Trim wheels and production aircraft history

flhrci

flhrci

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David
I am curious. As with all innovations and stuff we use every day, many things come into existence with trial and error and/or a "need."

I am curious if any one knows when trim came into existence or did someone, even including the Wright brothers, realize right away it was needed.

This just kind of popped into mind yesterday and I had to ask. Obscure question but some one may know.

David
 
I'm sure people understood the need for trim, the need including the term, comes from nautical roots. The question I think you're properly asking is when PILOT CONTROLLABLE trim came into being and I suspect you're even asking about pitch trim more than anything else.

In fact, the first controllable aerodynamic trim dates from the Zepplins in 1905. Most of the early airplanes didn't have them, but by the twenties they were getting fairly commonplace. The need for a pilot adjustable trim didn't really come until the engines got powerful enough that there was actually a "range" of speeds over which the aircraft was expected to fly in stable flight.

Anyhow, it's an interesting question. I've dropped a line to one of the Smithsonian curators with an aerodynamics background to see if he knows.
 
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flyingron said:
I'm sure people understood the need for trim, the need including the term, comes from nautical roots. The question I think you're properly asking is when PILOT CONTROLLABLE trim came into being and I suspect you're even asking about pitch trim more than anything else.

In fact, the first controllable aerodynamic trim dates from the Zepplins in 1905. Most of the early airplanes didn't have them, but by the twenties they were getting fairly commonplace. The need for a pilot adjustable trim didn't really come until the engines got powerful enough that there was actually a "range" of speeds over which the aircraft was expected to fly in stable flight.

Anyhow, it's an interesting question. I've dropped a line to one of the Smithsonian curators with an aerodynamics background to see if he knows.
Click to expand...


Ron,

You understood my question exactly.

Thanks for the explanation. I enjoy learning new things and that seemed like an interesting subject I have never read about before.

David
 
The Taylor (later Piper) Cub had a pilot controllable trim (it moved the entire horiz stab) but it wasn't the first (it came out in 1930 and I've seen some earlier Waco's that appear to have controllable trim).
 
Exceptionally excellent thread. :yes:

As my aviation career ripens with age I find the history of aircraft development very interesting.
 
Roger Connor from the Smithsonian Air and Space Museum tells me that the Germans had used pilot controlled mechanical trim in WWI. The article he forwarded me shows a trim lever that used strings to modify the control forces. He places the first trim tabs on airplanes at about 1927 first appearing on rudder and then elevators.

He also sent me a 1916 article on the design of an electric control system (not apparently ever implemented) that not only pretty much defines fly-by-wire but also talks about trim capability.
 
flyingron said:
Roger Connor from the Smithsonian Air and Space Museum tells me that the Germans had used pilot controlled mechanical trim in WWI. The article he forwarded me shows a trim lever that used strings to modify the control forces. He places the first trim tabs on airplanes at about 1927 first appearing on rudder and then elevators.

He also sent me a 1916 article on the design of an electric control system (not apparently ever implemented) that not only pretty much defines fly-by-wire but also talks about trim capability.
Click to expand...

Any chance you could post that article? I think it would be fascinating!
 
random data point:
Just talked to a gentleman working on the trim system for his 3/4 scale DeHavilland DH4 replica - he is working from the description in some German publication from 1917 describing a captured aircraft. It uses a jack screw to move the horizontal stabilizer up and down.
 
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Capt. Geoffrey Thorpe said:
Just talked to a gentleman working on the trim system for his 3/4 scale DeHavilland DH4 replica - he is working from the description in some German publication from 1917 describing a captured aircraft. It uses a jack screw to move the elevator up and down.
Click to expand...

I imagine you mean horizontal stab rather than elevator unless it uses a stabilator. In our small private planes, although trimming the stab is ultimately superior to using an elevator servo tab, it might be hard to justify the complexity and expense. For one thing, unlike automobiles, airplanes are mostly flying at a single speed so a servo tab can be designed to be a non-issue at that specific point. One of the more interesting concepts is the Mooney which hinges the entire tail section. Why they decided to do it that way always left me scratching my head.

The linked article from 1916 was quite interesting. The author I believe most definitely was not a pilot however as I can't imagine trying to control an airplane with three separate switches while watching ammeters :rolleyes:
 
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