Stemming from a query on Prze's Dolphin build re tailplane gaps, I posted an explanation re Allied trim controls but suggested Achim be contacted for his expert input on Axis types and Zac has opened a separate topic in the Info/Question here with his reply.
In order to open this maybe to a wider group, it's probably worthwhile re-posting here the Allied procedure - which may be unfamiliar to some - and explain that wheel in the cockpit!
If you've already read this, or knew it before, please ignore.
........................................
Back in 1917 aircraft did not have trim tabs on the elevators as they do now. (Trim being the minor adjustments to ensure the aeroplane flew straight and level in normal neutral flight.)
Instead (on most RFC/RAF aircraft) trim was achieved by moving the entire one-piece tailplane (horizontal stabilizer) up or down in the fore/aft plane. Often this was attached to a wheel (Tailplane Actuating Gear) in the cockpit so, for example on a bomber, trim could be adjusted in flight. after the weight of bombs had been dropped.
Whether set on the ground, or in flight, this meant the gap between fuselage and tailplane could vary according to the trimming - so a gap could often exist. Similarly you'll frequently see a gap between the fin and the tailplane for same reason.
According to the series of Official Rigging Notes, the Dolphin for example, would be trimmed on the ground after testing, but the SE5a could be trimmed in flight via cockpit wheel and here is the relevant bit for TAG setting from the SE Notes.
Sandy
