Airworthiness Question

Laissezfaire

Laissezfaire

New Member
I am currently working on my commercial rating at an FBO in Phoenix. The school does not have a single-engile complex aircraft, so they have arranged for me to fly an old '76 Arrow II owned by another company on the airport.

Earlier this week, I went out to the Arrow for a flight and discovered two items of concern:
1. Neither the strobes or rotating beacon were operating (both activated by a single switch).
2. The ADF unit had been removed from the dash, and no update had been made to the aircraft weight and balance.

Regarding 1:

FAR 61.205 requires an approved anticollision lighting system be installed for aircraft certification and for all aircraft operation, though only for aircraft certificated after March 11, 1996. The Arrow is a 1976 model, and the anticollision lighting system was not originally installed equipment (per the aircraft equipment list). Far 91.209 states that no person may operate an aicraft that is equipped with an anticollision light system unless the lights are "lighted," with the exeption of when the PIC determines it is in the interest of safety to turn them off. Unfortunately the Arrow does not operate under an MEL. So, it appears the lights are not VFR-day required equipment under 61.205, but they are required to be operative if installed, under 91.209.

Are the lights required to be operative or not (for VFR day)?

Regarding 2:

It is my understanding that if permanently installed equiment, such as the ADF unit, is removed from the aircraft, the weight and balance computation for the aircraft must be updated by an authorized mechanic in order for the aircraft to be airworthy. The owner of the Arrow insists that I or my instructor may, as the PIC, revise the weight and balance ourselves. I am having difficulty locating a specific regulation addressing this procedure. Any one out there know for sure?

Thanks for your help.
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My understanding (except I think it's 91.205 not 61.205) on both is that you're correct. The lights have to be working if installed, and the ADF needs to be placarded INOP if installed or the weight and balance needs to be changed if removed.

Had the same problem with a GPS that had been removed from a 172.
 
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My understanding (except I think it's 91.205 not 61.205) on both is that you're correct. The lights have to be working if installed, and the ADF needs to be placarded INOP if installed or the weight and balance needs to be changed if removed.

Had the same problem with a GPS that had been removed from a 172.

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Thanks for the response...

Any word on who can update the weight and balance?
 
An aircraft mechanic needs to sign off the weight and balance. I've sat down and revised the weight and balance data for my own plane and come up with a new weight and balance sheet. There has to be a mechanic sign off to make it legal, though.
 
According to AC 43.13-1b 10-1, removal of standard parts of negligible weight or addition of minor items of equipment such as nuts, bolts, rivets, washers, and similar standard parts of negligible weight on fixed-wing aircraft do not require a weight and balance check.
If only the ADF receiver or indicator has been temporarily removed for maintenance, there is no need to re calculate the weight and balance sheet. If you are particularly concerned, you can paper clip a sheet to the current weight and balance showing the calculations with the ADF removed. You are likely to find that there is almost no difference at all in empty weight CG.
 
Check out 91.213. This section deals with inoperative equipment. I would say that the aircraft is not airworthy untill both of those systems are disabled, placarded, and appropriate log book entries made.

Even if the aircraft was not origionally typed with anticollision lights, they still need to operate if they are installed. I assume that whoever installed them got an STC (suplimental type certificate) for the work.

I'm not positive if a mechanic has to ammend the weight and ballance, but I'd have an A&P do that at the same time he is disabeling the other items.

-Dave
 
Under 91.213 the equipment only has to be placarded if it is installed and required by 91.205, or it is required equipment according to the POH. An ADF is not required for VFR flight and it is not required equipment listed in the Arrow II POH. The ADF has been removed so it does not need to be placarded.
 
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According to AC 43.13-1b 10-1, removal of standard parts of negligible weight or addition of minor items of equipment such as nuts, bolts, rivets, washers, and similar standard parts of negligible weight on fixed-wing aircraft do not require a weight and balance check.
If only the ADF receiver or indicator has been temporarily removed for maintenance, there is no need to re calculate the weight and balance sheet. If you are particularly concerned, you can paper clip a sheet to the current weight and balance showing the calculations with the ADF removed. You are likely to find that there is almost no difference at all in empty weight CG.

