Acrobatics in a Kingair?

[YesTAM]

From this Morning's Age. Is this a slap on the wrist with a feather or what?????



Acrobatics land pilot Grollo in hot water


By Steve Butcher
May 16, 2006


A member of the Grollo construction family has faced court after recklessly piloting a plane over the Victorian alps, taking passengers on a wild aerobatic ride and damaging the plane's engines.

Mark Leon Grollo, 33, son of Rino and nephew of Bruno Grollo, had passengers floating in zero gravity when he performed a steep climb and dive over the Mount Hotham resort on May 11, 2002, a court heard yesterday.

Grollo performed the stunt as he flew a group of friends to a private function at the resort in a hired Beech King Air 200.

Prosecutor Vicky Arjitis told Heidelberg Magistrates Court that damage to both engines was caused by Grollo flying the plane in a way it was not designed for.

Grollo pleaded guilty to seven charges, including operating an aircraft recklessly and making a false or misleading statement.

Terry Forrest, QC, defending, said Grollo's conduct was "so completely out of character as to constitute an aberration".

He said the incident occurred after Grollo's first marriage failed and he "took up with a slightly sportier crowd" who were not as "focused" as his client.

A highly regarded pilot, Grollo had accepted his behaviour was a case of "showing off" to friends.

Mr Forrest said the plane's owners had assessed the damage at $492,000, which indicated Grollo might face civil action.

Magistrate Jill Crowe put Grollo on a non-conviction, two-year good behaviour bond.

She also ordered him to pay $3000 to the court fund, $1000 costs and $5000 to the Royal Flying Doctor Service, for which he had been working at the time of the incident.

[Hugh Jarse]

Oh well.

You can't put brains in a statue:D

[Arm out the window]

If it was just high-speed pull-ups followed by zero-g pushovers, they probably couldn't get him for illegal aerobatics, not having exceeded normal pitch or bank limits and staying within the aircraft's g limits, so maybe they were a bit hamstrung by allowable penalties for 'recklessly piloting'.

Paying for the damage caused would probably be a big enough penalty in normal circumstances, but I guess getting hold of some money wouldn't be that difficult for him.

[Squawk7700]

They got him easily on the "aerobatic" clause, and can get you very easily because when you climb an angle of attack where you are unable to maintain a constant (flyable) airspeed, that is classified as an aerobatic manoeuvre. Eg, steep pull-up resulting in a negative g push-over. That being said though, a stall is not an aerobatic manoeuvre and can legally be executed at any height. The 3,000ft or so that instructors use is a guide / best practice only.

If you do a "beat-up" down the runway, pull up fairly steeply then push over negatively to regain speed, you have completed an aerobatic manoeuvre and as such require an aerobatic endorsement, low level waiver and an appropriately certified aircraft.

There's always a way for them to snaffle you if they need to.

I also raise the question of whether or not the passengers were qualified to determine if "aerobatics" had actually been performed in the aircraft. A non-aviation individual may not know enough to know better; especially if some pre-dinner drinks had been consumed.

Sounds like a nice night out with friends turned bad when a neat little push-over did damage to the engines that the pilot didn't know would happen when executed.

[RENURPP]

Squawk7700

Ineterested to know where you found your definition of aerobatics?

The old CAR's or maybe even ANR's used to define aerobatic maneouvre as one were pitch exceeded 60 degrees Or AoB in excess of 60 degrees.

[Squawk7700]

I understand where you are coming from, however airspeed must come into play when determining an aerobatic manoeuvre.

Are you suggesting that 55 degrees angle of attack / pitch is not an aerobatic manoeuvre at any altitude? What happens to essentially any aircraft when 55 degrees AOA or pitch is maintained?

Would you pull a 59 degree angle of attack / pitch departure on takeoff at Moorabbin or Bankstown say after holding the aircraft down after takeoff whilst the CASA licencing and airlaws field officer is sitting in the tower? I don't think so....

[RENURPP]

Mate, I am not suggesting anything. Your instructors definition or aero's is way off the mark.
The legal definition may have changed from what I recall, I don't know, I can assure you that what you have said would not come close.

Remember there is a difference between sensible, safe and LEGAL.

[Squawk7700]

Mate, I am not suggesting anything. Your instructors definition or aero's is way off the mark.
The legal definition may have changed from what I recall, I don't know, I can assure you that what you have said would not come close.
Remember there is a difference between sensible, safe and LEGAL.

