Mid-Air at KBDU

flyingcheesehead said:
I've said it before, and I'll say it again: The Cirrus is perfectly capable of recovering from a spin as well as any other no-intentional-spins single. They wanted the chute anyway, and by getting the FAA to allow the chute as an alternative, they didn't have to go through the full battery of spin tests, thus saving them both time and money on the certification.
Click to expand...

How can you speak to the Cirrus' spin behavior when the manufacturer didn't do the full spin series?


Trapper John
 
weilke said:
The ratio is meaningless without taking absoluted numbers and usage into account. Every low-speed runway excursion by a student in a 172 or DA20 will drive down the ratio of deadly accidents.

If you hit a mountain or fly into a thunderstorm, you are just as dead in a 172 as you would be in a Cirrus.
Click to expand...


There are Lies, Damn Lies, and then there are Statistics. :D

Look up a study done by the Insurance Institute for Highway Safety a few years back. They studied the number of driver fatalities per 1000 vehicles (or perhaps it was vehicle miles) based on the make / model of the vehicle. (They just looked at the driver to remove bias due to the number of people in the vehicle.)

One thing that sticks in my mind from that study is that statistically you are almost exactly twice as likely to die in a Mercury Grand Marquis compared to a Ford Crown Victoria.... But, they are the same design (aside from some trim changes).

Oh - safest on the list was the Chevy Astro mini-van. I don't remember what was the worst. I think the worst Ford was the Mustang which was in the bottom 10.
 
Everskyward said:
Do you think it's possible to see, in all situations? Like some other posters here, there have been a number of instances where ATC has called out traffic, I see it on the TCAS but I never get any visual contact even though I have a good idea of where to look. I think there are definite limitations to "see and avoid" which a lot of people seem to want to gloss over because that would mean that it's out of your control, at times.
Click to expand...

VERY true...and a sentiment I agree with. I look, and look hard when flying, but I STILL have to look in the cockpit to scan gauges, glance at the 496, change a freq, grab a sectional....and I have had a plane come from a direction I cannot see do to my wings.

Sorry but see and avoid is OK, but NOT the end-all-be-all in VFR collision avoidance, some of it is just plain luck, and I accept that.
 
I haven't been through the whole thread, so I apologize if this has been covered already:

Where was the Cirrus headed? To Boulder? From Boulder? Transitioning Boulder?

I saw the video of the Cirrus coming down under the chute: Is there an attitude where the the chute can't be deployed without tangling up in the wings or tail of the airplane itself? I'm wondering because I would expect that if the wing were damaged that badly at impact the plane would begin to roll or spin pretty soon after.
 
SteveinMichigan said:
Mooney M20J
74 non-fatal crashes, 17 fatal crashes, 91 total; 18.68% fatal

Cirrus SR22
50 non-fatal crashes; 41 fatal crashes; 91 total crashes; 45.1% fatal
Click to expand...
...and THAT's one of the big reasons I chose to purchase a M20J instead of a Cirrus recently. I really like Mooney's steel "roll" cage to protect its occupants.
 
Capt. Geoffrey Thorpe said:
One thing that sticks in my mind from that study is that statistically you are almost exactly twice as likely to die in a Mercury Grand Marquis compared to a Ford Crown Victoria.... But, they are the same design (aside from some trim changes).
Click to expand...

You are also typically twice as old if you are driving a Grand Marquis :blush:.

May have changed, but at this time the differences don't look so startling:
http://www.iihs.org/research/hldi/composite_cls.aspx?y=2006-2008&cls=2&sz=5&sort=name

If you look a couple of years back, it's actually the other way around.
http://www.iihs.org/research/hldi/composite_cls.aspx?y=2004-2006&cls=2&sz=5&sort=name


Wonder whether the Police Interceptor model was counted under the Crown Vic.
 
weilke said:
You are also typically twice as old if you are driving a Grand Marquis :blush:.
Click to expand...

Exactly.
May have changed, but at this time the differences don't look so startling:
http://www.iihs.org/research/hldi/composite_cls.aspx?y=2006-2008&cls=2&sz=5&sort=name

If you look a couple of years back, it's actually the other way around.
http://www.iihs.org/research/hldi/composite_cls.aspx?y=2004-2006&cls=2&sz=5&sort=name


Wonder whether the Police Interceptor model was counted under the Crown Vic.
Click to expand...

