USA question on aircraft requirements

[goobersnuftda 0]

I have a question about jump aircraft in the USA.

Here in Canada, our Cessna 182 has an engine life span of 1,500 hours.....thats it. You can run the engine on condition but once the slightest thing needs to be done on the over timed out engine, it is done right then and there and you loose your $5,000 core deposit towards a new engine.

Likewise, just as soon as our Twin Otter's run out of their time by Canadian rules, the USA snatches them right up. The big reason is that here we are regulated just the same as Air Canada or West Jet. We are a commercial company carrying commercial passengers.

From what I have heard and known in the past, the USA does not classify a skydiver as a "person" but they fall under "cargo" rules and therefore they can do much more with a plane or it's engines than we can in Canada.

So shut up already and ask the question ...:) OK, how long can you use a Cessna 182 in the USA?

[davelepka 4]

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OK, how long can you use a Cessna 182 in the USA?

Until the NTSB sends out a guy to investigate the wreckage.

Maybe not, but pretty close. Our engines have a TBO (time before overhaul) but it's not enforced on skydiving. Generally, I think it's a little higher than 1500 hours, more like 1800.

Regardless of the time, you can always get an overhaul, and you don't lose anything if it's past TBO.

[pilotdave 0]

We operate under FAR part 91 in the US, which doesn't require operators to follow engine manufacturer's TBO recommendations. Part 135 or 121 operators do need to follow TBO requirements. I doubt 1500 hours is a life limit, but rather a time before overhaul... engine just gets taken apart, cleaned, inspected, and rebuilt. Not as intense as a factory remanufacture...

Dave

[riggerrob 643]

... the USA does not classify a skydiver as a "person" but they fall under "cargo" rules ...

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

That is a myth spread by skydivers.
I have never seen it written in a FAR or CAR.

It falls under the "as long as they keep the fatality rate low, we don't care" department at the federal gov't.

[heyyou 0]

Here's a pretty good article... Might give a little insight.

http://www.avweb.com/news/savvyaviator/savvy_aviator_45_how_risky_is_going_past_tbo_195241-1.html

[goobersnuftda 0]

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Here's a pretty good article... Might give a little insight.

http://www.avweb.com/news/savvyaviator/savvy_aviator_45_how_risky_is_going_past_tbo_195241-1.html

I would like to read that article but I sure am not going to pay the web site to read it. Do you have another link to something that can be read without shelling out $$$?

[pilotdave 0]

Avweb is free.

BTW, they did a podcast recently with Ed Scott from USPA about the growth of skydiving and the relatively safe year we had last year.

Dave

[chutejump 0]

TBO here in the states is 1800 hours on most cessna recips, I personally perform majors on my cessnas at 1000 hours well below the manufacture recommended limits. The reason? The standards set are for the average joe blow whom is out cruising around at a reduced power setting, hence 1800 hours of use will pretty much use up the rotating and recipricating parts wear limits.
We on the other hand operate our power plants at full power on every lift to altitude, stabilize temp than dive into the dirt and attempt to keep the now very hot engine from super cooling from the increased airflow and speed of descent. This is very hard on the power plant and I have found that over the years if I go past 1000 hours, I start to cause extra wear on hard parts that are very costly to recondition or replace. Yes! it costs more to perform the major overhaul sooner but in long term I save from the purchase or recondition of hard parts, and lower the chance of a hard part failure while in operation.

[airtwardo 7]

Hey Tom, I like your way of thinking!

Just curious...what's the average cost of a major (with no broken hardware)..not 'your' cost, but cost to mr. jo pilot guy?

~ If you choke a Smurf, what color does it turn? ~

[heyyou 0]

I know that experience can make a huge difference in this arena but in the avweb article there is real data that shows that the risk of failure is much higher in the first few hundred hours since overhaul.

----- here's the quote from thje article -------

Is TBO-Busting Risky?

While there's no question that the highest risk of catastrophic failure occurs in the first few hundred hours after engine assembly, I have yet to find any evidence that the risk rises significantly as the engine is continued in operation beyond the manufacturer's recommended TBO.

------------- end quote ----------------

The guy (writing the article) makes some very good points. I'd like to hear your thoughts on them.

