What's the difference SEP to SET?

[alex90]

I have been wondering for some time the difference between: SEP (single engine piston) rating with Turbo differences, and a SET (single engine turbine) rating (in EASA land...).

After doing some digging it seems that most of the HPA (high performance aeroplanes) tend to require a SET with SP (single pilot) HPA rather than a SEP with turbo differences and SP HPA.

For instance, the Cessna Caravan, TBM930, PC-12...etc... Require SET type rating, despite them having an engine with a propeller. (in my mind that means Turbo-Prop - rather than Turbo-Fan). Yet, to fly a turbo arrow, or a Saratoga, or an SR22T... You only need a SEP with Turbo differences. Would it not make sense for it just to be on the SEP with SPHPA (where SEP would mean Single Engine Prop) Alternatively, wouldn't it make sense for these other turbos (PA28RT, SR22T, PA32....etc...) to also require a SET instead?

Anyway - probably too logical an argument! But I'd be glad to have a little light shed on this!

[PA28181]

IMHO it's the difference between a turbine "jet" engine and a Turbo-charged "piston" two totally different beasts, in simple terms.

[MrAverage]

As PA28181 says, you're getting your engine types mixed up Alex. An SEP with turbo differences training is just what it says - a single engine piston.

The turbo differences training is about turbocharging on that piston engine. Nothing to do with turbines, which are jet-prop engines.

.........the turbine is an integral part of the jet engine, whether pure jet, fan jet or jet-prop.


.........the turbocharger is an ancillary added to a piston engine, as on many cars, as an alternative to a supercharger. They are sometimes referred to as exhaust superchargers.

[Jonzarno]

But don't worry, you're not alone in being confused. There have been a number of cases of turbo Cirrus SR22s being fuelled with Jet A1 instead of Avgas in the US when the fuel guy saw the Turbo markings.

[9 lives]

The requirement for training in turbine powered aircraft as distinct from piston, is because principally, the methods of starting, operation, possible exceedences, and limitations are very different. Turbocharged piston engines are just a little bit different in most cases. The requirement for differences training is a good idea.

[S-Works]

It's an SET Class Rating to be exact. Requires an approved training course and test to add the Cass Rating. The non complex SET Variants are grouped such as the Cessna SET Rating allows you to fly Andy Cessna SET and you do differences training between the variants. You can move between different non complex SET by training as required and a skill test.

Multi engine turbine is always a Type Rating.

I run loads of these on various SET classes all the time. Caravan last week and this week Dornier Type Rating Courses.

[alex90]

Thank you everyone!

I think - the confusion / issue is probably stemming from the training I received when I did my differences training (some time ago now...)

I was definitely handed a sheet outlining engine function which in fact is jet-prop and not a turbo similar to the turbo in a car! How strange! I was explained the basics of a jet-prop instead of a standard turbo, then plonked me into a PA28RT and given different start instructions (different from carbureted and from fuel injection engines I had flown) so I just assumed (to this day) that this was how the engine ran!

How naive is that!?! I blame my training...

Although looking back if that's the only difference, why require differences training at all!

Thank you for helping me understand my idiocy! (without killing me!)


Actually thinking of it now... There were no mention of engine cycles, there was however mention of hot starts and other elements that also allude to the instructor teaching turbine rather than turbo...

[9 lives]

The starting of a turbocharged piston engine will be the same as for the normally aspirated version of that engine - indeed, I have ferried home aircraft with seized turbos, they ran fine, other than you just had no boost. The turbo in a plane may require some pilot "management" depending upon how that specific system works, unlike the turbo in a car, which is entirely transparent to the driver in its operation.

Turbine engines are an entirely different thing. In most cases, they are easier to start, but if you get it wrong, you can make it very bad very fast. A piston engine will at worst have a carburettor fire, melted starter motor, or just a flat battery.

A turbine engine, other than very modern FADEC controlled engines, is always vulnerable to pilot abuse, more so than a piston. Both types can be abused, but there will be one or two orders of magnitude difference in cost for the damage done by abuse.