I can't find the study any more- but it was just counting driver deaths, not other factors.

Ok, found it: http://www.iihs.org/externaldata/srdata/docs/sr4003.pdf

Crown Vic 53 deaths per million registered vehicle years
Grand Marquis 83 (Ok, it wasn't quite twice - call it a senior moment)


The PI is a Crown Vic so I assume it was counted as such - I didn't see a seperate listing in the study for the PI.
 
Last edited:
Trapper John said:
How can you speak to the Cirrus' spin behavior when the manufacturer didn't do the full spin series?
Click to expand...

Talked to the test pilot who spun it. (Many folks seem to think that they never did). He said it spun and recovered like pretty much any other airplane.

So maybe it's not so nice in certain CG situations but to say it has "no practical ability to recover from a spin" is simply incorrect. Besides, who cares? It's not like you're gonna spin the thing intentionally unless you're stupid, and if you get into a spin that you can't recover from it's an emergency and you pop the chute. That's what it's there for. It's also a LOT more foolproof than a traditional spin recovery. So you try the traditional method if you have time to, and pull the handle if it doesn't work. I'm not sure why this is so controversial. :dunno:
 
flyingcheesehead said:
Talked to the test pilot who spun it. (Many folks seem to think that they never did). He said it spun and recovered like pretty much any other airplane.

So maybe it's not so nice in certain CG situations but to say it has "no practical ability to recover from a spin" is simply incorrect. Besides, who cares? It's not like you're gonna spin the thing intentionally unless you're stupid, and if you get into a spin that you can't recover from it's an emergency and you pop the chute. That's what it's there for. It's also a LOT more foolproof than a traditional spin recovery. So you try the traditional method if you have time to, and pull the handle if it doesn't work. I'm not sure why this is so controversial. :dunno:
Click to expand...

Interesting article here: http://www.whycirrus.com/engineering/stall-spin.aspx

I'm a bit confused by this statement:

Aerobatic designs such as Extra and Sukhoi products are, of course, certified for spins – but the mainstream general aviation four-seat designs such as Cirrus, Cessna (182, 350/400, etc), Diamond, Mooney, Piper etc. are not certified for spins. Few 4-seat designs have ever been tested or certified for spins.
Click to expand...

Hunh?
 
The Cirrus is perfectly capable of recovering from a spin as well as any other no-intentional-spins single.
Click to expand...

Which is to say, not perfectly capable in any practical sense. I heard from several people associated with Cirrus- including three different Cirrus sales reps - things to the effect of 'There's a reason it is a "no-intentional spin aircraft'. Spin it and you won't like what happens. There is no practical recovery except from great altitudes." The great altitudes comment was a direct comment from one of the senior sales reps at Oshkosh a couple of years back. When asked to elaborate what he meant by "great altitudes", his comment was (and I quote) "In the hands of an average GA pilot? 4,000 to 8,000 feet would be a reasonable guess." I'm sorry but that's not recovering from a spin just because the plane impacts the ground in a level attitude. If it weren't for the chute, the aircraft would not be on the market.

There are Lies, Damn Lies, and then there are Statistics.
Click to expand...

Ah...a great quote from Mark Twain, but one meant not to denigrate valid statistics but those that were flung around solely for the purposes of advancing a cause regardless of ethics or concern for the truth (he was speaking about yellow journalism if memory serves). That is not the case here.

One thing that sticks in my mind from that study is that statistically you are almost exactly twice as likely to die in a Mercury Grand Marquis compared to a Ford Crown Victoria.... But, they are the same design (aside from some trim changes).
Click to expand...

I know of a study that may well be the one you are talking about and the difference in mortality was attributed nearly solely to the frequency of restraint use. Those in Crown Vics were much less likely to be restrained which obviously decreases your chances of survival quite significantly. It does not make the statistics invalid just because they do not have a hard and fast explanation- this is science, not religion- or one where the reader does not see/understand/agree with the findings and/or explanation.

