The video is unsatisfyingly vague and short.

Was it truly in flight at max chute speed?

At gross?

In a fully conforming example?

All the way to the ground? With gear up?

Etc.

I'd love to see the whole sequence. A few seconds of video in the middle of the sequence doesn't constitute proof the test was done full up.

I'll note that serial #003 last flew (per flightaware) March 30, 2017 to KDLH and hasn't flown since. It seems to be coming from Mojave where one might expect such a test to be performed, yet it seems to be flyable after such a test, not what one would expect. I suspect the chute was cut away in mid air and the plane allowed to fly back to a normal landing, thus not completing the test in full, especially the part about protecting the occupants on impact.

I believe the first customer pull will be the first time the chute sequence is completed in its entirety, from in flight to ground impact. I do not believe Cirrus has performed the full chute test.


The special condition has a LOT of requirements (see below). It is pretty clear this course of action did not result in much work reduction, perhaps more.


Further reason the SC made no sense if they actually did the test. The SC is a liability since it can be used to imply Cirrus did not want to test the chute. Any decent lawyer will asks why Cirrus did not want to do the test. Whatever answer Cirrus gives will not help their case.


This is particularly true when it comes to theoretical analysis, which once again makes a real up test worthwhile.

To be specific, here is what the FAA required Cirrus had to show in SC 23-275-SC. This looks like far more work than simply doing the test itself, plus all the haggling over what the numbers mean in the analysis with FAA types who aren't the brightest engineers a lot of the time.

Accordingly, pursuant to the authority delegated to me by the Administrator, the following special conditions are issued as part of the type certification basis for Cirrus SF50 airplanes.

1. Whole Airplane Parachute Recovery System With Flight Control and Deployment Augmentation.

(a) System Validation.

(1) The applicant must demonstrate by test, or analysis supported by test, that the system will not cause an unacceptable hazard or otherwise exceed the system deployment design loads for the critical flight conditions.

(2) The recovery system activation envelope must include speeds at or near VS up to at least Vo. The applicant must satisfactorily demonstrate by test, or by analysis supported by test, the logic and automatic control interface that allow the recovery system activation over this speed range.

(b) Occupant Restraint.

Each seat in the airplane must be equipped with an approved restraint system, which will protect the occupants from serious head and upper torso injuries during a recovery system deployment and ground impact at the critical load conditions.

(c) Parachute Performance.

(1) A 1.5 factor of safety applied to the limit load must be used for all components of the recovery system as well as the attachment structure, the cabin structure surrounding the occupants, and any interconnecting structure of the airplane. Limit loads are defined as the parachute deployment forces developed within the operational envelope of the system. Lower factors of safety for airplane weight and velocity may be used, so that when combined in the energy equation, represent a 1.5 factor of safety of the energy equation.

(2) Stitching must be of a type that will not ravel when broken.

(3) The applicant must show via test, or analysis supported by test, that with the recovery parachute deployed and the airplane structure damaged, the airplane impact during touchdown will result in an occupant environment in which serious injury to the occupants is improbable.

(4) The applicant must show via test, or analysis supported by test, that with the recovery parachute deployed, the airplane can impact the ground in various adverse weather conditions, including winds up to 15 knots, without endangering the airplane occupants at and after touchdown.

(d) System Function and Operations.

(1) The installation design and location of the extraction device must consider fire hazards associated with the activation of the parachute system and reduce this potential as much as possible without compromising function of the extraction device.

(2) A system safety analysis will be conducted on the recovery system that will consider the effects of annunciated and un-annunciated failures. This analysis will address both losses of function as well as malfunction (including un-commanded system activation). The applicant must show that they do not adversely affect proper functioning of the equipment, systems, or installations covered by § 23.1309, and do not otherwise adversely influence the safety of the airplane or its occupants. It must be shown that reliable and functional deployment in the adverse weather conditions that the airplane is approved for have been considered. For example, if the airplane is certified for flight in icing conditions, and flight test in icing reveals that ice may cover the deployment area, then the possible adverse effects of ice or an ice layer covering the parachute deployment area should be analyzed.

(3) The recovery system must be designed to safeguard against inadvertent activation. Two separate and intentional actions will be required to activate the system.

(4) It must be demonstrated that the system can be activated without difficulty by occupants of various sizes, from a 10th percentile female to a 90th percentile male, while sitting in the pilot or copilot seat.

(5) The system must be labeled for identification, function, and operating limitations.

(6) The airplane must be equipped with ASTM F 2316-06 conforming placards suitable to draw attention of first responders. Section 11 of ASTM F 2316-06, specifies that the airplane should be marked with a “danger” placard placed adjacent to the exit point of each rocket/parachute, an “identifying” placard attached to each rocket, and “warning” placard(s) applied where occupant(s) enter the airplane or where rescue personnel can readily see the placard(s).

