The most unnecessary chute pull ever?

[Adrian N]

I would want to know what compromises they have made elswhere in the design which render the aircraft too dangerous to fly without it.

None.

It is an integral part of the aircraft which couldn't be removed without making significant design changes; if you take the parachute pack and rocket out, the CG moves a long way forward. And then the FAA and EASA require it to be operational because they certified it as the means of recovering from a spin in a Cirrus. They could have demanded a full spin test program - but they both agreed with Cirrus that using the parachute was a better way to recover from a spin with minimum loss of height - 920ft lost in a 1 turn spin with a parachute recovery, and typically between 1,200-1,800ft lost in a 1 turn spin with a normal aerodynamic recovery.

[Mach Jump]

Ps. I also think that aircraft should be certified to operate, without limitations or modifications, both with, and without the system being operational.

...which couldn't be removed without making significant design changes...

I wasn't considering complete removal of the system, only flying with the system inoperative.

...but they both agreed with Cirrus that using the parachute was a better way to recover from a spin with minimum loss of height - 920ft lost in a 1 turn spin with a parachute recovery, and typically between 1,200-1,800ft lost in a 1 turn spin with a normal aerodynamic recovery.

This comparison would only stand up if the end result of a 'chute pull' was the same as a successful aerodynamic recovery, which it clearly isn't.

It seems to me that a compromise has been made here.


MJ

[Adrian N]

Well, the certifying authorities have said that it has to be operational because they believe that it offers the best protection to the occupants in the event of a spin. Cirrus also believe this - so why would they spend a lot of money re-certifying the aircraft to a lower safety standard?

I see it as analagous to a stick pusher. A Pilatus PC12 has one of those. It adds weight and complexity, and it is there because the manufacturer and the regulators agreed that it offered the best protection for the occupants. You're not allowed to fly a PC12 if it is inoperative. It's not that Pilatus have cut corners and the PC12 is too dangerous to fly without the pusher - it's just the way they designed their aircraft to meet the certification standards.

[mad_jock]

It's not that Pilatus have cut corners and the PC12 is too dangerous to fly without the pusher

Yes it is, it either means that the elevator doesn't have enough authority to recover in the stall due to aerodynamic effects eg super stall.

Or it displays stall behaviour which the average competent pilot wouldn't be able to recover from.

If the plane doesn't need it they don't fit it.

With that much torque on the front from the turboprop I imagine if the wings are stalled and you fire wall it the hull is going to start turning the opposite direction and the rudder won't be enough to stop the yaw.

[Mach Jump]

I see it as analagous to a stick pusher..

No it isn't. The end result of a stick push is the same as a successful stall recovery. The aircraft flies home and lands safely in both cases.

The certification authorities have allowed a compromise in the need for spin recovery testing by making a serviceable BRS a requirement.

Yes it is, it either means that the elevator doesn't have enough authority to recover in the stall due to aerodynamic effects eg super stall

Exactly.

I'm not going to get into an argument here though. We all have our views, and I accept that we are just not going to agree on this.


MJ

[Pace]

I went back and read some of my earlier posts and you are right, my phraseology made some of the posts veer into a personal challenge, rather than challenging the content of the discussion. So for that I apologize.

BPF

My apologies to you too I have said this before my posting style is designed to encourage passion in these discussions so sometimes colourful sometimes challenging sometimes stupid but I can usually waken a dying thread So I can only expect some of the responses I get

regarding the Hero i was being pedantic in the use of the word and purist in its meaning as the Press /media have watered down the true meaning and appear to attach that word to anyone who has been in anything threatening.

As for the Captain of the Hudson water landing he was not just doing his job but showed extreme skills and ability in pulling something off which as you say most in the sim could not replicate. That still does not truly describe the word HERO.
i was being pedantic and in no way trying to take away from the amazing skills displayed by the Captain in landing that aircraft and saving so many lives in doing so.

Pace

[Adrian N]

Yes it is, it either means that the elevator doesn't have enough authority to recover in the stall due to aerodynamic effects eg super stall.

I bow before your aircraft certification expertise! You must have a lot of experience to make such a decisive statement. Maybe they did just design an aircraft with dangerous handling, despite years of experience building aerobatic military training aircraft.

