Hazelton in the News

[gaunty]

So you've got ice (and the conditions were ideal for clear ice) the aircraft stalls without warning and the AP finishes you off.

SAAB states - "Do not perform training with iced up aircraft. Real stall might be encountered prior to stall warning."

If this is true then "Do not operate the aircraft in clear icing conditions and in other than 1G flight . Real stall might be encountered prior to stall warning."

[The Messiah]

SAAB 340 @114 kts, flap 20 in known icing conditions at night?

Gaunty says the aeroplane shouldn't be licenced? This is getting funnier by the minute.

[amos2]

Ok! Gaunty...you asked for it...you're getting it!
You are being hysterical!!
Been in this business for 43 years...currently a Sim Instructor(jets of course)..."accelerated stall behaviour"...never heard of it!!

Suggest you rethink your contributions to this forum!

If you don't know what you're talking about , say nothing!

[amos2]

By the way Gaunty...
"real stall may be entered prior to stall warning"
Where did you get that crap from?
If you want to mix with the professionals I suggest you put in your 40 years like the rest of us!
Then, we may take you seriously!

[gaunty]

amos2

Feeling better now that you have had a good beat of that very hairy chest of yours, I must have had the volume turned down as I missed the Tarzan call.
Harrumph.......... goodness I mean "after 43 years and a Sim instructor (jets of course)" you must know nearly everything.

gaunty is not good at patronising mode but I'll give it a go.

You say;

Been in this business for 43 years...currently a Sim Instructor(jets of course)..."accelerated stall behaviour"...never heard of it!!

my bold

I say go to Google and type in "accelerated stall" and find out that you after 43 years and a Sim instructor (jets of course) are one of the FEW pilots around who have never heard of it. But then that might not be so either.

You might call it something different, I'd be interested to know what? Mr Newton had some advice to offer and a glance at a text on rotational dynamics might also be edifying.

I give you just ONE example from the Canadian DOT manual, I thought I'd keep it simple for you.

ACCELERATED STALLS

Instructor and Student Practice

At a safe altitude, set the aircraft up at 80% of the appropriate manoeuvring speed (Va) for the weight of the aircraft.

Demonstrate the difference in stall speed by approaching the stall in level unaccelerated flight and noting the airspeed at which the stall warning activates. Then demonstrate a 60° bank level turn and note the speed at which the stall warning activates. Emphasize that the stall is a function of angle of attack not airspeed. An aircraft can stall at any speed and any attitude. Emphasize these stalls could occur during any phase of flight in which abrupt or excessive control movements produce an increased load factor on the aircraft such as steep turns, pulling out of a dive or sudden changes in direction of flight. Emphasize the possibility of a spin developing from these types of stalls.

Demonstrate a 45° bank turn and gradually decrease power while trying to maintain altitude with increasing back pressure until the stall occurs . Demonstrate a 45° bank turn at cruise or climb power and "tighten the turn" with rapid back pressure on the control column. Demonstrate an abrupt pull-up (at low speed).

Yup that's right the difference between 1G and accelerated flight, that is the moment you apply ANY change in direction of the aircraft you are applying an "acceleration", ipso facto, changing its "weight" and therefore it's stalling "speed".
If you want I can go into the theory of why the rotation 'post stall' in this instance (with unswept wings anyway) is usually in the opposite direction of the turn. Which is why so many pilots get such a big suprise.

Oh and while we are about it, shall we talk about the relevance of "acceleration" to "Buffet Boundaries" in relation to turbulence for high altitude flight planning.??

Oh and in regard to

"real stall may be entered prior to stall warning"

If you weren't in such a hurry to show what a big deal you are, you would have seen that was a direct quote from SmallGlassof Ports post

Going thru old notes I did find a comment from SAAB Flight Procedures section 25/12-page 1 stall recovery. SAAB states - "Do not perform training with iced up aircraft. Real stall might be encountered prior to stall warning."

fj-100 says

The Saab 340 has a history of stalling prior to any warnings caused by the accumulation of ice.

I can only assume from your bravura statements that REAL pilots such as yourself don't need stall protection and can sense, using the vast experience at your disposal of flying aircraft loaded with ice, the onset of stall without it. Neither need you worry about encountering accelerated stall conditions in these conditions as they obviously do not exist. I mean, as well, ice doesn't weigh very much at all really, does it.

My point is/was that if this is true, it is totally unacceptable and obviously caught the crew by surprise, when we are trained and trained and trained not to be so.