[chutejump 0]

Year before last I built 3, we rechrome the cyinders, new pistons, regrind cam, recondition lifter bodies, magnaflux all hard parts, polish crank, resize rods, bush, and new bolts, replace valves as necessary the same with seats and guides, new gaskets, bearings, ring, seals, and recondition carb, mags, starter, and generator, plugs and check wires, recondition govenor, inspect and shot peen prop blades.
My average cost per power plant, (all work inhouse) about $15,500.00 per unit. So it would come out about $15.50 per tack hour of operation for engine costs.
Of course this can vary as the prop requires overhaul, or you may not need to recondition rods, (were fresh from last rebuild) turn crank to 0.010 under if below specs. It changes from more to less from overhaul to overhaul, but as I have looked lately the cost of hard parts for overhauls is getting pretty steep!

[chutejump 0]

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I know that experience can make a huge difference in this arena but in the avweb article there is real data that shows that the risk of failure is much higher in the first few hundred hours since overhaul.***

I agree! especially if you have installed many new hard parts. Many people don't realize that a new hard part must be seasoned with continued heating and cooling of the parts though operating th engine, also these parts must wear-in. If they are going to fail it will occur within a couple hundred hours of operation after a recondition.

----- transplant. here's the quote from thje article -------

Is TBO-Busting Risky?

While there's no question that the highest risk of catastrophic failure occurs in the first few hundred hours after engine assembly, I have yet to find any evidence that the risk rises significantly as the engine is continued in operation beyond the manufacturer's recommended TBO.

------------- end quote ----------------

The guy (writing the article) makes some very good points. I'd like to hear your thoughts on them.

He's correct, people assume because an item is new or fresh that it is guaranteed to be the best? not always the fact you are placing new and untested components in a situation. Sometimes they fail. Just part of the game, this applies to anything that is powered by petroleum distillates. Most people don't realize that when you jump on a jet to fly to some distant destination that if the engines on board have been reconditioned, that before they were installed, they were operated in a test pod than disassembled and inspected before installation to minimize the possibility of failure.

[heyyou 0]

So, it looks like if you take some of the info from the article which basically says, "don't just overhaul BECAUSE the engine is at TBO (instead use some form of metrics to determine when to OH) and combine it with performing your own overhaul (like you explain above), a DZO could save a LOT of money...

[chutejump 0]

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So, it looks like if you take some of the info from the article which basically says, "don't just overhaul BECAUSE the engine is at TBO (instead use some form of metrics to determine when to OH) and combine it with performing your own overhaul (like you explain above), a DZO could save a LOT of money...

Several things involved here! Lets say you have a "Factory New" power plant, I have seen them go 2500 plus hours! On cruisers, I have myself put 2000 on a "Factory New" engine hauling jumpers. A new motor has every part in prime size and condition, with a rebuild you will recondition to within the minimum to maximum tolerances that are allowed, so your rebuild will never be as perfect as new! The only exception to this would be a blueprinted rebuild, this means that every component measures at maximum value, and any part that may still be within usable tolerances would be discarded for a factory new or size item, the cost for this build would be the same or possible even more expensive than a "Factory New" engine.
The key to deciding when is the appropriate time to rebuild is by testing your power plant at your 100 hour and annual inspections, Compression, Log and check oil consumption, oil changes at 25 hours (we hauling jumper beat oil to oblivion in a short time) always pull, inspect and clean the screen, or oil filter if you are lucky enough to have one. Another very good program is oil annailsis, it costs some cash but their test your oil same, and can tell you what rotating components are wearing the fastest in your motor, if the wear is on the average expected items, bearings, cam, lifters, rings etc, (there will be minute and exceptabe amounts that are deposited in the oil for average use) you are good to go but if they come back with metal from hard parts such as crankshafts or connecting rods, or making brass from drive gear bushings you need to make a move soon before the engine fails in flight. If you perform your own recondition you need to be either an A&P tech or work directly under the supervision of one (FAA rules) there are many items you need to measure and inspect, and missing any of these items could prove to be very costly in the long run.
But with proper inspections and support you can do you work inhouse and have your aircraft provide better service, perform better and lower the cost.