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13

While the other answers are correct they are missing a key point: Because it was certified that way When an aircraft is certified with particular equipment, changing that can be difficult and may require the filing of a MAJOR REPAIR AND ALTERATION form. Its likely cheaper for Boeing to keep the trim wheels the way they are. The common 737 type certificate ...


7

The leading edge of the horizontal stab on jets is driven up and down for trim using a very large acme thread style screw jack. The Cessna 180/185 family and the Piper Cub/Super Cub/Pawnee family also do nearly the exact same thing, just with much smaller cable operated screw jacks. The early jets using jackscrew driven stabs included electric motors but ...


28

Trim pitch "wheels" as you describe date back to the time when turning that wheel actually pulled on steel cables that were connected to the hinge mechanism for the control surface itself. This mechanical/manual system was a simple and robust method of manually trimming the aircraft and was very widely used before electronic/fly-by-wire control systems were ...


3

From this copy of the flight manual for the 737: Glide Slope Pointer and Deviation Scale ... At low radio altitudes, with autopilot engaged, the scale turns amber and the pointer flashes to indicate excessive glide slope deviation. Each pilot’s deviation alerting system self-tests upon becoming armed at 1500 feet radio altitude. This ...


10

This is a differential pressure and cabin altitude indicator. The outer dial indicates the difference in pressure between the inside of the cabin and the outside in psi. During takeoff and landing, it must not be larger than 0.125 psi, as the note below the instrument says. If it exceeds 9.1 psi, the pressure relief valve will release the pressure to ...


2

As per this article, it's a Cabin & Differential pressure gauge (Boeing). Here's an explanation: The differential pressure gauge shows the difference between the pressure inside the aircraft and the pressure outside. So you would expect that diff pressure would be zero when you are on the ground and the passengers are boarding. When you are climbing, ...


30

These are called Split Scimitar Winglets and they are offered as an upgrade for some existing Boeing 737 NG series aircraft: Split Scimitar Winglets are offered by APB for the 737-800 and 737-900ER and came into service in early 2014. They are available as a retrofit to existing winglet aircraft. A set of SSWs weigh 133kg (294Lb) per aircraft but ...


6

@Jpe61 is correct in his comment that it's likely an electronics issue, since indeed a VSCF is mechanically simpler. VSCF is also used on the MD-90, with poor initial reliability$^1$ – MDC went back to IDGs for the MD-95 (717).$^1$ It's also used on the 777 (only for backup, also with poor initial reliability$^2$), and on the F/A-18.$^3$ Capacitors The F/...


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