I need help identifying a Boeing 727 maintenance task that would be suitable for a research project on improving maintenance instructions.

Ideally, the task should meet the following criteria: - the task should take about 1 hour to complete in a base maintenance environment; - the task should have a safety risk that is prone to human error (for example, potential to do an incorrect installation of a component).

This is for a research proposal to improve the quality of maintenance instructions. I have a commercial aviation training school that is interested in participating. They have a 727 which is a type I've never worked on and I don't have access to any of the 727 manuals either.

I'm trying to table several options that I can put to the school. What I have so far is removal/installation of an AC generator or perhaps the generator constant speed drive. Further suggestions would be very much appreciated!


1 Answer 1


It's been a while since I worked the 727. It was a very forgiving airplane, so you had to do a lot to make a critical safety error from a maintenance perspective.

However, I do remember elevator position transmitters being a major pain to adjust. Although the manual wasn't necessarily bad, I never felt comfortable with the adjustments because of how sensitive they were. The manual made it sound so easy, when in all reality, I would have felt better if there was some note that said something to the effect of "this may take a while." Plus, you always had Skydrol dripping in your face when doing it off a lift in the howling wind.

Even tightening the bolt of the transmitter down was enough to bring it out of tolerance. So, ordinarily, you had to rig it out of tolerance, then hope that the tightening of the bolt brought it in tolerance. Sometimes it'd take 5 minutes. Other times it could take all night.

There is also a "dog bone" that attaches between the transmitter and the flight control surface. Sometimes the bearings in that dog bone would develop slop, and cause autopilot issues as well.

  • $\begingroup$ I read Skydrol as Skydrool and thought you meant rain. I'm guessing that's some kind of lubricant or hydraulic fluid, instead. $\endgroup$
    – FreeMan
    Dec 15, 2015 at 17:38
  • $\begingroup$ Yes. Skydrol is a mechanic's favorite. It's an Esther based hydraulic fluid that burns like crazy when it touches your skin. It's usually found in places where you have to look straight up so that it can drip in your eyes. It's corrosive as hell too. $\endgroup$
    – Frank
    Dec 15, 2015 at 21:17
  • $\begingroup$ Thanks @Frank. Is a removal / installation of the transmitters a one man job? As for Skydrol... You used to be able to tell apart the mechanical from the avionics guys in the hangar: early onset of grey hair thanks to close encounters with Skydrol! $\endgroup$ Dec 21, 2015 at 2:25
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    $\begingroup$ As I recall, the transmitter replacement itself is a one man job. The adjustment of it is usually a two man job. I'm pretty sure you need someone in the cockpit with a breakout box and a multimeter checking for null voltage. However, I believe you could fashion a breakout box for the connector at the transmitter and read it at the tail. In that case, you would only need one person. $\endgroup$
    – Frank
    Dec 21, 2015 at 2:36

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