Midair Collision over Denver • Hacker News Board

Re: Midair Collision over Denver

#161

Post by stevehawk » Thu, May 13, 2021, 3:25 PM UTC

jmpman wrote: post #135

JohnJamesRambo wrote: post #88

Earlier quoted context omitted.

Thank you, I was so confused. I was thinking the pilot a genius for bringing and activating a parachute. Now I see it was just great design. > As of 1 May 2021, CAPS had been activated 122 times, 101 of which saw successful parachute deployment. In those successful deployments, there were 207 survivors and 1 fatality. No fatalities had occurred when the parachute was deployed within the certified speed and altitude p…

21 of 122 failed? That’s a concerning statistic. I’d expect closer to 99% success, not 82%. How many fatalities when the parachute failed to deploy? 100%? If so, then you have almost a 1/5 chance of dying when you engage the parachute?

the chute has deployment parameters (altitude, airspeed of plane, etc) that aren't always met by the pilot in an emergency.

Re: Midair Collision over Denver

#162

Post by toss1 » Thu, May 13, 2021, 3:25 PM UTC

Leherenn wrote: post #50

ahartmetz wrote: post #47

Earlier quoted context omitted.

It may sound pointless unless you consider that the pilot will not need to be replaced.

There's the issue that in many cases people tried to save the airframe rather than activate the parachute, knowing the aircraft was likely to be written off, and died doing so. It the same when the pilot is equipped with a parachute.

Yes, and this happens also in many other arenas. I've only done a bit of flying, but in my experience in speed sports such as Downhill ski racing and auto racing, you must be mentally able to switch your goals in a fraction of a second, from [win the race] to [save the run] to [save your life], without hesitation.

Sometimes you succeed in [save your life] and are still on-track / on-piste pointing in the right direction and are back to [win the race] in the space of a few seconds. Other times, you are on the sidelines, and hopefully not on the way to the field clinic.

But the switch in perspective must fully committed and absolutely not include [save the equipment], which is replaceable, even custom one-off gear. Anything else is over-constraining the problem and inviting disaster.

Re: Midair Collision over Denver

#163

Post by stevehawk » Thu, May 13, 2021, 3:27 PM UTC

cesarb wrote: post #117

londons_explore wrote: post #114

Earlier quoted context omitted.

The plane flying missing half the fuselage suggests to me that fuselage was excessively strong (and therefore heavy and expensive). A tube is only strong when complete. Cut away half the tube and bending resistance probably goes down ~10x.

> The plane flying missing half the fuselage suggests to me that fuselage was excessively strong (and therefore heavy and expensive). It's probably the opposite: that the fuselage was only strong enough to resist the air pressure differential, and that the real structural component was the cabin floor. And that, luckily, the control cables for the tail were routed through the cabin floor, instead of through the top o…

It's not the cabin floor. it's what the cabin floor is attached to. Most fuselages have all of their longitudinal strength in their stringers, which are usually run along the floor. If the Cirrus had ripped through the bottom of that plane and not the top then that jet would have torn apart.

Re: Midair Collision over Denver

#164

Post by elliekelly » Thu, May 13, 2021, 3:31 PM UTC

sokoloff wrote: post #134

elliekelly wrote: post #104

Earlier quoted context omitted.

Are there any fees associated with an emergency landing like that? I imagine La Guardia runways are in pretty high demand but pilots have a culture that prioritizes safety above all else so I’d be curious which takes precedence.

There are no emergency-specific fees. Whether Newark (I think it was EWR, not LGA) would assess a normal landing fee is probably not a consideration for the pilot, especially back then. Landing fees are quite reasonable. Off peak, the landing fee would be $25 now. On peak, it would be $125. https://www.panynj.gov/content/dam/airports/pdfs/scheduleofc...

Wow that's surprisingly low! I was imagining the fee was thousands of dollars.

Re: Midair Collision over Denver

#165

Post by hyperbovine » Thu, May 13, 2021, 3:42 PM UTC

stevehawk wrote: post #163

cesarb wrote: post #117

Earlier quoted context omitted.

> The plane flying missing half the fuselage suggests to me that fuselage was excessively strong (and therefore heavy and expensive). It's probably the opposite: that the fuselage was only strong enough to resist the air pressure differential, and that the real structural component was the cabin floor. And that, luckily, the control cables for the tail were routed through the cabin floor, instead of through the top o…

It's not the cabin floor. it's what the cabin floor is attached to. Most fuselages have all of their longitudinal strength in their stringers, which are usually run along the floor. If the Cirrus had ripped through the bottom of that plane and not the top then that jet would have torn apart.

Nit: SA-226 is a turboprop not a jet.

