Magnum, BRS, or GRS?

[JimParker256]

Also things like this https://www.aviation.govt.nz/assets/Upl ... ations.pdf

Wowser! That is certainly concerning.

GRS chutes descent at about 14 mph arriving as if dropped from a height of 1.8 m and are designed to have the plane land horizontally using landing gear as its cushion ( which is the only structural part of a typical LSA designed to actually absorb large impact forces )
Sufficient to say, as far as available data indicates, there has never been a deployment that resulted in a serious injury due to a successful chute deployment.

The website states that they have 105 "saves" since they started back in 1984 (36 years ago), or just under 3 "saves" per year. That's good, but there is absolutely no way to know how many of those "saves" might have survived, with or without minor injuries, had they NOT had the chute. And many of those saves were likely ultralight type vehicles (to use the FAA term) with questionable (to me) structural integrity, flown by "pilots" with little to no training.

The technical data on their website shows the LSA-rated chutes descend at vertical speeds between 7.1 and 7.5 meters per second at 600 kilos (1320 lbs). That translates to roughly 1400-1475 fpm (15.9 to 16.8 mph). The claim that their chutes are designed to land with the plane touching down horizontally using the landing gear as its cushion is ludicrous. The chutes are round, and there are no "steering lines" for the pilot to control. The airplane attachment bridle connects to the chute bridle at a single point, therefore the only force acting to "align" anything in that equation would be the aerodynamics of the airplane, causing it to eventually align with the prevailing wind. Thus any "horizontal" component will be minimal, and basically wind-directed. There is no way to predict whether the plane will land perfectly vertically (thin odds) or be drifting right/left/forward/back at the time of impact.

With a 10-mph wind, you'd be dealing with both the vertical component and the horizontal component, thus the total angular velocity at impact using the average of 16.3 mph vertical component (7.3 m/s) would be approximately 19.1 mph (simple Pythagorean principle math: square root of (16.3 squared + 10 squared). Aside from that, GRS' technical data also shows that it requires 6 seconds from the time you pull the trigger before you would have a fully deployed chute. Their diagrams (and videos of actual chute deployments) show significant pendular action would result from a chute deployment. If you're low when you deploy, that pendular action could either decrease or increase the horizontal component of the forces, depending on whether you impact the ground swinging into or away from the drift direction. Of course, if the wind is blowing perpendicular to the "swing", you've got yet another force component to be dealt with. How good is the side impact protection on your airplane (or ANY airplane, for that matter)?

Obviously, the higher you deploy the chute, the less a factor that 6-second delay and the "swing factor" become, but "holding off as long as possible" before deploying the Cirrus "CAPS" system was leading to a LOT of injuries and fatalities in Cirrus airplanes. Their accident / fatality record was significantly higher than expected (higher than Cessna's for single-engine planes, for instance). They started a massive educational campaign with specialized training focused on using the CAPS properly (pull high and early), and insurance companies began requiring that training before they would insure or renew policies. They eventually got it turned around, and now their record is somewhat better than the rest of the fleet.

Personally ,if given enough reasonably clear space to land, I would always opt for a normal emergency landing but ... if you are out of options, even most skillfully executed emergency landing will result in about 35-45 mph forward velocity impact which is much more likely to result in a serious injury than the chute based 14 mph vertical descent alternative.

But that's the whole point of Bob Hoover's advise to "Fly the airplane as far into the crash as possible." You're never out of options as long as you have some degree of control. There have been literally thousands of people who've experienced engine failures in flight in single-engined airplanes. Their accident survival rate is actually higher than that of twin-engined aircraft that also have a single engine fail in flight. (That's a twin-engine pilot training issue, but let's not go there right now.) Selecting the best crash site, and flying the aircraft to that site under control, using whatever aerodynamic and mechanical braking available before impacting that "immovable object" leads to surprisingly low injury and fatality rates. Yes, you may initially touch down at 35-45 mph, but if you're flying the airplane under control, you shouldn't hit anything hard at that speed. By using maximum braking action (or aiming the airplane between smaller trees) you can reduce the G-forces of the deceleration if/when you finally do hit something immovable.

