VansAirForceForums  
Home > VansAirForceForums

- POSTING RULES
- Donate yearly (please).
- Advertise in here!

- Today's Posts | Insert Pics

  #11  
Old 04-15-2008, 07:12 AM
the_other_dougreeves the_other_dougreeves is offline
 
Join Date: Jan 2006
Location: Dallas, TX (ADS)
Posts: 2,180
Default

Quote:
Originally Posted by N941WR View Post
For most installations, including the Cirrus, there is a minimum deployment speed for the BRS systems. Check this site for some numbers.

Should you have a structural failure, such as Scott Crossfield did, the aircraft would accelerate so fast that deploying the BRS may not save your life. It is also very possible that the quick onset of high G forces after losing a wing may inhibit one's ability to reach up and activate a BRS. (However, it would be nice to have that option in such a situation.)
I think you mean maximum deployment speed? The Cirrus' max BRS deployment speed is rather low in relation to its structural cruise speed. On LSA, it's not such an issue, since the max deployment speed is normally well above the max cruise speed.

However, for "traditional" RVs, you'll normally be cruising well above the max BRS speed. This doesn't mean that the BRS won't work if you deploy it at above the max recommended speed, but it might not work. For example, BRS save #100 was a CT undergoing flight test. He overstressed the airplane and the wings came off about 9g (right where they were supposed to) and the pilot pulled the BRS at 160+ kt and lived to tell about it.

As lots of people have said, BRS might save you, but don't count on it. Use it only when you have exceeded the limits of your piloting or decision making skill, or when the airplane has gone wrong somehow.

TODR
__________________
Doug "The Other Doug Reeves" Reeves
CTSW N621CT - SOLD but not forgotten
Home Bases LBX, BZN
Reply With Quote
  #12  
Old 04-20-2008, 10:24 PM
Mike Armstrong Mike Armstrong is offline
 
Join Date: Feb 2005
Location: near San Diego
Posts: 170
Default

Quote:
Originally Posted by JimLogajan View Post
Odd request - there appears to be no debate here. The original question was about whether anyone had considered putting a BRS on an RV-12 (I have considered the possibility too). None of the posters is explicitly arguing against installing one - and several have given relevant information to installation questions. So it seems premature to categorize this thread as containing any sort of serious debate.

Agreed. Those of you with better flying credentials than Scott Crossfield and against a safety device such as the Ballistic Parachute please chime in, I'd like to hear your expertise as to how YOU would have safely landed Mr. Crossfields desintergrating aircraft. I think even Mr. Crossfield would have appreciated having the option of launching that 'chute rather than the certainty of augering in.


Mike

Last edited by Mike Armstrong : 04-20-2008 at 11:49 PM.
Reply With Quote
  #13  
Old 04-20-2008, 11:36 PM
Andy_RR Andy_RR is offline
 
Join Date: Oct 2006
Location: Melbourne, Australia
Posts: 427
Default

Mike,

It's not necessarily about flying credentials, but about the acceptable level of risk. What's acceptable to one person is not to another. Risk of airframe failure, whilst not a zero probability, is pretty low down in the scheme of things, especially compared to the myriad of other potential ways of killing oneself (and others) with an aircraft.

If ESP, ABS, airbags etc were the panacea to road safety, we would see startling reductions in RTA fatalities by now. In reality, in most places the statistics are only slowly improving (and in some cases going backwards) suggesting it is more about driver attitude to risk than having the tools to deal with the consequences. I suspect that it would be a similar situation in aviation if there were enough statistics to meaningfully tell the story.

By all means choose whatever safety devices you wish to have, but there's no need to foist them on everyone, nor deride those who chose to compromise differently.

A
Reply With Quote
  #14  
Old 04-21-2008, 12:39 AM
Mike Armstrong Mike Armstrong is offline
 
Join Date: Feb 2005
Location: near San Diego
Posts: 170
Default

I disagree.

I've spent the last 25yrs as a Paramedic and Firefighter and have seen first hand the advantages bestowed apon those unfortunate enough to be involved in the carnage of a severe vehicular accident. Before airbags and crush zones body removal was the alternative to those now surviving the destruction of what they considered the relative safety of the metal cage around them. Nobody thinks a brush with death awaits them whether pulling out of their driveway or taxiing from their hanger.

