Interesting items can arrive in the post. Earlier today I opened a small parcel to find a collection of grey coloured pieces of material. To anyone else they would appear exactly as they do – pieces of material stamped with numbers.
LEFT: OEM dust covers for the Boeing throttle.
The throttle quadrant I use is original equipment manufacture (OEM) and once plied the skies above Europe. As such it is a used item with the usual wear and tear you expect from a well-used aircraft part.
One item that continually caught my attention was the dust curtains or skirts that sit behind the two thrust levers. In my throttle, the curtains had been abused at some point and were torn and the edges looked rather ragged in appearance. Although a replacement curtain could have been made by using vinyl or another similar material it would not be the same.
The numbered pieces of material now have a home – they are OEM dust curtains that will replace the damaged curtains on the throttle.
Installing the Dust Curtains
The B737 throttle quadrant has three dust curtains. Two on the outer side of the thrust levers and one double-sided curtain that resides between the thrust levers. Each curtain comprises three parts sandwiched together and held by three screws.
The parts are:
(i) The thin aluminium arc which is the outer face plate;
(ii) The actual curtain; and,
(iii) The plastic arc retainer.
LEFT: Dust curtains have been removed and the plastic retainer and aluminium arc can be seen along with one of the three attachment screws (click to enlarge).
Replacing the curtains is straightforward. Remove the three screws that hold the metal arc in place to the throttle, then gentle pry loose the aluminium strip beneath which are the dust curtain and plastic arc retainer. It’s wise to ensure that you place the parts anatomically on the workbench as each of the items must be reassembled the same way it was removed.
One aspect of Boeing philosophy which makes building a flight simulator much easier is their reuse of parts from earlier airframes. Boeing do not always redesign a part from scratch, but add to or change existing parts. This philosophy can save the company millions of dollars.
For those who study this type of thing, you will know that dust curtains can come in differing colour shades. In general, the older classic style throttle used a paler grey/cream coloured skirt whilst the Next Generation airframes use a standard light grey colour. But, I would not get too concerned if the colour does not exactly match.
Why are the Dust Curtains Important
The main purpose of the dust curtainsis to minimise the chance of foreign bodies falling into the throttle mechanism. Think pens, rubbers, straws, paper clips and coke can pull tabs (or anything else pilots play with in the flight deck). The dust curtains are made from a fire retardant material (not asbestos) which minimises the chance of any fire/sparks from licking up the sides of the thrust levers in the unlikely event that a fire devlops inside the throttle quadrant.
For those keen to find replacement OEM dust curtains the stock numbers are: 69-33918-8 REF, 69-33918-9 REF-F and 69-33918-10 REF-F.
Anatomically – Meaning items removed are placed on a table in the same position as they were when they were in place.
Curtain Arc – the semi circular arc that the dust curtains are attached to.
OEM – Original Equipment Manufacture (aka real aircraft part).
Plastic Arc Retainer – A piece of heavy duty plastic shaped as a curve (arc).