Lightning: Warning System

06 Nov 2018 04:26 - 06 Nov 2018 05:20 #40746 by Algernon
Following on from a brief discussion elsewhere regarding the warning system, I've found a description of the T4's warning system in pilot's notes on Avialogs , which I assume will not be too far different from the T5's.

This description gives a pretty good idea of how things work - I'll post a summary of my understanding of this, and with anything I don't understand, once I've read it all. It seems pretty manageable though - two warning panels, Standard (SWP) and Auxiliary (AWP), with clangers and attention getters operating when an SWP warning is active. Not entirely clear on the day/night switch and "two sets of captions", but everything else seems to make sense.

Please Log in or Create an account to join the conversation.

06 Nov 2018 05:32 #40748 by Algernon
One question for you already, Scott - you mentioned that the generator and alternator indicators go out when either engine is above fast idle, and current is being generated...

So what happens at fast idle, or ordinary idle? Where is the lectric for all the instruments and stuff coming from, if you're in the air with the throttles pulled right back? I ask this first off, as it might require a modification to the electrical system to make it realistic.

Is there just one generator and one alternator, driven mechanically by a gearbox by either engine, or one of each unit per engine? (I guess the former, like the Eurofighter)

Please Log in or Create an account to join the conversation.

06 Nov 2018 09:19 #40749 by ScottBouch
Hi Algy,

The T4 will be more akin to the F1, F2 aircraft and will be misleading for the T5.

For the T5, the most similar aircraft (systems-wise) will be the F3, and most of the F6, as it was the trainer for these aircraft.

I'll be able to share some good info with you later today form the correct AP's.
The following user(s) said Thank You: Algernon

Please Log in or Create an account to join the conversation.

06 Nov 2018 10:14 - 06 Nov 2018 10:16 #40750 by ScottBouch
There is one common air-turbine that's fed from both engines compressor bleed air (via non-return valves). This turbine rotates a DC generator and an AC alternator via a gearbox. Teh air flow needs to be sufficient to get the speed up of this turbine.

Fast Idle is 58% RPM. At least one engine needs to be above this for the AC and DC generators to rotate and generate power. When one engine reaches 58%, the warning indicators will go out. I should have a video somewhere that shows which one will go out first, and also re-illuminate first on engine shut-down.

(Below this RPM in flight, you only have DC from the aircraft battery for the essential systems.)

However, there is a physical stop on the No2 throttle to keep you above Fast Idle, there is a lever to press to overcome this stop and come down to Idle. This is so at least one engine stays above Fast Idle. No1 doe snot have this stop.

(Both throttles have a further stop at Idle which has to be overcome by another lever to shut-down the engines.)

Lots more systems depend on engine air too, requiring Fast Idle; cabin pressurisation, canopy seal inflation, cooling air for lots of equipment. So I can't imagine you'd ever really have both engines below fast idle in flight.

Please Log in or Create an account to join the conversation.

06 Nov 2018 10:25 #40751 by ScottBouch
Day / night switch and the two sets of lamps is only applicable to the earlier aircraft. One set of lamps was behind darker Perspex for night time.

The T5 has a slotted sheet of Perspex that slides over a single set of lamps for night time, a much simpler solution. The F6 (and maybe F3, I'll check) upgraded to something similar too.

I have the guts of an F2A AWP which has the 2 sets of lamps and day/night switch.

This is a T4 confusion; I'll send you what info I have for the latter aircraft later today.

Please Log in or Create an account to join the conversation.

06 Nov 2018 11:21 #40752 by ScottBouch
Ok, here is the AP extract on the T5 Warning systems!

www.scottbouch.com/AP-101B-1005-1B_Secti...ergency-Services.pdf

Please let me know when you have downloaded it so I can remove it from my raspberry pi.
The following user(s) said Thank You: Algernon

Please Log in or Create an account to join the conversation.

06 Nov 2018 12:41 #40754 by ScottBouch

Please Log in or Create an account to join the conversation.

06 Nov 2018 14:26 #40756 by Algernon

ScottBouch wrote: Please let me know when you have downloaded it so I can remove it from my raspberry pi.


Downloaded. Thanks!

Please Log in or Create an account to join the conversation.