Safety devices do not discriminate. They do not not care if your the best driver in the world or the best pilot. They are there because they have been PROVEN to save your life when not having them has proven to be fatal in the same set of circumstances. To think your better than that is foolish. Just ask the thousands of vehicular crash survivors or the over 200 documented aircraft survivors that have deployed their BRS. Do you think any of those folks would be willing to drive or fly again without those same devices installed and ready to save their unlucky souls once again?

Ofcourse a Ballistic Parachute is no substitute for good airmanship, nor is an automotive airbag and seat belts a substitute for good driving skills, but accidents happen. Whether a drunk driver t-bones you in an intersection or your wings come off in turbulance, at that point in time it's not up to you anymore but instead only about what measures have been taken before hand to prevent you and your loved ones from being killed in the event at hand.

Just as automotive safety belts have long ago found their way into saving lives in the cockpit, eventually airbags and ballistic parachutes will be just as common. Why? Because they have been proven to work despite how good a driver or pilot you think you are.
Reply With Quote
  #15  
Old 04-21-2008, 06:33 AM
Ironflight's Avatar
Ironflight Ironflight is offline
VAF Moderator / Line Boy
 
Join Date: Jan 2005
Location: Dayton, NV
Posts: 12,256
Default Risk Management

Mike, I agree with you on the huge reduction in traffic injuries and fatalities that I have witnessed in 25 years of running traffic accidents in the fire service. Friday nights on our local stretch of highway used to always mean blood and broken glass - now we roll up and the two parties involved are standing outside their wrecked vehicles (airbags deployed) fighting over who was at fault - a silly but safer scenario.

However....just because a safety device is possible or available, that doesn't ALWAYS mean that it MUST be adopted. The BRS isn't a panacea - many Cirrus fatal Cirusses crashes have pr oven that. Any system that adds weight to an aircraft will exact a subsequent performance "charge", and needs to be looked at as a risk versus gain trade. If you actually look at accident statistics, you'll find that most fatal GA experimental accidents occur in regimes where the BRS simply doesn't apply - take-off and landing, or in the pattern. Very few are due to inflight break-up.

You can target any particular risk with a custom-designed solution, and see a huge reduction in risk in that area, but then you need to look at th big picture and see what you have gained. Spending the time building a reliable fuel and engine system, and then making sure that your pilot is well trained, sharp, and has good judgment will eliminate far more risks than those which can be solved with a BRS. (More Line of Duty firefighter fatalities can be eliminated by good driver training and better fitness standards than by all the interior attack and RIT training ever done....look at the statistics.)

This is NOT, in any way, written to denigrate someone's personal choice of BRS, and I think that anyone that wants one should go ahead and push the technology. But I generally disagree that simply because a safety device exists, it must be incorporated in any every aircraft - after all, the safest aircraft is one that never leaves the hangar. But that is not what planes are for.....

Paul
__________________
Paul F. Dye
Editor at Large - KITPLANES Magazine
RV-8 - N188PD - "Valkyrie"
RV-6 (By Marriage) - N164MS - "Mikey"
RV-3B - N13PL - "Tsamsiyu"
A&P, EAA Tech Counselor/Flight Advisor
Dayton Valley Airpark (A34)
http://Ironflight.com
Reply With Quote
  #16  
Old 04-21-2008, 08:25 AM
Steve Brown Steve Brown is offline
 
Join Date: Oct 2007
Location: Alviso, CA
Posts: 405
Default I'd like to have one for mountainous terrain

Assuming responsible maintenance practices and power management, an engine-out is not controllable, predictable, or preventable. Yes I would fly differently if I had one. I would fly over the rockies at night to visit my daughter and her family. I'd do the same in a twin. Gives an option besides dying in the very unlikely event of an engine out.
It would not change the weather I fly in, the amount of fuel I carry, fly aerobatics in a non-aerobatic airplane, etc.
__________________
Steve Brown
N598SD - RV9A second owner
O-320, 9:1 pistons, Catto 3 blade
KRHV - Reid Hillview airport, San Jose, CA
Reply With Quote
  #17  
Old 04-21-2008, 06:39 PM
L.Adamson's Avatar
L.Adamson L.Adamson is offline
 
