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Oct
24
2016

ROTORwrench…Tips, Tricks, and Info - October 2016

Posted 3 years 289 days ago ago by ScottSkola     0 Comments
ScottSkola

Helicopter Maintenance Blog 

October 2016

Battery powered helicopter* 

Who would have thought? 

For those who didn’t read about it, a company in California replaced the conventional powerplant on an R44 with lithium batteries and two electric motors. 

And flew it for 5 minutes.

I wonder if my A&P certificate covers the maintenance on it. Or, maybe I will need to get an endorsement and have an AP&B certificate.

With all these electronic gizmos on the horizon, we’ll have to add reciprocating engines, hydro-mechanical systems, and pilots to the “back-in the-good-old-days” list along with dope & fabric, wooden M/R blades, and Loran C.
*batteries not included

And here we go…

TIPS and TRICKS

GENERAL

Stuck screws. What a pain sometimes. But before you drill the screw head off, here are a few tips to try.

This is mainly for Phillips style screws, but can be adapted to other types. 

First, clean out the “cross” area completely. Use an awl or pick, if necessary. Any debris like paint, dirt, or rust will prevent the driver tip from fully seating into the cross. If the tip is not seated correctly, it will damage the screw drive areas on the first attempt. If the screw is buried under a layer of paint, remove the paint from the entire screw head area. 

Be sure to select the correct driver bit or screwdriver. A Reed & Prince #2 bit will strip out a Phillips #2 screw head. And vice versa. Ensure the bit or driver tip is not worn smooth. If possible, use bits with serrations on the drive flanges. 

On stubborn screws, use a speed wrench to gain torque and control. Try tightening the screw a tad before loosening.

For those who use electric drivers, be sure to select the “drive” speed verses the “drill” speed. You gain a greater torque rating at the bit. A side note, if removing and installing titanium screws with an electric driver, you can super heat the screw at drilling speeds which may seize the fastener in the nutplate.

If it’s still stuck, try one of the commercially available screw removers. Some fit on a rivet gun, while others use mechanical advantage.

When all else fails, the next step involves physically altering the screw head itself. On dome heads, you can cut a single slot and try a flat tip screwdriver. In other cases, you might be able to get a small chisel to bite the edge and tap the screw loose with a hammer.

A step further brings us to easy-outs and other similar tools. Since each type works a little differently, be sure to follow the instructions.

As a final option, there is the dreaded “drill-the-head-off” method. This works provided you: use the correct sized drill bit, can access the remaining shank and threads, and the screw is not titanium.

One final tip. A little preventative maintenance prior to screw installation may actually reduce or eliminate the need for the above mentioned tips. Except in areas of critical torque requirements, a minute dab of anti-seize or grease on the threads and shank will yield better odds on removing that hardware without difficulty in the year(s) ahead. Where torques are critical and no lubricant is permitted on the threads, a light coat of grease on the shank and underneath of the head will also increase your odds.

One final tip, part two. Whenever possible, replace screws with bolts. For example, AN3 bolts are structural equivalents to AN525 screws. And the same goes for MS screws and bolts.   
[Submitted by Pecos Bill]

MAINTENANCE QUESTION
A two-part question this month:

Who is responsible to record preventative maintenance in the aircraft logbook?  And, is adding a quart of oil to an engine considered preventative maintenance?
[Submitted by Jerry, aspiring private pilot]

The answer for the first part is owner/operator. They are held accountable not only for the airworthiness of an aircraft, but also for ensuring the appropriate entries are made in the aircraft record per FAR 91.405(b).   

For the second part; yes, replenishing oil is a preventative maintenance action and technically requires a logbook entry. Now, if a non-certified person adds the oil under the direction of the pilot, then the pilot would be required to make the entry as the non-certified person cannot.

SUBMITTING MAINTENANCE TIPS/TRICKS/QUESTIONS/INFO: 
Have an old tip or trick you’d like to share with your fellow mechanics? Or maybe a question that you can’t seem to find an answer to? Or just some info to pass on?  Send an email to [email protected].

About the author: After 32 years maintaining helicopters in various capacities, Scott concluded a full time career with a major operator in 2014. When not pursuing future writing projects, he can still be seen around the flight line tinkering on aircraft for beer money.  He can be contacted at [email protected].

*And to keep the hounds at bay, the information contained in this blog is for discussion purposes only.*






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