06 Nov 2018 15:30 #40759 by ScottBouch
Cool. I'm also putting together some logical conditions for all the warning lamps of the AWP and SWP.
The following user(s) said Thank You: Algernon

Please Log in or Create an account to join the conversation.

06 Nov 2018 15:44 #40761 by Algernon
Splendid. In the mean time, do you know if you have any photos from your recent expedition of the AWP and SWP? It might be handy at this stage to assess them for modelling - getting the model into a workable state makes testing the code behind it easier and more fun :)

Please Log in or Create an account to join the conversation.

06 Nov 2018 16:20 - 06 Nov 2018 16:22 #40768 by ScottBouch
AWP:

Please note the original lettering in the windows had fallen off over time, these have been re-printed, but the font is not quite the same as the original. I'll get some more info on the correct lettering.



Attachments:
The following user(s) said Thank You: Algernon

Please Log in or Create an account to join the conversation.

06 Nov 2018 16:26 - 07 Nov 2018 08:11 #40770 by ScottBouch
SWP:

The modern lettering is more visible here... Also please note I think it should be coloured lettering on a black background. I'll check some historical photos from before this mod was done.





Attachments:

Please Log in or Create an account to join the conversation.

06 Nov 2018 16:28 #40771 by ScottBouch
I have a couple of similar warning panels here that we can sample the lettering from, and take measurements of the height from the panel, wire loop, etc..

Please Log in or Create an account to join the conversation.

06 Nov 2018 16:41 #40773 by Algernon
OK, great. I'll probably start doing some Blender work on this in a few days time - am off to my parents house to disassemble my car interior (again) after tonight's night shift...

Please Log in or Create an account to join the conversation.

06 Nov 2018 16:48 #40774 by ScottBouch
Great I'll get some dimensions for you in the meantime.

Good luck with the interior! I've never been able to get them quite right again after refitting!

Please Log in or Create an account to join the conversation.

06 Nov 2018 17:11 #40777 by Algernon
Ugh, tell me about it. I actually HAVE managed to do it a few times now, but only with such methods as putting down old sofa cusions so I can lie in horrid painful positions, swearing a lot, watching loads of YouTube videos of other people doing it, buying special tools, and going back and redoing stuff... then finding the battery's not quite happy enough to start the engine, from having the doors open and all the interior lights on all day...

Please Log in or Create an account to join the conversation.

06 Nov 2018 17:25 #40780 by ScottBouch
Not envious!

Last time I did anything like this was installing a Raspberry Pi Zero in the car headlining plastic work, using OSMC to provide a stream of Disney films to the rear seat occupants for some pretty long journeys!

What car is it? and what's the reason?

Please Log in or Create an account to join the conversation.

06 Nov 2018 17:55 #40783 by Algernon
A new topic in Bar and Lounge explains it all . I might actually be able to improve my design by tapping your brain a bit...

Please Log in or Create an account to join the conversation.

08 Nov 2018 10:35 #40805 by ScottBouch
Algy,

Here a re two more images from a few years ago. They show the flaking off lettering and how it was applied originally.

Basically the inverse / negative of the lettering was painted in black onto a coloured perspex sheet, leaving the light to shine through the letters.

So:

SWP = Orange letters on a black background


AWP = Red letters on a black background


Over years the paint started to peel, which is why the images I took the other weekend show modern replacement lettering.

Cheers, Scott.
Attachments:

Please Log in or Create an account to join the conversation.

08 Nov 2018 10:39 - 08 Nov 2018 10:50 #40806 by ScottBouch
Dimensions...

I have a warning panel from an unknown aircraft, it's shape is quite different - think it's more modern... but I'd say the only useful dimensions I can take from it with items that appear similar tot eh Lightning are:

Overall depth to panel: 13mm
Stepped out base to panel: 8mm
Piano hinge diameter: 4mm
Wire latch wire thickness: 1.5mm diameter
Wire latch overall length: 45mm
Wire latch overall width: 6mm

The windows on this random box are 14mm x 5mm, and text height is 3mm. These may be within a mm or so of the Lightning's dimensions, but are a good start

Please Log in or Create an account to join the conversation.

Time to create page: 0.316 seconds
Powered by Kunena Forum

PM Mailbox

You are not logged in.

Latest updated downloads