Seneca no 3 greens if nav lights on?!?!

[welliewanger]

Hello Peeps!
Having just had a mind focusing experience in a Seneca, I've been told that "all senecas" have this problem. When the nav lights are on - the 3 greens are off! No matter whether the gear is down or not.

Can anyone shed any (green) light on this?

TIA
Welliewanger

[Squealing Pig]

Think they may be just dimmed and hard to see in day light if the navs are on for night ops

[TheBeak]

Yeah it's the same for all retractable gear light aircraft I have flown for the reason Squealing Pig has given.

[Final 3 Greens]

This is standard on many Pipers, 28Rs,32Rs, Senecas etc.

As squealing pig says, they are not off, but dimmed and therefore not noticeable in sunlight.

When you select gear down and you don't subsequently get the 3 greens, always ensure the nav lights are off, before adopting headless chicken mode ;)

(Its a classic instructors trick to quietly switch the nav lights on and then await the student's reaction in due course.)

[senecadriver]

It happened to me many moons ago at Biggin flying G-BBLU a Seneca 1.

Did the usual re-cycling gear etc plus fly past the tower and landed with
fire engine waiting on taxi-way. CFI not amused saying I shud have know navs being on ( it was a murky day ) meant greens would not illuminate.

Later models I understand do not have the same problem.


Senecadriver

[Peter Fanelli]

Have you not read the manual?

[bfisk]

Aaah, the oldest trick in the book wrt the Seminole at least... put the nav lights on and hey presto... Gear down, three... wait, the what? Go around!

Strange dimming feature based on the assumption that nav lights are only used during nighttime.

[SNS3Guppy]

Having just had a mind focusing experience in a Seneca, I've been told that "all senecas" have this problem. When the nav lights are on - the 3 greens are off! No matter whether the gear is down or not.


Have you not read your aircraft flight manual?

The gear lights are dimmed when the nav lights are on. If it's daytime you may not see the gear lights at all. This illustrates just one more reason it's important to know your aircraft systems.

System logic in your airplane (indeed many airplanes) uses the nav/position lights to tell the airplane when it's night. At night when you illuminate the position lights, the gear lights are dimmed to prevent blinding you.

If you drop the gear and don't see the lights, one of your first actions should be to check the nav lights and see if they're on.

[eckhard]

If you get two greens showing and an unilluminated third, try removing the red 'gear unsafe' light from its holder and replacing it in the unilluminated position. If it illuminates (red) you know you have three wheels safely down and need to replace one of the green bulbs.

Less stressful to all concerned than declaring a MAYDAY and conducting flypasts before landing on a foam carpet on three perfectly good wheels!

Of course, you should only try this when the situation allows: ideally get your co-pilot/instructor to help (one flies, the other fiddles with the light bulbs). If you're on your own, give yourself time and space to accomplish this safely. We don't want another 'Everglades' scenario!:(

[powerstall]

Think it would be dimmed. :ok:

[eckhard]

Sorry, I assumed that the two illuminated green lights were fully visible and that the 'dimming' problem had already been addressed!

[Fargoo]

Airboos logique.....?

on a Seneca?

[Denti]

Weird, the Senecas we used during initial training had an extra NIGHT/DAY lighting switch between both annunciator panels to control cockpit lighting and gear indicator light intensity. Could have been a factory build custom modification though. I guess the red gear warn annunciator light and the aural landing gear warning horn is standard on other senecas?

[welliewanger]

Wow, lots of responses, thanks.

I am aware of the lights dimming with the nav lights, however, it was sunset and the sun was behind a very big cloud, so pretty dark already. Maybe the system dimmed it too much, or maybe a wiring fault meant the "dimmed" circuit, was just "off".

Lesson learnt

[Fargoo]

Oui....

Its a generic rather than type specific term used to explain or justify a hair-brained design feature on any aircraft type....