Well, when you do know Mr. RENURPP or you work it out or you find a link or someone else who knows, then post... don't flame others and then have no evidence / info to back up your claims..

I think you will find I am right... prove otherwise. I await your post.

[DirectAnywhere]

CAR155 (http://www.casa.gov.au/download/act_regs/1988.pdf) (CAUTION: Large Download 2.2 MB) Clause 2 states that straight and steady stalls and turns in which the angle of bank does not exceed 60 degrees are not acrobatic flight. It makes no specific reference to pitch attitude and I'm not sure if this is covered elsewhere?

Incidentally, SQWARK 7700, I'd like to see any civilian aerobatic aircraft maintain a 55 degree agle of attack. I guess you meant pitch attitude but reread your post. It's an important difference!

PS. Does anyone know if there's an html version of the CARs rather than PDF?

[Squawk7700]

Play on words on your behalf; let's make it broad and say pitch OR angle of attack at 59 degrees.... either way, both of them are bl**dy steep and non-sustainable as you say in practically any Civilian aircraft.

A good example of the rules are at airshows. If you were able to perform a 60 degree pitch / aoa whatever, people in non-aerobatic aircraft would be zooming down the runway and performing steep pullups.. they don't... I wonder why?

Someone find a reg to prove othewise...

[RENURPP]

Sqwak 7700,
I simply asked were you got your definition from. It sounded off the mark.

This is from CAR 155. I will find some more for you and post.

(2) For the purposes of subregulation (1), straight and steady stalls or
turns in which the angle of bank does not exceed 60 degrees shall be
deemed not to be acrobatic flight.


From what I can find the limit on pitch has been removed, therefore I would take that to mean as long as the aircraft doesn't stall, or is a straight and steady stall, then it is not an aerobatic maneouvre.

Don't get so touchy when questioned.

[Squawk7700]

That's exactly what I said in my earlier post...

I'm looking for the bit that says high pitch / aoa is aerobatic.


"That being said though, a stall is not an aerobatic manoeuvre and can legally be executed at any height. The 3,000ft or so that instructors use is a guide / best practice only."

[DirectAnywhere]

We're getting off topic but let me make it clear for you. Angle of attack is not relevant to this discussion. If the aircraft was capable of it you can fly a 55 degree angle of attack (your arbitrary figure) and be flying straight and level. This is apparently not an acrobatic manoeuvre.

You brought AoA into the discussion and no civilian aircraft is going to get near 55 degrees AoA before it falls out of the sky. Typical stall AoA for civilian aerobatic aircraft are nearer to 20 degrees than 60.

You need to delete any reference to AoA in your posts and replace it with pitch attitude.

Pedantic? Perhaps. But it undermines your argument when your defined criteria are incorrect.:ugh:

[Squawk7700]

I now modify my argument to suggest that at extreme angle-of-attack or pitch angles an aircraft would be unable to maintain speed, thus any execution of such angles is inherently classified as an aerobatic manoeuvre.

It was suggested that this is not an aerobatic manoeuvre. I believe this is wrong and am waiting for someone to provide a clear definition of this.

Leading back to the Grollo incident where I believe he DID commit an aerobatic manoeuvre when people said he didn't.

[Blown Seal]

Definitions. In this AC the following definitions apply:
aerobatic flight means manoeuvres intentionally performed by the pilot that involve:
(a) bank angles in excess of 60 degrees; or
(b) pitch angles in excess of 45 degrees, or otherwise abnormal to the aircraft type;
or
(c) abrupt changes of direction, angles of bank, angles of pitch, or speed.
copied from:
Advisory Circular
AC 91-075(0) SEPTEMBER 2001
GUIDELINES FOR AEROBATICS

[Squawk7700]

Thanks Blown Seal, that's exactly what I was looking for!!!

Seems that the interpretation of "abrubt" determines if one has conducted aerobatics, thus I would suggest that negative G's with passengers "floating" in the cabin could be interpreted as aerobatic and as such the aircraft is not certified to perform this action.

As a secondary, if one were to fly at 45 deg pitch and speed was to decay an abrupt change of pitch or roll would be required to regain speed, thus it could be construed as aerobatic.

Abrupt changes in speed could be caused by flying at a high pitch angle... thus it looks like I was right all the time.

It's amazing what you find when you bother to look into the regs and not just make stuff up.