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Thanks for pointing me to this AC. I have reviewed it and still have some concerns. First, "negligible weight" is defined as a change of one pound or less for aircraft whose weight empty is less than 5,000 pounds (like my Arrow). I do not have the equipment list readily available, but I'm sure the ADF receiver weighs more than a pound.

Second, part 10-15a of the AC addresses repairs and alterations and states:

"Repairs and Alterations are the major sources of weight changes, and it is the responsibility of the aircraft mechanic making any repairs or alteration to know the weight and location of the changes, and to compute the new CG and record the new empty (EW) weight and EWCG date in the aircraft flight manual."

So, I certainly won't "paper clip a sheet to the current weight and balance" as you suggest. But this certainly does answer my question. I difinitively cannot fly the Arrow with the anti-collision lights inop, and I cannot fly it until the ADF has been placarded inop and the weight and balance data updated by a mechanic.

Thanks to all of those who responded
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Under 91.213 the equipment only has to be placarded if it is installed and required by 91.205, or it is required equipment according to the POH. An ADF is not required for VFR flight and it is not required equipment listed in the Arrow II POH. The ADF has been removed so it does not need to be placarded.

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The ADF is certainly not required equipment. However, only the receiver--not the actual nav head--has been removed. So, It would seem prudent to placard the nav head, wouldn't it? (Though I do realize the ADF head won't do a damn thing without the receiver).
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Yes, the nav head must be placarded.
Well, considering I just passed my airframe license practical test and am now a certificated Airframe Mechanic, I still disagree. AC 43.13 is not approved data, only acceptable where no other approved data or regulations are available. 91.213 only requires that the mechanic make log book endorsements in accordance with 43.9, which does not include weight and balance. Check with your local A&P mechanic to be sure, he/she should be willing to sign the amended weight and balance if you show him the computations, but there is no regulation I can find, or have been taught about in my regulations and inspections classes, that require a new weight and balance to be computed for something as small as an ADF. What type of ADF was it? I can tell you the weight if you know, the receivers are quite light.
Perhaps USMCech can add his thoughts as he too just finished his A&P.
 
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Under 91.213 the equipment only has to be placarded if it is installed and required by 91.205, or it is required equipment according to the POH. An ADF is not required for VFR flight and it is not required equipment listed in the Arrow II POH. The ADF has been removed so it does not need to be placarded.

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I disagree. If an airplane is certified with a piece of equipment, such as and ADF, and that equipment is inoperative then it must be disabled and placarded. 91.213 d(2) only states that an airplane may not be flown if a piece of equipment required by 91.205 is inop for that kind of operation. If the pilot feels that the inop equipment does not constitute a hazard to the aircraft (such as a landing light for day VFR) then it must be removed or diabled and placarded.


-Dave
 
My understanding was that the equipment had been removed. In that case it could not be placarded because it is not there to placard! The circuit breaker should be disabled though.
If the nav head is still in the aircraft then it must be placarded.
 
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My understanding was that the equipment had been removed. In that case it could not be placarded because it is not there to placard! The circuit breaker should be disabled though.
If the nav head is still in the aircraft then it must be placarded.

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Wow! Who would have thought this issue was so complex!
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Thanks again for your imput. A new development... I just spoke with the chief pilot from my FBO. She apparently contact the FSDO and they confirmed anyone with at least a PPL can alter the weight and balance data to account for the removed equipment. They did not address, however, whether or not a revision of the weight and balance data was even required.
 
It is definitely prudent to make new calculations every time something is added or replaced, simply because, over time large variations can occur and it is easier to keep track of things as they change, however, there is no legal requirement that I am aware of to do so if the changes are small, and no 337 is required for the change.

As far as placarding is concerned, you can placard the nav head yourself while you are flying the aircraft, and you will be legal while you're flying, even if they remove it right after you get out of the aircraft.

