I was reading the SR20 POH. It indicates the descent rate with the parachute deployed is 1600 to 1800 feet per minute. I was also reading the Columbia 300 description. According to Lancair the full stall descent of the Columbia 300 is 900 feet per minute. If I am reading this correctly then lose of power in IMC in the mountains is safer in the Columbia 300 (as long as the wings don’t fall off) than the SR20. Am I missing something?
Art,
You are missing the most critical piece of this: The wing, fully stalled (and flown PERFECTLY), is still moving forward at more than 60knts. With the parachute, you carry only the vertical piece (plus any wind). I’m not a physics expert but the total amount of energy unload would be very, very high with your “stalled wing” theory.
I’ll take the chute any day!
Chris SR22 #95
I was reading the SR20 POH. It indicates the descent rate with the parachute deployed is 1600 to 1800 feet per minute. I was also reading the Columbia 300 description. According to Lancair the full stall descent of the Columbia 300 is 900 feet per minute. If I am reading this correctly then lose of power in IMC in the mountains is safer in the Columbia 300 (as long as the wings don’t fall off) than the SR20. Am I missing something?
As long as you don’t mind smacking those mountains with probably 40-60(?) knots of forward velocity (depending on flaps) in addition to the 900 fpm vertical. A rudder-controlled full stall (as opposed to a flat spin or some other unusual attitude) simply means that you have exceeded the critical angle of attack, not that you have come to a stop in the air. Descent on the Cirrus parachute system, in contrast, will have a forward velocity imparted by the prevailing winds, which unless you are flying in a hurricane will probably be less than 40 knots, and might be only a few knots. IMHO
Phil
I was reading the SR20 POH. It indicates the descent rate with the parachute deployed is 1600 to 1800 feet per minute. I was also reading the Columbia 300 description. According to Lancair the full stall descent of the Columbia 300 is 900 feet per minute. If I am reading this correctly then lose of power in IMC in the mountains is safer in the Columbia 300 (as long as the wings don’t fall off) than the SR20. Am I missing something?
I was reading the SR20 POH. It indicates the descent rate with the parachute deployed is 1600 to 1800 feet per minute. I was also reading the Columbia 300 description. According to Lancair the full stall descent of the Columbia 300 is 900 feet per minute. If I am reading this correctly then lose of power in IMC in the mountains is safer in the Columbia 300 (as long as the wings don’t fall off) than the SR20. Am I missing something?
Art: The stall, by definition, is not a stable attitude of the aircraft. It is the point where the wings loose lift due to turbulant air on the top surface of the wing. At that point the nose is going to drop due to lack of lift. There is no way to keep the aircraft in a stalled condition for your descent in IMC in the mountains. If you knew when to cause the stall, you wouldn’t be in IMC.
If you did suffer a power loss in IMC over the mountains and knew you couldn’t make lower flat terrain and VMC you would want a stable attitude at a constant descent at a rate that would be survivable. Given that circumstance, I don’t know of any other option than the parachute.
You could stall, recover, and then stall again with the hope that your contact with the terrain would occur during the stall. The problem is that the descent rate during the recovery from the stall is going to be substantial and if you were unlucky enough to hit the terrain during the recovery phase of the stall-recover-stall sequence that ground contact would be definatly not be survivable.
So far as the comment about the wings falling off, that is not applicable to the stall. The overstressing of the wing would likly occur during an unsuccessful attempt at recovey from a dive or spin. These are manuvers that you clearly don’t want in IMC over mountains, or even in VMC over flat land!
This is only a first stab at this. I am sure others will correct any of my mistaken notions of the aerodynamics involved.
Interesting subject. Good points made by all. Tell me all the circumstances of a particular emergency and I’ll tell you which plane I want to be in. Lacking that information I’ll take my chances with 900 fpm and 40-60 knots forward speed.
If it’s IMC to the ground I made the wrong choice. (If I’ve lost a lot of plastic in a mid-air I’ve also made the wrong choice.) Fog goes to the ground. Most of the IMC we fly in does not go to the ground.
Pull the Cirrus rip cord and you may as well take a coffee break. Your chores and choices are done until after landing. Exactly where you touch down is up to serendipity, as in entirely out of your control.
As long as we are dealing with hypotheticals let me ask, what if you break out of the clouds before plunk down? Would you rather be descending at 900 fpm travelling at 40-60 knots with the ability to resume a controlled descent or be out of options, descending straight down to, whatever, at 1600-1800 fpm?
I know, it depends. But you don’t have the answer to “it depends” beforehand.