[Diatryma]

Author: Nikki Protyniak
Publisher: News Ltd
Publication: Herald Sun, Page 024 (Tue 16 May 2006)
Keywords: Mark (1),Grollo (1)
Edition: 1 - FIRST
Section: NEWS


Grollo fined for antics

THE pilot nephew of retired developer and property tycoon Bruno Grollo will keep his pilot's licence despite dangerous aerial stunts that left a $500,000 damage bill.

Mark Grollo, 33, yesterday admitted ``showing off'' when he ignored safety warnings to perform risky stunts during a joyflight with friends in a hired plane around Mt Hotham.

The Heidelberg Magistrates' Court heard his three passengers were left floating in mid-air above their seats -- an effect of zero gravity -- during the wild ride.

Red engine warning lights came on within seconds of the stunts and Mr Grollo was forced to land, the court was told.

Mr Grollo yesterday pleaded guilty to seven charges, including operating an aircraft recklessly, creating a hazard and making false and misleading statements.

Prosecutor Vicky Arjits, for the Civil Aviation Safety Authority, said he had bragged to his friends before takeoff that he ``would show them what the plane could do''.

Ms Arjits said the plane climbed steeply and dived sharply several times. She said Mr Grollo lied by saying the engines were damaged by turbulence.

Engineers in Canada, where the disabled engines were sent to be checked, ruled out Mr Grollo's explanation.

It took six months and $493,000 to repair the Beech 200 King Air plane.

``Mr Grollo flew the aircraft in a manner for which it is not designed and not certified,'' Ms Arjits said.

But she did not ask the court to revoke his commerical pilot license.

Defence barrister Terry Forrest, QC, told the court it happened in May 2002 when Mr Grollo was very upset and lonely, and had taken up with a racier set of friends after his first wife left him.

``He accepts that he was showing off. It's something he has never done in a plane before or since,'' Mr Forrest said.

Magistrate Jill Crowe placed Mr Grollo on a two-year good behaviour bond and fined him $3000 without conviction.

She also ordered him to donate $5000 to the Royal Flying Doctors' Service.


Actually the damage bill will be more like $800K

Di

[RENURPP]

Blown Seal well done thankyou.

Squawk7700,
you are a real tosser.
It's amazing what you find when you bother to look into the regs and not just make stuff up.
You have offered no information from the regs, that info came from Directanywhere, myself and Blownseal. You relied on info from "what my instructor said".



I understand where you are coming from, however airspeed must come into play when determining an aerobatic manoeuvre.

Really. Where is that in the REGs

You were waffling on about being able to maintain speed at certain AoA, 55 degrees being your chosen figure! They got him easily on the "aerobatic" clause, and can get you very easily because when you climb an angle of attack where you are unable to maintain a constant (flyable) airspeed, that is classified as an aerobatic manoeuvre. Eg, steep pull-up resulting in a negative g push-over.

I am not aware of any "civilian" aircraft that can do that at 45 degrees. I would regard 45 degrees as steep. The steepest I see these days is 20 degrees on climb after take-off, and I would suggest not many types climb that steep.


JEEEEEZ

[Squawk7700]

Um, like yeah RENURPP says this:

"From what I can find the limit on pitch has been removed, therefore I would take that to mean as long as the aircraft doesn't stall, or is a straight and steady stall, then it is not an aerobatic maneouvre."

- Um, so what CASA pulled parts out of the regulations, and you reckon I'm a tosser!

As if they removed references to pitch. You just removed them because it didn't suit your argument, then you thank Blown Seal for putting them back in again???

I originally said words to the effect of decaying airspeed was an aerobatic manoeuvre to which it was said that I was wrong.

I was not wrong.

I asked for someone to provide the regs to which you replied with nothing useful.

You provided this:

"The old CAR's or maybe even ANR's used to define aerobatic maneouvre as one were pitch exceeded 60 degrees AoB OR in excess of 60 degrees."

- 60 degress, comeone, get off the drugs! You post this crap, then tell me off for posting opinion! 60 degres pitch! Oh and "pitch exceeded 60 degrees AoB," what the heck does that mean?


I said my instructor told me and I believe him; he was right. My instructor probably taught your instructors instructor 20 years ago to perform aerobatics and I absolutely knew he was right.

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.

You might prefer a forum more suited for your skills and knowledge; it's located at www.ultralight.net.au although your posts would probably be pulled straight away for being crap.

[Squawk7700]

Quote from Squawk:

"I understand where you are coming from, however airspeed must come into play when determining an aerobatic manoeuvre."

Quote from RENURPP:

"Really. Where is that in the REGs"

Supporting regulation:

aerobatic flight means manoeuvres intentionally performed by the pilot that involve:
(c) abrupt changes of direction, angles of bank, angles of pitch, or speed.