But, just maybe, they thought that a stick pusher would be the best way to keep pilots and passengers safe in the PC12? Maybe they took deliberate design decisions, like giving it a T tail so that it's easier to drive up to the cargo door, because they were using technology to avoid any risk of a deep stall? Maybe they thought it would be pointless to fly the full spin test matrix (hundreds of spins in different configurations of CG, fuel balance, flap settings, power settings, etc.) in an aircraft the size and weight of a PC12, risking their test pilots' lives, when the risk of spinning could be eliminated with a stick pusher? And the accident record would seem to suggest that they didn't do a bad job.

The certification authorities have allowed a compromise in the need for spin recovery testing by making a serviceable BRS a requirement.

Just as they have allowed a compromise in the need for stall / spin avoidance in a PC12 by making a serviceable stick pusher a requirement. Pretty much every other single engine aircraft has had to do hundreds of stalls and spins; the pusher allows a PC12 to demonstrate an equivalent level of safety by using technology - exactly the same idea as a Cirrus with BRS.

[mm_flynn]

Originally Posted by Jonzarno

Whilst I can't argue with the basic sentiment of this, I would be interested to know a bit more detail on how these failures are being caused. Improper mixture control leading to detonation / pre-ignition or failure to add oil suggest themselves but, although I know of one or two examples, I don't recall reading about many of these.

However, I am aware of a number of maintenance induced failures and would have thought that is probably a bigger problem.

Remember forced landing due to 'Engine Failure' just means the engine was unable to maintain power, not that it actually fell apart. So the first and second most common pilot induced engine failures must be either running out of fuel or mismanaging the fuel selectors to run the engine out of fuel.
Third is probably failure to apply carb heat when needed.

Other common ones would be running the boost pump and getting a rich cut, not checking the fuel for water, pulling the mixture rather than the throttle, leaving the primer unlocked, etc. None of these actually break the engine, just result in no/low power.

There are some more subtle ones, like taking off knowing (or not having checked) that the mixture is too lean to generate full power, both mags are not working, knowing oil consumption has dramatically increased, etc.

[Pace]

I have had 3 engine failures

One pilot enduced just after I had got my PPL force landed into field SEP. perfect touchdown in field PAX panicked and crawled onto wing with me holding his jumper.
Plane crossed field with no one at controls. By time I got back to controls after letting him go and took out hedge. Cut off tree stump in hedge demolished wing.

One Seneca 4 3 rocker shafts sheared just after takeoff discovered incorrect torque at manufacture 30% PWR available till 800 feet then shut down as vibration impossible

One Seneca five /spurious rough engine with engine cuts then complete failure.
Nearly new aircraft Piper literally replaced everything in the fuel system to eliminate the problem.
Engine completely stopped in IMC just out of Weston.so 2 out of 3 not pilot enduced

Pace

[mad_jock]

I bow before your aircraft certification expertise! You must have a lot of experience to make such a decisive statement

err no its in the ATPL syllabus and also it was in a selective course during my engineering degree.

From memory the original 747 design didn't have one because it was in limits during test flying. Then when they stretched it with further models it wasn't so they had to fit it.

The reason why the Pc12 has it is the huge torque delivered by the prop/engine and it wouldn't be controllable with max torque and stalled wings.

So its a completely different kettle of fish, you will die if you stall a PC12 and put max torque on before unstalling the wings.

Cirrus they couldn't be bothered finding out and used the BRS as and excuse not to test. In all likely hood you would be able to recover normally its just nobody knows. Well they more than likely do but nobody will admit to it.

[India Four Two]

m_j,

The Cirrus was spun as part of its evaluation prior to EASA certification.

Quite benign characteristics as I recall. I remember thinking I would certainly have a crack at recovering, if high enough, before pulling the red handle.

I've got the report somewhere. I'll dig out the reference.

[Pace]

looking at the aircraft configuration there is no reason apparent why it should not recover from a spin. Aircraft which flat spin usually make do with a drag chute the BRS is a bit overkill
And I cannot see any reason why this would flat spin

pace

[Adrian N]

The reason why the Pc12 has it is the huge torque delivered by the prop/engine and it wouldn't be controllable with max torque and stalled wings.

If that were the case, other single engine turboprops would require a stick pusher. There's nothing special about the PC12. The certification requirement (in the US it's 14CFR Part 23.201(f)(5)(iii) - don't know the EASA ref.) says that a turboprop aircraft only needs to demonstrate a power on stall at "thrust necessary to maintain level flight at 1.5 VS1 (where VS1 corresponds to the stalling speed with flaps in the approach position, the landing gear retracted, and maximum landing weight)", and in those conditions there must be no more than 15 degrees of roll or yaw (up to 25 degrees allowed above 25,000ft).

