Sterndrives draw less when slightly tilted up. However, inboards draw less than a sterndrive does if the sterndrive is all the way down (inboards need less water to float). Trimming down allows quicker acceleration. It also allows smoother rides when trimmed up. This allows you to raise the sterndrive up when loading/unloading or when in shallow water.
When the captain turns the steering wheel, the entire drive turns.
The drive unit is both the transmission and propulsion. Both have pros and cons and are two completely different machines.įirst of all, let’s start by explaining what exactly sterndrives and inboards are.Ī sterndrive is a marine propulsion system that is attached to a sterndrive, also known as an outdrive. In this post, we’ll present the facts and let you decide on the rest. The B-52 BTW has only an inboard aileron with spoilers to assist roll-rate.For years there have been debates about whether sterndrives or inboards are better. Maybe I'm getting confused with the B-52 though. They feature a large inboard aileron, and I think they use spoilers to augment roll-rate at low speeds. They are attached and extend as one.Īdditionally, some aircraft don't have outboard ailerons. It has double slotted flaps inboard and outboard, and flap-gap is filled with a single slotted flap. If you look at the 757 also, it does not have a gap. Additionally the wings are deliberately strengthened so that the ailerons do not impose twisting loads on the wings. They don't have very large wingspans and their wings naturally don't flex as much at the tips. Some aircraft feature just outboard ailerons. There is a thrust gate though to allow the thrust to go through right behind the engine (DC-8 only). The DC-8 has the inboard and outboard ailerons paired together, so does the A-330 and -340, and just one huge flap. Where the inboard aileron is, is where the gap in the flaps are.
The inboard ailerons usually have a larger range of travel as well. At higher speeds the inboard ailerons can produce the same roll rate as the outboard aileron could at low speeds. Once the flaps go up as a rule the outboard ailerons are centrally locked in the neutral position and only the inboard ailerons work. At low speeds both inboard and outboard ailerons work together. Usually short in total span, and placed on a thicker area of the wing that isn't going to bend. So they put an inboard aileron in at about a third the plane's total span. There's also a risk that it could overstress the wing. However at higher speeds they produce twisting loads on the wing which can nullify the ailerons and even reverse the aileron direction (turning the column left could make the plane bank right). Having the ailerons as far out on the span work best for controlling roll rate.