[alex90]

The differences training was not where I learnt to fly. Let's just say an ATO on the South Coast... Perhaps it was just the instructor having a bad day. He came highly recommended.

I do not wish to name any names

[alex90]

It isn't the first time that I received incorrect information from instructors.

I was once told (again no places, no names) and given several sheets about a particular aeroplane I wished to rent, stating that the plane had long range tanks installed. I checked the POH which did not highlight wether or not it was fitted with one or the other giving performance figures for both. The aeroplane did not have any markings either in the aeroplane or on the wings with regards to the quantity held in the tanks. So I assumed that this was correct, until the day (about 2 or 3 rentals later having never fuelled up more than just a little top up) - only about 10 hours after I passed my PPL. When I noticed neither of my gauges were fluctuating wildly anymore (as they always did), my calculations including safety buffer stated that I had just over an hour of fuel left in the tanks after a long day trip, but on the side of caution re-ran the figures with the normal range tanks (as the lack of fluctuation made me doubt the quantity left) stating that I only had about 10 minutes left (thankfully only 2 minutes from my destination which happened to be the closest airport). Upon landing I found that the plane did not in fact have long range tanks and only had a few litres of AVGAS remaining. Thankfully I had a friend with me during the checkout ground session who vouched for the information given, but I really had to fight my corner!!

This event had taught me to be wary about information given, but when someone comes highly recommended, and charges you a bob or three. Also boasts about doing people's type ratings in many HPA over a cup of tea. And gives you printed literature (which I found by the way) stating black on white that I will be flying a turbine engine driving a propeller... I didn't want to argue! To be honest - I didn't really care what was inside the engine providing that it would fly me a little bit faster to my destination & knew which temp gauges to look out for on start, during flight and shut-down as well as how to use the digital engine management system the rest didn't really matter... I now know I've been made a fool twice!!

These people are people who you trust, and the only reason you're paying them is to impart a small amount of their wealth of knowledge. So you do have a tendency to trust them... Perhaps a little older and a little wiser now - I will learn to only trust the people who have earned my trust!

[9 lives]

When receiving more advanced "type" training, it's wise to understand the experience of the person offering the training - what has that pilot flown? How many hours? If less than 100 hours turbine time themselves, they really have little standing to be training it in any detail.

For fuel capacity, for any GA 'plane I can think of, it is a type certificate data sheet requirement that the fuel capacity be placarded near the tank filler, and in the flight manual. 'May also be at the fuel selector. If that information is not there, the plane is not airworthy.

Don't always take as gospel what you are told, do some research (like asking here) to verify what you think you have learned!

[alex90]

Step Turn - Nope... There was a faded number/letter which was illegible on the top side of the wing in red. I assumed that was the old sticker stating AVGAS. Fuel selector didn't have any real markings, just a faint engraving of Left, Right and Both. Perhaps you are right - perhaps it wasn't airworthy! I have heard that this particular plane was flown accidentally without CofA for 2 days because nobody else checked the documents. I did have a look at all documents I could get my hands on (especially after landing) but was unable to find anything re: fuel tank types.

TangoAlphad - it was her bigger sister... 172! Sounds like you made the right call!! Scary how both the too much fuel, and the not enough fuel situation is a potential killer...

I completely agree with you - had you, or I crashed as a result of the information given to us, something tells me that this would be put down to pilot error, and not implicate any third party despite it clearly being a combination of faults. Neither you, nor I had any accessible means in knowing this information, so in my mind the instruction on check-out is at fault!

(I heard stories about solo flights during training ending in disaster due to incorrect instruction - including one at Biggin where the instructor didn't drain the water from the fuel tank before flight, nor did the student, and I believe that the student pilot ended up in a tree just off the runway at Biggin. Not sure what the implications to the instructor were, but I doubt it was as severe as was deserved!)

[bingofuel]

What type of fuel did the differences instructor say you should use?
Just curious?

[alex90]

I'll be honest - it has been a long time since that day! I cannot remember what was said about the fuel type. The sheets state JET A1, but having never fuelled that particular plane, I have absolutely no idea. I am (especially now) assuming that it must have been AVGAS in the tanks - and not JET A1!

