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-   -   Aircraft with engines 'on condition' How are renters supposed to know? (https://www.pprune.org/private-flying/551812-aircraft-engines-condition-how-renters-supposed-know.html)

Mach Jump 24th Nov 2014 18:44

Aircraft with engines 'on condition' How are renters supposed to know?
 
Do people even think to ask if the engine of the aircraft they are renting is 'on condition'?

Should it be required to show the status of the engine in the 'Tec Log'?

What do you think?


MJ:ok:

9 lives 24th Nov 2014 18:56

'Doesn't matter. The whole plane's on condition anyway!

Mach Jump 24th Nov 2014 19:22

I'm not sure of the rules in Canada, ST, but here(UK), engines are allowed to continue in use indefinitely beyond either their TBO/calendar lives + any % extensions granted.

This is subject to regular checks of the condition of the engine, and is restricted private use only. (No renting)

The problem is, when renters collect an aircraft, they have no way of knowing, short of asking to see the engine logbook, if the engine is 'on condition' or not.


MJ:ok:

Genghis the Engineer 24th Nov 2014 20:01


Originally Posted by Mach Jump (Post 8755979)
Do people even think to ask if the engine of the aircraft they are renting is 'on condition'?

Should it be required to show the status of the engine in the Tec Log?

What do you think?


MJ:ok:

The tech log kept in the aircraft is only a travelling record. There is no legal requirement even to have one.

The important documents are the airframe, engine and (if required) variable pitch propeller logbooks.

The engine logbook will show the status of the engine, that is a legal requirement. If you are concerned, you only have to ask to see it.


As a rule, any organisation who don't want renters to read the technical records of the aeroplane they're going to fly should be walked away from anyhow.

That is the only way that I can see.

G

Mach Jump 24th Nov 2014 20:40

I agree, Gernghis.

All the information to determine the aircraft servicability should be readily available without having to ask.

The problem is, many flying schools/clubs operate aircraft they don't own, and the aircraft logbooks are rarely available for inspection.

All you get is a pseudo Tec Log, which, if you're lucky, will enable you to work out the date and hours the next check is due, and if you're really lucky, will give you some information on defects.

There was a time before EASA when rental aircraft had to have a proper Tec Log. Maybe we should go back to that?


If you are concerned, you only have to ask to see it.
But, without the infomation, how do you know if you should be concerned?

I know we cant change the system, but I just wondered if anyone else shared my concern.



MJ:ok:

ChickenHouse 24th Nov 2014 20:46

If my memory recalls correctly, engines in plane to rent or charter are forbidden to run "on condition" in most countries. At least in most european countries renting and chartering is commercial operation and "on condition" is only allowed for private use.

smarthawke 24th Nov 2014 20:47

To get the terminology correct (for UK registered aircraft):

An engine operating 'in extension' is TBO plus a maximum of 20% of hours or calendar time (2000 hr TBO/12 yr ---> 2400 hr/14.4 yr).

An engine operating 'on condition' is beyond 'TBO + 20%' (2000 hr TBO/12 yr ---> beyond 2400 hr/14.4 yr).

At and beyond TBO, the engine has to be inspected in accordance with CAA CAP747 GR No 24 - 100hr/12mth inspections and continuous monitoring of oil consumption, leaks etc).

For private hire/flight training the engine must be within TBO or into its 'extension' period.

When 'on condition', the aircraft can only be used for 'private' purposes. Beware non-equity groups who's engines are 'on condition' would be my advice, incidentally.

As GtE said, probably the only place that you will find the age of the engine is in the engine log book, it doesn't tend to get publicised elewhere.

Mach Jump 24th Nov 2014 21:20


Beware non-equity groups who's engines are 'on condition' would be my advice, incidentally.
I share your waryness, Smarthawk.

This is an area where the difference between 'renting' and 'private use' can easilly seem to be blurred.

Personally though, I think the dividing line is clear:

If you pay a monthly subscription to be a member of a group, and fly the aircraft as much as you like, without further charge, just topping up the fuel and oil to previous levels, this can be argued to be 'private use', and the engine can be 'on condition'.

If you pay any fee, in any form. with regard to individual flihghts, ie. any form of hourly rate, then that is renting, and the engine cannot be 'on condition'.


MJ:ok:

Ps. I'm not involved with any 'non equity groups'

9 lives 24th Nov 2014 22:22


But, without the infomation, how do you know if you should be concerned?
[The on condition rules in Canada are about the same as the UK]

If, as the pilot, you can't tell by the way the engine is running, and the aircraft has a valid C of A, I would not worry about it. If you're renting, it's not on condition, if you co own, you'd know, if you're borrowing a private aircraft, that's between you and the owner. But, I'd tread lightly, you might insult an owner by expressing doubt as to the airworthiness of their aircraft based upon a number.

What would you do if someone told you the engine was 2k beyond TBO anyway? If, as the pilot, you can't tell from how the engine runs, why worry?

To be safe for flight, an engine needs five things: Fuel and Fire where and when you need them. If they are not, you can tell right away. Decent compression is good, but you'll know if you don't have that, it won't develop power. It needs oil pressure, which you can tell right away. And, it should not be making metal, but you'll never know that, unless you check the oil filter.