To look at it another way, it's all confounding variables that you have to watch out for: Could it be due to the differing uses for the vehicles? Also there are several models of Crown Vic (such as the police interceptor version, etc) that are quite different in terms of performance and given the risky use of that particular vehicle (and the police departments that use standard CVs because of cost issues thereby negating the easy ability to weed out the difference between the versions) not to mention the mindset of people who purchase the vehicle. I know a lot of "rescue Randy" types from my days on the volunteer fire department who liked to own Crown Vics because they were "cool" in their eyes versus the people who go for the Grand Marquis. The Crown Vic had a problem with it's gas tank:
Wikipedia said:
The reports that the cars were more prone to fires during a rear collision was a simple combination of four things. First, most law enforcement agencies rely heavily on the Crown Victoria as their primary vehicle, meaning that any police-related auto accident is very likely to involve a Crown Victoria. Second, the accidents occurred as the result of the officers intentionally parking their vehicles close to active traffic to shield a stopped motorist - something most civilians would never do. Third, the impacting vehicle was often traveling at, or above, the posted legal limit (70-75 mph in most jurisdictions).


The condition was exacerbated by police equipment installers drilling over the package tray in the luggage compartment. Due to the gas tank's orientation, drilling through the package tray may result in drilling into the gas tank. Installers also used screws set directly into the bulkhead and facing the fuel tank. In the event of a high-energy collision, these screws could be forced into the tank, both rupturing the tank and possibly acting as a spark source. Long bolts for mounting heavier equipment were also directly suspect. The manufacturer provided an aftermarket shield to help prevent these items from puncturing the tank during impact. Further, many investigations, both performed by federal/state agencies, and the police department themselves, have found that removable items in the trunk were improperly stowed. These items became tank-piercing projectiles during the rear-collision scenarios.

Source: http://en.wikipedia.org/wiki/Ford_Crown_Victoria#Fuel_tank_safety_concerns
Click to expand...

Despite the fact that a LOT of the problem was due to after-market modifications and driver behavior, the design was still modified to alleviate the issue (and to eliminate the pesky lawsuits associated therewith; which they were never found liable in just for the record). This is the difference between the automotive and the general aviation industries: problems are identified and addressed in the automotive industries whereas if an aviation company's design may well be killing it's customers at a higher than "normal" rate (indicating problems) it is simply brushed under the carpet by "fans" such as the "Cirrus police" and the blame is leveled solely on the pilot and nothing is changed to improve safety. Granted,

Also, every GA company should market like Cirrus, or GA will be dead soon. I think it's more the personalities that gravitate toward such a plane than it is the marketing itself.
Click to expand...

So if I thought it was a good idea to start training people to fly in a modern remake of the P-51 or wanted to build spot-on replicas of 1970s Pintos and market them as a great vehicle in which to teach teenage girls to drive, everyone should turn a blind eye because this is what we need to do simply to make the GA or automotive industries survive? If you were to die in a crash, would you really want to eulogized as "He died so the GA market didn't take a hit. His face did and the casket is closed for it, but hey! Cirrus' stock is up today!"?

What is wrong with marketing only to those who really should be flying it? Not every person who made it through basic flight training in WWII got to fly the Mustang or Thunderbolt- a lot of people got stuck flying the L-4 or C-47 despite wanting to have been a fighter jock. Likewise, not everyone who graduates with their PPL really has any business in a high-performance aircraft (at least not right away...you wouldn't want a 200-hr private pilot having the controls of the 737 you're riding with your wife and kids to Disneyworld on would you?) regardless of how much money they have to throw around.

I'm not saying the government should tighten the regs (god knows they meddle enough as is) but perhaps this is where that saying about either we keep ourselves in check or eventually someone else will do it for us comes to mind. It's a valid adage in terms of dealing with the TSA and it rings just as true for safety concerns.
 
Re: Towplane/Cirrus mid air in Boulder

flyingcheesehead said:
That's a good thing - Active COPA members, statistically, are much less likely to crash their Cirri. Not because they're COPA members, mind you, but more likely because they're the type of pilots who continue to learn and have an active commitment to safety (unlike your average Type-A Cirrus crasher).
Click to expand...

He's mentioned this to me before. I know that he is an extremely safe pilot and is always taking refresher courses to be learn something new. Even so, those crash stats don't make me feel great.
 
flyingcheesehead said:
Talked to the test pilot who spun it. (Many folks seem to think that they never did). He said it spun and recovered like pretty much any other airplane.

