Electrical Engineers - Advice needed

[cbennett]

Hi all,

Im currently in an electrical engineering apprenticeship which involves a day release to a local college. For our college course we are required to spend a year on a project designing an electrical system of some kind. At the end of this year we are required to present our idea and work to our employers in a presentation. I wanted to make my design avaition related as it seems the most logical idea seen as this field i am training to go in to.

The idea i have come up with is an automatic lighting system which illuminates the appropriate aircraft lights depending on the level of light exposed to a LDR; fairly similar to automatic lighting systems used in the automotive industry.

My question is in your experience have you come across this system on an aircraft before?

I have researched this idea and i can't find any information on the internet on similar system's already in place in the aircraft industry. My instructor has also not encountered a similar system. I find it hard to believe such a simple system is not currently used. I am just trying to avoid embarisment by presenting a design to my employers, which is already frequently used.

Thanks in advanced.
:)

[jmig29]

That is just not feasable (at least in modern comertial heavy jets, maybe on light aircrafts), because crews are required to turn on their lights (landing, runway turnoffs, beacons, strobes and other) according to the flight phase (i.e. taxi, takeoff, landing, cruise...).

It is indeed a very strict and regulated business.

Hope this helped

[Sonic Bam]

External lighting, as jmig says, is a no go as far as regulations go.

Internal (flight deck) lighting might be worth you exploring. Glass cockpit displays normally have auto-brightness built in but analogue instruments don't. You could also apply it to switch lights / legends - you will normally find a dim / bright, night / day two position switch but not an automatic dimming system.

Bear in mind that this is a theoretical exercise to show that you can apply what you have learned on your course not a task to design a product for certification and installation on an aircraft.

[Northbeach]

The Boeing 737NG (Next Generation) I fly is equipped with a Flight Dynamics HGS (Head-Up Guidance System). The Combiner I look through has a two position brightness control knob. In the AUTO position the brightness of the presentation in the combiner is controlled by a sensor in the combiner. This allows the visual display viewed through the combiner to stay relatively clear as the pilot transitions from IMC (Instrument meteorological conditions {flying in the clouds & can't see a thing}) to minimum visual references during a low visibility approach.

Boeing makes the jet. Flight Dynamics make the HGS. The manuals I have are written for pilots. Meaning, I can find the information on how to adjust the brightness, but don't have source software/hardware documentation or electrical diagrams available to me.

Many EFIS (Electronic Flight Information Systems) have a sensor that adjusts the brightness of all the displays as the flight progressed through different lighting conditions.

Respectfully,

Northbeach

[cbennett]

As sonic bam has explained i need to prove to my instructor and an external verifier that i am competent designing and working with electrical systems.

My initial thoughts were to implement the automatic device into the anti-collision lights and the navigation lights. As far as i can determine from my research it is only mandatory for the navigation lights to be operational between sunset and sunrise. The device in question would illuminate these lights when the light levels fall below a certain level (IE poor light conditions). The lighting would also be on a three way toggle switch with on, off and auto options.

I didn't think of the cockpit lighting but that is without doubt an area to look in to. I was just cautious as it would be extremely embarrassing to present a room full of aviation professionals, with a design which has been in use for many years.

Thanks for the replies :ok:

[NSEU]

The device in question would illuminate these lights when the light levels fall below a certain level (IE poor light conditions).

Knowing where to put the light sensors would be something of a challenge. I don't know where they put light sensors in cars, but you could have the sun rising on the left side of the aircraft, and the right side of the aircraft in total shadow. If you mount it on top of the fuselage, with a 360 degree view, you would have to drill holes in a pressurized fuselage, have the sensor withstand 400kt winds, be capable of operating in -60C temps to +60 temps, etc, etc.

If you mount remote sensors on both wingtips, you're looking at 100's of feet of wiring = added weight = not something you need in an aircraft

You've certainly picked a tough assignment.

Rgds.
NSEU

[aveng]

I think NSEU has hit the nail on the head - besides would light sensors be cost effective? They would be costly to install with extra wiring involved. Perhaps a more cost effective solution would be to have the 'airshow' software remind the cabin crew to tell the pilots to turn the lights on!!!!:O

[jmig29]

Here's an idea...

With all the improvements nowadays, pilots tend to start using HUD (Head Up Displays). You could build an eye-sensitivity-meter so when the pilot identifies himself to the system (the aircraft), it would measure the pilot's eye sensitivity and auto regulate the cokpit lights and annunciators. It would also recognyze the problable lighting conditions on every moment of the flight, by considering the aircraft's geo-position, its altitude, its relative position to the sun and so on... You could also propose a modification for replacing all of those tiny (there are hundreds of them) little lamps for the annunciators by LEDs. With the proper intensity regulator, of course.

This can be looked as a joke, but then again, think again. You have no use to build a system for today's environment, specially if the job can take years.

So, it all depends on how much time are willing to apply on that work. The more time, the more far ahead you have to look and maybe, guess...

Hope this helped. :)

[Blacksheep]

A lot of of the old incandescent cockpit warning/indicator lamps are being converted to LEDs these days, for the improved reliability. The old way to control the brightness vis-a-vis day/night was a two level dim/bright switching system, usually using a box full of printed circuit cards. Perhaps you'd like to try designing an ambient-light sensitive brightness control for warning/indicator lights to replace the Dim/Bright system and its heavyweight nest of PCBs?

Such a system works fine in my British built Japanese car, but we don't yet have such a thing in the far more expensive big Boeings.