The Messiah has a go at me as well, fine I've got big (fat) shoulders, but from the evidence, something is not right and I thought that we were in the habit of winkling out these issues here.

It's either a system or training issue or both.

Shall we talk about the litttle problem the ATR had with icing now. If I recall it was known or at least suspected but it took a severe embarrassment before anything was done.

Hopefully some of us continue to keep asking, asking and asking questions.
I know you would like to continue with the hairy chested REAL PILOTS dont need all this woosbag BS to stay alive and feel relevant, but I hold a different view.
If my Granny can stay out of trouble as a pilot in it, then we are getting close to ideal and would demonstrate that we have actually learned something over the last 43 years of designing and building aircraft.

So why don't we discuss and learn about rhetorical questioning and never accept the obvious as the status quo.

Last sally;

If you want to mix with the professionals I suggest you put in your 40 years like the rest of us!
Then, we may take you seriously!

Surely you are not serious, we ARE speaking for ALL of the other professionals out there are we. Then God help us.

Sorry but I asked for it and you got it.

[Sierra Squared]

Gaunty, you make several excellent points (and several pointed ones )

But one general question (a genuine one from an inexperienced background and not an attempt at being a smart arse); why would the FO call 'airspeed' if it was an unexpected (and unrecognised) icing encounter? Wouldn't the onset of stall be a surprise in this case?

[Capt Claret]

Sierra Squared, an ejumicated guess.

The F/O, who I presume was the PNF, had less on his/her hands and was able to observe the IAS either lower than expected for the phase of flight and power set, and/or decaying because of ice accumulation, and/or decaying because of wind shear.

Any of the above would be cause for the PNF to bring to the PF's attention, the fact or suspicion that all was not as it should have been with regard to the IAS.

[amos2]

Hmmm...reminds me of the time Greg Norman lost the US Masters after leading by six strokes going into the last round. At the press conference he was asked what happened!

"Simple" he said..."I got my ass kicked."

I know the feeling!!

Amos2 slinks off vowing never again to open that second bottle of red while reading Prune late at night.

[gaunty]

amos2

It takes a big man.......... I thought it was a bit out of character.

No offence taken and next time invite me around too, I'll bring some of Margaret Rivers finest and we can compare notes on how much fun we've had in this crazy business.

[Willie Nelson]

Once again Gaunty you dazzle us with your outstanding knowledge and insight into the secrets of our profession. On this occasion however, my hat goes off to AMOS 2

It does in fact take a very big man to make a true apology like this, given that many on this forum would have simply changed usernames.

This type of humility is all too often sadly lacking, not only on this forum but in our aviation community.

Gentleman I congratulte you both on your attitude!

[Planned Root]

[Astroboy]

I would like a bit of information from a current Saab driver. What would be a typical attitude and power setting for a max weight Saab flying straight and level @ 135kt with flap20 and gear down? What is the stall speed of a max weight aircraft in the same config? According to the manufacturer, how far above stall should you get stall warning. ie. stick shake.

Thanks in advance.

The more I read the preliminary report, the more I ask myself.......What The?

[farrari]

GO GAUNTY

[The Messiah]

The thing people (especially Gaunty) must realise is that stall warning devices are nothing more than angle of attack sensors, and for an aircraft with a decent load of ice they are virtually useless as the normal critical angle of attack is no longer relevant.

Any warnings written by governments or manufacturers in flight manuals etc are usually for their own protection in the event of litigation following an accident.

No aircraft crashes doing the correct airspeed in the correct configuration. (excluding CFIT)

Give it up. The crew stuffed up and worse still, tried not to tell anyone. I never had any problem with SAAB's, MU-2's or Mooneys. Others did.

[amos2]

Don't know too much about the Saab, but about 10 to 15 knots before the stall is the usual regime for SS to activate.

[gaunty]

The Messiah
I understand very well what and how the stall warning and protection systems work.
It is also a requirement for flight in known icing conditions that the stall warning protection devices must have ice protection that will enable them to operate notwithstanding.
For those who are interested here are the US certification requirements for Transport Category aircraft. The SAAB people might have their own ideas but they will or should be similar and they will or should be used as a baseline reference or better by CASA.
The speeds for stall warning operation aren’t arbitrary and are fixed or required to be demonstrated according to the following certification requirement.
You say;

an aircraft with a decent load of ice they (the stall warning protection) are virtually useless as the normal critical angle of attack is no longer relevant.

