Landing Light

[Bruce Fenstermacher]

If it is installed it must work unless you have a minimum equipment list you are using and it's not required on that list and it's then placarded.

You could uninstall the light if it doesn't work which would be legal just like wheel pants.

[GAHorn]

George- How could the landing light, which was installed at the factory be considered optional equipment? It would be a tough argument with a maintenance or the FAA guy who also would have be looking for answers.

My question, if it is installed isn't it required to be airworthy and operational unless it is either placarded, commerical or non-commerical.

Yes, if installed it must be working or handled thru a MEL. My previous comment was only intended to address whether it was required to be installed (for non commercial purposes.)

[auxtank]

If a shield prevents the filament from shining upon the reflector, which in-turn redirects it generally forward.... how does a shield placed at the fuselage/pilot's side of the filament prevent the light from being projected to the outer reflector where it is reflected towards the fuselage/pilot?

George,

I think the answer to your question is: The filament shield in the GE 4522 is not designed to "prevent the light from being projected to the outer reflector." Rather its purpose is to prevent light from being radiated directly from the filament to the forward area of the aircraft and, more importantly, the prop.

Although I have not been able to find a patent document for the GE 4522, I have found some patent information pertinent to filament shields in sealed beam lamps.

U.S. Patent 4182970, dated January 8, 1980, a patent relating in particular to a new material for filament shields, discusses such shields and their purpose. The second paragraph of the patent states: "Filament shields are well known in the prior art as a means for controlling light: the light is, in theory, simply blocked from directly radiating through the lens."

Additionally, in U.S. Patent 4029985, titled Rectangular Headlamp Filament Shield and dated June 14, 1977––which relates to "rectangular vehicular headlamps adapted to produce one or more light beams"––the inventor states that "n lower beam headlamps, round or rectangular, a filament shield is used over the lower beam filament to prevent light from the filament from going directly to the lens." he goes on to say that "o far as is known, no one has proposed using a filament shield to prevent light from reaching portions of the reflector of a headlamp."

These and other patents can be searched for at:

http://www.uspto.gov/patft/index.html

I have taken pictures, from from three pertinent vantage points, of the Grimes landing light on my plane. I have posted them over at the thread where the question of filament-shield orientation was originally asked. Please take a look at those pictures.

http://cessna170.org/phpBB2/viewtopic.php?t=4069

I believe they show clearly that when properly orientated on the inboard side of the lamp the filament shield protects the forward area of the plane (most importantly the prop) from being bathed in direct light from the filament.

George, thank you for the opportunity to add pictorial and patent information in support of Neal Wright's anecdotal evidence (describing the factory tags) that the 4522 lamp should be installed with the filament shield on the pilot's side.

Here are a few rhetorical questions:

If Grimes supplied Cessna with landing light assemblies that had tags calling for the lamps to be installed with the shield on the inboard side, is an airplane with the filament shield on the outboard side of the lamp unairworthy?

If so, is it unairworthy only for flight at night, or is it also unairworthy for flight during the day when the light assembly is in the "up and locked" position?

Since Galaxy 4522 lamps don't have shields, are they legal to install as replacements for 4522 lamps with the shields?

Gordon Sandy

[wa4jr]

Allow me to throw a twist into this thread. I've been thinking for some time about installing a pulseligt system on my aircraft to pulse each of the two wing lights in sync. I've also seen that Texas AeroPlastics has wingtips for the 170B that include forward facing halogen landing lights...and I've thought about using these with a pulselight circuit. Has anyone installed a pulselight circuit in their 170? Seems it would be an easy 337 to push through in the interest of increased safety. On another note, I've installed a Q4509 and have yet to burn it out...but would sure like to increase visibility by pulsing the light.

[thammer]

FAR 91.213(d). You are not required to have an MEL to fly with inoperative or deactivated instruments/equipment. Naturally certain conditions apply.

tye

[thammer]

Allow me to throw a twist into this thread. I've been thinking for some time about installing a pulseligt system on my aircraft to pulse each of the two wing lights in sync. I've also seen that Texas AeroPlastics has wingtips for the 170B that include forward facing halogen landing lights...and I've thought about using these with a pulselight circuit. Has anyone installed a pulselight circuit in their 170? Seems it would be an easy 337 to push through in the interest of increased safety. On another note, I've installed a Q4509 and have yet to burn it out...but would sure like to increase visibility by pulsing the light.

Seems to me there is a lighting manufacturer out there that has an STC and product for pulsing landing lights. I know I've read about it quite a long time ago.

edit: These guys have a system, no mention of an STC though.

http://www.avtek2.com/pulsar_info.htm

edit number 2: Here's the STC link

http://www.avtek2.com/STC.htm


tye

[GAHorn]

FAR 91.213(d). You are not required to have an MEL to fly with inoperative or deactivated instruments/equipment. Naturally certain conditions apply.

tye

I think you've misread that Tye. The section you are quoting simply states that if a MEL has not been developed for that aircraft, then the aircraft may be operated with inoperative equipment. BUT... the Cessna 170 does indeed have a MEL developed for all single-engine aircraft and published by the FAA. Otherwise the inoperative equipment must not be required by the aircraft certification, must not be indicated as required on the aircraft equipment list, and may not be required by any other rule for the kind of flight, or req'd by AD, or req'd by 91.205 (which is a pretty lengthy list.) If the equipment STILL is not req'd and is inoperative... according to (d)(4) it must be REMOVED or DEACTIVATED and placarded. Therefore the FAA's MMEL must be followed.
The section being quoting must be read in it's entirety in order to understand the intent.

[Bruce Fenstermacher]

George where can I get a copy of the FAA MEL for a 170?

