Piper People - Need Help

[Ventucky Red]

I need some help figuring out the math for the Piper wing AD.

One of our locals is looking at a PA28-140 with 3,890 on the airframe with 28 100 hour inspections.. So does this look right?

(N × 100) + [T - (N × 100)] / 17 = Factored Service Hours (FSH)

(28 × 100) + [3890 - (28 × 100)] / 17

2800 + 1090/17

3,890/17

FSH = 229

I didn't find anything here...

X

Thread 'Upcoming AD for many more PA-28 and PA-36 wing spars. 100 anomalies and 6 cracked wings found'

Sep 23, 2024

Dynamic Regulatory System

drs.faa.gov

Forthcoming AD on Piper wing spars for much of the PA-28 and PA-32 fleet. Of the 2800 eddy current inspection reports from the prior interim AD around 100 "anomalies" and 6 fully developed fatigue cracks were found. The spar was cold formed leading to high residual stress near the bolt hole locations. Piper has changed the manufacturing process to machine the bend to avoid this issue on all new airframes.

The proposed AD has more info but it appears a variety of scenarios can eventually develop...

• xenadu
• Replies: 193
• Forum: Maintenance Bay

• 
• 

In advance... thanks

 

[dmspilot]

The math isn't right. You're dividing the sum of both terms by 17 when only the second term should be divided by 17.



Should be 2800 + {[3890 - (28 × 100)]/17} = 2800 + 64 = 2864

Make sure you counted 100-hour inspections in accordance to the AD. Eg., an annual done after 10 months in lieu of a 100-hr is to be counted.

 

[Half Fast]

@dmspilot nailed it.

@Ventucky Red , please see this mathematical thread. https://www.pilotsofamerica.com/community/threads/8-2-2-2.149781/

 

[Half Fast]

BTW, the correct answer to 100N + (T-100N)/17 is "Beechcraft."

 

[Ventucky Red]

The math isn't right. You're dividing the sum of both terms by 17 when only the second term should be divided by 17.

View attachment 151542

Should be 2800 + {[3890 - (28 × 100)]/17} = 2800 + 64 = 2864

Make sure you counted 100-hour inspections in accordance to the AD. Eg., an annual done after 10 months in lieu of a 100-hr is to be counted.

Thanks.. I wish log books going back to the Nixon administration were easy to read..

@dmspilot nailed it.

@Ventucky Red , please see this mathematical thread. https://www.pilotsofamerica.com/community/threads/8-2-2-2.149781/

Had a feeling this was going to come back and bite me in the hind quarters..

 

[Clip4]

My advice is not to buy a 140.

 

[Ed Haywood]

Piper People picked a pack of Pabst and pizza.

 

[Half Fast]

Piper People picked a pack of Pabst and pizza.

I was trying to figure out something having to do with a one-eyed, one-horned flying Piper people eater, but I couldn’t quite make it work....

 

[Racerx]

Piper People picked a pack of Pabst and pizza.

I resemble that statement

 

[Ventucky Red]

My advice is not to buy a 140.

Why? Are these not the Honda Accords of the sky?

Plane is not for me, I am helping someone that has started their lessons and want to dive into ownership.

Has the 160 upgrade along with a bunch of other stuff including duel breaks..

 

[Mikey52]

Why? Are these not the Honda Accords of the sky?

Plane is not for me, I am helping someone that has started their lessons and want to dive into ownership.

Has the 160 upgrade along with a bunch of other stuff including duel breaks..

I'm not the grammar police, but breaks and brakes are two different words. Even though, they sound the same in English. Then, there are the words duel and dual.

 

[Domenick]

For those who missed it the first time, here's a FSH Excel calculator:
https://www.dropbox.com/scl/fi/1iuf...ate.xlsx?rlkey=l4w7mng7e6wfc15dmiog4wdnv&dl=0

 

[Ventucky Red]

I'm not the grammar police, but breaks and brakes are two different words. Even though, they sound the same in English. Then, there are the words duel and dual.

Trotzdem stehst du hier laut und stolz. Englisch ist nicht meine Muttersprache.

 

[Ventucky Red]

For those who missed it the first time, here's a FSH Excel calculator:
https://www.dropbox.com/scl/fi/1iuf...ate.xlsx?rlkey=l4w7mng7e6wfc15dmiog4wdnv&dl=0

Thanks Domenick. Quick question: Are the 100-hour inspections based on a 100-hour cadence or a total lifetime accumulation? I've noticed many 100-hour/annual inspections logged outside the 100-hour Hobbs intervals.

 

[Ed Haywood]

duel breaks..

Duel breaks are useful. Fighting can be exhausting, especially with swords.

 

[JScarry]

1000 hour inspections are due when the plane is used for hire with a 5 hour grace period to get it to an A&P. In the case of a 140 for hire usually means instruction.It can be rented out or flown by the owner even though it is past the 100 hours. But that doesn’t reset the 100 hour clock; you need to subtract those hours when determining when the next 100 hour is due. That’s probably what you are seeing.