I say not so;
The aircraft under normal flight conditions certainly in the approach phase should not be anywhere near the critical stalling angle of attack.
A of A indicators or stall warning devices are usually either in the wing leading edge or a slotted rotating cone on the fuselage forward of the wing. Either way they are or should be relatively unaffected by any local effects of ice build up on the wing and should have protection for that in any event. So you will or should always get an absolute reading of Angle of Attack with a warning set at the critical angle for the type.
If it is loaded with ice it weighs more, therefore at a given airspeed and level flight or descending flight the angle of attack must be higher than normal (to produce the required lift) and therefore much closer to the stalling angle of attack. There will be some variations due to deformation of the wing but it will be a relatively high angle.
The stall-warning device if it is functional and iced up will or should still herald the approach of the stalling angle of attack.
So if you fly a speed and power setting set for a normal weight you will with a substantial ice build up experience a loss of lift and descent. If you attempt to recover the uncommanded descent by a pitch up, you accelerate the aircraft, or if you are performing a landing bank, you accelerate the aircraft, either way you increase the weight of the iced up airframe further, if you are attempting both, remember you are also at the wrong end of the lift/drag and power curve in this configuration, unless you either unload the wing, increase power and airspeed or all three you will very quickly enter a stall condition.
So what happened here, was there a discussion of the possibility of icing in the pre-landing brief, was the stall warning protection system operational and was the ice protection system operating. A thorough pre-flight should reveal that. Or is there some other problem not yet revealed.
There was a “hidden” problem with the MU2 that took a few lives to suss, but the evidence that all was not well was always there in the primary flight instruments if the stall warning did not immediately herald an imminent departure.
While I’m on that subject does the SAAB have an Angle of Attack display in the cockpit? This very simple indicator should be compulsory for the wealth of information it provides for TO, climb, cruise, descent and landing.
I agree the crews subsequent actions if true were inexcusable

Any warnings written by governments or manufacturers in flight manuals etc are usually for their own protection in the event of litigation following an accident.

With respect you ignore those warning at your own peril, they are there for a very good reason.

14 CFR - CHAPTER I - PART 25

§ 25.201 Stall demonstration.
(a) Stalls must be shown in straight flight and in 30 degree banked turns with --
(1) Power off; and
(2) The power necessary to maintain level flight at 1.6 VS1 (where VS1 corresponds to the stalling speed with flaps in the approach position, the landing gear retracted, and maximum landing weight).
(b) In each condition required by paragraph (a) of this section, it must be possible to meet the applicable requirements of § 25.203 with --
(1) Flaps, landing gear, and deceleration devices in any likely combination of positions approved for operation;
(2) Representative weights within the range for which certification is requested;
(3) The most adverse center of gravity for recovery; and
(4) The airplane trimmed for straight flight at the speed prescribed in § 25.103(b)(1).
(c) The following procedures must be used to show compliance with § 25.203;
(1) Starting at a speed sufficiently above the stalling speed to ensure that a steady rate of speed reduction can be established, apply the longitudinal control so that the speed reduction does not exceed one knot per second until the airplane is stalled.
(2) In addition, for turning flight stalls, apply the longitudinal control to achieve airspeed deceleration rates up to 3 knots per second.
(3) As soon as the airplane is stalled, recover by normal recovery techniques.
(d) The airplane is considered stalled when the behavior of the airplane gives the pilot a clear and distinctive indication of an acceptable nature that the airplane is stalled. Acceptable indications of a stall, occurring either individually or in combination, are --
(1) A nose-down pitch that cannot be readily arrested;
(2) Buffeting, of a magnitude and severity that is a strong and effective deterrent to further speed reduction; or
(3) The pitch control reaches the aft stop and no further increase in pitch attitude occurs when the control is held full aft for a short time before recovery is initiated.
[Doc. No. 5066, 29 FR 18291, Dec. 24, 1964, as amended by Amdt. 25-84, 60 FR 30750, June 9, 1995]

[gaunty]