(e) Design and Construction.

(1) All components of the system must be protected against deterioration due to weathering, corrosion, and abrasion.

(2) Adequate provisions must be made for ventilation and drainage of the system compartments and associated structure to ensure the sound condition of the system.

(f) Materials and workmanship.

(1) The suitability and durability of materials used for parts, the failure of which could adversely affect safety, must—

i. Be established by experience or tests;

ii. Meet approved specifications that ensure their having the strength and other properties assumed in the design data; and

iii. Take into account the effects of environmental conditions, such as temperature and humidity, expected in service.

(2) Workmanship must be of a high standard.

(3) The parachute(s) must be identified with a data panel that defines the Manufacturer, Date of Manufacture, Part Number, and Serial Number.

(g) Systems Maintenance and Inspection.

(1) Instructions for continued airworthiness must be prepared for the system that meet the requirements of § 23.1529.

(2) Adequate means must be provided to permit the close examination of the system components to ensure proper functioning, alignment, lubrication, and adjustment during the required inspection of the system.Start Printed Page 45968

(h) Operating Limitations.

(1) Operating limitations must be prescribed to ensure proper operation of the system. A detailed discussion of the system, including operation, limitations, and deployment envelope must be included in the Airplane Flight Manual.

(2) Operating limitations must be prescribed for inspecting and overhauling the system components at approved intervals.

Mike C.

I guess the question with all that is: does SC 23-275-SC cost less than destruction and rebuild/replacement of the airframe? I'm guessing it does since Cirrus chose to option for it.

Chip-

Serial #3 was never going to be sold to any customer. It hasn't flown since March, at least not visibly to flightaware. Not clear the airframe had much value.

I think the bigger issue is subjecting the Cirrus test pilot to the chute event. There are a lot of things that could go wrong.

The SF50 chute is the first installation of a BRS where the plane's autopilot is involved. Triggering the chute first causes the autopilot to establish a level attitude and pulls the engine power back to idle. Once established in this state, then the chute is fired.

This of course begs the question of why you need a chute if the autopilot can establish control over the airplane, or what happens if the autopilot can't establish control. If the plane achieves the chute deployment envelope and attitude, seems like there are very few reasons to use the chute. The only one I can think of is engine failure at a sufficiently high altitude the chute works, but not so high that there are adequate landing options within gliding distance. That's a pretty narrow use case.

Eventually, a customer will trigger the chute and then we will have a lot to talk about.

Mike C.

The video is unsatisfyingly vague and short.

Was it truly in flight at max chute speed?

At gross?

In a fully conforming example?

All the way to the ground? With gear up?

Etc.

They did some chute test, but we only have a few seconds showing only a part of it.

I am pretty sure they did not do a chute flight test in a way that would have satisfied the FAA certification requirements outside the SC.

I am pretty sure they did not do the test to ground impact.

I am pretty sure the first customer use of the chute will be the first end to end test of the system to the ground.

Mike C.

I'm pretty sure you will never admit to being mistaken about any topic.

I'm pretty sure you are wrong about that. :-)

Mike C.

Just like drop tests conducted on helicopter airframes to test crashworthy systems. I would think Cirrus "drop tested" a fuselage test bed airframe at the rate that their computer and engineering data reflects.

[youtube]http://youtu.be/EsiYEXt_Iok[/youtube]

To use a Don Lawton sign off

BWTHDIK

I'm not an engineer with mad google-fu skills aiming to prove everyone on the Internet wrong.

I'd tend to agree, but what about pilot incapacitation? I'm pretty sure the autopilot doesn't include autoland.

This thread is like walking past a strip joint on Bourbon Street, there is nothing to be gained by going in, but it is it's hard not to look in if the the door is open when walking by....

History with the SR series shows this is exceedingly rare to non existent. I don't believe there has been a single case where a passenger has initiated a chute pull. There has been one case where a passenger pulled the handle, but that was at the direction of the pilot.

We have plenty of examples of pilots not pulling the chute when they should, so why would we expect a passenger can handle that task properly?

But, all that being said, that is one case you can come up with for a fully functional and under control airplane to be "saved" by the chute. Pilot incapacitation is exceedingly rare, so much so that there may never be a case of it in the entire operational history of the SF50.

Mike C.

it doesn't matter of it's real or not. To a non-pilot spouse it is real, and that is enough to sell the airplane that has the red handle

Very likely they did do that with something they felt was representative. Maybe that was the end of serial #3 back at the factory.

If this was the case, then the argument to not do the full test to save an airframe isn't correct, the airframe was going to be lost anyway.

Still not a full up flight test, of course. A customer will do that first.

Mike C.

The chute is a great marketing gimmick, no doubt, because the chute's value is constantly overestimated by both pilots and non pilot passengers. That is its greatest weakness, comforting pilots into risk they would not otherwise take without the chute.

Mike C.