A, B, C aircraft type classification

[matj1986]

Hi,

I'm having the hardest time understanding the AC perfs classes.

Please have a look at that list :


Turbojets
Jets
Turbine
Turboprops
Turboshaft
Turbofan
Propellors
Small reciprocating engines
Large reciprocating engines
Piston

What would you put into wich class of aircraft ?

Regards,
Mathieu

[Tom]

Hi there - if you have the Bristol notes, in Chapter 1 (or Lesson 1), you have a list of definitions that you will find useful as you go through the course. These definitions are copied from Regulation (EU) 965/2012 Annex 1 Definitions. You can also find this information through the EASA Documentation web site (Google EASA Document library - search for Easy Access Rules for Air Operations (Regulation (EU) No 965/2012)

The numbers in the lists (EASA v BGS notes) do not agree because the list in regulations has been updated - but you will find:

(93) performance class A aeroplanes means multi-engined aeroplanes powered by turbo-propeller engines with an MOPSC of more than nine or a maximum take-off mass exceeding 5 700 kg, and all multi-engined turbo-jet powered aeroplanes;

(94) performance class B aeroplanes means aeroplanes powered by propeller engines with an MOPSC of nine or less and a maximum take-off mass of 5 700 kg or less;

(95) performance class C aeroplanes means aeroplanes powered by reciprocating engines with an MOPSC of more than nine or a maximum take-off mass exceeding 5 700 kg;


Hope that helps - do not forget the list - it will be useful!

Tom

[matj1986]

Thx, for your answer,

Regards,

Mathieu

[matj1986]

Tom , I have another concern.
In wich class do you put :
Turboprop ME with MOPSC < 9
Prop with MOPSC > 9
Reciprocating with MOPSC < 9

Thank you for your help,
regards,
Mathieu

[Tom]

Mathieu - we need to consider maximum take-off mass as well

(93) performance class A aeroplanes means multi-engined aeroplanes powered by turbo-propeller engines with an MOPSC of more than nine OR a maximum take-off mass exceeding 5 700 kg, and all multi-engined turbo-jet powered aeroplanes;

(94) performance class B aeroplanes means aeroplanes powered by propeller engines with an MOPSC of nine or less AND a maximum take-off mass of 5 700 kg or less;

(95) performance class C aeroplanes means aeroplanes powered by reciprocating engines with an MOPSC of more than nine OR a maximum take-off mass exceeding 5 700 kg;

So, considering each of these

Turboprop ME with MOPSC < 9 CLASS A if MTOM > 5700 kg, otherwise CLASS B
Prop with MOPSC > 9 CLASS C
Reciprocating with MOPSC < 9 CLASS C if MTOM > 5700 kg

I hope that makes sense - I'm beginning to doubt myself now!

Tom

[matj1986]

I see, so it is assuming that a plane that doesnt meet the "performances requirements linked with MTOM/MOPSC limitations" of its class automatically falls back to the class below.

So far I considered engine type being a requirement too. I mean on the EASA report, they say "Perfs class C are reciprocating engines meeting certain weight and capacity conditions"... a Propeller engine airplane doesn't become a reciprocating engine airplane just because it has more than 9 seats...
But in the end its just about performances. Lighter planes have better performances, propeller engine gives better performances, and both factors are used to calculate performances.
So I guess I got it.
Thanks a lot, best regards,

Mathieu