I'm a big proponent of "keeping things simple" in aviation. The fewer decisions that must be made in an emergency situation, the better the odds I'll get it right. Most studies show that it takes 6 seconds after an engine failure for the pilot to get over the shock and react. Hopefully, that reaction is pushing the nose over to roughly "max glide" speed, then selecting and turning towards the best available emergency landing spot (critical!). Then we run the engine failure emergency checklist (fuel and magnetos are the major items, right?). So we're maybe 20-30 seconds after the engine quit, and we've lost probably 500-800 ft of altitude (and possibly a lot more). So, how long can I hold off the decision to pull the chute, before I'm too low to do any good with it? The GRS tech data says minimum deployment height is roughly 110 meters (360 ft), so I gotta pull above that altitude or I've just made matters worse. If I was 1500 AGL when the engine quit, I might have <5 seconds between "stabilized at Vg, heading toward my selected landing spot" and the minimum altitude to pull the chute. Not much time to think through the variables and come to an educated decision...

If you elect to go with a chute, PLEASE think through these scenarios ahead of time, and establish FIRM parameters on where and when you WILL pull the chute. Don't be like those early Cirrus pilots, and put it off until it can no longer help you! Better to pull early, and have the insurance company's airplane destroyed than to pull too late.

[Warmi]

.
....
The website states that they have 105 "saves" since they started back in 1984 (36 years ago), or just under 3 "saves" per year. That's good, but there is absolutely no way to know how many of those "saves" might have survived, with or without minor injuries, had they NOT had the chute. And many of those saves were likely ultralight type vehicles (to use the FAA term) with questionable (to me) structural integrity, flown by "pilots" with little to no training.

The technical data on their website shows the LSA-rated chutes descend at vertical speeds between 7.1 and 7.5 meters per second at 600 kilos (1320 lbs). That translates to roughly 1400-1475 fpm (15.9 to 16.8 mph). The claim that their chutes are designed to land with the plane touching down horizontally using the landing gear as its cushion is ludicrous. The chutes are round, and there are no "steering lines" for the pilot to control. The airplane attachment bridle connects to the chute bridle at a single point, therefore the only force acting to "align" anything in that equation would be the aerodynamics of the airplane, causing it to eventually align with the prevailing wind. Thus any "horizontal" component will be minimal, and basically wind-directed. There is no way to predict whether the plane will land perfectly vertically (thin odds) or be drifting right/left/forward/back at the time of impact.
....

Of course these chutes don't have control lines and thus the "designed to land vertically" part only applies in relatively calm wind and , as you said, given enough time to stabilize ....and of course you are taking some risk deploying it but the whole point of this discussion is that you are free to evaluate risks of deploying the chute at the time of your emergency and act accordingly (and yes, it certainly helps to have your deployment envelope worked out ahead of time)

BTW. The original issue with Cirrus training was not so much delayed chute deployment but rather not considering it at all as a viable option in anything other than outright structural failure scenarios.

[fatsportpilot]

Also things like this https://www.aviation.govt.nz/assets/Upl ... ations.pdf

Wowser! That is certainly concerning.

Yes it is concerning but it is CAA and they are notorious for being trigger happy. Those sorts of events do make me worry but it's very hard to get an airplane into a flat spin, and the Bristell did go through rigorous testing by a test pilot (a google search of "bristell flat spin" will show their response to the CAA's action). It is enough to make me want a chute.

[Warmi]

Another GRS save - I think 6th or 7th on the Sting.

https://aviation-safety.net/wikibase/237684

[MrMorden]

Perhaps I am missing something here ,but are there any downsides to having another safety device like BRS onboard ?

In a Cirrus, no downside at all. LSAs are another matter, because they are useful load challenged already. For the weight of a BRS, I can carry an extra hour of fuel. In most accident scenarios, the extra fuel is a more useful safety device. (Of course there are exceptions.)

My airplane has a 575lb useful load, and the parachute weights 35lb. Since my airplane is ELSA, I could remove the BRS and have a larger 610lb useful load. I'm keeping it. When I had the scheduled chute repack and rocket replacement last year, I took the airplane out of service for a month of summer flying until it was reinstalled rather than fly with it out of the airplane.

