Common to use a maintenance/assembly checklist?

[RBD]

Originally Posted by Webb

You are correct.....there is a third....heaven forbid but finger tight.

I really don't know but since there is a human factor here, anything is possible....It's also a very good reason why we use a checklist and don't "cheat".

This recent thread about a critical nut coming loose reminded me that I wanted to ask you all if it is is common to use a maintenance or assembly checklist? Being new to airplane ownership, I'm not sure what is standard practice. As was mentioned in the other thread, it is not at all difficult to conceive that one could finger tighten a nut, and forget to torque or safety wire it before buttoning the plane back up or moving on another task.

Case in point (and the reason I say that the other thread reminded me to ask about this), is that I had my cowling off this past weekend to measure the dimensions for an air filter that I'm going to install for my alternate air. As I put the plane back together, I only inserted the hinge pins (vertical hinge attaching the sides of the lower cowl to the firewall) about 1 inch into the hinge to make sure I had everything lined up correctly. I then put the top cowl on and went home. This was on Saturday. Sunday night as I was laying in bed talking my wife, I politely interrupted her, got out of bed, and went and stuck my airplane keys in an envelope, sealed it, and wrote the following on the outside: "INSERT HINGE PINS ALL THE WAY, IDIOT!!!" I'm not exactly sure why this potentially hide-saving thought popped into my head during a completely non-related coversation, but I have a good idea where it came from.

After this experience, I will be coming up with checklists for different maintenance tasks and/or areas of the plane. Seems to me that if we use them in flight to prevent ourselves from forgetting the routine, there is no good reason to NOT use them during maintenance. If there is any existing documentation that I should be aware of, please let me know.

[az_gila]

...create a true checklist for every possible maintenance task.

But, in the case you mention of an interrupted task, I find that a Sharpie note written on a piece of blue masking tape and stuck on the incomplete part can help your memory the next day...

A friend makes his own sub-task list up each time, and then checks off each item as it is completed and re-assembled.

As mentioned on the other thread, the application of Torque Seal on all torqued nuts and fittings is a really cheap $2.95 safety item.

[roee]

Ditto everything Gil said, plus:

I find the following principle universally applicable to flying, building, maintenance, scuba diving, engineering, you name it. As a matter of practice, if you have to leave something partly done and come back to it later, don't leave it in a condition where it appears done. That's just asking for it. If it's not done, leave it in a condition where it'll be obvious and conspicuous that it's not done when you come back. It's a good habit to get into. Following this principle will greatly reduce the probability of that one out of N times where you will forget to complete the task and not notice it until it becomes a major problem.

So Ryan, in your case for example, better practice would have been to either insert the cowl pins all the way (task complete), or simply leave the top cowl off (task obviously and conspicuously incomplete).

Another example: If the engine is off, turn off the mags and remove the key. I'm sure we've all been taught this one from day one, and that's an application of that same idea. One of my old CFI's actually insisted on keys visible on top of the glare shield during preflight & postflight. Good idea.

Yet another example: Never close the canopy and not latch it. Either it's propped open (task obviously and conspicuously incomplete), or it's closed and latched (task complete). Follow this and you will not likely ever take off with an unlatched canopy.

And yet another example (from scuba): I've seen this one several times. A diver sets up his gear, opens the tank valve to check the regs and inflators, then closes the tank valve back up until ready to suit up. But the system is still pressurized and so appears ready to go (the trap has been set!). One of N times the diver then forgets to open the valve back up before getting in the water, but doesn't realize it because he's got pressure. Upon descent, he gets several good breaths off the reg until the residual pressure in the hoses has been used up, then ... gasp! Very unpleasant, and easily prevented. If you must turn the tank valve off, purge the reg to depressurize the system. Tank valve on, pressure. Tank valve off, no pressure. Then there's no mistaking it. Sorry for injecting a scuba reference, but I think this one gets the point across pretty well even to non-divers.

BTW, Gil's suggestions are all essentially specific ways to apply this principle.

[Cfrisella]

Does a list of every fastener and location exist for each RV model(aside from the BIG plans). The lists will be long, but may be nice to hav before that first flight. Something overlooked that kills the engine is one thing. An overlooked item that takes out a control surface is another. I personally would rather land without a running engine then pitch/bank controls. If anything else it would give a little peace of mind to the questions, " Did I check everything?" or "Did I double check that?"

[az_gila]

Originally Posted by roee

..... One of my old CFI's actually insisted on keys visible on top of the glare shield during preflight & postflight. Good idea.
.......

I was taught that too in the 70's.

Given the number of times I'm asked about it, I guess that "keys in sight on the dash" must not be the present standard....

[Mel]

Originally Posted by roee

Another example: If the engine is off, turn off the mags and remove the key. I'm sure we've all been taught this one from day one, and that's an application of that same idea. One of my old CFI's actually insisted on keys visible on top of the glare shield during preflight & postflight. Good idea.

Be careful! This rule can bite you too. I've seen ignition switches worn enough that the key would come out in the "Right" position. I saw a Globe Swift start when the prop was turned with the keys in the owner's pocket.
The mixture was in "idle-cutoff" and the airplane had been sitting for a week. You just never know for sure!

[sjjonesnz]

...and then there's those of us that don't have keys to leave on the dash...'tis all switches...hence the habit of treating every prop as 'live' until/unless confirmed otherwise.

[n5lp]

Originally Posted by sjjonesnz

...and then there's those of us that don't have keys to leave on the dash...'tis all switches...hence the habit of treating every prop as 'live' until/unless confirmed otherwise.

It's pretty hard to confirm "otherwise" though. I had the experience of unintentionally starting the engine on a Champ with the switches off. Fortunately I still have all my fingers because I was treating the prop with respect while pulling it through prior to a planned start. Bad mag ground, obviously.

[Ironflight]

Originally Posted by Cfrisella

Does a list of every fastener and location exist for each RV model(aside from the BIG plans). The lists will be long, but may be nice to hav before that first flight. Something overlooked that kills the engine is one thing. An overlooked item that takes out a control surface is another. I personally would rather land without a running engine then pitch/bank controls. If anything else it would give a little peace of mind to the questions, " Did I check everything?" or "Did I double check that?"

While building a complete, comprehensive list is a nice idea, I would be afraid that no matter how hard you tired, it might never be absolutely "complete". The way I do it is to trace continuity - from my fingertip on the stick, all the way to the trailing edge of the affected control surface. I touch and check every bolt along the way. I use a "Condition Inspection" checklist to make sure that I have not missed any subsystems, but in essence, the airplane is my checklist when it comes to controls. The trick is to not jump around. Do the pitch channel, from end to end. Then the roll. Then the yaw. Then the Throttle - etc. Check every fastener along the way - that's how I found a loose nut at the stick end of my elevator push rod a few years ago. i make no excuses - I must not have tightened it, because once I did, it has not moved since.

Paul

[gasman]

Originally Posted by Mel

Be careful! This rule can bite you too. I've seen ignition switches worn enough that the key would come out in the "Right" position. I saw a Globe Swift start when the prop was turned with the keys in the owner's pocket.
The mixture was in "idle-cutoff" and the airplane had been sitting for a week. You just never know for sure!

This happened on my WARRIOR. The switch was in the off position, and the key in my pocket. The switch had 2000 hours on it, and you could turn it past off (to the left) by about 1/16" and remove the key.......... By design, the mags were still hot! Later came an AD....

I gave up on key switch ignitions. They provide nothing in value, but are a pain to wire..... are heavy.... and expensive.