Trimmable elevator--when did it come into use?

[Stephan Wilkinson]

Many Gloster Gladiator pilots--an airplane I'm currently writing about--refused to use the airplane's four split landing flaps because they "upset the airplane's trim," which makes me think the pilot had no way of adjusting pitch trim. And I see no elevator trim tab on any Gladiator photos. Was there commonly a system, on airplanes of this generation, that could be cranked or manipulated to vary horizontal stabilizer angle of incidence?

When did easily adjustable (in flight) pitch trim come into common use?

[quemerford]

I think, "an airplane I'm currently writing about" might be a bit steep: looks like a lot of it has come from Google and the good folks here. I hope they'll receive due credit.

[Stephan Wilkinson]

It's called research, and I am entirely open about what I am doing and why I am doing it, and I use my full name, not an alias. If you disagree with it, you are certainly welcome to decline to participate.

I use the Internet, I go to libraries, I read books and articles, I interview people, and I post queries hoping to get authoritative answers and information.

[quemerford]

If you think it's research then fine. But many queries would be better answered by reference to primary source data rather than anecdotal.

[Archer]

Interesting question. The Piper Cub certainly had an adjustable horizontal stabiliser so that's another example from the 1930s, but I cannot think of where it would have originated. Common sense says that trim would have emerged with the increasing speed ranges of various types, and I'm pretty sure that the DC-2 for example had it. The Fokker triplanes did not have elevator trim, at least not the early ones which turned up in the 1920s. So based on that (which is not much more than my memory, a bit of gut feeling and three minutes of looking at images on the internet) it doesn't surprise me that a 1930s type did not have a trim tab or adjustable horizontal stabiliser. I guess it emerged on larger and smaller types throughout the 1920s and 1930s to become pretty much standard by the late 1930s.

[Stephan Wilkinson]

Thank you, Archer.

[Dana M Bell]

If you think it's research then fine. But many queries would be better answered by reference to primary source data rather than anecdotal.

That's easily said. I do primary research for fun and profit - but it's been mighty impossible for the last two years with all the archives and museum research sections closed to the public. In their absence, places like this become the resource - many of us have primary documents in our collection...

Cheers,


Dana

[Baldeagle]

Sopwith airplanes had adjustable stabilizers as early as 1916. Surely the Gladiator did also.



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[Baldeagle]

Trim wheel on the left of the seat



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[Hooligan2]

Pretty sure Pilot published a flight test of the Gladiator (by Andy Sephton?) about 20 years ago when James Gilbert was still at the helm, I recall Shuttleworth's example gracing the cover - I might still have my copy in the loft somewhere...

[Baldeagle]

Question already answered in his other thread:

unit/Tailplane

The tail unit assembly consists of a port and starboard tailplane, port and starboard elevators, fin and rudder. The tailplane is adjustable for incidence (providing pitch trim control) and is mounted at the rear of the fuselage. The tailplane front spar is braced by two external bracing wires on each side, the wires running from the outboard ends of the spar diagonally up to fittings attached to the fin leading edge structure and spar post. The underside of the tailplane front spar is also braced by a single wire on each side, the wire running diagonally down to a fitting connected to the fuselage lower longeron. The tail plane front spars are connected to the bearing beam of the fuselage, and the rear spars to the after end of the tail adjusting gear locating arm by means of which the incidence is varied.


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[Stephan Wilkinson]

Baldeagle, thank you. That photo is pretty authoritative.

I am going to stop querying members of this forum, however. Seems some people don't like it.

[quemerford]

Baldeagle, thank you. That photo is pretty authoritative.

I am going to stop querying members of this forum, however. Seems some people don't like it.

Yay.

[JohnB]

Though I'm not claiming these were early examples, I was surprised to see a WACO UPF-7 with an adjustable stabilizer and even more surprising was the Hamilton H-47 Metalplane.
That might be the first use on a metal airliner.

I enjoy seeing your questions, please feel free to continue.
Last time I checjed, it's still a free country, so ask away.
Those who don't like them don't have to read your threads or participate.

Simple.

[Jim MacDonald]

Stephan,

Seems like only one person had issues, screw him. Others learned something from your query. So I say keep querying away.

Mac