Re: Midair Collision over Denver

#166

Post by mnw21cam » Thu, May 13, 2021, 3:45 PM UTC

qayxc wrote: post #81

mdip wrote: post #62

Wow, that's incredible. Goes to show that people do walk away from plane crashes with some regularity. My father was a pilot[0]. He sold his plane about 15 years ago (to a group of owners, one of which was a priest, I'm sure there's a joke in there). A few of winters later, he was called out to Romeo Airport; the pilot flying the plane that was formerly his had crashed the aircraft a few miles short of the runway in…

> The weight is so critical that the 7-seat plane can realistically only seat 4-5 adults. I think you overlooked an important factor there. The plane was indeed designed to realistically seat 7 adults. The issue is that in the 50 years since the plane was originally designed, the average weight of adults (in the US) increased by about 18% [0] and the average adult woman today weighs as much as the average adult man i…

There's also the fact that an aircraft like that may be able to carry 7 adults in some conditions. If you're at sea level in cold dry weather[0], then you'll have a lot more performance available than if you're trying to take off from Denver airport on a hot summer day just after a load of rain. There have been (usually light) aircraft that have crashed on takeoff/landing because the pilot didn't take the hot day into account, the minimum flying speed was higher than they expected, and the engine performance was too low.

[0] https://en.wikipedia.org/wiki/Density_altitude

Re: Midair Collision over Denver

#167

Post by mdip » Thu, May 13, 2021, 3:45 PM UTC

throwaway0a5e wrote: post #137

mdip wrote: post #62

Wow, that's incredible. Goes to show that people do walk away from plane crashes with some regularity. My father was a pilot[0]. He sold his plane about 15 years ago (to a group of owners, one of which was a priest, I'm sure there's a joke in there). A few of winters later, he was called out to Romeo Airport; the pilot flying the plane that was formerly his had crashed the aircraft a few miles short of the runway in…

> The weight is so critical that the 7-seat plane can realistically only seat 4-5 adults. I remember being shocked that they had to weigh the paint they applied when he had the plane re-painted. I used to work in general aviation. If my eyes could fly a loop in my skull they would have. Were the occupants required to use the bathroom before flying? That's how much weight you're potentially saving by weighing the pain…

Very interesting. I remember thinking it was positively "nuts", but then when you're in the aircraft being slapped around by the breeze, it starts to click.

Re: Midair Collision over Denver

#168

Post by jrockway » Thu, May 13, 2021, 3:47 PM UTC

osenthuortuh wrote: post #101

sillysaurusx wrote: post #93

Earlier quoted context omitted.

Did his wife survive?

The second link is the crash report. There were four occupants and only one fatality, so only he died. Looks like he tried to land in bad weather, descended before he could see the runway, and clipped some trees. Weather is an alarmingly common cause of accidents in general aviation.

> Weather is an alarmingly common cause of accidents in general aviation.

Well, flying VFR into IMC anyway.

Re: Midair Collision over Denver

#169

Post by [deleted] » Thu, May 13, 2021, 3:48 PM UTC

rubicon33 wrote: post #156

mdip wrote: post #62

Wow, that's incredible. Goes to show that people do walk away from plane crashes with some regularity. My father was a pilot[0]. He sold his plane about 15 years ago (to a group of owners, one of which was a priest, I'm sure there's a joke in there). A few of winters later, he was called out to Romeo Airport; the pilot flying the plane that was formerly his had crashed the aircraft a few miles short of the runway in…

There is a similar story in rally car safety. In the 80s and 90s going off the road at high speeds almost certainly meant death or serious injury. By comparison, there are some horrific crashes today that drivers are walking away from. [1] [1] https://youtu.be/YpNdoV6xv2s

[deleted]

Re: Midair Collision over Denver

#170

Post by mdip » Thu, May 13, 2021, 3:49 PM UTC

qayxc wrote: post #81

mdip wrote: post #62

Wow, that's incredible. Goes to show that people do walk away from plane crashes with some regularity. My father was a pilot[0]. He sold his plane about 15 years ago (to a group of owners, one of which was a priest, I'm sure there's a joke in there). A few of winters later, he was called out to Romeo Airport; the pilot flying the plane that was formerly his had crashed the aircraft a few miles short of the runway in…

> The weight is so critical that the 7-seat plane can realistically only seat 4-5 adults. I think you overlooked an important factor there. The plane was indeed designed to realistically seat 7 adults. The issue is that in the 50 years since the plane was originally designed, the average weight of adults (in the US) increased by about 18% [0] and the average adult woman today weighs as much as the average adult man i…

Not so much overlooked as omitted ... I had originally written "average American adults" but I didn't want to distract into the territory of "how bad our diets are in this country".

My Dad almost always flew alone. So much so that when the plane was packed and we were making an approach into the Sandusky, OH airport, we had a sudden "dip" on the way down that everyone noticed (we were headed to Cedar Pointe, so it was preparation, I guess). My Dad explained that he wasn't used to landing with so much weight and hadn't adjusted the trim correctly[0].

[0] If it wasn't abundantly clear, all of my flying experience ended at about age 17, which was a while ago, and I was never a pilot, so to the extent that I get any of this wrong -- that's why :)