Post by thread:[OT] Airline Safety (was: TWA 800 and Airline Safe

'[OT] Airline Safety (was: TWA 800 and Airline Safe'

On Sep 25, 2004, at 4:55 AM, Russell McMahon wrote:

>> Flying through it during an approach in a jet (like the Delta flight 

>> in Dallas) can be deadly because right at the time you need the power 

>> the turbines are spun down

>

> I recall an account of the situation when "wind shear" was first being 

> recognised after a commercial crash. The results from the flight 

> recorder was used to programme a simulator with equivalent conditions. 

> Experienced pilots were asked to fly a simulator approach and only 

> told "save the aircraft at all costs, land if you can". Thus warned 

> that something "unusual" was going to happen, but with no warning 

> about what it was, about 80% crashed.

>

Hi Russell, I wondered if you'd jump in here.  ;-)  How's your flying 

going?

That was the Delta crash - same one.  The microburst that hit the 

aircraft during final approach caused speed excursions in excess of 40 

knots if I remember correctly.  One of the major indications that this 

is happening (without outside wind references) is major changes in 

airspeed (and groundspeed if you have something like GPS on board) 

during the approach with no changes in pitch or power (angle of 

attack).

Crews now train to immediately engage TOGA (Takeoff-Go Around) if the 

aircraft is equipped and execute a go-around during wind-shear events, 

and most of the data that supports that procedural change can be tied 

directly back to the Delta crash in Dallas.

The only solace for me is that statistically now that I've had it 

happen once to me directly, I'm not statistically likely to have it 

happen again.  On the other hand, Dr. Fujita (his name is where the 

name of the "F-scale" like "F-5 Tornado" comes from) did much of his 

study for his insightful wind-shear, microburst, and severe weather 

studies about 20 miles from my home in an open field.  That open field 

is less than a mile from where Denver International Airport sits today. 

  Gotta love bureaucrats - picked a lovely place for an airport!  Oh, 

that's also why DIA gets all of the high-tech wind-shear warning 

gadgets very early in their test-cycles too!  Modifications to 

controller procedures now include required callouts on the tower's 

arrival and departure frequencies of wind-shear events as measured by 

those tools.  You hear "Attention all aircraft: Wind Shear Alert in 

progress.  Wind at north airport boundary 350 @ 10, Mid-runway 270 @ 

15..." etc, quite often when listening to DIA's tower.  The engineer 

that created those tools for the controllers has probably saved a few 

lives.

You guys are making me want to get away from this computer and go over 

to APA for a little zooooomin'!   (Keep it up!  Heh!)  I love flying 

from an airport where the ATIS includes "Check Density Altitude" on hot 

days!  :-)

Speaking of TOGA, I was reading in ASRS about a number of incidents 

where the TOGA switch was inadvertently toggled during taxi 

operations... whoooooosh!  Heh.  Amazing how something designed to take 

workload off the pilot like TOGA, where one just pushes a button and 

proper takeoff power is set automagically, can also be a royal pain in 

the hind-end when not wanted.

Hmmm... you guys have me wondering if any of the current crop of PC 

flight sims can simulate a windshear or even cooler, a microburst 

event.  Probably not, but that'd be fun to code up the WX data to have 

people try to shoot an approach in one in a light aircraft.  Could be 

used as an eye-opener for new instrument pilots.

Nate

_______________________________________________

http://www.piclist.com

View/change your membership options at

http://mailman.mit.edu/mailman/listinfo/piclist