As much as I hate to use an anecdote to reinforce a point this one is too good to pass up, "there was a loud pop then silence. I stabilized the
airplane and ran the checklist. I informed Center that we were declaring an
emergency and that I would need vectors to the nearest airport. We were
right between Eagle and Aspen so we flipped a coin and took Eagle. Center
also informed us that we would loose radar below 12,000 due to terrain.
granite of the Front Range.
Odds were that we were about to do the same.
At about 12,000 feet the up till that day trusty Lycoming started to cough
and I was able to get a restart, albeit at reduced power and rough. I’ll
take it! moments later Hamid spotted Eagle through a break in the clouds. A
three G turn while deploying the speed brakes put us through the hole. We
contacted Eagle tower and were informed that there was a helicopter in the
pattern. "Tell hBy this time our situation was reasonably serious. We were hard IFR with
turbulence and icing, no engine, about to attempt an IFR approach into an
unfamiliar airport that was 8,000 feet BELOW MEA. All we needed would be for
night to fall and have an electrical failure for this to be a "perfect
storm". I focused on keeping the airplane level and flying in the right
direction and [pilot passenger] monitored the moving map I had built for the plane.
Below us the clouds terminated in the cumulousgranite of the Front Range.
Odds were that we were about to do the same.
At about 12,000 feet the up till that day trusty Lycoming started to cough
and I was able to get a restart, albeit at reduced power and rough. I’ll
take it! moments later [pilot passenger] spotted Eagle through a break in the clouds. A
three G turn while deploying the speed brakes put us through the hole. We
contacted Eagle tower and were informed that there was a helicopter in the
pattern. “Tell him to get out of the way!” I was in no mood to be nice.
After what we had been through it was a relief to do a partial dead stick
landing in light rain to an unfamiliar high altitude field. We made it!"
True story, coincidentally in a Lancair.
Stephen, the stall characteristics you describe would fit most planes. However the Columbia goes into a wings level mush with almost no porpoising. I’ve flown two of them and no matter what I did could not get them to act otherwise in a stall.
Art,
You are missing the most critical piece of this: The wing, fully stalled (and flown PERFECTLY), is still moving forward at more than 60knts. With the parachute, you carry only the vertical piece (plus any wind). I’m not a physics expert but the total amount of energy unload would be very, very high with your “stalled wing” theory.
I’ll take the chute any day!
Chris SR22 #95
I was reading the SR20 POH. It indicates the descent rate with the parachute deployed is 1600 to 1800 feet per minute. I was also reading the Columbia 300 description. According to Lancair the full stall descent of the Columbia 300 is 900 feet per minute. If I am reading this correctly then lose of power in IMC in the mountains is safer in the Columbia 300 (as long as the wings don’t fall off) than the SR20. Am I missing something?
Yeah, that is definitely the point! 60kts = 6000+ feet/minute which is obviously a lot more than the vertical component of 1600-1800 feet/minute that the author refers to for the 'chute.
I was told by my Cirrus salesperson that the impact is comparable to dropping the airplane from a height of 10.5 feet (although the SR22 POH says 13 feet).
He also told me something very interesting. He said that the rate of decent for the airplane with 'chute deployed is the SAME as it is with BRS’s ultralight 'chutes! If true, this really bodes well for us, as they have over 130 saves
on such aircraft. And think of how much more protected and cushioned you are in the Cirrus than you are in an ultralight! (E.g., the impact-absorbing seat.)
My concerns regarding deployment in worst case scenarios (night/IFR) are more focused on the attitude of the aircraft when it impacts the ground. My “what if” reads “What if you settle onto trees or terrain features that flip you sideways (or worse) just before you hit?” But hey, clearly it is still enormously better than no 'chute at all.
I’ve also been thinking about ditching. Ditching itself is a very survivable event. What’s critical is getting out of he airplane with the raft and vests intact and usable. (You all have rafts, right? If not, see http://www.equipped.com/ and read about ditching and survival.) And that boils down to the time before sinking and getting/keeping the doors open.
In rough seas, no doubt the 'chute would be best. In calm / shallow water, probably still best, but maybe not. Would you prop the doors open with a shoe? Supposed to keep the doors closed for impact with the 'chute, but I don’t want to be under water finding / tapping with some little ball peen hammer. I want out. So I think I’d prop the doors open anyway. However…
With ditching, even with fixed gear, you’re likely to act like a skipping stone to some extent, maybe with a nose dip and a quick bob to the surface. With 'chute impact, I bet the entire aircraft would end up submerged. Would it quickly bob to the surface, allowing egress? Hmmm - maybe those doors should remain closed after all.
