Instrument lighting on light aircraft ?

Read the forum code of contact

Member for

14 years 1 month

Posts: 4,996

Watching the Ch4 documentary on the chap who managed to land the Cessna after the pilot died, I was wondering
about instrument lighting in light aircraft.

I don't know the age of the aircraft involved, but was surprised to learn that there is no permanent lighting.
Is this the case in all light aircraft ?

Even with most cars nowadays, as soon as you turn the ignition on, the instruments light up.
Them dim when the road lights are turned on.

Original post

Member for

13 years

Posts: 6,535

Most a/c of the American 'spamcan' type (Pipers/Cessnas) and others capable of night flying, have switchable panel lighting.

I make it a point always to carry two small torches.

Member for

17 years 6 months

Posts: 8,983

On smaller Cessna's some of the instrument s are illuminated, mainly to do with radio, compass etc, the rest are illuminated by a red light in the ceiling between the pilots, this casts a glow over the panel, there is also a white roof light too, later C172R etc have cockpit lighting. Pipers tend to have an Individual light per instrument.

The Cessna one does work well. As John said, most carry a red torch at night.

Member for

14 years 1 month

Posts: 4,996

On smaller Cessna's some of the instrument s are illuminated, mainly to do with radio, compass etc, the rest are illuminated by a red light in the ceiling between the pilots, this casts a glow over the panel, there is also a white roof light too, later C172R etc have cockpit lighting. Pipers tend to have an Individual light per instrument.
.

Thanks for that.

I assume that these lights, apart from the radio and transponders which are illuminated anyway, need to be physically switched on ?

Member for

17 years 6 months

Posts: 8,983

Correct, the instructor was correct in saying to your right side there is a row of switches, that's if you are in the pilots seat, as a pax they are to the left of the carb heat, throttle and mixture control, past that far left is the ignition switch which is a barrel with a key, however he might knock the radio master or the battery / alternator off, there is also a dimmer for the roof lights..

http://www.azflyers.org/aircraft/172Panel.jpg

If you look at that one, the dimmer switch is on the far left near the ignition barrel below the two red switches which are the battery master and the alternator ones, to the left of those is the primer, if he turned that and it popped out the engine would have ran like a bag of nails, if he knocked off the battery he would lose everything electrical, but could turn it back on, alt would put on a warning light , but he could reset that too, though you would still have battery power still for about 30 mins if you didn't . The other switches near the engine controls really just do external lights, pitot heat etc... Saying that, there are variances between aircraft models of 172 and radio fit.

Member for

14 years 1 month

Posts: 4,996

Thanks again for the info

Member for

14 years 1 month

Posts: 4,996

http://www.azflyers.org/aircraft/172Panel.jpg

The ergonomics of the switch positions is not exactly what you would call user friendly. Especially as you need to look down to operate them.
I suppose that if you are familiar with the aircraft you soon get to learn which are the important ones, but having switches close to each other, where pushing the wrong one could cause a heart stopping moment, surely can't be a good idea.

Then again the designers of the panels must know what they are doing, you'd hope so anyway.

The panel shown above wouldn't make it very easy to fly from the right hand seat either ? (speaking as a non-pilot)

Member for

13 years

Posts: 6,535

Re 7

Alan

When a majority of these panels were designed, the word 'ergonomics' hadn't been invented. You are correct. Most panels are a nightmare of in-accesibility. I've spent the last eight years flying the same a/c and still, I pause, as I do with all a/c, deploying that vital mental check for a split second which asks, 'is what I'm about to do correct?'

I though that John Wildey did a great job. He was calm, didm't flap and maintained admirable composure in a very stressfull situation. Full marks.

