Kobe Bryant Helo Incident

[Gatordev]

Oh, and to add to @bubblehead et al... There's a glitch in the system, so the other thread is stuck behind the private forum area. I was going to combine the threads, but several mods have lost the ability to move it when attempted.

 

[squorch2]

Spatial Disorientation > Unusual Attitudes > Improper Control Inputs > CFIT

I could see a scenario where pilot enters the goo, keeps outside scan, initiates a turn to get away from rising terrain, starts descending, loses SA/orientation, and starts over controlling with cyclic, resulting in opposing VSI/airspeed peaks as oscillations get worse.

 

[picklesuit]

Spatial Disorientation > Unusual Attitudes > Improper Control Inputs > CFIT

I could see a scenario where pilot enters the goo, keeps outside scan, initiates a turn to get away from rising terrain, starts descending, loses SA/orientation, and starts over controlling with cyclic, resulting in opposing VSI/airspeed peaks as oscillations get worse.

Basically your avatar...

 

[bubblehead]

Again, a radar doesn't do anything for you. It's for weather, not terrain.

I thought TAWS was for terrain (Terrain awareness and warning system)?

 

[Gatordev]

I thought TAWS was for terrain (Terrain awareness and warning system)?

TAWS is a GPS-based system coupled to a map database.

 

[Scimitarze]

Even if the S76 had a EPGWS and radar altimeter, the probing window doesn't encompass the sides and aft of the ship, correct?

 

[Jim123]

what i don't get is, being a helo, why did he have to keep up his speed? i saw somewhere that he was still going 180 kts or so.

in know what that feels like in a jet, but in a helo can't you just slow down and maybe stop before going into IMC?

Yes, you certainly can slow down much slower than that. IIRC, for certification there is a minimum airspeed for IFR operations that is based on stability, controllability, flight control system characteristics (or something along these lines) and multiplied by some factor. In the Bell 206 this was 65 knots, and as you slowed down below about 50 knots and slower then the machine feels like it needs more of your attention to maintain basic airwork (heading, altitude, etc.). It's somewhat analogous to an airplane's Vref and the relationship with 1.3×Vso if that helps explain what it actually feels like in a stick and rudder sense.

But to answer your question, yes, you can slow down quite a bit, and you can also make extremely tight turns at low airspeed that aren't particularly demanding of the machine's aerodynamic margins- a 45-60° angle of bank turn at 60-80 knots is okay, notwithstanding the passengers' reactions or the pilot possibly giving himself spatial disorientation doing that right under a low ceiling.

Hope all that makes sense. All I'm talking about in this post is the lifities and the bernoullis, not aeronautical decision making.

 

[Gatordev]

Even if the S76 had a EPGWS and radar altimeter, the probing window doesn't encompass the sides and aft of the ship, correct?

Typically, at least the TAWS commercial systems I've seen, put a bubble around you and depict what's where on the display, as well as gives an aural warning. So yes, it's giving you more than just what's in front of you.

TAWS isn't exactly like EGPWS, though they may be coupled. TAWS is positional, EGPWS is more active (from the radalt/sink rate).

 

[johnboyA6E]

But to answer your question, yes, you can slow down quite a bit, and you can also make extremely tight turns at low airspeed that aren't particularly demanding of the machine's aerodynamic margins- a 45-60° angle of bank turn at 60-80 knots is okay, notwithstanding the passengers' reactions or the pilot possibly giving himself spatial disorientation doing that right under a low ceiling.

thanks,

i know absolutely nothing about helos (except something about a Jesus nut) . i was thinking that it is orders of magnitude easier to avoid IMC in a helo than in a fixed wing. for instance, flying into a box canyon with a low ceiling is often fatal in a fixed wing, but in a helo i would assume you can slow down and descend very low, and even land rather than fly into the soup - but maybe that is a bad assumption in this type of scenario

i'm guessing that didn't happen here - he probably just flew into the clouds and got disoriented and flew into the hill....

even with the right training and equipment CFIT happens - in the early 90s we lost several east coast A-6 crews in the mountains, and it was our job to fly low up the valleys at night on radar only

 

[Gatordev]

for instance, flying into a box canyon with a low ceiling is often fatal in a fixed wing, but in a helo i would assume you can slow down and descend very low, and even land rather than fly into the soup - but maybe that is a bad assumption in this type of scenario

As I mentioned in the other thread, landing isn't always that easy, especially in a high-population density location like the LA basin. Just the sheer amount of wires everywhere is crazy.

 

[xmid]

I'm still trying to understand what looks like a precipitous descent priot to impact. As some have suggested, perhaps an attempt to to a quick 180 and get out of the clouds, but it seems like a very aggressive move if you don't know what's below you or around you.

Although it didn't apply on low levels, it was pretty common to brief that if you went IIMC you would do a 180 and fly for 30 seconds, if you were still IIMC you'd climb to MSA (briefed) and pick up a squawk. So this mentality definitely is prevalent. A single pilot trying to do this while shifting between instruments and also pick up ground reference and its pretty easy to see how you could give yourself spatial D.

 

[squorch2]

it was pretty common to brief that if you went IIMC you would do a 180 and fly for 30 seconds,

sidebar - this mentality is crap and needs to die. If you are IIMC and below MSA you are in an emergency right then and there. The turn and 30 second timer just makes it worse.

 

[xmid]

i know absolutely nothing about helos (except something about a Jesus nut) . i was thinking that it is orders of magnitude easier to avoid IMC in a helo than in a fixed wing. for instance, flying into a box canyon with a low ceiling is often fatal in a fixed wing, but in a helo i would assume you can slow down and descend very low, and even land rather than fly into the soup - but maybe that is a bad assumption in this type of scenario

As Jim pointed out, things can get squirrelly if you slow down too much in IMC. We had a new HAC flying plane guard for CQ's one day and after recovering the jets, the carrier drove in to a fog bank. His first CCA he broke out about 30 feet over a chained rhino at about 80 knots, and couldn't get it slowed down to land. Me and another senior HAC ran down to CATC to try to help him out. The next approach he over compensated by slowing down too much and actually started flying backwards directly behind the boat. He felt like he was flying forward. The AW's called out that they were taking a lot of salt spray in the back and the tail was dangerously low to the water. The Boss sent him to the beach.

 

[xmid]

sidebar - this mentality is crap and needs to die. If you are IIMC and below MSA you are in an emergency right then and there. The turn and 30 second timer just makes it worse.

I totally agree.

 

[Brett327]

Spatial Disorientation > Unusual Attitudes > Improper Control Inputs > CFIT

I could see a scenario where pilot enters the goo, keeps outside scan, initiates a turn to get away from rising terrain, starts descending, loses SA/orientation, and starts over controlling with cyclic, resulting in opposing VSI/airspeed peaks as oscillations get worse.

Is it really CFIT though if you've inadvertently induced an attitude/flight path that may be unrecoverable given the surrounding terrain? I may be splitting hairs, but if that is what happened, then I'd have a hard time calling that "controlled."