CASE CLOSED.

That is all.

[tanglewood]

Actually Squawk, case not closed. An AC is certainly not a Regulation and the definition of aerobatic flight used there is not a statutory definition, although it may be used by CASA to demonstrate their interpretation of a regulation.

[Blue Sky Baron]

Squawk,

I think you might be barking up the wrong tree. :rolleyes:

An aircraft such as the one flown in this instance can climb rapidly with a gentle application of elevator at cruise speed and conversely with gentle application of forward elevator the aircraft could easily progress into a negative G situation. As long as the aircraft G limits are not exceeded I cannot see how this could be deemed as aerobatic, not smart, := but not aerobatic.

Please recheck your facts with your CFI. :ugh:

BSB :ok:

[Arm out the window]

BSB, I was about to post a similar thing - you can get a few seconds worth of zero g in just about any aircraft by, for example, getting speed in a dive, pulling up (30 NU would be ample), then pushing forward to get and maintain zero g - all gentle, smooth and non-aerobatic.
However, as Mr Grollo found out to his discredit, if engines or other systems need positive g to function correctly it is not a smart thing to do in machines that have such limitations.

The pitch and bank limits quoted in the AC are angles reference the aircraft's axes, as opposed to AoA which as we hopefully all know is the angle between the chord line of an aerofoil and the relative airflow.

[1224]

How was he able to damage the engines on a zero G pushover? Was it an oil deprivation thing or an over-speed thing?

[Lodown]

Maybe covered elsewhere or on an earlier thread, but are there any specifics on the damages, how, why, when, etc.? I can imagine that oil was forced to flow where it was not supposed to and not to flow where it was supposed to, but that's only my imagination running rampant. What are the facts?

[Diatryma]

Metal in oil due to rubbing and seizure of the 1st stage planet gear bushings and shafts due to a momentary reduction of oil lubrication.

Di

[Avgas and Fanta]

I would have thought it would cope with a few seconds of 0 G, After all, its not that different to flying though a storm.

[Diatryma]

A & F,

Hmmmmm......perhaps it was more than just a few seconds???

:\

Di

[VH-XXX]

Perhaps (based on that) the damage did occur during "turbulence" as he said...

[VH-XXX]

I wonder... did they fly home back to Essendon after stage 1 siezed?

[Capt. Wingdrop]

If one was to fly an aircraft, such as a C182 for example, and attempt a zero 'g' attitude change for approximately 5 seconds, what effects would this have on the engine.

I'll admit engines are a weak area for me. :O

[Diatryma]

VH-XXX,

He's fessed up didn't he - turbulance was a fib wasn't it???

They didn't fly it back of course - It sat on the hill for months.

Di :hmm:

[VH-GRUMPY]

Who cares about the regs and bush lawyers will argue until as one would say until the cows come home.

This clown was operating a sophistocated aircraft (at least by my standards) recklessly - he endnagered people's lives and hopefully has learned a lesson. I don't give a sh&&t that his marriage had just broken up - he can go and get pissed and kill himself in a car accident - hopefully on his own.

This stupid event had the potential to cause a lot more damage.

Out of character - hardly. :}

[enginair]

i'll be surprised if you sent any turbine engine away for inspection and for the engine shop not to find anything wrong . i don't condone aero's in the king air but where is a negative g defined as an aerobatic manouver

[AerocatS2A]

Squawk, the quote you are using says "abrupt". I can assure you, that I can achieve zero "g" in an aircraft with a gentle pull up to less than 45 degrees pitch, followed by a gentle lowering of the nose. In fact, I can quite happily do loops, rolls, and stall turns, outside loops etc (in an approved aircraft of course) without anything ever being "abrupt".

Also, you don't seem to understand angle of attack, I suggest you go back to the books on that one (hint: 55 is not a number you'd ever see associated with "angle of attack".)

[Centaurus]

Squawk 7700.
That being said though, a stall is not an aerobatic manoeuvre and can legally be executed at any height. The 3,000ft or so that instructors use is a guide / best practice only.


The guide or best practice only of 3000 ft is certainly best practice for ripping off a student. For decades flying schools have perpetuated the myth that recovery from practice stalls must be completed by 3000 ft. It originated from Tiger Moth and Chipmunk days when the propellers of those early types were prone to stopping during aerobatics and stalling.

