BeechTalk - BT - Citation trivia

Username Protected · **Posted:** 28 Dec 2018, 10:37

Username Protected wrote:

At the top, you have the structural issue of containing and supporting the window. You don’t have that at the bottom. Having the door edges closer let’s you put vertical support structure that works well to stabilize the door edges and the window because it’s close to both.

I'm guessing you are on the right track, but it has to do with the fuselage. The bulkheads on either side of the door are tapered together at the top to reduce their size because the horizontal span is less and make the cabin larger inside. And the header at the top of the door would be shorter and could be smaller.

That's my guess anyway :scratch:

Username Protected · **Posted:** 28 Dec 2018, 10:39

Here's a cutaway of a 550 and you can sort of make out the door frame is tapered between two straight frames:

Attachment:

CII.JPG

Mike C.

Username Protected · **Posted:** 28 Dec 2018, 10:42

Username Protected wrote:

Cross-promotion with Queen’s 1978 release of “Fat Bottomed Girls”?

That's definitely in the running for "best wrong answer".

Mike C.

Username Protected · **Posted:** 28 Dec 2018, 11:04

My guess is that the lifting/closing mechanisms (struts, latches, etc) need to fit between parallel frames leaving less space for the door. Down at the bottom there is nothing but the horizontal hinge so the door could be wider.

Username Protected · **Posted:** 28 Dec 2018, 11:08

Pressure distributed unevenly prevents door from jamming while cabin flexes?

Shape causes door to open in crash?

Username Protected · **Posted:** 28 Dec 2018, 11:12

Accomodates attach points for the BAS chute?

Username Protected · **Posted:** 28 Dec 2018, 11:30

I don't know, but I'm really enjoying the puzzle of it!

Username Protected · **Posted:** 28 Dec 2018, 11:37

First I thought maybe because of the width of the stairs.

But now I think the width is there so the pottie can be serviced without tipping it?
A spill could be sort of bad.....

Username Protected · **Posted:** 28 Dec 2018, 11:43

Could it be for weight balance? Need the bottom to be heavier than the top so that it doesn’t come over center and get too heavy to lift out and away to open from the inside?

Username Protected · **Posted:** 28 Dec 2018, 12:49

I think it is because of the door closing mechanism. The door is down to clear the latches, then moves up to engage the locking tabs. It is narrower at the top so the tabs can clear the door opening.

Username Protected · **Posted:** 28 Dec 2018, 12:57

SUBSTRUCTURE BETWEEN RIB'S ( DOOR SUB FRAME )

TOP AND BOTTOM ARE DIFFERENT SIZE ?

:popcorn:

Username Protected · **Posted:** 28 Dec 2018, 13:15

Allows the window of the door to be equal dimensionally to the other windows?

Username Protected · **Posted:** 28 Dec 2018, 13:44

The tapered door design was appropriated from the cruise missile.

Don't ask me how I know.

Username Protected · **Posted:** 28 Dec 2018, 14:01

A trapezoidal opening and plug/door is stronger than a square or rectangle. The vertical (fore and aft) angles offer gusset type reinforcement to the cabin.

Username Protected · **Posted:** 28 Dec 2018, 14:24

Triangular door is stronger than rectangular door of same area. Jam-bolts form tighter seal too.

Citation trivia - the tapered door