Aircraft with engines 'on condition' How are renters supposed to know?

[Mach Jump]

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]

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

[Mach Jump]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

@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]

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]

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]

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]

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]

"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]

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]

Good point. Once again a misunderstanding about leaning.

Over-lean = rough running = no power.

Shock cooling = cracked cylinders.

flyme.

[Pirke]

Detonation can't be good for the engine either...

[9 lives]

Detonation can't be good for the engine either...

No, it certainly isn't. Happily, if you've used the correct fuel it's near impossible to have detonation on a type approved engine installation. If a CS prop engine is operated anywhere near its recommended temps and power settings, there is no risk of detonation either. The margins are very good, I've done the testing on O-470's and O-520's. A pilot would be horrified as to what you had to do to begin detonation. I have no fear that a rental pilot would ever get an engine in that state.

[Jetblu]

I guess the one of the most costliest problems presented to owners by renters is from engine mismanagement/abuse.

Tech logs can still help decipher the culprit even if an electronic fuel management system s not equipped. I operated a PA28RT201 with the Lycoming IO-360-C1C6. I only rented to what I thought to be experienced pilots. Nevertheless one 600 hour PPL decided to take the aircraft away into Europe for a week touring. The tech log/tacho suggested that he had flown 20 hours but only burnt about 170USG. The flight times in the tech logs also gave things away. Suffice to say, not only had the engine been starved of fuel, very recent cracks were found by engineers on compression tests due to shock cooling which the EDM also later confirmed

[9 lives]

A PA28RT201 is certainly an aircraft type for which greater than normal care in engine operating technique is vital to maintain good engine condition. Failure to do so will not result in an immediately unsafe condition (or for the next pilot) but it will cause added maintenance expense down the line.

Operation of these types of faster aircraft in controlled airspace adds to the problem, when ATC request quick descents, and pilots close the throttle to comply. Sometimes better to reply "it's not a turbine, I cannot comply". The worst is an orbit, while you slow down easily.

[Big Pistons Forever]

"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"

You can certainly hurt the engine quite quickly if you go to full power to climb but leave the mixture in the cruise leaned position. Even at full rich you can still have excessive and damaging CHT's on prolonged ful power climbs at low airspeeds on hot days.

[Ebbie 2003]

Look in the logs and maintenace records - just as we are supposed to do before every flight;)

[9 lives]

Look in the logs and maintenace records - just as we are supposed to do before every flight;)

Well, yes, the maintenance logs are the source of the information hours in service, and work accomplished information. Extra points to the pilot if he/she knows what the maintenance requirements for the engine are to begin with, particularly out of phase items. That information is nearly never in the logs, as it is not required to be there.

It's sort of like driving down a road, watching your speed carefully, but having no speed limit signs along the way to tell you what you're supposed to be limiting yourself to!

I'm delighted to think that a pilot would take the interest to delve into the the maintenance records for the aircraft they are about to fly. Once you have those records in your hands, a thorough job of that will be at least an hour or so. I certainly have done this when I have bought aircraft, or test flown them for suspected maintenance defects. I can't say I have ever done it when I just took one for a flight.

Informed, knowledgeable pilots are great. Yet a huge amount of our flying safety depends totally on trusting someone else, that they have done what they should. We trust that the most recent recorded maintenance was accomplished correctly and completely, we trust the the parts and materials were correct for the application, and in suitable condition, and we trust that the pilot before us they detected (or caused).

If every pilot who snapped closed the throttle to begin a descent, made a defect entry in the maintenance logs saying: "throttle closed too quickly, please inspect for possible cracked cylinders", I would be stunned....

Research as much as you like, but still choose aircraft whose "people" you have faith in.....

[S-Works]

Steepturn,

Am I the only one who is totally lost with the point you are trying to make? All I can glean from it is either check the records or trust the renting organisation.

Are you one of these paranoid types who mistrusts everything in life? Must make for a pretty sad existence?

When I rent a car I asume its legal. When I rent an aircraft I do the same.

We have to have a little faith in others in order to make our way in life.....

[9 lives]

Are you one of these paranoid types who mistrusts everything in life?

Nope, anything but.... I have ferried many dozen planes cross continent, having nothing more than the location of the aircraft, and the keys to start with. Looking at logs was not offered, I just looked at the plane and ran it - never a problem I could not handle. About 20 of those planes went on to fly Transatlantic to the UK right after I dropped them off in Maine. Never a problem.

