this blog that will direct you to some of the products discussed and some of those links will pay me a percentage if you buy from them.


Here is a sample minimum tool list for new hires at one of the US’s largest commuter airlines. While it is a good basic starting point I see tools that I no longer carry in my personal flight line bag.

There are a lot of ways to fill the Minimum List and depending on how you obtain your tools there is a wide margin on what you can spend. My current line bag contains about $1,500 worth of tools. You can get by with less cash outlay, or more. I used to carry about $4,000 worth of Snap-on tools, but I don’t have tool insurance and I found out that if some dishonest baggage handler took a shine to them, my current employer would not cover my loss. The airline baggage policy is pretty worthless in that regard too. Down grading was my best choice and to be honest I can get by without most of the high dollar tools that I used to carry. There are some tools that I just couldn’t do without. It will all eventually depend on what works best for you.