Food for thought, although there are certainly more fun Cirrus thoughts to think!
Gordon
Art,
You are missing the most critical piece of this: The wing, fully stalled (and flown PERFECTLY), is still moving forward at more than 60knts. With the parachute, you carry only the vertical piece (plus any wind). I’m not a physics expert but the total amount of energy unload would be very, very high with your “stalled wing” theory.
I’ll take the chute any day!
Chris SR22 #95
I was reading the SR20 POH. It indicates the descent rate with the parachute deployed is 1600 to 1800 feet per minute. I was also reading the Columbia 300 description. According to Lancair the full stall descent of the Columbia 300 is 900 feet per minute. If I am reading this correctly then lose of power in IMC in the mountains is safer in the Columbia 300 (as long as the wings don’t fall off) than the SR20. Am I missing something?
With 'chute impact, I bet the entire aircraft would end up submerged
you’re kidding, right? With all that wing area hitting the water flat, no way is it going to submerge on impact under the chute. How long it will take to sink, I don’t know, but for my money, I would have the doors wide open (forget propping them open, you’ve got zero forward airspeed, the doors will definitely open and stay open) and immediately after impact be releasing the seatbelts and climbing out onto the wing (taking raft and EPIRB). Egress of 4 occupants from the SR20 with the doors open should take only seconds.
Hello Clyde,
I think I would leave the door ajar. Here is my reason: 1. The door would be used as a shield (body protection) in case of any flying objects that may want to enter the cockpit at impact. 2. Once the door is out of its closed and lock position if the fuselage bends the door will not bent with the fuselage because it is not in the lock position (so there is no fear that I wont be able to get out because the door is on the way) This bring another question. I bet if the door is in the closed and lock position it will provide much better integrity for the cabin area during impact. Well now that we have that out of the way, which did come first the egg or the chicken? If all else fails go with #1. DonÂ’t forget to ask the rear passengers to open the baggage door, this will be used as a back-up to the normal entrance/exit. DonÂ’t worry if the need is there I can get out via the ash tray I hope you can too. How else are we going to come back to your beautiful site and report on what to do if it happen to you. Have a great Cirrus down under day. 
Woor
With 'chute impact, I bet the entire aircraft would end up submerged
you’re kidding, right? With all that wing area hitting the water flat, no way is it going to submerge on impact under the chute. How long it will take to sink, I don’t know, but for my money, I would have the doors wide open (forget propping them open, you’ve got zero forward airspeed, the doors will definitely open and stay open) and immediately after impact be releasing the seatbelts and climbing out onto the wing (taking raft and EPIRB). Egress of 4 occupants from the SR20 with the doors open should take only seconds.
At 1800 feet/minute, 30 feet/second, the momentum will almost certainly result in the aircraft submerging, if only briefly, at least to the extent of water coming over the top of the wings. If the doors are open, water may indeed enter the cockpit.
The question is, would enough water enter the cabin quickly enough to preclude rapid surfacing of the aircraft? I don’t think so, especially as the wings will provide boyancy as well.
If you think that, at 30 feet/second, it is going to gently pancake onto the water and not submerge at all, you are kidding, right?
Gordon
With 'chute impact, I bet the entire aircraft would end up submerged
you’re kidding, right? With all that wing area hitting the water flat, no way is it going to submerge on impact under the chute. How long it will take to sink, I don’t know, but for my money, I would have the doors wide open (forget propping them open, you’ve got zero forward airspeed, the doors will definitely open and stay open) and immediately after impact be releasing the seatbelts and climbing out onto the wing (taking raft and EPIRB). Egress of 4 occupants from the SR20 with the doors open should take only seconds.
If the doors are open before impact wouldn’t the g forces on impact slam them closed and maybe distort them so they were harder to open? The baggage door can not be opened from the inside. When I asked Cirrus about this the answer was that the FAA would not certify it as an exit because of its size and thus there could not be an inside latch.
I think I would leave the door ajar. Here is my reason: 1. The door would be used as a shield (body protection) in case of any flying objects that may want to enter the cockpit at impact. 2. Once the door is out of its closed and lock position if the fuselage bends the door will not bent with the fuselage because it is not in the lock position (so there is no fear that I wont be able to get out because the door is on the way) This bring another question. I bet if the door is in the closed and lock position it will provide much better integrity for the cabin area during impact. Well now that we have that out of the way, which did come first the egg or the chicken? If all else fails go with #1. DonÂ’t forget to ask the rear passengers to open the baggage door, this will be used as a back-up to the normal entrance/exit. DonÂ’t worry if the need is there I can get out via the ash tray I hope you can too. How else are we going to come back to your beautiful site and report on what to do if it happen to you. Have a great Cirrus down under day.