The point I am making is that if one is not willing to trust those who went before with the plane, you should buy your own plane, or give up flying. 95% of pilots are entirely unable to make a meaningful assessment of the condition of the plane more than one or two defect reports back in the logs.

Have faith in the provider of the aircraft, or don't fly it. There's little a pilot can do beyond a good walk around check, and engine run up. So don't worry, just go and fly it......

[Kinger]

I'm still curious as to the source of that "alternator tin/ferrous material". How did metal from an external accessory get in the engine oil?

[9 lives]

Some accessories, like vacuum and hydraulic pumps are pad mount. Isolated from the inner of the engine. Others, like gear driven alternators, gear drive starters, and mags have a part of the accessory in the engine (more common on Continentals), so the failure of a part on the "engine" side of the accessory can put metal into the engine.

[glendalegoon]

SHOCK COOLING

yup...and at one little outfit I flew at over 30 years ago we had "STAGE COOLING" descents.

Yes, a reduction in power, each and every 1000' timed perfectly all the way to idle at touchdown.

YES, it was almost impossible to do in IFR reality. But we tried and the engines kept working. You know the type of place, flying bank checks way back when.

I seem to recall that any airplane used FOR HIRE in the USA has to comply with the TBO (time between overhauls) indicated by the manufacturer.

Not sure what you guys do in England. Why not ask your CAA inspector and get a straight, LEGAL answer? Have you tried?

[Mach Jump]

Why not ask your CAA inspector and get a straight, LEGAL answer? Have you tried?

We already have the 'LEGAL' position, which is that aircraft offered for hire must have engines within their TBO, plus any extensions allowed.

The problem is that owners are no longer obliged to provide any paperwork to you to show that the aircraft is flying legally. You just have to take their word for it.


MJ:ok:

[9 lives]

You just have to take their word for it.

... Which is fine if everyone trusts everyone else. If a rental pilot is not confident the aircraft is safe and legal, they don't have to fly it!

[A and C]

If someone offers an aircraft for hire it is their responsability to ensure that the aircraft is fit for purpose, not having an engine that complys with the law for aircraft rental would in any UK court be at the very minimum breaching the duty of care that one has to the customer ( as well as the ANO ).

Any problems that occurred during the rental would eventualy bounce back to the rental company who would not have a leg to stand on in court.

[glendalegoon]

IF your rental company will not allow you to see the MX logbooks, you should not fly the plane. PERIOD.

I wouldn't in the USA and screw em if they won't!

[A and C]

It is usual for the maintenance company to hold the log books and the rental company to use a Technical log for day to day operations, it depends on the type of log system they are using if total engine hours are shown. ( hours to next maintenance check or time critical maintenance task are)

This system is not a problem with most companies who are reputable but I can see how the bottom feeders in the industry could corupt the system.

Having said that the sort of people who would corupt a log without the total engine time shown would likely do the same to a log book that had the total engine time shown in it !

[Mickey Kaye]

I've worked for about half a dozen flying schools on and off and I've never come across one of them that operated and aircraft out of years or hours. And I do check.

I am only familiar with three non-equity aircraft and all of their engines were " on condition"

Mach Jump as to why nothing gets done about it well I wonder if the CAA actually took an operator to court would they actually win?

An on condition o-320 with say 2500 hours on it is actually safer than one with 100 hours on it and this evidence for this is well published.

[MrAverage]

Mickey Kaye

If those 3 aircraft are really non-equity with on condition engines they are operating illegally.

[A and C]

One flying club at Cardiff was prosecuted by the CAA for not keeping accurate log books.

This came to light when the aircraft was sold and it became clear from the condition of the engine did not match the log book hours, this was reported to the CAA.

They checked the aircraft logs against the airfield movements log and found that only one in three flights had been recorded, this practice was reflected across the club fleet so the owner was convicted of two counts of log book faulsification for each aircraft ( lucky for him the aircraft did not have VP props or it would have been three counts ). If i remember the total fine was IRO £25 K ten or so years back.

[Mach Jump]

The problem to which I'm trying to draw attention, is not falsification of records, but the lack of information upon which the pilot can base his decision to fly, or not.

The Tec Log does not routinely show the age and hours of the engine, and as Genghis pointed out earlier, since the arrival of EASA, aircraft offered for hire are no longer required to have to have a Tec Log at all!


MJ:ok:

[A and C]

It is not the renters problem !

The aircraft should not be offerd for rental if the aircraft is outside the life extention window. To release an aircraft for a type of service that is in breach of the regulations.

No one can expect an aircraft to be flown by multiple pilots in a rental environment without some sort of technical hand over document.