I bought my 150 with 1750 hours on the engine (1800 hour TBO). I put it on condition, did the required maintenance along the way, which included changing cylinders as needed. I ran it to 3550 hours with no problem. I split the case then because of unknown ferrous metal. The inside of the engine was excellent - the metal had come from a crimped on alternator tin part of no consequence. I'm not unhappy I zero'd it, but it would have run fine for some time to come.

Bear in mind that the manufacturer's TBO times, which form the basis of going on condition. Those TBO numbers are not as well established as one might think. The certification test only requires a 150 hour block test, not a TBO run for certification. My experience has not been to place too much value in them. I have flown sweet over time engines, and scary engines not far out of a poor overhaul.

Whenever I fly a new plane, all my Spidy senses are out there for how it "seems" to me. If the aircraft is otherwise airworthy, and the engine "seems" okay to me, that's all I need. If I'm going to buy the plane, and assume the cost of a possible repair, I'll look deeper. I bought a 182 for a friend, with a 600 hour engine. I did all the logbook prepurchase review, good records. I jumped in, it purred, I flew it home 3500 miles, it purred. I took it out and sold it, as planned from the beginning. The new owner was not entirely happy with it, so he split the case - crack in the crankshaft! Who knew?

Just go and fly and enjoy. Be alert all the time to what the engine is telling you, but don't worry, as long as you have provided the fuel, and it is running smoothly....

Big Pistons Forever 24th Nov 2014 23:21

Whether or not an engine is on condition is way down the list of thing syou should be paying attention to when renting an aircraft. As others have mentioned the airworthiness of the entire airplane is far more important.

That means before walking out to it, knowing its inspection status for both scheduled calendar and hour based inspections as well as out of phase inspections like AD,s as well as deferred defects. Then having a good look at it during the walk around inspection to make sure that the aircraft has no obvious problems.

Mach Jump 24th Nov 2014 23:23


If you're renting, it's not on condition
Perhaps you should be able to assume that, but, over the years, I've been offered aircraft for hire that have turned out to have had expired Annuals/checks, on condition, or just time expired engines, expired insurance, etc. :eek: All taken on trust, and flew fine.

I like to be able to see for myself these days. ;)


MJ:ok:

9 lives 25th Nov 2014 05:18


All taken on trust, and flew fine
Airplanes can't read - so they don't know what their records say. They do know how they've been treated though!

ChickenHouse 25th Nov 2014 07:22

@MachJump: the dividing line is much clearer. If you have a contract, stating you are, wholly or in part, owner or have owner-like status with all duties and rights, it can be argued as 'private'. Reason: as an owner you do have the right and duty to have a look at the engine tech log. If you don't have that contractual base, you are 'commercial' renter and the engine cannot be 'on condition'.

I know, this is strict on the book and in reality there is far more potentially criminal deviation from obeying the rules of your social surrounding.

Thanks also to the CAA interpretation. I was unaware of the 'extension' TBO thing. Does this hold under EASA rules?

Mach Jump 25th Nov 2014 08:13


I was unaware of the 'extension' TBO thing. Does this hold under EASA rules?
I believe that the rules regarding engine operation 'in extension' and 'on condition' are the same throughout EASA.


MJ:ok:

ericferret 25th Nov 2014 11:43

I remember going to do some work at an airfield in the North. They were in the process of changing a cylinder that had a cracked head.

Apparently cylinder/valve damage were common faults on their rental fleet and I was shown a few more damaged cylinders. Cause of damage was hirers over leaning to save fuel.

Could be that if renting the issue of whether the engine is on condition or not is the least of the potential hazards.

Mach Jump 26th Nov 2014 01:55

Thanks for the comments everyone.

It seems that the general view is that renters shouldnt worry too much about the legal status of the engine, so long as it seems to run ok.


MJ:ok:

Jude098 26th Nov 2014 10:13

ericferret Quote "Apparently cylinder/valve damage were common faults on their rental fleet and I was shown a few more damaged cylinders. Cause of damage was hirers over leaning to save fuel."


Just a question: If hiring at an hourly wet rate why were they leaning?

piperboy84 26th Nov 2014 11:16

Aircraft with engines 'on condition' How are renters supposed to know?
 
"Apparently cylinder/valve damage were common faults on their rental fleet and I was shown a few more damaged cylinders. Cause of damage was hirers over leaning to save fuel. "

If you are running your average spamcan 4cylinder rental at cruise at75% power or less how can you "overlean"

9 lives 26th Nov 2014 11:35


If you are running your average spamcan 4cylinder rental at cruise at75% power or less how can you "overlean"
It's near impossible.

Cracked cylinders are generally the result of throttle abuse, not mixture control abuse. For those aircraft equipped with a cylinder head temperature indicator, watch how the temperature cools as you carefully reduce power in cool air. Then think what happens after a hard climb, and the throttle is suddenly closed.... Shock cooling equals cracked cylinders.

Generally, and aircraft with cracked cylinders will produce somewhat less power, but will continue to run safely, so is not a safety concern for the next pilot, but certainly a cost concern for the aircraft owner.

flyme273 26th Nov 2014 18:27

Good point. Once again a misunderstanding about leaning.

Over-lean = rough running = no power.

Shock cooling = cracked cylinders.

flyme.


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