M20J Landing Light Aiming

[dtcom]

Does anyone know if the cowl mounted landing light in a 1985 M20J can be aimed?  I noticed that when taxiing at night, I can see the second story on buildings very clearly, but cannot see the yellow line on the taxiways!  Could the bulb (recently replaced) be mounted upside down or sideways? 

What is the correct orientation of the bulb?

[Jeff_S]

Yes, the bulb can be aimed. It may be possible for the PAR46 bulb to be inserted upside down...I don't remember if it has a flange on the back that fits into a housing. My cowl-mounted landing light was inexplicably (and undocumentedly!) altered at some point in its life so that there is an insert now that takes a standard PAR36 bulb instead of the usual PAR46 for that installation. And I know my A/P did a little jiggering of the housing to get it aimed correctly.

[Hank]

My light shows some of the ground when taxiing, but illuminates the hangars all the way to the roof. On final, though, with T/O or more flaps, it seems to shine right on the numbers or just past.

Seems like there is some alignment on the bulb--but you have to drop the lower cowl to reach it. Haven't changed mine in a while, though, so my memory isn't the best. Check your maintenance manual to confirm.

[carusoam]

When I first purchased my C, the bulb was aimed using thick rubber electical tape.  I believe the rubber tape may have been an attempt at vibration dampening also.

Otherwise, the back of the bulb seats in the cowling, the retaininig ring has slotted fastener holes allowing for this "tape modification."  I never really flew the M20C at night, but I remember testing to see how well aligned the light was during dusk hours.  On the ground, it fully lit the hangar in front of me.  From the air, on a normal approach, it lit the numbers up pretty well.

During the flare, things seem to go dark as the light points off to the heavens.......

Best regards,

-a-

[Shadrach]

On my '67 F there are 2 set screws at about the 10 and 5 O'Clock positions on the back side (inside cowling) of the light housing. They do an almost reasonable job of allowing adjustments for windage and elevation. I would hope that a machine that is some 18 yrs newer would have a more sophisticated and effective set up.

[sleepingsquirrel]

While it's apart the bulb likes to have the filiment vertical instead of horizontal . It's supposed to last longer. Rough landings you know!

[Magnum]

Quote: Hank

My light shows some of the ground when taxiing, but illuminates the hangars all the way to the roof. On final, though, with T/O or more flaps, it seems to shine right on the numbers or just past.

Seems like there is some alignment on the bulb--but you have to drop the lower cowl to reach it. Haven't changed mine in a while, though, so my memory isn't the best. Check your maintenance manual to confirm.

[dtcom]

It seems that the bulb has a shield inside the lens.  If the GE logo is right side up, the shield is on the right side of the bulb, looking at it head on, or towards the pilot's side.  Does anyone know what this is for?  I've been told that it keeps the light off of the propeller.  Any thoughts on that?

 

David

[Txbyker]

I have been trying to post and it has not been working so hope this doesnt post multiple times....

I changed mine this weekend.  I put the new one in exactly as the old one came off.  Top of "GE" is pointing at 3 o'clock facing the light and the screw post on the back of the light are vertical.  I believe you can reach the adjustment screws through the cowl flap with a short screwdriver perhaps.

[Hank]

Quote: dtcom

It seems that the bulb has a shield inside the lens.  If the GE logo is right side up, the shield is on the right side of the bulb, looking at it head on, or towards the pilot's side.  Does anyone know what this is for?  I've been told that it keeps the light off of the propeller.  Any thoughts on that?

[flyingvee201]

Sorry to revive an old post.

I had my landing light repalced at annual but the mx never aimed it. It also is shining into the heavens. I'd take it back but he is on vacation (one man shop) and I dont want to wait. I figured its simple enough.

I have a M20F, with a J cowling, so....I assume I need to refer to a J style landing light assembly.

I can reach the light from the back by disconnecting the right cowl flap.

I noticed there are six fasteners. 3 are Phillips oriented at 12, 4, 7 o'clock and 3 are nuts with a spring in the shaft fo the bolt.

 

So.....which ones do I use to make adjustments?

I tried the Philips ones. Turned the 12 o'clock screw fully clockwise to "try" to push the top of the light down, then the 4 and 7 counter clockwise to "pull" the bottom for the light.

 

I dont think it did much good.

 

Any suggestions, beside removing the bottom cowling and fiddling with it that way?