Because these aircraft were not equipped with starter motors, the only way to get a stationary prop to turn and start the engine was to dive steeply often to Vno. Thus the 3000 ft could be quickly used up in the dive leaving not much time and height to plan a forced landing if the engine failed to start. In fact part of the safety checks prior to stall practice was to ensure a forced landing area was within gliding distance.

Of course, the minimum height for practice stall recovery will vary with aircraft type but to flog a C152, C172 or a Warrior or a Jabiru all the way up to 3-4000 ft just to conduct stall recovery practice, is cheating an unsuspecting student out of lots dollars which ultimately puts the money into the instructors pocket and the flying school account.

One regional CASA's view (I have this on paper) is the minimum height for stall recovery practice is not a regulation. It is whatever height the flying school publishes in its Operations Manual. It can vary from school to school. But whatever restriction is published in the flying school operations manual is what CASA and its lawyer will hang you on. In Australia 3000 ft is the common figure and a common rip-off.

[Pass-A-Frozo]

pitch angles an aircraft would be unable to maintain speed, thus any execution of such angles is inherently classified as an aerobatic manoeuvre.
Your earlier definition would mean any "converting of excess speed to height" is aerobatic. If you enter a climb from cruise speed, set a higher than sustainable attitude to bleed the speed back to best rate, you are doing aerobatics?????? :E

The real word in that reg to examine is "abrupt" (in relation to an abrupt change of airspeed). Mainly because I'll bet my left one.. [well, actually no, maybe a beer] that Grollo didn't get the KingAir going 45 degrees nose up.

[rove'd]

She also ordered him to pay.... and $5000 to the Royal Flying Doctor Service, for which he had been working at the time of the incident.

This lunatic wasn't a B200 driver with the service was he....? :*

[Cloud Basher]

Next someone will be arguing that an aircraft stall is caused by lack of air speed:mad:


CB

[Captain Nomad]

3000' AGL may be a guidline from CASA, and an old one at that, but it is not altogether unreasonable. I know of at least one pilot (quite an experienced one) who reckons he would have been dead if it wasn't for the fact he had that extra height BEFORE stalling/spinning. Not only that, but there is a difference between stalling a C152 by yourself knowing full well what you are doing and doing the same with a nervous student who has frozen solid on the controls. A difference again between stalling a C152 and then stalling a twin with a ham-fisted student looking after the throttles (and potential significant assymetric thrust around Vmca). Let me tell you - it is not just a ploy to draw out money from the student and extend a lesson! :yuk:

[Capt. Wingdrop]

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.

[Centaurus]

Capt Windrop,

a chance to practice climbing again

You need practice at climbing? And at four bucks a minute.... My case rests

[Capt. Wingdrop]

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.

[Macrohard]

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?

[Brian Abraham]

Can anyone elaborate as to the damage done to the aircraft/engines?

[youngmic]

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.

[Arm out the window]

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.

[YesTAM]

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.

[AerocatS2A]

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.

[Squawk7700]

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...

[Arm out the window]

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.

[Runaway Gun]

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.

[RENURPP]

http://www.aerospaceweb.org/question/aerodynamics/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.

[Andy_RR]

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

[Lefthanded_Rock_Thrower]

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.

[Arm out the window]

Hear, hear.

[Diatryma]

So too - perhaps - should the pilot in question?????

;)

Di

[QNH1013.2]

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.

[Arm out the window]

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?

[AerocatS2A]

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.

[Squawk7700]

Squawk clearly knows the difference between AOA and pitch. What frustrated Squarker is that someone said that 60 degrees pitch wasn't aerobatic and Squarker disagrees. Let's be serious, 60 deg AOA or 60 deg pitch are pretty serious angles and quite obviously not quite in the ordinary flight envelope of most aircraft. Squarker thinks that someone who knows him personally was attempting to have a dig over this.

[AerocatS2A]

Can Squawk give an example of an aircraft or wing that will fly at 60 degrees AoA? What about 45? 30?

[DirectAnywhere]

Got some video of an SU-30 somewhere. This link isn't it but gives some idea of what the aircraft is capable of:

http://www.crazyaviation.com/movies/CA_SU-30.wmv


Anyway, the other piece of footage shows an AoA of roughly 120-130 degrees sustained for up to 10 seconds. It uses thrust vectoring and a whole lot of other fancy stuff including canards. It's not really relevant to the discussion at hand but it's worth watching anyway!:ok:

The one thing the Soviets got right was their aerodynamics. SU-27, MiG-29 and on were, and still are, far superior to anything the US had or has. Not sure how the F-22 etc. will compare.