Woor
With 'chute impact, I bet the entire aircraft would end up submerged
you’re kidding, right? With all that wing area hitting the water flat, no way is it going to submerge on impact under the chute. How long it will take to sink, I don’t know, but for my money, I would have the doors wide open (forget propping them open, you’ve got zero forward airspeed, the doors will definitely open and stay open) and immediately after impact be releasing the seatbelts and climbing out onto the wing (taking raft and EPIRB). Egress of 4 occupants from the SR20 with the doors open should take only seconds.
If the descent rate is 30 feet per second this equates to a 20.45 MPH impact with what ever you hit. Since the plane will have little forward momentum (to keep it simple we will assume the plane is tracking or orientated forward with the wind) the impact should not be as bad as we would think.
If you do land in water I hope it is because of fuel starvation. No fuel equals big floats (wings). Now as to the question of having the doors open or closed???..I personally do not know. I have never had to ditch or land offsite so my opinion is moot.
Have a good day.
Bob 509
If the descent rate is 30 feet per second this equates to a 20.45 MPH impact with what ever you hit. Since the plane will have little forward momentum (to keep it simple we will assume the plane is tracking or orientated forward with the wind) the impact should not be as bad as we would think.
If you do land in water I hope it is because of fuel starvation. No fuel equals big floats (wings). Now as to the question of having the doors open or closed???..I personally do not know. I have never had to ditch or land offsite so my opinion is moot.
Have a good day.
Bob 509
I’d hate to be trying to get the doors open with water pressure on them, or breaking a window with that same presssure. The doors are tricky enough to open on the ground at the hangar! My vote would be breaking one of the windows before hitting the water, with the parachute open.
Why break the window in the air? Why not just open the doors all the way on the way down? Remember, with little or no forward velocity they will almost certainly stay open. I think you’d be plenty busy on the way down performing emergency procedures, making mayday calls, and maybe getting the raft out of the back seat.
One significant advantage of the parachute water landing is that stuff in the cabin is much less prone to becoming missiles as it is with the rapid deceleration of a ditching. So you could have the raft, EPIRB, etc. ready to go, although I wouldn’t put them in my lap.
One other note. You really should be wearing a life vest when traveling over water, especially for a departure over water, as you’ll never have the time or presence of mind to put them on on the way down or in the water. There are some good “pouch type” life vests that you wear like a fanny pack. I can’t wear them in my Bonanza because the yoke is so low and practically in my gut. With the Cirrus, plenty
of lap room for the pouch.
Gordon
I’d hate to be trying to get the doors open with water pressure on them, or breaking a window with that same presssure. The doors are tricky enough to open on the ground at the hangar! My vote would be breaking one of the windows before hitting the water, with the parachute open.
Gordon,
One concern that has not been brought up on this forum is the entanglement danger from the chute. All the lines and the chute it self can pose a great hazard during a ditching. Make a note to pack a good knife that has a blade length of at least 4"-6".
FWIW:
I recommend the suspender type life jackets that are now availble. They are often used by fisherman. They are easy and comfortable to wear and have almost no bulk. Look in Cabellas or the like to locate them. One note though, do not get the type that self inflate when they contact water. This would be a big problem if you where still in the aircraft.
Bob 509
Why break the window in the air? Why not just open the doors all the way on the way down? Remember, with little or no forward velocity they will almost certainly stay open. I think you’d be plenty busy on the way down performing emergency procedures, making mayday calls, and maybe getting the raft out of the back seat.
One significant advantage of the parachute water landing is that stuff in the cabin is much less prone to becoming missiles as it is with the rapid deceleration of a ditching. So you could have the raft, EPIRB, etc. ready to go, although I wouldn’t put them in my lap.
One other note. You really should be wearing a life vest when traveling over water, especially for a departure over water, as you’ll never have the time or presence of mind to put them on on the way down or in the water. There are some good “pouch type” life vests that you wear like a fanny pack. I can’t wear them in my Bonanza because the yoke is so low and practically in my gut. With the Cirrus, plenty
of lap room for the pouch.
Gordon
I’d hate to be trying to get the doors open with water pressure on them, or breaking a window with that same presssure. The doors are tricky enough to open on the ground at the hangar! My vote would be breaking one of the windows before hitting the water, with the parachute open.