A PC12 doesn't need a whole lot of torque to fly at 1.5 VS1, and there's a high likelihood that it could meet that certification test requirement - just as aircraft like the Meridian or TBM do. And at the worst some aerodynamic fixes could be applied to make it meet the requirement - much more easily and cheaply than installing and certifying a stick pusher. The Piper Meridian or Socata TBM don't have stick pushers, but if you apply maximum torque at the stall there is no guarantee that they wouldn't roll on their backs, as it's not something that they needed to demonstrate to achieve certification.

Cirrus they couldn't be bothered finding out and used the BRS as and excuse not to test.

I'm afraid that's just wrong. It would have been way simpler and cheaper for Cirrus to do a full spin test program than to certify the parachute. It is not an add-on to cover up poor handling or design - no matter how much some Cirrus detractors would like it to be.

In all likely hood you would be able to recover normally its just nobody knows. Well they more than likely do but nobody will admit to it.

As India Four Two says, it was spun for EASA certification. At least 60 spins, which always recovered within the parameters required for part 23 certification. The outcome of the testing was that EASA agreed with Cirrus and the FAA that using the parachute was the safest way to recover from a spin with minimum loss of altitude.

[mad_jock]

I don't have a clue what nasty's go on to require it. But there must be something for them to loose the payload of the hydralic actuator and lines.

Well technically you don't recover. You go from one completely stalled state of the wings to another.

[India Four Two]

Spin testing:

http://www.peter2000.co.uk/aviation/...spinreport.pdf

[Pace]

India Four

Interesting write up showing there is nothing wrong with the Cirrus SR20 spin behaviour

Also interesting that the testing was carried out on the SR20 not 22.
I have had low experience in both the SR20 and 22 but of the two found the lower powered SR20 had a more balanced feel to the aircraft rather than the 22.
Maybe someone with experience on both can confirm?

More interesting was the recommendation to use the BRS for recovery from a spin citing poor pilot ability and lack of knowledge in spin recovery.
Yet again coming back to a lack of training and poor handling skills in modern pilots regarding spin recovery.

Nothing much wrong with the Cirrus but a lot with the pilots and the training regime.
Again not Cirrus pilots but an emphasis on the training which is turning out avoidance pilots without handling skills.

now I await the flack

Pace

[007helicopter]

More interesting was the recommendation to use the BRS for recovery from a spin citing poor pilot ability and lack of knowledge in spin recovery.
Yet again coming back to a lack of training and poor handling skills in modern pilots regarding spin recovery.

OK, I will bite

a) Spin recovery is not now taught and never will be for PPL training so how could I (or others) be expected to recover from a spin.

b) Why the hell would a competetent Pilot in control of the aircraft get into a spin? if he has let it go that far and out of control I would suggest the last thing I would rely on is him to get out of it competently.

So lack of knowledge I agree, I have never been taught to recover from a spin. I do not have this knowledge or skill.

Lack of training and poor handling skills, complete and utter BS

Cirrus they couldn't be bothered finding out and used the BRS as and excuse not to test. In all likely hood you would be able to recover normally its just nobody knows. Well they more than likely do but nobody will admit to it.

I think fully explained above and more old wives tails

[Pace]

So lack of knowledge I agree, I have never been taught to recover from a spin. I do not have this knowledge or skill.

I would thoroughly recommend any pilot investing in some aerobatic training with a competent instructor.
The anti spin brigade cite spins being low level but many are loss of control at high level.
I also ask how do you identify between a spin and spiral dive?
we have had pilots who are scared of even stalling because of the big bad bogey man that lies beyond of what they have experienced who have written their concerns in these threads.

nothing to do with Cirrus or Cirrus pilots but a change to avoidance flying! Sadly avoidance while being the first line of attack does not always work.

Yes regarding the Cirrus the BRS is probably the way forward and safest way to recover the aircraft

pace

[mad_jock]

Spinning is taught but its optional in the ppl. Most of mine opted to do it in a tommy.

Just another excuse for poor skill levels from incompetent pilots.

If you know you have a hole in your skill set get it bloody sorted, don't presume a handle is going to fix it. 200 quid and one afternoon will get it done. About the same amount as you waste in fuel lugging a brs around for 100 hours.

[thing]

If you know you have a hole in your skill set get it bloody sorted

Stop beating around the bush mate and tell it like it is...

I get a mag from the CAA and this month's has an article about chute pulls. Interesting stuff and pictures to look at.