So maybe it's not so nice in certain CG situations but to say it has "no practical ability to recover from a spin" is simply incorrect. Besides, who cares? It's not like you're gonna spin the thing intentionally unless you're stupid, and if you get into a spin that you can't recover from it's an emergency and you pop the chute. That's what it's there for. It's also a LOT more foolproof than a traditional spin recovery. So you try the traditional method if you have time to, and pull the handle if it doesn't work. I'm not sure why this is so controversial. :dunno:
Click to expand...

Just so we're clear, I didn't make any claims either way about the spin behavior. I don't think anyone really knows, since a full spin series wasn't completed.

I do really question their decision to not follow the normal certification path. And I really don't buy the argument that not doing the spin series was cost driven. Let's do a little cocktail-napkin figuring. Let's say the spin series consists of 500 spins (which I think is reasonable, since I heard a similar number for Cessna's 162 test program). Assuming each spin takes an hour, which I think is really generous, that's 500 flight hours. So you've got a prototype with instrumentation, a test pilot, a chase plane and chase plane pilot for 500 hours. At $1,000/hour, that's $500,000. Now let's say there are 3 engineering hours for test setup, data reduction, analysis and reporting per spin at $150/hour. So, there's another $225,000, for a total of $725,000.

I've seen sales figures of north of 2,000 units for the SR-20 & SR-22. $725,000/2,000 = $363/aircraft. Even if my scratchings are off by a factor of 3, you're only at $1,000/aircraft, which isn't that much for something that's trading for close to half a million bucks per.

I think a parachute in addition to good aerodynamic design (that yields good, certifiable spin behavior) is a good thing. I also think that a parachute as a substitute for good aerodynamic design is a product of the, "We couldn't fix your brakes, so we made your horn louder" school of engineering and product development.


Trapper John
 
...and THAT's one of the big reasons I chose to purchase a M20J instead of a Cirrus recently. I really like Mooney's steel "roll" cage to protect its occupants.
Click to expand...

Precisely.

You are also typically twice as old if you are driving a Grand Marquis
Click to expand...

That in and of itself could explain part of the difference in the driver fatality rate; given equal severity of injuries, older persons are less likely to survive.


Talked to the test pilot who spun it. (Many folks seem to think that they never did). He said it spun and recovered like pretty much any other airplane.
Click to expand...

Key words in that sentence: TEST PILOT. Not only in terms of skill level (the difference between a 300 hr PPL with no instrument rating and a qualified test pilot is about as broad as the difference between a first year med student at Hollywood Upstairs Medical College and the chief of neurosurgery at Cleveland Clinic) but there's a big difference between an intentional spin/stall you know is coming and that "Oh f**k!" moment where the aircraft rolls left and you see the ground rushing up to meet you and you suddenly wish you weren't carrying a solid fuel rocket and a lot of fuel.

I think a parachute in addition to good aerodynamic design (that yields good, certifiable spin behavior) is a good thing. I also think that a parachute as a substitute for good aerodynamic design is a product of the, "We couldn't fix your brakes, so we made your horn louder" school of engineering and product development.
Click to expand...

That's the funniest damn thing I've read in a LONG time, but so, so true. Do you mind if I use that in a presentation I have coming up?

It's not like you're gonna spin the thing intentionally unless you're stupid, and if you get into a spin that you can't recover from it's an emergency and you pop the chute. That's what it's there for. It's also a LOT more foolproof than a traditional spin recovery. So you try the traditional method if you have time to, and pull the handle if it doesn't work. I'm not sure why this is so controversial.
Click to expand...

Because most inadvertent spin/stalls occur outside the envelope where the CAPS is of any benefit? It's a false sense of security, a red herring so to speak and it's not as foolproof or an "easy out" as you seem to believe. That is not to mention most pilots- including a lot of us on this forum- don't want to admit we can't handle a situation which explains why a lot of these crashes where the chute might have helped still wind up only having the CAPS deployed when the plane smashes into the ground killing all on board. That doesn't sound very foolproof to me. It's like anything else, it's a tool- it's not an excuse for stupidity and incredibly half-ass engineering.
 
SteveinMichigan said:
Which is to say, not perfectly capable in any practical sense. I heard from several people associated with Cirrus- including three different Cirrus sales reps - things to the effect of 'There's a reason it is a "no-intentional spin aircraft'. Spin it and you won't like what happens. There is no practical recovery except from great altitudes."
Click to expand...

