Watching a pre-buy

farmerbrake

farmerbrake

Line Up and Wait
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farmerbrake
(Not sure if this is the right section for this or not, if not feel free to move it mods.)
So on Monday I'm headed to the airport to watch the mechanic perform a pre-buy. Anything in particular I should make sure I see or ask? It'll be my first time working around a plane in the shop.
The plane is a piper arrow if it makes much difference.
Thanks in advance!
 
Make sure he checks thoroughly for corrosion, and honestly, if all looks good at face value, convert the "pre-buy" into a full-blown annual. I did that due to the advice of a trusted mechanic, and glad I did... it saved my hide to the tune of $17,000.

It's like buying a house and having a house inspector stand outside and walk around versus having them do a complete inspection inside and out.
 
Honestly, I would have a discussion with him beforehand covering a printed list of what needs to be inspected; then leave him alone with the plane for a day...asking him to leave it open so you can look through it or see anything he found.
 
What's a pre-buy? Is it standardized? Does a mechanic sign his name to it?

Sarcasm, but you get the point. I hope you've found a sweetheart airplane.
 
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I've already talked to the mechanic a few times, and he asked if I wanted to watch so I said sure!
Not buying outright, just looking at buying a partner out. They just had an annual done about 2 or 3 months ago.
I asked this to get more of an idea of what I will see as a first time seeing a plane get worked on.
 
farmerbrake said:
I've already talked to the mechanic a few times, and he asked if I wanted to watch so I said sure!
Not buying outright, just looking at buying a partner out. They just had an annual done about 2 or 3 months ago.
I asked this to get more of an idea of what I will see as a first time seeing a plane get worked on.
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A Pre-buy inspection is about material condition. An annual inspection is an airworthiness inspection. why would anyone think one suffice for the other?

It may be airworthy, but I wouldn't buy it .
 
Not here to start a debate guys.

Just looking for cool things to see/ some information to know ahead of time, while being in the shop
 
You could ask for the mechanic to start with a borescope and compression check while you watch. That does not take long, and seeing the borescope yourself is better than hearing a description. You could also ask for the oil sample right away, to get that started.
 
farmerbrake said:
I've already talked to the mechanic a few times, and he asked if I wanted to watch so I said sure!
Not buying outright, just looking at buying a partner out. They just had an annual done about 2 or 3 months ago.
I asked this to get more of an idea of what I will see as a first time seeing a plane get worked on.
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If you have never seen an airplane apart there is a lot to be learned about flying one from seeing the innards. Understanding systems makes one better at diagnosing issues in the air. You can see control cables, engine components, and other moving parts. If he finds any corrosion, and most aircraft in our fleet have some "frost", have him show it to you. It shouldn't necessarily scare you, but it is good to know what it looks like.

As others have said there are variations in airworthy and safe, but it sounds like you are more interested in how things work. If you have an A&P you trust let him do his job and find the safety concerns. My advice would be if it moves take a peek just to see what happens when you push a control.
 
OK, since you're not interested in an annual, I won't preach you my gospel anymore.

All of that aside, IF the mechanic opens up the plane, I found it very interesting to see the innerds and really understand the pulleys, cables, and all systems that you read about in the books. Really learning the layout and function of the engine has already helped me in the 20 hours I've flown my new bird.

For instance, I got really nervous about a single hot CHT. I opened up the cowl (which I am now comfortable with) and took a look at the probes (which I now know what they look like) and discovered that the probe on that cylinder is different than the others... and that that style probe can run 50* hotter than the others.

Take a LOT of pictures of the plane when it is opened up. I have referred back to those a half dozen times in my short 20 hours with my new bird. You will get a bunch of "how is that supposed to be?" or "was it like that before?" questions which the pics can answer.

Another tip: Don't let anyone who can't stomach it see the plane. My wife is good with systems and stuff, but my dad saw the plane all opened up and freaked out. Thought that it would never fly... and said he would never fly in it (he will). But still, letting future passengers see a plane opened up is like doing stalls with passengers. Some would love it and some would hate it.

I hope that helps! Good luck and congratulations!
 
On the arrow, I'd like to see the gear swung and having the power unit and actuators inspected. I'd also like to have any access panels on the left wing root area (top and bottom) pulled and look there for corrosion.
 