[GAHorn]

Your FSDO can certainly provide one, but I'll do an online search and see if there isn't a link that will provide one. It's not a MEL that is directed at Cessna 170's per se, ... it's the MMEL that is directed for all Single Engine Landplanes that do not have an approved MEL developed. (In other words, it covers all certificated airplanes that haven't had one approved already.)

[lowNslow]

BUT... the Cessna 170 does indeed have a MEL developed for all single-engine aircraft and published by the FAA.

The the way I read the the following AC:
http://www.airweb.faa.gov/Regulatory_an ... hap1-2.pdf
A MEL is aircraft model and serial number specific and is only issued by the FSDO under which you operate. It is issued as an STC for your aircraft. I think any "MEL" you are refering to is only a guidance document and not a legal requirement. As a small (under 12,500lbs) non-turbine powered a/c we are not required to comply with an MEL.

As you state above, other than equipment required under certification and specific kind of flight (i.e. VFR, IFR, night) all you have to do is deactivate and placard inop.

[GAHorn]

The link Karl provided was very helpful in a discussion with my FSDO inspector who explained this confusing issue to me.
Tye, you are owed a beer from me.

A 170 may be operated without a MMEL or MEL and with inoperative equipment provided that the rules are followed in accordance with 91.213(d) (like Tye said.) Here's the pertinent part of the rule:

==============
(2) The inoperative instruments and equipment are not—

(i) Part of the VFR-day type certification instruments and equipment prescribed in the applicable airworthiness regulations under which the aircraft was type certificated;

(ii) Indicated as required on the aircraft's equipment list, or on the Kinds of Operations Equipment List for the kind of flight operation being conducted;

(iii) Required by §91.205 or any other rule of this part for the specific kind of flight operation being conducted; or

(iv) Required to be operational by an airworthiness directive; and

(3) The inoperative instruments and equipment are—

(i) Removed from the aircraft, the cockpit control placarded, and the maintenance recorded in accordance with §43.9 of this chapter; or

(ii) Deactivated and placarded “Inoperative.” If deactivation of the inoperative instrument or equipment involves maintenance, it must be accomplished and recorded in accordance with part 43 of this chapter; and

(4) A determination is made by a pilot, who is certificated and appropriately rated under part 61 of this chapter, or by a person, who is certificated and appropriately rated to perform maintenance on the aircraft, that the inoperative instrument or equipment does not constitute a hazard to the aircraft.
An aircraft with inoperative instruments or equipment as provided in paragraph (d) of this section is considered to be in a properly altered condition acceptable to the Administrator.
====================

As an example, I marked in BOLD the portion that might apply if one has deactivated one's parking brakes.

[Metal Master]

That is a very good explanation George. You got it posted before I wrote this .
The MEL that George is referring to is provided by the FAA but it is in fact what is referred to as a MMEL (Master Minimum Equipment List). It is made for single engine aircraft and then from that you have to modify it for the specific aircraft you want the MEL for. However I have not been able to get the FAA to work on these for the past several years for any aircraft that is not being used regularly in a 135 operation. They just do not have the time to review and make sure that each action that must be taken for the items a person wants on the MEL complies with the requirements the FAA has for the inoperative system or item. One of my Cessna P210 owners wanted to develop an MEL for his airplane. He called and called the FAA about it until my local ops inspector called me and asked that I could have a heart to heart talk with the guy and get him to stop pestering them about it because they did not have the man power or time. The P210 owner sold both of his P210’s before he ever got any action. That is part of the reason the FAA wrote the FAR that allows inoperative equipment on part 91 aircraft. It allows inoperative equipment: If the equipment is not required for certification of the aircraft. Is not essential for the intended flight and does not cause a flight risk. It must be disabled and placarded inop. It must repaired at the next maintenance interval. It is my experience that in most cases the actions required by the FAR are more difficult than just fixing the Item.

[thammer]

FAR 91.213(d). You are not required to have an MEL to fly with inoperative or deactivated instruments/equipment. Naturally certain conditions apply.

tye

I think you've misread that Tye. The section you are quoting simply states that if a MEL has not been developed for that aircraft, then the aircraft may be operated with inoperative equipment. BUT... the Cessna 170 does indeed have a MEL developed for all single-engine aircraft and published by the FAA. Otherwise the inoperative equipment must not be required by the aircraft certification, must not be indicated as required on the aircraft equipment list, and may not be required by any other rule for the kind of flight, or req'd by AD, or req'd by 91.205 (which is a pretty lengthy list.) If the equipment STILL is not req'd and is inoperative... according to (d)(4) it must be REMOVED or DEACTIVATED and placarded. Therefore the FAA's MMEL must be followed.
The section being quoting must be read in it's entirety in order to understand the intent.

I thought it was pretty clear both in how it's written and the intent, though our definitions of intent might vary. The part I question is how you determined that all single-engine aircraft have an MEL. That has never come up in any discussion during training, pilot or A&P, or orals, checkrides etc.

edit: I should read more posts before I reply, we're even on the beers.

[thammer]

That's a very interesting advisory circular, thanks, I've added it to my library. Of note within it are the references that an operator has the option of using the MMEL or operating under 91.213(d). There is a section laying out the decision process and actions required to decide whether you can operate or not. It also appears that "deactivation" could be as simple as turning an item "off". That it doesn't necessarily require disabling so the pilot can't turn it back on in flight. I could use some help on that interpretation.

tye

[GAHorn]

Disableing might consist of pulling the CB, using a tie-wrap on it, and placing an "INOP" sticker on the device. Technically, you must repair the item at next regular maintenance/inpsection.