I'll take the word of the test pilot who's actually done it over the sales reps. Besides, again, who cares? Anyone who gets a Cirrus into a spin is going to find a way to kill themselves eventually anyway, and if they were to own, say, a Columbia and get THAT into a spin, they would be more screwed than they would be in a Cirrus.

Bottom line: Anyone who gets a Cirrus into a spin, probably is not a good enough pilot be able to recover from a spin in ANY aircraft, so this is all a moot point.

If it weren't for the chute, the aircraft would not be on the market.
Click to expand...

Bogus.

This is the difference between the automotive and the general aviation industries: problems are identified and addressed in the automotive industries whereas if an aviation company's design may well be killing it's customers at a higher than "normal" rate (indicating problems) it is simply brushed under the carpet by "fans" such as the "Cirrus police" and the blame is leveled solely on the pilot and nothing is changed to improve safety.
Click to expand...

I'm not the "Cirrus Police" nor do I think they do everything right. However, you are a "Cirrus Criminal" (going with that metaphor) and bash them for EVERYTHING, even those things they do right. If you weren't so one-sided about this, we wouldn't even have these arguments.
 
SteveinMichigan said:
That's the funniest damn thing I've read in a LONG time, but so, so true. Do you mind if I use that in a presentation I have coming up?
Click to expand...

As much as I'd like to lay claim to that one, I can't. It came from an old civil engineer I used to work with, who shared other timeless engineering truisms, like:

You want it bad, you get it bad
The worse you want it, the worse you get it
Don't worry, in time this project will be just another bad memory
If you don't know what's happening, just walk fast and look worried
It's about time for the guys in Italian loafers to show up and take all the credit


Trapper John
 
Trapper John said:
I do really question their decision to not follow the normal certification path. And I really don't buy the argument that not doing the spin series was cost driven. Let's do a little cocktail-napkin figuring. Let's say the spin series consists of 500 spins (which I think is reasonable, since I heard a similar number for Cessna's 162 test program). Assuming each spin takes an hour, which I think is really generous, that's 500 flight hours. So you've got a prototype with instrumentation, a test pilot, a chase plane and chase plane pilot for 500 hours. At $1,000/hour, that's $500,000. Now let's say there are 3 engineering hours for test setup, data reduction, analysis and reporting per spin at $150/hour. So, there's another $225,000, for a total of $725,000.

I've seen sales figures of north of 2,000 units for the SR-20 & SR-22. $725,000/2,000 = $363/aircraft. Even if my scratchings are off by a factor of 3, you're only at $1,000/aircraft, which isn't that much for something that's trading for close to half a million bucks per.
Click to expand...

But that is now, and this was then. When Cirrus was doing this stuff, they were the manufacturer of a kitplane that hadn't sold very many units for a LONG time. Cirrus was around since 1984, 15 years, but there's only about a dozen VK30's. So, at the time they were doing the certification, $700K would be a HUGE amount of money.

Or maybe they were just lazy. ;)

CirrusVK-30N94CM01.jpg
 
Last edited:
SteveinMichigan said:
Key words in that sentence: TEST PILOT. Not only in terms of skill level (the difference between a 300 hr PPL with no instrument rating and a qualified test pilot is about as broad as the difference between a first year med student at Hollywood Upstairs Medical College and the chief of neurosurgery at Cleveland Clinic) but there's a big difference between an intentional spin/stall you know is coming and that "Oh f**k!" moment where the aircraft rolls left and you see the ground rushing up to meet you and you suddenly wish you weren't carrying a solid fuel rocket and a lot of fuel.
Click to expand...

I think your average 300 hour PPL is not going to recover from an unintentional spin at less than 3000 feet or so in ANY aircraft. So, clearly, the problem here is the PILOT, not the AIRPLANE. But you're blaming the airplane, when it's the ONLY one that has a backup method to maybe survive a situation that no halfway-decent pilot is going to get into in the first place.

Because most inadvertent spin/stalls occur outside the envelope where the CAPS is of any benefit?
Click to expand...

But those same stall/spins are UNRECOVERABLE IN ANY AIRCRAFT, no matter whether it's been through spin testing or not!

