Thorp Air Command - T18.net

I have a big hole in the bottom of my plane where a retractable grimes landing light used to be. I wanted to rig up a new, lighter landing light that would fit into this hole. I plan to use a hinge and a push/pull cable to lower (i guess more a more accurate word would be "rotate") the new light into the airstream. Obviously the rotating down part won't be a problem, but when I get ready to retract (pull on the push/pull cable) the light, will I be able to pull it up out of the airstream?

Sounds like a lot of Monkey Motion going on with this set up ? I would put a cover over the hole and install a lite in the leading edge of the wing or some folks put a lite in the cowl intake .

RB

I like the idea of that light as well Ryan and have been rattling that idea around with the 20 others that dent the inside face of my skull. My thoughts are more along the lines of one of those trim servos attached to an arm with some throw to it. Under my seat is a good location on my plane.....with the added benefit of creating the illusion that I blow bright sunshine out of my.......seat. After so many things having been done to my plane, I'm in flying mode now, so might not get to it for awhile.

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Fraser MacPhee
N926WM
Serial #279-1
Angel Fire, NM (KAXX)

I like the idea of a servo, but the cheapo in me says a push pull cable. Push pull seems easier too. Also, I have grown less enthusiastic about running more wires, breakers, and switches.

I have been thinking about the cowl inlet also, but I worked so hard on those baffles, I don't wanna booger them up (or create hot CHTs) with a failed attempt at mounting lights. I am also concerned about reflection off the prop. Anyone have first hand experience with lights in the cowl that can comment about the reflection concern?

There have been several AC outfitted with the cowl lite . I just can't remember who did it ? Pretty sure they made comments that they did not have an over heating problem .

RB

Ryan - with regard to a cooling inlet light, and as best I understand it, cooling at speed is not impeded with a light there - many T-18s have oil coolers mounted on the left side just inside the inlet (on the flat part of the baffling - larger in area on that side as number 2 cyl. is set back)
It's kinda like a pressure cowl setup if properly baffled, creating high pressure air driving down over the cylinders and out the bottom....and a light mounted on either side opening should not affect the "amount" of air (and hence the pressure) entering the cowl. I think the amount of air is measure in inches per second per second.....or something like that...!

I still like the belly light idea though.

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Fraser MacPhee
N926WM
Serial #279-1
Angel Fire, NM (KAXX)

My landing light is under the prop and starter. There is a curved piece of plexiglass covering it. The light is a rectangular automotive sealed beam. It seems to blend in real nice to the point where it is not noticable. I have tried to upload a picture. I can take a better one tonight when I am at the hangar.

Jim

I have a LL in my right cowl. It works fine and does not reflect off the prop. I don't think it messes with the cylinder temps, but I cannot swear to it as I do not have all cylinders instrumented. Been that way for 26 years.
Cubes

Report back in another 26 years !

RB

Ive seen a half dozen at least with the light in the cowl and never heard of any heating troubles, Phil key and Ira and I believe Dean have theirs in the cowl opening with no troubles? I carry mine in my map box to shine through the wind screen, this hasn't caused any heat troubles either.......Dan

Dan...you need to get rid of that kerosene lamp !

RB

that was funny Dan. I think I'll try the cowl inlet first. Then, if I don't like that, Im gonna do this. I mocked it up tonight to fit in the grimes light hole on the bottom of the plane. I plan to use a Firgelli L16 plunger arm http://www.firgelli.com/products.php?id=42
Here is a picture of the L16 (you have to click on the picture to see the whole picture of the plunger below)



Here is the mock up of the landing light and the firgelli arm. The plunger extends 5.5 inches, which is exactly what I need!
Here it is in the closed position


And here it is in the open position

I flew a lot this Cessna 180 during night and I never had problem with the landing light passing true the propeller arc.


I try to do the same with my Thorp. Install the light inside the nose ball cowling. The retractable light under the wing is not a bad idea but in small aviation I prefer the easy way.

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Thierry
French Canadian T-18
C-FPVE #091

Hey guys,

My lights are in the wings, but for anything you want to put into the slipstream I'd arrange a lever to pull it out. Then take advantage of dynamic pressure to help retract it when you have a cable trying to weakly push it back in. Kinda depends if the hinge is leading or trailing. Something to think about.

I love gizmos,
Les Krumel

I vote for wing landing lights . LED...high output , low draw ! Will last longer than Fraser !

RB