Thanks to my new acquired knowledge, and a little Google... It seems improbable that a PA28 was in fact fitted with a turbine / jet-prop engine. (a good pilot never stops learning right?)

[bingofuel]

just as well you did not put jetA1 into a turbo piston engine, it would have really spoilt your day.

[alex90]

Ha! Can you imagine had I rented that particular plane!? Unless it was clearly written on the tanks - I could very easily, and innocently filled it with JET-A1!!! Now THAT would have been interesting! I wonder what the insurance company would say to that accident...

[Sir Niall Dementia]

Alex90;

Back in the 1980's several aeroplanes were filled with the wrong fuel exactly because of confusion over "turbo" stickers on the side. That's why we now have to have coloured labels with the type of fuel to be used either on or very adjacent to the filler caps.

SND

[alex90]

SND,

I have flown at least 4 different aeroplanes in the last 18 months which had neither colour, nor lettering suggesting the required fuel type... Stickers fade / get destroyed and seem seldom replaced by some owners / maintenance facilities.

This type of attention to detail is often also reflected on the inside of the planes, where the interior is falling apart, the seats are damp / wet due to the seals not being watertight anymore, instruments are only partially working yet still carried... I actually remember my entire left side being soaked and partially frozen after going through a raincloud on the way to VFR on top. They are called spam cans for a reason - and that is my reason for not flying in these particular machines anymore.

But that was a very good idea!

[9 lives]

They are called spam cans for a reason - and that is my reason for not flying in these particular machines anymore.

Hang on there... It's unfair to brand an aircraft or group of aircraft based upon the maintenance (or not) performed on them. I've owned a C 150 for 30 years, which is extremely presentable, with a very nice interior, and all placards legible - because I keep it well maintained. I fly a 1977 C 182, into which the owner has a total investment exceeding $900,000. I bought it for him as a very presentable, though totally original aircraft. It spent 4 years in restoration/modification. Since I first flew it after the restoration, it has flown more than 300 hours with zero snags nor defects. It's all about the maintenance! A brand new glass plane can be left to deteriorate, while a '70's mass production metal can be maintained and restored to be a delight. "Spam can" is a misused term, when associated with maintenance - or lack of!

If you choose to fly an aircraft with defects, it's all up to you, you accepted that plane. Your preflight inspection is your opportunity/obligation to determine that the aircraft is airworthy, and that you understand what you need to to operate it safely. This might include a review of the maintenance records. If you are not satisfied, don't fly it! If an operator consistently has their airplanes on the lower edge of airworthy, and all of their renters decline to fly until they are brought up to spec, they're going to be maintained. Pilots accepting compromised aircraft are not working toward better maintained aircraft.

In every late '70's and since Cessna, and most other types, the flight manual, in section 2, limitations, will present every placard which should be legible on/in the aircraft. The aircraft is not legally airworthy if all of those placards are not in place.

If you feel that you can manage a safe flight without that information, you might choose to take the plane, but you accept the responsibility. Light aircraft do not come with approved minimum equipment lists, so the pilot has very little wiggle room to justify taking an aircraft with a known defect. The best example would be a day flight with a known burned out nav light bulb - you're probably okay. But if you have a fuel exhaustion accident, you as the pilot are on the hook, more so if you flew the aircraft with missing placards for the fuel quantity.

Failure to maintain an aircraft is not an offense. Flying an unmaintained aircraft is the offense. The only way that a pilot can fly an aircraft with an obvious defect, and not be responsible is if there is a false or misleading maintenance entry for its rectification.

We've drifted from the topic of powerplants, but we are solidly in the theme of instructors not teaching new pilots what they are actually responsible for when flying. Assuring an airworthy aircraft prior to flight is a pilot responsibility. Not actually doing the maintenance, but at least noticing the obvious things, and reviewing the maintenance entries for the aircraft. An aircraft provider who rents out "lesser" condition aircraft, may have instructors who find this to be normal and acceptable. It is not. Pilots must be trained that acceptance of defects should be a rare and considered exception, not a norm!

[Jim59]

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