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Midair Collision over Denver

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Re: Midair Collision over Denver

#81

Post by qayxc »

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 in the 1960s.

[0] https://www.newsmax.com/US/average-weight-man-woman-obese/20...

Re: Midair Collision over Denver

#82

Post by mannykannot »

sokoloff wrote: post #61
_s wrote: post #4

Private Pilot here - just thought I'd chime in quickly; Many aviation enthusiasts / pilots first go to is to have a look at the flight data - usually available on FlightAware / FlightRadar24 and a few other websites, plus LiveATC usually can provide recordings of the flights communications to towers as well. We should refrain from using just those data points to draw conclusions to the cause; the NTSB (and other orgs…

It’s not incredibly rare. Around 2 in 5 midair mishaps result in no fatalities. https://iflyamerica.org/midairs.asp This one was incredibly lucky, especially for the Key Lime aircraft.

Interesting - that's higher than I would have expected, but apparently explaind by most collisions being in the pattern or otherwise near an airport (makes sense now that I think about it.) At least in the pattern, for most of the time, everyone is going in approximately the same direction (even this case.)

Re: Midair Collision over Denver

#83

Post by mc32 »

bbojan wrote: post #45
cookguyruffles wrote: post #44

Earlier quoted context omitted.

Am I correct in saying after one usage, the parachute system generally needs replaced? I think I read this about Cirrus planes anyway

I believe the whole airplane needs to be replaced after BRS use.

Not necessarily. Frames can be repaired. Frame repairs and overhauls are common. If the damage is too extensive and expensive then you use it for parts.

Re: Midair Collision over Denver

#84

Post by mannykannot »

t0mas88 wrote: post #18
franciscop wrote: post #13

No deaths nor injuries involved, which I feel like this should be in the headline. I came in expecting to see at least a commercial flight was involved (how does it make to #1 on HN otherwise?) but was very relieved to see it was two small aircrafts with 1 and 2 pilots respectively and everyone survived safely.

The Metroliner isn't really a small (private) aircraft, it's more a commuter type aircraft, 19 seats. But in this case it was only carrying cargo so the place of impact didn't have any people in it. Another lucky point is that it was at low altitude and at slow speed (preparing to land). Higher up it would have been much more likely to break up due to way higher speed and larger pressure difference between the cabin…

Other inches-from-death aspects: there was no-one in the aft of the cabin; the collision missed the pilot; it missed the empennage; it missed the wings; it missed the control cables; and possibly (I'm speculating wildly here) it left the cabin floor intact, without which, I doubt the tail would have stayed on.

Re: Midair Collision over Denver

#85

Post by sokoloff »

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…

I find it very hard to agree that a PA-32 was "designed to realistically seat 7 adults". I don't think they even imagined 6 adults as a typical cabin load, but rather a max of 4 adults and 2 kids and a typical of 2 adults and 2-4 kids. It is one of the more roomy cabins among light singles, but every one of them that I see for listed for sale right now is configured with seating for only 6, which is great for 2 adults and a few kids.

Re: Midair Collision over Denver

#86

Post by mannykannot »

throwaway0a5e wrote: post #79
Aeolun wrote: post #72

Earlier quoted context omitted.

I think it’s amazing planes can fly sort of straight with only one engine providing thrust though.

He was on final. The engine was providing little more than idle thrust. If he were taking off some serious rudder input would have been required.

... and that rudder input would have put additional stress on the weakened fuselage.

Re: Midair Collision over Denver

#87

Post by jaywalk »

cookguyruffles wrote: post #44
t0mas88 wrote: post #12

Earlier quoted context omitted.

The more generic system is called BRS, Ballistic Recovery Systems. They deliver this as an option for many small aircraft and it's popular for experimental / home built aircraft. One downside of the systems is that they typically have a maximum lifespan of 10 years while airframes last 50+ years. So every 10 years there is a large maintenance cost to replace/renew the parachute system. Much less an issue for a $ 800k…

Am I correct in saying after one usage, the parachute system generally needs replaced? I think I read this about Cirrus planes anyway

The parachute system will need to be completely replaced after usage no matter what. Activating the parachute involves firing a small rocket motor to pull it out quickly.

Re: Midair Collision over Denver

#88

Post by JohnJamesRambo »

nickcw wrote: post #7

Just in case anyone (like me) is thinking - wait did that aeroplane have a parachute? From: https://en.m.wikipedia.org/wiki/Cirrus_Airframe_Parachute_Sy... The Cirrus Airframe Parachute System (CAPS) is a whole-plane ballistic parachute recovery system designed specifically for Cirrus Aircraft's line of general aviation light aircraft including the SR20, SR22 and SF50. The design became the first of its kind to becom…

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 parameters

Re: Midair Collision over Denver

#89

Post by mannykannot »

Denvercoder9 wrote: post #53
omegant wrote: post #40

Earlier quoted context omitted.

Looking at the youtube video of the radar with the radio sound that someone posted below, the Cirrus is cleared to runway 17R but he turns to runway 17L. There are 3 possibilities : 1- he mistakes one runway for the other visually, 2- he wrongly thinks he is cleared for the 17L runway 3- or he makes a too wide turn going for the 17R, intruding the 17L area. The cirrus is the one that makes the mistake. The 17 runways…

> The 17 runways are quite separated laterally so it’s more probable that he was wrongly going for the 17L thinking he was aiming for the correct runway. > https://flttrack.fltplan.com/AirportDiagrams/KDENapt.jpg This is the diagram for a different airport (Denver International, KDEN). The accident happened at Centennial Airport (KAPA), where the two runways are only separated by about 700 feet.

17R is shorter and narrower than 17L. If the pilot mistook 17R for a taxiway, it would have been a mirror-image situation to the relatively recent one at SFO, were an airliner was making its approach to a taxiway.

Re: Midair Collision over Denver

#90

Post by papercrane »

t0mas88 wrote: post #30
Grustaf wrote: post #22

Earlier quoted context omitted.

What is KAPA and do people know what it means?

The ICAO airport code as used for navigation. They're different from the IATA 3 letter codes that most passengers know. US airports start with K, European with E (e.g. EF for Europe-France). Often for large airports the code is very similar to the IATA code for passengers, e.g. KJFK for JFK and KSFO for San Francisco. But not always, as in EGLL for London Heathrow which is LHR in passenger codes.

> European with E (e.g. EF for Europe-France).

EF is Finland actually. The first letter is region code, and Europe is divided into multiple regions. Northern Europe is E, Southern Europe is mostly L (so France is LF).

Wikipedia has a nice map showing the different boundarys on it's ICAO airport codes page.

https://en.wikipedia.org/wiki/ICAO_airport_code#/media/File:...

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