Member for

17 years 6 months

Posts: 8,983

Alan, the panels you were looking at are legacy panels from the sixties that as John said was never designed to be ergonomic, later panels these days are, they have gone over to EFIS and utilise two panels as the main screens.

http://glasspilot.com/wp-content/uploads/2008/06/cessnaskyhawkpanel.jpg

This is a modern 172 panel, the three analogue instruments in the middle are for back up in case of electrical failure.
Though the panels show the primary instruments on the left, the map on the right with the engine instrumentation down the left side, they are conform able and can be swopped from side to side or items like the engine instruments pulled up to full page. The map can have GPS overlaid, charts. Radio frequencies etc, indeed they can even download and display weather in real time over them.

They still get things wrong, a couple at Leicester were killed in a 182, as the pilot opened the throttle his hand hit the autopilot switch turning it on and the trim ran one way, the aircraft stalled and went in. They later modified the Autopilot requiring holding the power button down for 5 seconds to activate it, they also introduced voice warnings to notify of trim runaway, such is the evolution in aviation.

Member for

14 years 1 month

Posts: 4,996

That looks a pretty user friendly display, and I assume you can swap the displays , depending who is flying the aircraft ?

Thanks again chaps.

Member for

17 years 6 months

Posts: 8,983

Yes you can, you can also change them from what is shown there to bring up other ones for fuel, engines, radios etc.

Member for

13 years

Posts: 6,535

I don't know whether anyone else does this. I've got a Garmin moving map in my panel and one of my pre departure checks is to change from map page to instrument page. The idea being that if I lost everything on my panel, at least I'd have satellite derived info which would enable to to fly the a/c with, if need be, the Garmin switching from a/c power to battery power in an instant.

Member for

17 years 6 months

Posts: 8,983

I'm not a big fan of the full EFIS panels John, if they go wrong it means the lump out and send it away for repair, at least with the steam driven items you can buy and replace individual items cheaper and replace single instruments thus reducing down time. We often found pilots tended to get stareitus at all the pretty displays to the detriment of looking outside.

Member for

14 years 1 month

Posts: 4,996

Just out of interest. I assume the Garmin must be linked into the aircraft systems to give a true airspeed rather than ground speed ?
What other instruments does it give you ?

Member for

17 years 6 months

Posts: 8,983

Sorry Alan, missed your post, the EFIS panels as shown can give you altitude, heading, Speed, location, real time weather, all the radios, radio frequencies, airfield details, plates etc, they also can give you fuel qty, all the engine data, oil pressure, cylinder temps, etc. basically it replaces all the aircraft instruments, GPS and Radios, the smaller steam driven instruments below them are simply there as back up incase of power failure.

Member for

13 years

Posts: 6,535

Re 13

Tony, I couldn't agree more. Pretty pictures and all that but, I am a bit of a conservative. Flight info from the Garmin is just a supplement.

Member for

13 years

Posts: 6,535

Re 14

Alan,

My Garmin gives ground speed. Useful for air speed/ground speed comparisons, tells me how fast I am not going somewhere !

Member for

14 years 1 month

Posts: 4,996

Re 14

Alan,

My Garmin gives ground speed. Useful for air speed/ground speed comparisons, tells me how fast I am not going somewhere !

Does it also have the ability to manually programme in wind speed and direction given by ATC, to give air speed ?
Or is that info transmitted via a data link direct to the Garmin ?

Member for

13 years

Posts: 6,535

RE 18

Garmin gives only ground speed from satellite derived info. Air speed arrives via the air speed indicator which is a 'stand alone' indicator with no other imputs other than the pitot.

Member for

20 years 7 months

Posts: 7,027

If you did lose your instruments do you get enough info through the seat of your pants flying so to speak to stand a good chance or is everything so power assisted ,geared that you hav actually lost that "feel".Of course it all comes down to experience and experience on the type being flown.

Member for

13 years

Posts: 6,535

Re 20

If your flight is in VMC (visual meteorogical condition) then yes. Most aviators will fly and land safely. It's a different matter if you're in IMC (instrument meteorological condition) then things become a bit more or, a lot more difficult depending on your experience.