Trimmable elevator--when did it come into use?

[Clifford Bossie]

Grumman F2Fs and F3Fs had adjustable stabs (not elevators) and I imagine there were airplanes prior to those.

[Dave Hadfield]

The Lysander certainly has one, and it is critical for the operation of the aircraft.

[Randy Wilson]

Stephan - you might want to post your question on the Aircraft Design Firsts thread started by Noah307. Just a suggestion.

I would imagine the origin may lie with the first of the large multi-engine aircraft, especially bombers such as the Gotha G-series which would have had major changes in CG due to the dropping of 300-400 kg of bombs and use of fuel on 5 hour-plus missions to England. However, since about 75% of these were lost in landing accidents and their aft-CG and low stability when lightly loaded are mentioned as part of the problem, they might not have had such trim control. Not to mention the R-planes (Giants). I am currently studying (in my "spare" time) these planes of "The First Blitz" but have not seen any mention of pitch trim specifically so far. All the best.

Randy

[Stephan Wilkinson]

Thank you all for your support and for the continuation of this thread in the best tradition of WIX's search for information and truth despite one person who would just as soon shut it down.

[quemerford]

Thank you all for your support and for the continuation of this thread in the best tradition of WIX's search for information and truth despite one person who would just as soon shut it down.

Oh please dearie. My only issue was with lazy "research". You decided to be a drama queen about it.

[Neal Nurmi]

Carry on, Stephan -- this has been interesting. Ignore the static...

[Randy Wilson]

Well, here is something interesting, I think. Quote from page 73 of The German Giants by Haddow & Grosz, third edition, 1988. The aircraft discussed is the AEG R.I 12/16 "giant" which first flew on 14 June 1918:

"No effort was spared in incorporating lessons learned from the earlier giants, and many improvements and innovations were tried. Particularly noteworthy were the electrically-operated tailplane trim controls, the all-steel fuselage and the mixed steel and duraluminium wings."

If this was the first or one of the first uses of "electrically-operated" tailplane trim controls, it suggests that there were earlier uses of manually operated controls. As a pilot, I can't imagine the amount of work to operate these early, complex and big giants. If I find more info, I will pass it on. All just FYI with regard to the original question.

Randy

[JohnB]

Was at the airport today, and again I was surprised, the Travel Air (the biplane not the Beech) had an adjustable stabilizer as well.

[Noha307]

A forum thread I found after a quick search reminded me that, similar to how wing warping was eventually replaced by ailerons, there was a precursor to trim tabs: the all-flying tail. It's essentially the same concept that Mooneys use, where the entire empennage was hinged to pitch up and down. As mentioned in a post in the aircraft design firsts thread, the Albree Pigeon-Fraser, which first flew in 1917, featured this design:
[Link to Oversize Image]
(Source: National Archives)

Others learned something from your query.

Our job as historians is to make more knowledge available to more people, so I love it when my research reaches a larger audience. As I've said before, the one caveat is that the information is properly cited. However, last time it came up, I only addressed half the reason why citations are so important. Yes, they are very important for locating other research sources. However, they are also important for providing credit where credit is due. My first history professor in college had warning that will always stay with me. To paraphrase: "If you plagiarize, you will be shot at dawn."

It's about respecting the wishes of the creator and their inherent value as a person. It's the reason that - I asked Jim whether he would be okay with uploading the target maps and approach charts to Wikimedia Commons - even though since they are public domain legally I didn't have to. It's the reason that - when I uploaded a bunch of pictures of the TSWM's Corsair to its Aerial Visuals dossier just the other day - I worked hard with the man who had provided them to ensure that each picture had the proper credit lines.

Sorry to get philosophical, it's just an subject I've dealt with and thought about a lot. Thanks for the question Stephan. I appreciate the answers everyone else have provided so far and look forward to seeing what else is dug up!

EDIT: Interestingly, two newspaper articles (1, 2) from 1943 not only describe how trim tabs work, but are written in such a way that suggests many people were unfamiliar with the concept - at least among the general public. (One of them is even titled "Tiny But Important-That's Tab Actuator That Moves Airacobra".) Furthermore, if you search "Trim Tab" on Newspapers.com, the usage graph drastically increases in 1941. So, while trim tabs were certainly in use before World War II, the broad awareness of the concept appears to have only occurred during the war. If I were to speculate it a bit, it might be tied to the introduction of boosted controls on aircraft like the P-38.

[Hooligan2]

It's essentially the same concept that Mooneys use, where the entire empennage was hinged to pitch up and down.

I hadn't realised the Mooney's entire empennage moved until I noticed one parked at Denham, a small airfield in northwest London, which appeared to have the the tail unit bent up and the fin leaning slightly forward. An accident during landing? A closer look revealed the whole unit moved and the aircraft had been parked with the trim left "nose up". Strange I'd never noticed before as the British distributors at the time (maybe 35 years ago) were at Biggin Hill, my local airfield, and I was up there regularly, wandering round with my camera.