Part 2
§ 25.103 Stalling speed.
(a) VS is the calibrated stalling speed, or the minimum steady flight speed, in knots, at which the airplane is controllable, with --
(1) Zero thrust at the stalling speed, or, if the resultant thrust has no appreciable effect on the stalling speed, with engines idling and throttles closed;
(2) Propeller pitch controls (if applicable) in the position necessary for compliance with paragraph (a)(1) of this section and the airplane in other respects (such as flaps and landing gear) in the condition existing in the test in which VS is being used;
(3) The weight used when VS is being used as a factor to determine compliance with a required performance standard; and
(4) The most unfavorable center of gravity allowable.
(b) The stalling speed VS is the minimum speed obtained as follows:
(1) Trim the airplane for straight flight at any speed not less than 1.2 VS or more than 1.4 VS At a speed sufficiently above the stall speed to ensure steady conditions, apply the elevator control at a rate so that the airplane speed reduction does not exceed one knot per second.
(2) Meet the flight characteristics provisions of § 25.203.
§ 25.203 Stall characteristics.
(a) It must be possible to produce and to correct roll and yaw by unreversed use of the aileron and rudder controls, up to the time the airplane is stalled. No abnormal nose-up pitching may occur. The longitudinal control force must be positive up to and throughout the stall. In addition, it must be possible to promptly prevent stalling and to recover from a stall by normal use of the controls.
(b) For level wing stalls, the roll occurring between the stall and the completion of the recovery may not exceed approximately 20 degrees.
(c) For turning flight stalls, the action of the airplane after the stall may not be so violent or extreme as to make it difficult, with normal piloting skill, to effect a prompt recovery and to regain control of the airplane. The maximum bank angle that occurs during the recovery may not exceed --
(1) Approximately 60 degrees in the original direction of the turn, or 30 degrees in the opposite direction, for deceleration rates up to 1 knot per second; and
(2) Approximately 90 degrees in the original direction of the turn, or 60 degrees in the opposite direction, for deceleration rates in excess of 1 knot per second.
[Doc. No. 5066, 29 FR 18291, Dec. 24, 1964, as amended by Amdt. 25-84, 60 FR 30750, June 9, 1995]
§ 25.207 Stall warning.
(a) Stall warning with sufficient margin to prevent inadvertent stalling with the flaps and landing gear in any normal position must be clear and distinctive to the pilot in straight and turning flight.
(b) The warning may be furnished either through the inherent aerodynamic qualities of the airplane or by a device that will give clearly distinguishable indications under expected conditions of flight. However, a visual stall warning device that requires the attention of the crew within the cockpit is not acceptable by itself. If a warning device is used, it must provide a warning in each of the airplane configuations prescribed in paragraph (a) of this section at the speed prescribed in paragraph (c) of this section.
(c) The stall warning must begin at a speed exceeding the stalling speed (i.e., the speed at which the airplane stalls or the minimum speed demonstrated, whichever is applicable under the provisions of § 25.201(d)) by seven percent or at any lesser margin if the stall warning has enough clarity, duration, distinctiveness, or similar properties.
[Doc. No. 5066, 29 FR 18291, Dec. 24, 1964, as amended by Amdt. 25-7, 30 FR 13118, Oct. 15, 1965; Amdt. 25-42, 43 FR 2322, Jan. 16, 1978]

§ 25.207 Stall warning.
(a) Stall warning with sufficient margin to prevent inadvertent stalling with the flaps and landing gear in any normal position must be clear and distinctive to the pilot in straight and turning flight.
(b) The warning may be furnished either through the inherent aerodynamic qualities of the airplane or by a device that will give clearly distinguishable indications under expected conditions of flight. However, a visual stall warning device that requires the attention of the crew within the cockpit is not acceptable by itself. If a warning device is used, it must provide a warning in each of the airplane configuations prescribed in paragraph (a) of this section at the speed prescribed in paragraph (c) of this section.
(c) The stall warning must begin at a speed exceeding the stalling speed (i.e., the speed at which the airplane stalls or the minimum speed demonstrated, whichever is applicable under the provisions of § 25.201(d)) by seven percent or at any lesser margin if the stall warning has enough clarity, duration, distinctiveness, or similar properties.
[Doc. No. 5066, 29 FR 18291, Dec. 24, 1964, as amended by Amdt. 25-7, 30 FR 13118, Oct. 15, 1965; Amdt. 25-42, 43 FR 2322, Jan. 16, 1978]

§ 25.231 Longitudinal stability and control.
(a) Landplanes may have no uncontrollable tendency to nose over in any reasonably expected operating condition or when rebound occurs during landing or takeoff. In addition --
(1) Wheel brakes must operate smoothly and may not cause any undue tendency to nose over; and
(2) If a tail-wheel landing gear is used, it must be possible, during the takeoff ground run on concrete, to maintain any altitude up to thrust line level, at 80 percent of VS1.
(b) For seaplanes and amphibians, the most adverse water conditions safe for takeoff, taxiing, and landing, must be established.