 

[Ventucky Red]

1000 hour inspections are due when the plane is used for hire with a 5 hour grace period to get it to an A&P. In the case of a 140 for hire usually means instruction.It can be rented out or flown by the owner even though it is past the 100 hours. But that doesn’t reset the 100 hour clock; you need to subtract those hours when determining when the next 100 hour is due. That’s probably what you are seeing.

Thank... I understand the difference with the 100 hour and annual.. My question is the aircraft has been in private ownership for the past 15 years and we're seeing a lot of entries that are signing off on both the annual and the 100 hour that are way outside the 100 hour Hobbs and inline with the annual cadence. What does that count as?

 

[Domenick]

Thanks Domenick. Quick question: Are the 100-hour inspections based on a 100-hour cadence or a total lifetime accumulation? I've noticed many 100-hour/annual inspections logged outside the 100-hour Hobbs intervals.

100 hour inspections are noted in the aircraft logs. They are NOT annuals.
My logbooks had 100 and 50 hour inspection entries such as:

This airframe has been inspected in accordance with 100/50 HR inspection and was determined to be in airworthy condition.
Date: dd mm yy, Tac: ####, Total time: ####
Name of Repair Station No. S-##-##
Authorized Signature: Signature
Details of this inspection/repair are on file at his repair station under work order ####

Annuals in my logs are noted like this:

I certify this Airframe has been inspected in accordance with a Annual inspection and was determined to be in airworthy condition. Total time: ####
Signature IA number

I would think, anything noted as a 100/50 hour inspection should be considered as such regardless of the time interval.

 

[JScarry]

They key to counting 100 hour inspections is found in the AD example calculations.

(h) (3) no 100-hour inspections is as follows: The airplane maintenance records show that the airplane has a total of
12,100 hours TIS, and only annual inspections have been done. None of the annual inspections were done for purposes o f compliance with § 91.409(b).

h (4) The airplane maintenance records show that the aurplane has a total of 10,600 hours TIS, and fifty-five 100-hour inspections for purposes of
compliance with § 91.409(b) have been done.

If the annual or 100 hour was done to comply with the 100 hour rule, it counts. If not then it doesn't count for purposes of the calculations.

 

[dmspilot]

Thank... I understand the difference with the 100 hour and annual.. My question is the aircraft has been in private ownership for the past 15 years and we're seeing a lot of entries that are signing off on both the annual and the 100 hour that are way outside the 100 hour Hobbs and inline with the annual cadence. What does that count as?

Annual

 

[Steamflyer]

The 100 hour items are done at annual. If the plane is for hire, they are also done every actual 100 hours.

Any mechanic can do the 100 hour items. Only an IA can sign the annual which basically says the aircraft conforms to its type certificate and ensuing documented modifications such as STCs. Which is why the annual can be signed off solely in the airframe logbook, though many sign off all three logbooks thusly. FAA has a letter somewhere saying either is ok.

That’s the basics. Devil in the details of course.

 

[Bell206]

we're seeing a lot of entries that are signing off on both the annual and the 100 hour that are way outside the 100 hour Hobbs and inline with the annual cadence.

What are the comparative dates to all those sign offs? For example, do any of the annual/100s have the same date?

 

[Ventucky Red]

What are the comparative dates to all those sign offs? For example, do any of the annual/100s have the same date?

Yes, from about 1985 on. Like I said upstream, many of them are flowing a annual date cadence.

 

[Bell206]

Yes, from about 1985 on. Like I said upstream, many of them are flowing a annual date cadence.

So from 1985, the dates for the 100hr and annual were the same or within days of each other with the annual the later sign off in each inspection sequence? And you're positive the aircraft was not used for training after 1985? As mentioned above, the key is if the 100hr or annuall was to comply with 91.409(b) or not. And to add, outside of the (b) requirement it is not uncommon to see a 100hr signed off during the performance of an annual on non-training aircraft for several reasons.

 

[Ventucky Red]

So from 1985, the dates for the 100hr and annual were the same or within days of each other with the annual the later sign off in each inspection sequence? And you're positive the aircraft was not used for training after 1985? As mentioned above, the key is if the 100hr or annuall was to comply with 91.409(b) or not. And to add, outside of the (b) requirement it is not uncommon to see a 100hr signed off during the performance of an annual on non-training aircraft for several reasons.

Unless I order a report from the FAA, there’s no way to know what the airplane was used for. and even then..... Looking at Windsock and AviationDatabase.com, I can trace records back to about 1990, and it appears the aircraft has been in private ownership rather than registered to a business or LLC.

From around 1992 onward, I see multiple entries like these that seem to reflect roughly year-to-year entries, with some showing over 100 hours and others less. Between about 1983 and 1992, the records are mostly annual inspections, with only a few entries similar to this.

 

[dmspilot]

It doesn't matter what it was called. What matters is whether the purpose of the inspection was to comply with the 100-hour requirement. What was the date and the time in service of the previous inspection?

 

[Bell206]

I see multiple entries like these that seem to reflect roughly year-to-year entries, with some showing over 100 hours and others less.

That is a typical dual sign off that I've seen before and something that I did myself on occasion. Since you or the local guy will be signing off the research portion of the AD, and you're still a bit hesitant, simply include the 100hr inspections you are not sure of and move on. It won't change the numbers that much and you can move forward.