The airframe looses its structural integrity in a crash situation, if the door is open. That’s why they provide the hammer, instead of having you crack open the door, like you would in a Piper for example.
I don’t think entangelemet will be a big issue, since there almost always will be some wind that will keep the chute/cords away from the airplane. And I think you’ll be able to open the doors while on the way down with the chute - see
http://www.cirrusdesign.com/images/gal_caps_bluechute4.jpg
I will have a knife, though, just in case!
Here’s my survival equipment:
Winslow Island Flyer raft http://www.winslowliferaft.com/
GPIRB (EPIRB w built-in GPS) http://landfallnav.stores.yahoo.com/landfallnav/-sgpirb.html
Survival kit: deHavilland http://www.epcamps.com/page323.html
I’ll check out those suspender vests. I’ve been looking at the SosPenders Waistbelt. The Pro Bass is like the ones you mentioned.
http://www.sospenders.com/models.html
Also, one of the “SeeRescue” streamers. Hands down the best signal for S&R to see you in the water (or even on land) http://www.rescuestreamer.com/
Gordon
Gordon,
One concern that has not been brought up on this forum is the entanglement danger from the chute. All the lines and the chute it self can pose a great hazard during a ditching. Make a note to pack a good knife that has a blade length of at least 4"-6".
FWIW:
I recommend the suspender type life jackets that are now availble. They are often used by fisherman. They are easy and comfortable to wear and have almost no bulk. Look in Cabellas or the like to locate them. One note though, do not get the type that self inflate when they contact water. This would be a big problem if you where still in the aircraft.
Bob 509
I’ll need to know more about the degree of structural integrity that it loses with the door open in that particular crash situation - water touchdown under the 'chute, before I’d make the decision whether to have the doors open or closed. In a water landing, you want out of the airplane fast, before the dang thing sinks.
The airframe looses its structural integrity in a crash situation, if the door is open. That’s why they provide the hammer, instead of having you crack open the door, like you would in a Piper for example.
At 1800 feet/minute, 30 feet/second, the momentum will almost certainly result in the aircraft submerging, if only briefly, at least to the extent of water coming over the top of the wings.
Some rough calculations based on a 10-20G deceleration suggests to me that the wings might penetrate the water to a depth of a foot or so. So I think it unlikely that the aircraft will submerge, but if it it did, I would not want to rely on it “bobbing to the surface”. It might, but more than likely part of the doors will be under water, making them hard to open.
So I would still go with opening the doors before impact. All the stories I’ve read about ditching seem to have one thing in common - the surprising rate at which the cabin fills with water. I would not want to be struggling to open doors agains the pressure, or trying to smash the window as the cabin filled. Even completely underwater, if the door is wide open in an SR20, it should be reasonably easy to get out the door (it’s a big opening).
And I would take ditching under the chute any day over flying onto the water, for similar reasons.
Yeah, I agree with that. I’d like to know more about the effects of the decreased cabin rigidity due to the doors being open. Would it be prone to clamshelling and possibly injuring you with your roof coming down at you?
I’m going to really think through the optimum procedure for the typical scenario I need to deal with: departing from a runway that puts you immediately over the ocean, heading directly away from shore. (Departing 15L/R from SBA.) Whenever I can, I avoid departing in that direction but sometimes there’s just no avoiding overwater flight from here (I’m talking IFR departures, including those into a relatively high ceiling - 1500 feet or so).
With the excellent climb performace of the SR22 and with my typical light loads, I can very likely be passing through 500 feet at the shoreline. I’d opt for a 90 degree turn and a beach landing if still in VMC. IMC, sure, pull the chute, but what would be the minimum altitude to do so? I guess that question’s been raised many times here.
Gordon
Some rough calculations based on a 10-20G deceleration suggests to me that the wings might penetrate the water to a depth of a foot or so. So I think it unlikely that the aircraft will submerge, but if it it did, I would not want to rely on it “bobbing to the surface”. It might, but more than likely part of the doors will be under water, making them hard to open.
So I would still go with opening the doors before impact. All the stories I’ve read about ditching seem to have one thing in common - the surprising rate at which the cabin fills with water. I would not want to be struggling to open doors agains the pressure, or trying to smash the window as the cabin filled. Even completely underwater, if the door is wide open in an SR20, it should be reasonably easy to get out the door (it’s a big opening).
And I would take ditching under the chute any day over flying onto the water, for similar reasons.