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Acrobatics in a Kingair?

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Old 16th May 2006, 23:34
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Although it's not written into the regulations, it will be written into most flying school's operations manual.

As Captain Nomad said there have been numerous occassions where stalls are being practiced, particularly stalls in the approach configuration, where a student does not react properly and a. loses a fair bit of altitude, or b. puts the aircraft into a spin.

To claim that the extra climb is used to make more money is rubbish. If anything it gives the student pilot a chance to practice climbing again, which they would have learned properly only two lessons prior.
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Old 17th May 2006, 00:27
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Capt Windrop,

a chance to practice climbing again
You need practice at climbing? And at four bucks a minute.... My case rests
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Old 17th May 2006, 02:56
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I don't understand your argument.

If after only a couple of lessons you can climb straight and at a constant best rate of climb speed I'd be amazed. In lesson three you were shown how to climb and descend, lesson four your get shown turning (which probably only involved a few minutes of climbing for the student during the whole lesson), then in lesson five the student gets the chance to climb again up to 3000ft.

The primary object of going to 3000ft is train at a safe height, I merely made the point that it gives the student a bit more climbing practice.

I can't comment on where every instructor does stalls, but in my area we'd do them in the same place no matter whether they were done at 3000ft or 1000ft. Given the same ground distance is being travelled, and by using a rough rule of thumb of allowing 1 minute for every 2000ft onto your travel time in a climb, the climb should only add an extra 1 minute to your trip time (climbing from 1000 to 3000ft).

Therefore, for you this would cost an extra $4. This is unlikely because most schools don't charge $240 per hour for initial training. That being said you aren't charged in 1 minute increments anyway, so this extra time is unlikely to make any difference to the training time in any way.
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Old 18th May 2006, 00:22
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I didn't need to find the reg myself, because I knew I was right, right from the start.

Boy this forum is full of w*ankers.
Crikey!! That attitude must be an asset when dealing with other crew? You'll go a long way with that attitude son - NOT. Take a deep breath and have a close look at youself. Like what you see?
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Old 18th May 2006, 02:19
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Can anyone elaborate as to the damage done to the aircraft/engines?
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Old 20th May 2006, 07:08
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I can quite clearly remember the the old CAR/ANR that made reference to 60 degree pitch up as a limit, it has since been removed. Abrupt changes of direction is somewhat subjective, is an Ag aircraft in the course of manouvering aerobatic? Never heard of anyone prosecuted for the pull up at the end of a spray run. Helicopters turning in short radius or on the spot abrubt? Doubt it.

Squawk 7700 I think you might have been misinformed, just because an instructor said it was so does not make it so. Old or young, instructors can still be wrong. As someone said a smooth pull up then gently into zero G is hardly aerobatic, unfortunate and somewhat suprising that this alone damaged engines, but I won't comment further as have not read the limitations section for that particular aircraft.
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Old 20th May 2006, 08:57
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Well, if CASA don't specify a pitch limit it's a mistake in my view - you can do a loop with wings level!
Ag work, mustering etc need some leeway, in that 'judicious manoeuvering appropriate to the task' (my attempt at lawyer-speak) is needed to do the job, and can be done safely, but a 60 bank / 45 pitch sounds more than reasonable to me as a limit for normal ops for legislative purposes.
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Old 20th May 2006, 09:06
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I seem to recall another thread that suggested that as a result of a period of negative G, chip detector lights came on for both engines. the gearboxes were found to be rather stuffed as a probable result of lack of lubrication.

I know that the Decathlon has a lubrication system (dry sump from memory) that contains a "slobber pot" and associated hardware to turn the vent into a suction line and vice versa depending on which way the aircraft happens to be oriented, so that there is always some nice pressurised lube flowing. I don't think a Kingair would have this feature (although a PC9 must have)

In other words, if the POH says that the G limit is -0.0 G, it says it for a reason.
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Old 20th May 2006, 13:52
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Originally Posted by YesTAM
In other words, if the POH says that the G limit is -0.0 G, it says it for a reason.
Is the limit 0.0 G though?