That is not to mention most pilots- including a lot of us on this forum- don't want to admit we can't handle a situation which explains why a lot of these crashes where the chute might have helped still wind up only having the CAPS deployed when the plane smashes into the ground killing all on board.
Click to expand...

And that right there is one of the big issues with the chute - It can't work if you don't pull the handle. :frown2:
 
However, you are a "Cirrus Criminal" (going with that metaphor) and bash them for EVERYTHING, even those things they do right. If you weren't so one-sided about this, we wouldn't even have these arguments.
Click to expand...
No, I have a laundry list of things that they've done right and I've had lunch with Alan Klapmeier and told him as much a few years back:
-The BRS (great idea, but the application is a little flawed, that's all)
-The "crumple zones" under the seats are a wonderful idea and probably one of the reasons the mortality rate isn't even higher in Cirrus crashes.
-Most of the avionics are what I can only hope for as a GA pilot in almost any other aircraft

Those are just the ones that jump to my mind now as it has been a long day...I have six or seven, but those are the major points. It's not that I think they have not contributed a lot to the aviation industry, far from it, however the flaws with the aircraft outweigh the positives. I mean, honestly, the compressible material under the seats does not mean a lot if the seats are broken lose because the cockpit comes apart. What is bad is that many of these fatalities (if I had to give my educated opinion on the subject, I'd say 10-15%) could be prevented if the cockpit integrity had been given a little more thought and focus. That doesn't sound like a lot- under most circumstances in the world of injury prevention, that's a pretty laudable achievement actually- but I'm betting you money if you were in that 10-15% you'd thank whomever pushed for the changes that got you there.

And that right there is one of the big issues with the chute - It can't work if you don't pull the handle.
Click to expand...
Right, which goes back to a problem in marketing- you market to people who think they are Maverick, things tend to go badly when you get into a flat spin. It's not a fault with the aircraft, but then again the misguided marketing of the aircraft is as much the responsibility of the company as the problems with the design.

But those same stall/spins are UNRECOVERABLE IN ANY AIRCRAFT, no matter whether it's been through spin testing or not!
Click to expand...
Right, but this aircraft has a higher than normal tendency to encounter those sorts of situations. It's a combination of high performance and low experience that is- not to sound like a broken record- at the heart of the Cirrus marketing strategy.

I think your average 300 hour PPL is not going to recover from an unintentional spin at less than 3000 feet or so in ANY aircraft.
Click to expand...
Point taken but it still doesn't mean you should put your faith in an aircraft that a USAF test pilot friend of mine described as the sort of plane "...you treat like a rattlesnake. If you give it more respect than most and don't get too close, you're golden, but look at her cross-eyed, don't give her respect or don't pay attention and you are in for a nasty bite."

So, clearly, the problem here is the PILOT, not the AIRPLANE.
Click to expand...
It's a bit of both.

But you're blaming the airplane, when it's the ONLY one that has a backup method to maybe survive a situation that no halfway-decent pilot is going to get into in the first place.
Click to expand...
Two things.

1. It's not the only one with the BRS fitted to it (another little "fact" I hear the Cirrus reps like to tell, so I won't fault you for repeating it), nor was it even the first. It was an idea they took from hang gliders and ultralights and scaled it up. Now it is one of the only ones with it considered standard, but the reasons for that are arguable but given that I like Mr. Klapmeier and respect the hell out of him for his efforts to make a safer plane (even if the end result has an appalling safety record...several of the subsystems in the aircraft should be considered standards by which any future design should be measured), I will take him at his word that it wasn't an engineering shortcut.

2. Everyone makes mistakes, even you and even me. Everyone. No one is above a moment of inattention. It's this "I'm better than that guy" or "He's a ****ty pilot and I'm not because...." attitude that gets people into situations where other egotistical pilots describe THEM in those terms when they are no longer around to defend themselves.

I'm not "blaming the airplane" solely and completely. It's a combination of factors and if you'd stop being so closed-minded and stop making assumptions about what I believe or don't believe you might see that most of my arguments frankly state that it's the fact the aircraft has some pretty glaring problems (and most of my concern is actually with things that have zero to do with the actual performance since I'm not an aeronautical engineer, I'm an injury prevention researcher), which are exacerbated by low hour pilots often with egos that would make Chuck Yeager look like Gandhi being seduced by Cirrus marketing these aircraft as if they are docile kittens with an easy "out" if you get into trouble. It's a bad theory that is getting a lot of us killed, like advocating we train people for their PPL in a Mooney M20K. THAT is what I am saying. I find it disgusting that you want to put the profits of a company ahead of the lives of our friends, colleagues and their families.

