EASA Part-66 Exam Preparation Online

Thank you for the report. You are right that the wording was ambiguous, and the stem has been corrected. The marked answer stands. What the question was describing is a nozzle at its design condition, with the throat choked and the exit flow supersonic. The gas arrives subsonic, accelerates through the converging section to reach Mach 1 at the throat, and then keeps accelerating through the diverging section as the now supersonic flow expands. Your reading was the reasonable one to take, and it is exactly why the stem needed changing. The area effect reverses either side of Mach 1: a converging duct accelerates subsonic flow, but it decelerates flow that is already supersonic. So on your reading of the old stem none of the three options would have been correct, which makes the wording a real defect rather than a matter of taste. Elsewhere in the bank that distinction is made explicit, with separate items keying air that enters a converging duct at sonic speed as decelerating. The st…

PART66Online replied to ewanroles13's question ·9h ago

The wording of the question suggests the airflow is supersonic before reaching the convergent-divergent nozzle

ewanroles13 asked a question ·10h ago

La doublure abradable est connue en nid d'abeille, en résine synthétique ou en plastique qui réduit le bruit. Il est fait également pour être poncé par les ailette de compresseur afin d'évité un espace.

hugohoarauhoarau replied to bucks's question ·2d ago

Thank you for the feedback. The marked answer is correct here, and it is worth setting out why. Leaning at high power does not take the engine straight to lean of peak. Coming back from full rich, the mixture first passes through the best power and peak cylinder head temperature region, and that is where the detonation margin collapses. The excess fuel that was providing charge cooling at full rich is no longer there, flame speed falls, and combustion carries further into the stroke. That is the condition this question describes, and it is why the operating procedures for most certified engines call for full rich above roughly 75 percent power. You are correct that well lean of peak brings cylinder head temperatures back down. That is a real technique, but it depends on fuel distribution good enough to support it, and it is not a high power setting, so it sits outside what this question is asking. Of the three options given, reduced fuel flow is a cause rather than a result, and oil…

PART66Online replied to jon@efm.ltd's question ·6d ago

This question is worded badly. If the mixture is set lean of peak, the cylinder head temperature will decrease, NOT increase. "too lean" is very ambiguous. Please be more precise in the wording!

jon@efm.ltd asked a question ·6d ago

Actually, option 1 is not incorrect due to missing keywords, it is incorrect due to scope. It limits the aim to occupational health and accident prevention, whereas a human factors programme addresses the interaction of personnel with equipment, procedures and environment, and therefore targets operational safety and efficiency as well as personal well-being.

svenj88 replied to wan.yc.justin's question ·14d ago

#1 being wrong is it because of the missing of keywords?

wan.yc.justin asked a question ·14d ago

2 dots equals 4 degrees. Each point represent 2 degrees and full deflection is 10 degrees

khalidjat asked a question ·16d ago

You are right, the stem is too broad. On a conventional turboprop the power lever runs to the fuel control unit and a separate lever sets the governor, so option A fits that case perfectly well. I am rewording the stem to name the single lever installation, which is the only one the marked answer describes. Thanks for flagging it.

PART66Online replied to josh93's question ·23d ago

What about a king air 200? The power control lever only operates the FCU via the connecting rod. The prop is controlled via a separate lever. That lever only controls the primary governor. So this question is not accurate. Not all aircraft have FADEC! A&B can be correct for this question so maybe it should read "on a modern turboprop aircraft the power lever controls?"

josh93 asked a question ·23d ago