 

thanks

[aaronk25]

Same prob on mine I pulled the bulb for the front side of cowl and put a rubber piece behind the bulb but in front of the adjustment to shim the bulb forward and left out one of the retaining screws on the metal bracket that holds the light as it wouldn't fit after shimming forward.

[flyingvee201]

+1.  I did the same thing as Aaron.  It took a lot of fiddling to get right.  As an aside, the orientation of the filament on the GE 4522 bulb is also critical to long(er) bulb life.  There is a service bulletin or instruction, on point, I believe. 

 

Jim

 

Thanks

I do have the bulb oriented correctly.

I just want to confrim....are the phillips screws the ACTUAL screws used to aiming? 

Im thinking these are just too short to be effective. Wondering if I can replace them with longer screws to help get the angle right?

I hate the thought of stuffing a piece of rubber to shimy it.

[fantom]

As an aside, the orientation of the filament on the GE 4522 bulb is also critical to long(er) bulb life.  There is a service bulletin or instruction, on point, I believe. 

 

Jim

 

And it works very well....if anyone is listening:

 

http://www.mooney.com/images/pdfs/si-pdf/sim20-104.pdf

[jetdriven]

I squirted some red RTV onto wax paper, and made a few different sizes of beads to use as spacer material,  then let it cure. Then I shimmed the bulb much like Jim R. did.  The HID has a very narrow beam and it took a few tries to get it dead on. Now, it illuminates the house 1/4 mile beyond the departure end of the runway in the flare. I bet he loves that.

[flyingvee201]

I squirted some red RTV onto wax paper, and made a few different sizes of beads to use as spacer material,  then let it cure. Then I shimmed the bulb much like Jim R. did.  The HID has a very narrow beam and it took a few tries to get it dead on. Now, it illuminates the house 1/4 mile beyond the departure end of the runway in the flare. I bet he loves that.

 Did you do this with the cowling on or off the plane.

Exactly where did you place the shims?

Did you have to remove or loosen the bulb first? or was it just jammed in there near the top?

 

Sorry for asking detailed questions. I just want to make sure I do this right and not break anything. :-)

[jetdriven]

Squirt the RTV onto wax paper and let it harden up, then use it for a shim. I placed the shim around the top of the bulb to lower it. it takes a few tries.

[NotarPilot]

Anyone try this reaiming procedure with the Whelen Par 46 LED light?

[BillC]

Flyingvee201 - I just replaced the cowl mounted landing light on my 79 M20J. There are three screws and three nuts with springs like you said. I backed off the nuts with the springs and then adjusted the lamp position. The three adjust screws were frozen so I had to use plenty of solvent to free them. The nuts with the springs, which provide tension to hold the lamp in place, are then tightned. i don't tighten them too much. Just enough to hold the lamp in a snug fit.

I have many seaplane friends here in Maine and the ALL orient the filament vertically. i did the same. Time will tell.

[flyingvee201]

Flyingvee201 - I just replaced the cowl mounted landing light on my 79 M20J. There are three screws and three nuts with springs like you said. I backed off the nuts with the springs and then adjusted the lamp position. The three adjust screws were frozen so I had to use plenty of solvent to free them. The nuts with the springs, which provide tension to hold the lamp in place, are then tightned. i don't tighten them too much. Just enough to hold the lamp in a snug fit.

I have many seaplane friends here in Maine and the ALL orient the filament vertically. i did the same. Time will tell.

AH!!

This was the EXACT info I was looking for!

Yes....this is the exact assembly on the back of my light too.

 

Thank you SO much!

I will try this technique first before I try the shimming technique.

 

-Vic

[Bob - S50]

Thanks for all the info.

 

We found that we were able to reach the aiming screws through the lower right engine cowl flap, however, for large adjustments it was easier for the two of us to just take off the lower cowl.

 

We removed the lens from the front.  We loosened the screws on the chrome trim plate (we felt they were used to limit the forward movement of the bulb).  They actually have slotted holes to allow forward and aft movement.  We then ran the 12 o'clock adjustment screw all the way in and the 8 and 4 o'clock (sideward adjustment) screws out as far as we felt comfortable.  We then put it all back together.

 

Definitely is aimed lower now but we have not flown it at night yet to test it out.

 

I also had not seen the info about aligning the filament vertically before we did that so next time up there I'll do that too.

 

Thanks again,

 

Bob