Thanks for all the suggestions. Especially the one about pictures!
I like doing my own maintenance on my jeep, and would like to learn to start doing sone of my own on the plane (assuming all goes well and the other partner won't mind).
I haven't seen a planed open up before so this will defiantly be a learning experience!
 
If he is offering to have you observe that is a whole lot different; go for it.
I would think a good inspection would start with a paperwork inspection (logs, work orders, A/D compliance, CofR/A, W&B, equip list etc), then proceed with a preprinted list based largely upon what is done at annual - most a/c service manuals will have a good 100hr/annual checklist, and you can add items that concern you, plus anything that members of a type club might point out.
Don't forget to check for liens, mechanic won't do that.
 
Let'sgoflying! said:
If he is offering to have you observe that is a whole lot different; go for it.
I would think a good inspection would start with a paperwork inspection (logs, work orders, A/D compliance, CofR/A, W&B, equip list etc), then proceed with a preprinted list based largely upon what is done at annual - most a/c service manuals will have a good 100hr/annual checklist, and you can add items that concern you, plus anything that members of a type club might point out.
Don't forget to check for liens, mechanic won't do that.
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He already has the logs and was going to look through them. Plus he works on the other arrows on the field so he knows what to really look out for.
And yes he offered without me even asking. I love learning as much as I can!
 
Being present at a prebuy isn't optional for me, its I'm going to be here every minute, or I'm finding someone else to do the prebuy.

You're talking about a lot of money here, being involved isn't just smart, not being involved is rather foolish.
 
I always had the mechanic review the logs,the ADs ,then borescope,and compression check. Then an overall inspection for corrosion. I usually let the mechanic do this uninterrupted . Time is money.
 
Look for cracks in the sheet aluminum by the gear where the pivots are riveted to the wing rib. There is an ad or a sb about it with a kit to fix it, but it will still cost a good chunk of change if it needs the repair. Kind of hard to spot if you don't know where to look.
 
Make sure every switch is labeled and that every switch turns the intended device on or off. Make sure every circuit breaker is labeled and actually interrupts the current to the device you expect. If there are any upgrade/modification/PMA parts installed, make sure the STC, ICAW, Installation data, 337 and STC use letter that installed the part is in the records. Make sure the insulation on the wiring isn't falling off the wire in the engine compartment. Note how many cracks there are in various fairings, lenses and plastic parts. Make sure all lights work. They will all take time and money to fix.
 
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Do you know what you're looking at? That's not a dig, it's a serious question that affects what I would suggest you do.

If you know what you're looking at when it comes to condition with these types of machines and systems, then I would suggest you conduct your own independent parallel inspection, take notes on anomalies, then compare notes at the end and discuss what is on your list and not theirs.

If you don't know, I would suggest you just quietly shadow them and let them work and point things out to you. If you have questions, take notes. When the inspection is over, bring them up.

Try not to interrupt the inspection in process with unsolicited questions. This is not only annoying to the mechanic, it costs you money in time. It also increases the chances something gets overlooked due to the interruption in thought process.

Quietly shadow, try not to get in his light, save your questions for the end.
 
Stewartb said:
What's a pre-buy? Is it standardized? Does a mechanic sign his name to it?

Sarcasm, but you get the point. I hope you've found a sweetheart airplane.
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Yep, that is the problem, there is no standardization or definition. Are you trying to establish value or condition?:dunno:

Basically it is an inspection to find if the equipment is in "as declared" condition (this doesn't mean perfect or even airworthy). It is only there to make sure the deal is as represented and really only has applicable value in civil court, the FAA has no concern with a 'pre buy' and playing the consumer advocate roll.

People think having a "full blown annual" gets around the problem, but that has holes in it too. An annual is a limited scope of condition inspection with pass fail criteria. Just because you pass an annual doesn't mean there isn't a $5,000 AD that is going to hit you next year that is fine this annual.
 
Henning said:
People think having a "full blown annual" gets around the problem, but that has holes in it too. An annual is a limited scope of condition inspection with pass fail criteria. Just because you pass an annual doesn't mean there isn't a $5,000 AD that is going to hit you next year that is fine this annual.
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But a proper annual will say, "Hey, this is due in 125 hours"
 
Henning said:
Yes, but you have to pay attention to something besides "Yep, passed annual just fine".
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Well all the annuals I've had done don't just say "yep passed" they all say time/date until AD such and such is due. Might be 5 years down the road, might be five months, but I know when.
 