I get it now :D

[GBALU53]

Not only the Seneca has dimmed u/c lights when the nav lights are on.
I think most Piper aircraft of that era Aztec, Cherokee Arrow, Lance to name but a few have the same problem.
A number of pilots do fly with nav lights on during the day, if you are not that currant on these types you can get caught out.
So remember if flying during daytime when comming in to land and you see no greens check your nav lights first to see if they are on then switch them off and all being well you will have nice green lighhts??
You could do a flypast and if there is air traffic there and they confirm you have them down, some controllers might say about you nav lights.:ok:

[Big Pistons Forever]

A and C

I would be carefull about calling anyone stupid since you are not being very bright yourself.

The green gear lights have absolutely nothing to do with the operation of the landing gear they simply indicate whether the gear leg is down and locked (green on ) and the red light tells you nothing about the position of the gear. The only thing the red light positively indicates is that the hydraulic power pack is recieving electrical power (red on). Obviously this should not occur with the gear fully up or down and the red light should be out. However it is perfectly possible for the gear to be down and the red light to be illuminated.

If one green light is not illuminated and the red unsafe light is out than the most likely cause is a burnt out bulb. Since all the bulbs and bulb holders are the same except for the color than it makes perfect sense to try removing the not illuminated green light and fitting the red bulb. Obviously you place the aircraft in a safe position or turn over control to the right seater before starting any trouble shooting. After the exchange, If the red light you have placed in the green gear position, illuminates, it means the gear down microswitch has closed and the gear is down and safe. Go ahead and make a normal landing and then fill out the appropriate maintainance defect documents. If the red gear unsafe light is illuminated with the gear handle in the down position do not fiddle with the bulbs, go to the emergency checklist. Similarly if the red light is out and you go ahead and exchange the bulbs but it will not illuminate in the gear position holder, you have a real gear problem and you should go to the emergency checklist

[DA-10mm]

Mr. Peter M...
Could not agree with you more.

Know your aircraft, plain and simple.
Checklists, though pesky and seemingly troublesome at times, actually work.

[stilton]

Agree with knowing your Aircraft, bit of a silly design though.

[Tmbstory]

This has been a problem with using navigation lights in daytime. I remember the Piper Aztec and Apache from the 1960's had this system.

As others have said know your systems.

Tmb

[Orangputi]

Dear ASFKAP

When are you Yanks going to get over the Airbus / Boeing thing? Look at the 787 it makes the A380 look like it was delivered early!

What this has to do with a Seneca beats me

[A and C]

I have removed my last post because it may confuse the issue, however the logic is that the disableing a system that is working correctly is not the thing to do in this situation has not changed.

Yes you are correct in saying the red light indicates power being supplied to the elec/hyd power pack but ithe power pack won't get the power if the "out of position" conditions are not met.

So it is very unlikely that after down selection when the red light has been on and then goes out that the gear is not locked down, so why mess with a system that is telling the truth? Surely if you want to check the green light in a leg why not swap the suspect bulb for one of the other greens, at lease that gives you one part of the system intact and working properly.

This assumes that there is only ONE malfunction in the system

The biggest problem with Piper main gears is bad/lack of maintenance, it is very hard to get grease into the bearings that support the gear due to grease gun access, if this is not done at the proper service intervals the gear will not lock down after a "free fall" if you have a power pack failure. The failure to "free fall" is due to internal friction. However the gear out of position will still work correctly even if the landing gear actuator CB tripps.

[Big Pistons Forever]

A and C

I did not fully understand your original post and thought you were saying that you should never swap landing gear bulbs to trouble shoot a problem. I see now you are simply saying don't use the red one. Fair enough. There are 2 reasons I swap the red one as the opposed to exchanging one of the other green ones.

1) If you have selected gear down and the red light has come on as the gear cycled and then went off, it has basically told you everything it is going to. So since it has done it's job it seems the logical one to sacrifice.

2) If you swap one of the other green lights than you will be landing with that one not illuminated and while intelectually I know it is OK it just creeps me out. I guess I really want to see a light for every gear leg before I land.

[porch monkey]

Hahaha! Priceless! Bit more research required there Orange one!