As my airplane spirals down to the ground after a midair shears a wing off, I will not be the guy saying: "well shit, I guess a BRS might be handy right about now." There are some scenarios which are 99.99% fatal without a BRS option. I would and have flown airplanes without a parachute, but the extra option one provides are excellent and operational history shows them to be supremely reliable and life saving when used as intended.

[MrMorden]

Personally ,if given enough reasonably clear space to land, I would always opt for a normal emergency landing but ... if you are out of options, even most skillfully executed emergency landing will result in about 35-45 mph forward velocity impact which is much more likely to result in a serious injury than the chute based 14 mph vertical descent alternative.

But that's the whole point of Bob Hoover's advise to "Fly the airplane as far into the crash as possible." You're never out of options as long as you have some degree of control. There have been literally thousands of people who've experienced engine failures in flight in single-engined airplanes. Their accident survival rate is actually higher than that of twin-engined aircraft that also have a single engine fail in flight. (That's a twin-engine pilot training issue, but let's not go there right now.) Selecting the best crash site, and flying the aircraft to that site under control, using whatever aerodynamic and mechanical braking available before impacting that "immovable object" leads to surprisingly low injury and fatality rates. Yes, you may initially touch down at 35-45 mph, but if you're flying the airplane under control, you shouldn't hit anything hard at that speed. By using maximum braking action (or aiming the airplane between smaller trees) you can reduce the G-forces of the deceleration if/when you finally do hit something immovable.
[/i]

Well, if we are talking apples to apples you make a good point. But it's not apples to apples. In general, off airport emergency landings in light singles have about a 25% fatality rate, and some types are MUCH higher (off airport landings in an RV-8 have about a 60% fatal rate).

Now contrast that to the fatality rate of a BRS system used to forego an off-airport landing attempt, and deployed whithin it's operating envelope. Those events have a 0% historical fatality rate. You read that right...ZERO.

I don't know about you, but I will take a statistical near-zero rate of dying any day over 25%. You can justify the low speeds of off airport landings all you want, but the reality is if you f*ck it up you can be head on into a tree as you come up short, end up in a massive sink that pancakes you in and crushes your spine, or a host of other issues. All landings come down to energy, and a 15-20mph impact on the landing gear designed to take those impacts is far preferable to the alternatives. My airplane has a minimum touchdown speed of 45mph (39kt) by the book. That is over twice the speed of a BRS touchdown. And energy increases by the square of the speed, so you are having to dissipate over *four* times the energy at minimum landing speed.

This is the same reasoning that led to the light weights and low speeds of the LSA rules in the first place. Lower speed = less energy = safer impacts.

My BRS plan is as follows: If I'm engine out I look for a landing spot and go there. If the approach looks at all in question, or the landing surface does not look excellent, BRS time. Period. My one job, and the airplane's one job, is to give me and my passengers the highest probability of survival. For off-airport landings, that will very often be the BRS.

[JimParker256]

In general, off airport emergency landings in light singles have about a 25% fatality rate, and some types are MUCH higher (off airport landings in an RV-8 have about a 60% fatal rate).

Now contrast that to the fatality rate of a BRS system used to forego an off-airport landing attempt, and deployed whithin it's operating envelope. Those events have a 0% historical fatality rate. You read that right...ZERO.

Out of curiosity, what is the source for both sets of statistics you quoted here? I'm a bit surprised to see those fatality numbers for light single emergency landings, since I've seen some significantly lower numbers quoted elsewhere (but also unattributed as to source). I'm not challenging your numbers, but I am interested in the source so I could do some additional learning.
Thanks!

[MrMorden]

In general, off airport emergency landings in light singles have about a 25% fatality rate, and some types are MUCH higher (off airport landings in an RV-8 have about a 60% fatal rate).

Now contrast that to the fatality rate of a BRS system used to forego an off-airport landing attempt, and deployed whithin it's operating envelope. Those events have a 0% historical fatality rate. You read that right...ZERO.

Out of curiosity, what is the source for both sets of statistics you quoted here? I'm a bit surprised to see those fatality numbers for light single emergency landings, since I've seen some significantly lower numbers quoted elsewhere (but also unattributed as to source). I'm not challenging your numbers, but I am interested in the source so I could do some additional learning.
Thanks!