EdFred said:
Well all the annuals I've had done don't just say "yep passed" they all say time/date until AD such and such is due. Might be 5 years down the road, might be five months, but I know when.
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Just trying to point out there are things you want to know on a Pre buy that won't necessarily be made an issue on an annual. Even knowing an AD is due is in and of itself not enough information in a prebuy, you have to see how that stacks against declared condition and what the dollar value effect it has on the deal.

A prebuy is about establishing overall condition and value, an Annual is a defined scope inspection of condition only.
 
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Henning said:
A prebuy is about establishing overall condition and value, an Annual is a defined scope inspection of condition only.
Click to expand...

I consider an annual more that just an inspection. Don't let Tom D hear that thought.
 
Henning said:
Just because you pass an annual doesn't mean there isn't a $5,000 AD that is going to hit you next year that is fine this annual.
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Don't you research the status of all AD's as part of the annual inspection?

When I did a full annual on the Baron as a pre-buy I got a list of all applicable ADs and when they were due next. I knew fully what major expenses I had to plan for in the near future.
 
EdFred said:
Well all the annuals I've had done don't just say "yep passed" they all say time/date until AD such and such is due. Might be 5 years down the road, might be five months, but I know when.
Click to expand...

Yeah that.
 
ahkahn said:
OK, since you're not interested in an annual, I won't preach you my gospel anymore.

All of that aside, IF the mechanic opens up the plane, I found it very interesting to see the innerds and really understand the pulleys, cables, and all systems that you read about in the books. Really learning the layout and function of the engine has already helped me in the 20 hours I've flown my new bird.

For instance, I got really nervous about a single hot CHT. I opened up the cowl (which I am now comfortable with) and took a look at the probes (which I now know what they look like) and discovered that the probe on that cylinder is different than the others... and that that style probe can run 50* hotter than the others.

Take a LOT of pictures of the plane when it is opened up. I have referred back to those a half dozen times in my short 20 hours with my new bird. You will get a bunch of "how is that supposed to be?" or "was it like that before?" questions which the pics can answer.

Another tip: Don't let anyone who can't stomach it see the plane. My wife is good with systems and stuff, but my dad saw the plane all opened up and freaked out. Thought that it would never fly... and said he would never fly in it (he will). But still, letting future passengers see a plane opened up is like doing stalls with passengers. Some would love it and some would hate it.

I hope that helps! Good luck and congratulations!
Click to expand...

Don't call it a "bird". That's weeny.;)
 
Are the logs complete and does the total time claimed add up based on what is in the logs? Any damage in the books that wasn't mentioned? Any signs of past damage? Any signs that the damage was worse than described by the seller? Among other things, ask about corrosion on structural elements, ask to see the bore scope pics, compression readings, AD and/or SB compliance etc. My mechanic reported on the relative quality of previous annuals also. In my plane's case, the person that owned the plane before the guy who was selling it to me spent his money on paint and avionics but had pencil-whipped annuals. The guys I bought it from had spent a lot of money getting it caught up.

The purpose is to find things that would significantly change the valuation of the plane -- IOW things that would cost you big time.
 
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Fearless Tower said:
Don't you research the status of all AD's as part of the annual inspection?

When I did a full annual on the Baron as a pre-buy I got a list of all applicable ADs and when they were due next. I knew fully what major expenses I had to plan for in the near future.
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Did the IA also tell you how much each AD would cost when it became do? Good on him/her if so, but that is a rarity IMX.

Certainly an IA who knows how to do a pre-purchase inspection will often give you lots of extra information on the annual because he/she understands that the purpose is in part to buy the plane. But then the inspection isn't really an annual inspection. It is a hybrid that combines the elements of an annual inspection with the elements of a pre-purchase inspection. Unfortunately, the vast majority of IA's don't know how to do a pre-purchase inspection or even know what information the buyer is looking for. Hence, all you get for your pre-purchase inspection annual is a run-of-the-mill annual inspection that tells you that the airplane is at least minimally airworthy at that moment.
 
When a buyer knows enough to do their own pre-buy, they are probably ready to own.
 
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