§ 25.1419 Ice protection.
If certification with ice protection provisions is desired, the airplane must be able to safely operate in the continuous maximum and intermittent maximum icing conditions of appendix C. To establish that the airplane can operate within the continuous maximum and intermittent maximum conditions of appendix C:
(a) An analysis must be performed to establish that the ice protection for the various components of the airplane is adequate, taking into account the various airplane operational configurations; and
(b) To verify the ice protection analysis, to check for icing anomalies, and to demonstrate that the ice protection system and its components are effective, the airplane or its components must be flight tested in the various operational configurations, in measured natural atmospheric icing conditions and, as found necessary, by one or more of the following means:
(1) Laboratory dry air or simulated icing tests, or a combination of both, of the components or models of the components.
(2) Flight dry air tests of the ice protection system as a whole, or of its individual components.
(3) Flight tests of the airplane or its components in measured simulated icing conditions.
(c) Caution information, such as an amber caution light or equivalent, must be provided to alert the flightcrew when the anti-ice or de-ice system is not functioning normally.
(d) For turbine engine powered airplanes, the ice protection provisions of this section are considered to be applicable primarily to the airframe. For the powerplant installation, certain additional provisions of subpart E of this part may be found applicable.
[Amdt. 25-72, 55 FR 29785, July 20, 1990]

[The Messiah]

Gaunty,

You can plagiarize all the regs and manuals you like. All it shows is your complete lack of experience and practical knowledge when it comes to actually flying.

You wouldn't even make a decent theory instructor as you would confuse The Wright Brothers.

Furthermore you are very boooring......padlock please.

[gaunty]

BIK_116.80

Thank you for that it, might be a bit too sophisticated concept for some, but is indeed true.

Neither have I flown a SAAB, but I would be amazed if it too didn't have a similarly sophisticated system given the flying conditions in the country in which it was designed.

The manufacturers spend a great deal of time and effort on this matter as it is almost impossible, especially for regional types, to operate 24/7/365 without encountering known icing conditions in the higher latitudes AND comply with the certification requirements.

Our CAA even approved an RPT service using a turboprop aircraft NOT fitted with "flight into known icing" which did not have the range required with reserves, were it forced to operate routinely without entering icing conditions and wondered why they got a hiding over the consequences.

The learning and development process continues even unto today.
Go here, for another of my attempts at what The Messiah calls "plagiarising"

FAA William J Hughes Technical Centre "Aircraft Icing"

it is an interesting article, The Messiah should save his download allowance as it doesn't contain anything he doesn't already know.

I see in my late night rant, that there are a couple of important words missing and that attempts to shorten the explanation have made simple matters more obscure than they should be but I also made the mistake of assuming that I was talking to someone who understands the subject and broke the FIRST rule of instructing. Sorry about that I'll go back and edit in bold my words lest any of the youngsters get it wrong.
I'll leave the rest of the "plagiarism" from FAR 25 there for any who may be interested in learning about some of the why and how the aircraft and systems they fly are designed.

The full text is available for "plagiarisation" at

FAR 25

The Messiah

I guess what I MIGHT have said was

The first two paragraphs of your post are absolute arrant nonsense
and
The third, whilst apprently correct is too broad without considerable qualication, there have in fact been many accidents where the crew thought they were flying the correct speed for the configuration.
and
The fourth, I agree completely with the first part but have a small problem with the second.

But then there are too many youngsters out there who may think you are correct.

It is obvious that you have a much superior ATPL than I but I have absolutely no intention whatsoever of dignifying your remarks with the old "I've got a bigger one than you"

I never stopped learning.

[The Messiah]

Gaunty,

I hope I never get stuck next to you at a dinner party.

My original point was the crew stuffed it up. 114 kts and no power added (according to the report) in an aircraft with a minimum maneuvering speed of (at that weight) 150 kts - flap setting ie 130 kts not counting the icing increment.

Whatever happened to fly the aeroplane? FAR 20 whatever aint gonna matter squat once you're 'drivin the bus'.

You don't work in a multi-crew job do you......always having to be right can be just as dangerous as Bathurst on an icy night.

Nothing further from me on this but look forward to your next ramble, knowing you have to have the last word..........that's it, you're a woman.........of course!