I'm not the "Cirrus Police"
Click to expand...
Could have fooled me.

(That type has the distinction of having a 100% kill rate in the NTSB database)
Click to expand...
You beat me to that one. I was going to make that point myself.
 
Last edited:
Re: Towplane/Cirrus mid air in Boulder

Dan Thomas said:
The tow release has no self-releasing feature. The tow rope is supposed to have a fusible link in it, calibrated to fail at a given strain.

See http://www.tc.gc.ca/civilaviation/certification/guidance/523/523-007.htm#4_0

Dan
Click to expand...

Some have a fusible link, at the glider end, I believe... another option is what our club uses: a rope made to break at a factor relative to the weight of the glider (I forget offhand what it is).

But it's not really relevant in this case...

Some reports said the Cirrus struck the tow rope itself, but others say the Cirrus and the tow plane collided, which would explain the damage seen on both aircraft while still aloft.

There's no way, even at typical Cirrus cruise speeds, that the rope would have done that kind of damage. And a tow rope fouled on another plane, even if the rope didn't break or the tow plane's release failed, would not cause immediate structural damage to a tow plane of that type.

There's quite a bit of strain on a tow rope when in use, but it's not like a cable between poles on the ground- there would be a lot of "give" when both ends are attached to airborne aircraft.

But, had the Cirrus merely gotten fouled in the rope, the tow pilot almost certainly would have noticed and been able to release it before it was too late (for him).

Also, if it was just the rope, and tow plane and glider both "got off", the Cirrus pilot could have pulled the 'chute and descended safely, as the ultralight pilot did in the video posted earlier in this thread.

The facts are not all in yet, but from what I've seen, I think the tow plane and the Cirrus actually collided.
 
SteveinMichigan said:
Pretty much. If people never took sides, there would be no disagreements and progress would never be made.
Click to expand...

I disagree.

Progress is made through agreement. Disagreement merely highlights the need for progress.
 
Disagreement merely highlights the need for progress.
Click to expand...
Yes, but that leads to the agreements, at least when disagreeing with rational, sane and open-minded people and not zealots (which is why you never get into a debate about politics or religion!).

Confrontation brings clarity.
Click to expand...
What he said.
 
vontresc said:
Hmm found this interesting article on "See and Avoid"

http://www.aviationweek.com/aw/generic/story_channel.jsp?channel=busav&id=news/bca0107c.xml
Click to expand...

Pete, that was a sobering, fantastic article. Thanks for posting it. It's worth the read. I learned some new things about flight vision physiology, aka "how the eye really works".

Further limiting the ability of pilots to see and avoid is the design of flight deck windows. Most cockpits severely limit the pilot's field of view. Obstructions to vision can include window posts, instrument and annunciator panels, glareshields, sun visors, eyeglass rims, windscreen bug splatter, windscreen imperfections, wings and the pilot beside you. Obstructions will not only mask some of the view completely, but will result in certain areas of the outside world being visible to only one eye, making it less likely to be detected. The eye has a natural blind spot at the point where the optic nerve exits the eyeball. Under normal conditions of binocular vision, the blind spot is not a problem as the area of the visual field falling on the blind spot of one eye will still be visible to the other eye.

However, if the view from one eye is obstructed (such as by a window post), then objects in the blind spot of the remaining eye will be invisible. Bearing in mind that an aircraft on a collision course appears stationary in the visual field, the blind spot could potentially mask a conflicting aircraft. The blind spot covers a visual angle of about five degrees horizontal, which is roughly 18 meters (59 feet) at a distance of 200 meters (656 feet), or enough to obscure a Hawker. A second undesirable effect of a window post or similar obstruction is that it can draw the point of focus inward, resulting not only in blurred vision but distorted perception of size and distance.
Click to expand...
 
Old Thread: Hello . There have been no replies in this thread for 365 days.
Content in this thread may no longer be relevant.
Perhaps it would be better to start a new thread instead.
Back
Top