[AerocatS2A]

Yeah, I knew someone would bring up those whizzy-doo military machines ;)

[Lord Snot]

Next someone will be arguing that an aircraft stall is caused by lack of air speedWell it's true. At a given Cl, rho and wing area, a sufficient reduction of speed will result in the development of a stall. Any pilot that does not know that should be driving a taxi.Effectively, we all already are...
This squawk individual probably thinks he's referring to 60deg Angle of Bank in these ramblings.
As for Grollo being an RFDS pilot..... say WHAT??? :ugh:
Never before have so many ignorant tossers gathered on one thread. Apart from me, of course.

[Runaway Gun]

Yeah, I was pulling someone's leg.

Just frustrated that AoA, AOB, Pitch and Coanda are terms bandied around seemingly interfrastically around here. :ugh:

[RENURPP]

What frustrated Squarker is that someone said that 60 degrees pitch wasn't aerobatic and Squarker disagrees.

What some body said was


The old CAR's or maybe even ANR's used to define aerobatic maneouvre as one were pitch exceeded 60 degrees Or AoB in excess of 60 degrees.


RTFQ = 1/2TFA

[Loose rivets]

I have always been a great believer in knowing your airplane. There is a distinct difference between nudging at the edge of the envelope to see how it really handles, and carelessly stressing the structure just for the hell of it.

The maneuvers described don't seem very dramatic to me so it has to be the way in which they were carried out. Bob Hover wouldn't end up with a bill for megga $'s after his breath-taking demonstrations. The guy that rolled the prototype 707 really didn't think that it was that big-of-a-deal.

Here, I know for certain that the BAC 1-11 and the Fokker lookalike have been rolled. All done without too many stresses and strains.

I have taken what was called ‘violent avoiding action' to miss something one day, and the 1-11 went past 90 degrees of bank. In fact, just for a moment, I considered carrying on with the roll as the smoothest way out of the situation. There was a socking great tool box on the floor, and it didn't budge. It was a strange thing, but when we were invited to try fast rolls during training (all done in the real airplane in those days) no-one that I knew, really pulled it round very fast. Fright is a funny thing.

I have also been in a storm for what seemed an eternity. Several time the horizon bar disappeared behind the top or the bottom mask. I wouldn't have expected the engines to all fail. Bl00dy glad they didn't, things were tough enough already.

I have also, in clear air over the Alps, gone down four or five huge drops of 1,000 feet each. It was like going down concrete steps. My jacket swung on its hook and almost reached the ceiling. So much for maintaining positive g. (There was a T-storm, well below us, 12NM to the West of our track.)

I think the point about gyroscopic effect causing unacceptable bearing loads, is the most lightly scenario. It still seems an extraordinary bill for just throwing the airplane around. Was there any airframe distortion? cos if not, it would seem that the engines/gearboxes are a tad vulnerable.

[wdn]

i can't believe how much such a simple statement in the regs can be misinterpreted:

centaurus:
The guide or best practice only of 3000 ft is certainly best practice for ripping off a student. For decades flying schools have perpetuated the myth that recovery from practice stalls must be completed by 3000 ft. It originated from Tiger Moth and Chipmunk days when the propellers of those early types were prone to stopping during aerobatics and stalling.


WRONG! I hate writing these things out but here goes:

CAR155(2)
For the purposes of subregulation (1), straight and steady stalls or turns in which the angle of bank does not exceed 60 degrees shall be deemed not to be aerobatic flight.

CAR155(3)

A person must not engage in acrobatic flight in an aircraft:
(a) at a height lower than 3000 feet above the highest point of terrain, or any obstacle thereon, within a radius of 600 metres of a line extending vertically below the aircraft; or.......


How can you say that all stalls can be conducted below 3000 feet? Only "straight and steady" stalls may be conducted in such a fashion.

What is a straight stall? It's impossible to conduct a stall with exactly zero degrees heading change at some point throughout the manoeuvre. Remember a .00000000000000000000000000000000000000000000000000000000000 00001 degree heading change is not "straight". I think the lawyers would have a lot of fun pointing that out to some smart arsed pilot who claimed the he/she could do a straight stall.

The people ripping you off are the ones that only teach or get a student to practice a so-called straight stall.

[Woomera]

Guys,
feel free to start a new thread about aerodynamics. The topic of this thread hasn't been discussed for a couple of pages, therefore it has run its course.

Woomera (Eastern States)