Join Date: Apr 2005
Location: KSLC
Posts: 4,021
Default

Quote:
Originally Posted by Steve Brown View Post
Assuming responsible maintenance practices and power management, an engine-out is not controllable, predictable, or preventable. Yes I would fly differently if I had one. I would fly over the rockies at night to visit my daughter and her family. I'd do the same in a twin. Gives an option besides dying in the very unlikely event of an engine out.
It would not change the weather I fly in, the amount of fuel I carry, fly aerobatics in a non-aerobatic airplane, etc.
I like those mountains too! There's a lot of mountain country out there, that's incredibly scenic; but an engine problem IS a major risk, that's always on the mind. For instance, northern Idaho in the winter is worth the flight ( to me, anyway); but the chances of setting down, when you can't see the numerous airstrips under the snow, is rather nill. The terrain is also very rough!

While I think the risk is worth it, many airline pilots that I know, are no longer willing to take that additional risk. Perhaps they've just become a lot smarter than me ; and I'm sure they have; but I also think they've become accustomed to aircraft with a lot more redundancy. A built in chute is just another form of redundancy, such as a good second turbine that most commercial airplanes have.

L.Adamson
Reply With Quote
  #18  
Old 04-21-2008, 07:21 PM
Andy_RR Andy_RR is offline
 
Join Date: Oct 2006
Location: Melbourne, Australia
Posts: 427
Default lies, damned lies and statistics

Mike,

I don't disagree with your anecdotal evidence regarding road traffic accidents, however NHTSA statistics show a 2% p.a. reduction in road fatalities on a distance travelled basis and a similarly small reduction on other bases.

My point is not to argue statistics except to say that if technological solutions to dealing with the consequences of accidents were as effective as they are claimed to be, you would expect to see significant reductions in road fatalities. The problem is that these technological solutions only deal with a limited range within the whole spectrum of accident scenarios.

Carrying a BRS exacts its price in weight, cost, and complexity (and the potential for things to go wrong too!). Some choose to accept this compromise, others not.

Some choose to fly in light aircraft, some don't. Some choose to ride motorcycles, many do not. Some choose to mess with nasty chemicals in their garage... Some choose to go skydiving etc. etc...

A
Reply With Quote
  #19  
Old 04-21-2008, 08:15 PM
JimLogajan JimLogajan is offline
Banned
 
Join Date: Jul 2006
Location: Dexter, OR
Posts: 96
Default Twin engines and BRS analogy

Since twin engine planes and motorcycles have been mentioned, that brought to mind something I read in the book ""Free Flight" by James Fallows, in the chapter that discusses the origins of the Cirrus SR20:

"...but the only aspect of the plane's design to provoke open hostility was the inclusion of a parachute. The reaction was like that of motorcyclists told for the first time that they had to wear helmets. There was one rational level of objection - that the parachute and rocket added eighty pounds to the weight of the plane, or nearly 10 percent of its entire useful load. Alan Klapmeier liked to ask, in response, how much the second engine in a twin-engine plane weighed. The answer was many hundreds of pounds, but many people found this a perfectly reasonable investment in safety and reliability - even though running a second engine nearly doubled the plane's overall operating and maintenance costs. Why all the fuss about eighty pounds?"

(The install weight for an entire BRS system for an RV-12 is probably under 35 lbs and cost under US$4500: http://www.brsparachutes.com/ViewDoc...?DocumentID=84 )
Reply With Quote
  #20  
Old 04-21-2008, 09:42 PM
szicree szicree is offline
 
Join Date: Jan 2005
Location: SoCal
Posts: 2,061
Default

Quote:
Originally Posted by Steve Brown View Post
[b]I would fly over the rockies at night to visit my daughter and her family.
I'm sure it's better than nothing, but coming down onto the rockies at night under that BRS seems like a pretty grim proposition to me.
__________________
Steve Zicree
Fullerton, Ca. w/beautiful 2.5 year old son
RV-4 99% built and sold
Rag and tube project well under way

paid =VAF= dues through June 2013
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -6. The time now is 07:07 AM.


The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.