The Pitts S2A has an inverted oil system. It runs indefinitely right way up, and runs indefinitely upside down, but put it on a knife edge (to the left I think) or do a nice vertical line and you may find the engine losing oil pressure.

The POH G limits aren't the be all and end all, a bit of common sense is sometimes required and a look at the oil pressure gauge wouldn't go astray when doing something out of the ordinary.
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Old 26th May 2006, 05:53
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I'm wondering why the PT6a in a Pilatus PC9 doesn't suffer from the same problems? I've seen a solo roulette flat spin their PC9 from quite some height. Perhaps negative G's are far worse than a flat spin and perhaps you can't negative G the PT6a...

Just wondering...
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Old 26th May 2006, 06:37
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There's an inverted oil system in the PC-9, has the PT6A-62 engine if memory serves me, and can tolerate negative g without adverse effects.
In an upright spin, there will be some positive g rather than negative. If the PC-9 you saw was doing some kind of stall turn / hammerhead type manoueuvre he would probably have had zero or some negative g for a bit, but the oil system can handle negative g including inverted flight for a good length of time, so it wouldn't be a drama.
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Old 26th May 2006, 06:59
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Now I don't know UP from DOWN

S7700, now I'm confused.

Can you please tell me what AoA is, and why/if that's different from pitch?

It seems that the other guys don't know what they're on about.
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Old 26th May 2006, 07:07
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http://www.aerospaceweb.org/question...cs/q0165.shtml

If that is a serious question you NEED to read the page on the link above.
Another key angle that is most often confused with angle of attack is called the aircraft pitch angle. Pitch angle is one of three angles that are called Euler angles. These three angles define the orientation of the aircraft in roll, pitch, and yaw with respect to a fixed reference coordinate system
Some further examples are also provided illustrating the key differences between these two important angles. The first set of examples shows three airfoils all at the same angle of attack but at different pitch angles. This situation demonstrates that a wing can easily be at the same angle of attack even when flying much different maneuvers, such as climbing or descending through a loop.

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Old 26th May 2006, 09:05
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The engine/gearbox damage was possibly due to excessive bearing loads caused by high rates of gyroscopic precession of the turbine/propellor. Even with full oil pressure, bearings are only rated to a certain load before bearing contact occurs

This might have been how the beak proved the 'abrupt' nature of the maneouvre.

A
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Old 26th May 2006, 09:17
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Pitch angle is with reference to the Horizon.

AoA is in relation to the Chord line and Relative Airflow ( Free relative airflow in some American texts ).

A stall is when the Critial angle ( AoA ) is exceeded, i.e. when the AoA is exceeded, not the Pitch angle.

Any pilot that does not know that should be driving a taxi.
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Old 26th May 2006, 09:56
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Hear, hear.
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Old 31st May 2006, 06:21
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So too - perhaps - should the pilot in question?????



Di
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Old 31st May 2006, 06:34
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AOA or pitch, it doesn't matter, 60 degrees is EXTREMELY excessive and was quite obviously aerobatic. I can't believe 60 degrees was even considered in anyone's argument.
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Old 31st May 2006, 07:06
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At the risk of sparking off another round of to-ing and fro-ing, nobody's said that this guy did get to 60 degrees, so saying 'it was quite obviously aerobatic' is jumping the gun.
As previously mentioned, he apparently stuffed the engines by subjecting them to unusually long periods of low g - aerobatics not required to do that, just ignorance.
Perhaps any King Air drivers could elaborate on flight manual limits, warnings or notes that should have stopped him doing it, if he'd read and followed them?
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Old 31st May 2006, 08:14
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I wonder if Runaway Gun may have asked the question, not because he/she didn't know the difference, but because they wanted Squawk7700 to explain the difference. This would show that Squawk7700 was just having a brain fart rather than demonstrating a worrying ignorance of aircraft physics and terms.
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