Posted on 05/12/2009 11:59:57 AM PDT by ArmstedFragg
WASHINGTON (Dow Jones)--The pilots of the Continental Connection turboprop that crashed in February near Buffalo N.Y., rushed through mandatory checklists in a matter of seconds, but spent almost the entire 59-minute flight from Newark, N.J., bantering about personal issues, job goals and the theoretical hazards of ice accumulation during winter flying, according to the cockpit recorder transcript released Tuesday by federal investigators.
(Excerpt) Read more at online.wsj.com ...
Oddly, the NTSB’s web site is down.
What were/are the gender/race of the aircrew? Affirmative action anyone.
One each, both anglo. The female co-pilot actually had more time in the aircraft than the first seat.
I don’t really think so. There are plenty of M clowns to go around.
Pretty near zero I'd say.
Sadly, the co-pilot actually speaks about desiring more winter flying time because she has no experience with ice and deicing and protocols. She also ominously notes the accumulation of ice on the surfaces. The pilot says he is comfortable with it.
“”Stalling at 1200 feet at 180 knots, what are the odds of recovery?”’
“Pretty near zero I’d say.”
Especially when you pull back on the stick to override the anti-stall system.
Sad, how many people died as a result of this.
Near as I can figure, the anti-stall system would have taken them into the ground about 20 seconds after it activated so I’d be interested in finding out whether any Freepers have successful experience in such a situation. Seems to me it’d be a squeaker at best.
Not good. The key is to avoid the icing conditions.
Icing stalls occur because the ice disrupts the normal airflow around the wing. Unless you get the ice off there can be no recovery no matter the altitude or airspeed.
Particularly when you over ride the stick pusher and pull up as this untrained captain did. Diving for speed could have saved them. The airplane was telling him this. He fraught the stick pusher and pulled up. Pulled up and killed them all.
Depends I guess. But if the plane went into a spin, then not much chance.
Prayers for Rebecca
Long, long time since I flew, but isn’t when you are in stall situation, the stall occurs because of lack of airspeed, right? Air speed is king (or at least air flow over/under the wing)!
The only two things you can do is (1) nose down, and/or (2) throttle up. If you can’t throttle up enough, you have to nose down.
At 1,200, that still doesn’t seem to leave you enough time to gain the airspeed you need, but at least it seems you pull up and level off and land hard, hot, better solution than crashing?
I am asking, I know there will be far more knowledgeable and experienced people than me.
I had to be at a minimum of 3000’ to practice stalls in a Piper Cherokee. Make it worse by spinning and you lose about 1000’ with each rotation. 1200’ with the Colgan plane that he probably also spun? I doubt he had a chance. The Colgan plane was on the ground oriented away from the approach vector. Nose down then apply power and try to level off above stall speed otherwise you lose control. If too low maybe you’ll develop enough speed and lift to just miss the ground or at least not hit so hard. Power for altitude, pitch for speed.
He was lower than that. Altitudes in ATC are measure above mean sea level. The field elevation at Buffalo International Airport is 728 feet above mean sea level. That means the aircraft was less than 500 feet above the ground when it stalled.
Zero, if you pull back on the stick.
With 500 feet of altitude, would the plane have gained enough airspeed as it pitched downward when the stick pusher initiated, to do anything?
It almost seems like the pilot instinctively pulled up knowing that there was so little room left to ground.
1200 ft vs. 500 feet is a significant difference in this situation. At 500 feet, there is not much chance for any other outcome, it would seem.
The NTSB site has the FDR printout available which provides a pretty accurate picture. Interestingly enough, the pusher activated, but there was no down pitch. They’re flying at a slight decent, then there’s an abrupt upward movement. He must have reacted very quickly.
About the same as my chance of dying a billionaire.
Well just some random thoughts:
I have not flown the DHC-8-400, but I have thousands of hours in the DHC-8-100s/200s/300s. It’s one of the best turboprop designs ever.
Ice isn’t the big scary monster the media makes it out to be: these aircraft are well equipped to shed ice that does stick to the leading edges of the wings. Heating systems on the windshield and propellers retard formation of everything except the heavier stuff. Turning off the autopilot, flying faster than the recommended ice penetration speed, and getting out of it if aircraft performance degrades are all tools the crew can be. The Dash 8 was built by DeHavallind in Canada; production is now handled by Bombardier.
I have not flown at Colgan; I know people that have/do.