The 60% number for the RVs came from an article a couple of years ago in Aviation Safety magazine. I can't remember where I read the 25% number, it might have been from the same article.

I think the 25% overall number is reasonable. If everything goes right and you pick a good field, judge the wind and distance right, and are on your game, it's probably more like 5%. If none of that works out it might be more like 50%. It depends on location as well...going to down in Kansas cornfields involves a lot less chance of death than going down in rocky, mountainous terrain (or a dense city block).

My main point was only that statistically, using a BRS instead of attempting an off airport landing is safer. It is sacrificial to the airplane, but that is far lower down on my list of priorities in that scenario. And of course every event is different, which is why I emphasize "statistically".

[Wm.Ince]

Concur with MrMorden totally.

[drseti]

Here's an alternative hypothesis, Andy. Isn't it possible that those who have 'chutes are more likely to pull them even when the situation is less hazardous than the pilot perceives (the attitude being "I have it, I might as well use it"?

In such a case, wouldn't accident scenarios that might otherwise have shown up in the non-chute, non-injury category end up in the yes-chute, non-injury data set? Thus, the presence of chutes might end up making the non-chute option look statistically more hazardous than it really is. A better analysis would to be to compare fatality rates for 1987 (before BRS hit the market) to now, when the percentage of chute-equipped GA aircraft is known, and non-zero.

That said, it is undeniable that a properly deployed chute will minimize injury for certain classes of accidents. I just shy away from "lives saved" statistics, until someone can convince me that every one of those lives would have been lost, had there been no chute.

[MrMorden]

Here's an alternative hypothesis, Andy. Isn't it possible that those who have 'chutes are more likely to pull them even when the situation is less hazardous than the pilot perceives (the attitude being "I have it, I might as well use it"?

In such a case, wouldn't accident scenarios that might otherwise have shown up in the non-chute, non-injury category end up in the yes-chute, non-injury data set? Thus, the presence of chutes might end up making the non-chute option look statistically more hazardous than it really is. A better analysis would to be to compare fatality rates for 1987 (before BRS hit the market) to now, when the percentage of chute-equipped GA aircraft is known, and non-zero.

That said, it is undeniable that a properly deployed chute will minimize injury for certain classes of accidents. I just shy away from "lives saved" statistics, until someone can convince me that every one of those lives would have been lost, had there been no chute.

Frankly Paul, your alternate hypothesis is a bit insulting. It presupposes the mere presence of a safety device makes pilots sloppy and more likely to make poor decisions. I don't know of any pilot itching to pull that red handle and destroy their airplane, nor do I or any pilots I know make decisions based on "fuck it, I have a parachute if anything goes wrong."

For somebody who is constantly beating the drum of aviation safety on this forum, I'm shocked that you take the position that having additional options that reduce aviation fatalities somehow perverts the pilot into a reckless idiot. You have said many times that lower weight and speed lead to safer airplanes because they carry less energy into any collision, yet now you're advocating that pilots are better off to be forced into higher speed impacts in the event they lose an engine? I simply do not follow your reasoning, it is inconsistent and illogical.

How many times do you drive like a maniac and crash into things based on the idea that "I have airbags, I might as well use them" ?

"Lives saved" is a marketing term, but the statistics are undeniable.

[drseti]

Frankly Paul, your alternate hypothesis is a bit insulting. It presupposes the mere presence of a safety device makes pilots sloppy and more likely to make poor decisions.

I didn't generalize, Andy, but with accidents being the exception rather than the rule, it's not too big a stretch to assume that some pilots are that sloppy or prone to poor decision making. When sample size is (thankfully) small, it doesn't take many accidents to skew the statistics.

[JimParker256]

Frankly Paul, your alternate hypothesis is a bit insulting. It presupposes the mere presence of a safety device makes pilots sloppy and more likely to make poor decisions. I don't know of any pilot itching to pull that red handle and destroy their airplane, nor do I or any pilots I know make decisions based on "fuck it, I have a parachute if anything goes wrong."

For somebody who is constantly beating the drum of aviation safety on this forum, I'm shocked that you take the position that having additional options that reduce aviation fatalities somehow perverts the pilot into a reckless idiot. You have said many times that lower weight and speed lead to safer airplanes because they carry less energy into any collision, yet now you're advocating that pilots are better off to be forced into higher speed impacts in the event they lose an engine? I simply do not follow your reasoning, it is inconsistent and illogical.