The lights are a problem though, they do need to be working if they have been installed. The anticollision lights and the strobes should be seperate circuits that are connected in parallel if they are on the same switch. It may be a relatively easy fix if the strobes are the causing the problem. Did the owner's give you any idea as to what might be wrong with the lights? Is the circuit breaker pulled and tied off? Are the bulbs burned out?
 
Per the owner, the lights had failed intermittently in the past, though they are working again now. Apparently he's had his mechanic look at the system and no problems were found.
 
Sounds good. If both systems were intermittent it would limit the problem to the wiring between the power bus, the breaker and the switch, the breaker itself, or the switch. That is a fairly easy problem to fix if it returns.
Good luck on your commercial!
 
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there is no regulation I can find, or have been taught about in my regulations and inspections classes, that require a new weight and balance to be computed for something as small as an ADF.

Perhaps USMCech can add his thoughts as he too just finished his A&P.

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I concur.

The only exception I would note is if the reciver was located back in the tail. A very small chenge that far back will creat a lage shift in CG.

Most avionics are located in the pannel which is very close to the CG, so their arm is very short. Changing 10 lbs here has a negligible affect.

The A&P who removed the reciver and signed the logbook certianly considered this and decided it wasn't nessacery to do a new CG. If you have any ?s ask him about it.


AC 43.13 is a very good maintence referance which I belive all CFIs should familerize themselves with. Note however that any specific instructions from the manufacturer superseed 43.13.

Example AC 43.13 states that any differential compression reading below 80/60 is cause for removal of a cylinder.

Howener TCM (contential) has published their own SB that states that low compresion readings alone aren't reason to fail a jug. Lycoming has not published anything similar.

So a TCM IO-540 that has readings in the 50s with air leaking past the rings is OK. But a Lycoming that shows a 59 must be pulled.
 
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Earlier this week, I went out to the Arrow for a flight and discovered two items of concern:
1. Neither the strobes or rotating beacon were operating (both activated by a single switch).
2. The ADF unit had been removed from the dash, and no update had been made to the aircraft weight and balance.




Regarding 2:

It is my understanding that if permanently installed equiment, such as the ADF unit, is removed from the aircraft, the weight and balance computation for the aircraft must be updated by an authorized mechanic in order for the aircraft to be airworthy. The owner of the Arrow insists that I or my instructor may, as the PIC, revise the weight and balance ourselves. I am having difficulty locating a specific regulation addressing this procedure. Any one out there know for sure?

Thanks for your help.
confused.gif


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Check out Advisory Circular 91.67. It is very lengthy, but well written and will answer all of your questions.

About the ADF. It would not require a weight and balance change. This would only be required for a major alteration or repair as defined in Part 43. Since the ADF is not required by FAR 91.205 (or any applicable AD's) it can be removed (or more simply just placarded and deactivated). The ADF removal can be accomplished as Preventive Maintenance, by at least a Private Pilot. Preventive Mtc items do not require a revision of the aircraft's weight and balance records or a Form 337 where the change would be documented.

The Private Pilot (minimum certificate grade) would be required document the removal as required by Part 43 Prev. Mtc. in the appropriate aircraft mtc log.


As far as the anticollision light system...it is required to be operating. However operation of the aircraft my continue to a place where repairs or replacement can be accomplished.
 
I difinitively cannot fly the Arrow with the anti-collision lights inop, and I cannot fly it until the ADF has been placarded inop and the weight and balance data updated by a mechanic.

Thanks to all of those who responded
spin2.gif


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Reference my above post...Since the ADF removal can be accomplished as Preventive Mtc...I do not believe the W&B needs to be revised by a mechanic or otherwise. I believe it is currenty legal assuming a proper logbook entry has been made reflecting the Prev Mtc performed (ADF removal).

At the next annual inspection you can have a mechanic revise the W&B...but I certainly do not believe it would be necessary.
 
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