How many times do you drive like a maniac and crash into things based on the idea that "I have airbags, I might as well use them" ?

"Lives saved" is a marketing term, but the statistics are undeniable.

I don't believe Dr Seti was attacking you personally, but was instead pointing out a proven observation, based on facts proven out with the Cirrus CAPS system... Let's try to keep the conversation civil. I, for one, am trying to learn something.

Like you, I sincerely doubt that there are many pilots who are intentionally making poor decisions just because they have the 'chute. But I do hear (constantly) from Cirrus pilots that they fly night IFR over the mountains in their Cirrus airplanes, and would not consider doing so without a 'chute. I'm not saying that in and of itself is a "bad decision", but merely pointing out that it is evidence that at least some pilots WILL make different risk-based decisions when they have the 'chute that they would not otherwise take. There's an old saying that "complacency kills..." Risk analysis is essential for aviation safety.

But let's return to the accident and fatality records for a minute... The safety statistics that I've heard indicate that survival rates for single-engine airplane off-field landings are surprisingly high - something like 95%. I'm not positive, but I believe that figure came from a Paul Bertorelli safety video on YouTube, and that he was quoting NTSB data. (But I've slept a couple of times since then, and can't be anything like certain of my source, either.)

But obviously, even a 5% fatality rate is still unacceptable – especially when it's your friends or loved ones in the plane.

I do find it notable that until just a few years ago, the Cirrus fleet of aircraft actually had a fatality rate that was more than twice that of the GA single-engine fleet average, despite the presence of CAPS in 100% of their airplanes. Cirrus partnered with the insurance industry and the FAA to study the phenomenon, and concluded that pilots were doing two things: 1) They were taking greater risks with Cirrus airplanes than they would with Cessna, Piper, Beech, etc. and 2) When they got into bad situations, they were waiting too long to deploy the CAPS - to the point that the 'chute could not make the "save."

Based on that research, Cirrus developed a really good transition training program (including training on when to trigger the CAPS), and included it "free" with the purchase of a new Cirrus. The insurance companies began pretty well mandating that ALL Cirrus pilots complete that training program as a condition for receiving insurance at "reasonable" rates. As that training rolled out, the fatality rate dropped over the next couple of years, to the point where I believe that the current Cirrus fleet fatality rate, while still non-zero, is now about 1/2 the GA average. Fantastic program!

So, do 'chutes work? Evidence seems to indicate that they can prevent deaths, IF deployed under the right circumstances, and in a timely manner. Does the mere presence of the 'chute reduce the fatality risk? For me, the jury is still out on that one, given the statistical data available that without the proper training, merely having a 'chute on board the airplane MAY have actually increased the fatality rate.

It would be really great if the S-LSA manufacturers that are equipping their planes with 'chutes would offer similar training on when and how to deploy them. Absent that, it's probably a good thing to take a good look at the Cirrus experience, and learn from it.

[3Dreaming]

I don't know of anyone personally who is taking grater risk when flying an airplane with a chute. I think the "fly it as far into the crash" and the "I'm a pilot, and not trained to pull the chute" are two of the major things that need to be trained out of the pilot populations for chute to really be an effective safety item. I know coming from a strong GA background I was leery of the chute to begin with. At first I didn't pull the pin when flying. The first time I did pull the pin was flying into a large flight instructor renewal clinic that the state of Illinois used to put on. A bunch of CFI's swarming to an airport all at the same time is about as unsafe of a condition as you can get. Then I had a chance during dealer training for Flight Design I had a chance to sit in a seat and feel what it was like to pull the handle. Then there was the story about the plane that crashed with a parachute. The structure where the handle was mounted was found to disformed from the pilot pulling on the handle. THE PIN HAD NOT BEEN REMOVED. From that point on the ignition key for my airplane was attached to the parachute pin. You couldn't start the airplane without the pin removed. I also realized that a couple of my earlier fears like being able to accidentally pull the handle was not possible.

[drseti]

Good post, Tom - thanks. I know if I had a plane that had a BRS (neither of mine does), I'd want some rigorous training on it - from somebody like you.