The NTSB is, as usual, spitting in the eye of the FAA. They love to harp on crew rest, and crew training. The airlines have heaps of paperwork to prove that they are complying with the standards set forth by the FAA. Airlines, and their lobbyists, resist any increase in regulation of duty times for crew members. Otherwise, they’d have to hire and the already razor thin margins become even smaller.
There are really good pilots and... some not so good pilots at every operation. Colgan’s not exactly the greatest place to work: the pay tends to be very low for a measurable amount of time. Most airlines will run you into the ground on your duty times if they can. Pilots are little more than a cog in the wheel in today’s industry.
The stall warning system in that aircraft is three-fold really: You have angle-of-attack indicators (AOAs) on each wing that constantly measure, in layman’s terms, how close to a stall the aircraft is. The higher the angle of attack, the less margin you have between the aircraft’s speed through the air and it’s stall speed. The second system is the STALL SHAKER. When the AOA reaches a critical point (5 knots or so above stall but it varies) the shaker activates. The appropriate response is to reduce the aircraft’s AOA by (1) adding power, and (2) lowering the nose. The last part of the system is the STICK PUSHER. If #2 doesn’t get anyone’s attention, and the aircraft is on the verge of stalling, the pusher will bring the control column down (forward) in an effort to reduce the aircraft’s angle of attack. The amount of force varies, but it is in the neighborhood of 50 pounds.
That aircraft is relatively heavy; any throttle application won’t instantaneously result in a change in aircraft speed given that they were near max capacity.
You don’t train for full stall recovery – the emphasis is on airspeed management and stall recognition/avoidance. For years there has been discussion about “upset” training for airline pilots (ie dealing with situations where you find yourself in an unusual attitude [UPSIDE DOWN]), but nothing formal has ever been implemented.
I’m sorry all these people died. You’ve got to pay attention all the time in this business, and even then sometimes you don’t come home.
You’re right about the NTSB vs FAA battle. The documents available on the NTSB website include a lot of interviews that seem to be emphasizing the crew rest and crew training issues. The pilot had a 7am call that day then ended up sitting around until the night. Similar with first officer, who’d commuted the previous night, missed a flight and arrived late, then spent half the day napping in the lounge.
The documents include the transcript of the cockpit voice recorder, which indicates there was no “sterile cockpit” atmosphere below 1000 feet. Prior to that, the co-pilot had missed/misunderstood a couple of radio calls because they were chatting. So, I think they’re looking to build a case in the tiredness/inattention area.
There’s also some plots of the actual output of the flight data recorder, and you can see the point the stick shaker activated and the pusher activated, which were the same moment. The nose then immediately pitches up. You can then see the throttle command, which was almost instantaneous, and then count the seconds before the speed began increasing. It’s pretty informative. They were on a normal approach pattern, and she had just deployed the flaps when it happened. The attitude plot shows there was no down response to the pusher, possibly because he’d pulled back on the yoke at about the same instant. She retracted flaps almost immediately. I’m sure if you look at them, you’ll see a lot more in the way the various indicators interacted than I (in my lay ignorance) did. If the NTSB.gov web site ever gets fixed, you’ll find them attached to the agenda for yesterday’s hearing.
One item that points a different direction, is an interview with another pilot who was flying the same aircraft type in about the same circumstance, with the icing speed offset dialed in when she got a sudden shaker and pusher activation. She just put a little power to it, and continued the landing without incident. She had a check pilot with her who NS’d her for speed, but there may be some indication there that there’s a bit of a hardware trap there that’ll emerge over time.
Thanks for the educational commentary!
I read a quote from someone today who I think was the head of training at the airline. He said that they should have been able to recover had they taken proper action.
From what I read a couple of days ago, icing had nothing to do with the crash in actuality. The flight crew programmed the wrong approach speed into the flight computer, and when the plane stalled, the captain responded incorrectly.
A couple of specifics from the FDR. Angle of attack had been climbing gradually for about 20 seconds, was at 10 degrees. Airspeed 140, ground speed 110. Radio altimeter was 1600. Flaps were at 5 going to 10. Gear was down.
The ice warning activated, then the shaker activated 2 seconds later, and autopilot shut off at the same time. Pressure on the column was immediate, and the nose began to come up one second after that. Pusher activated 3 seconds after the pitch change started, shut off five seconds later, then reactivated 6 seconds later. He applied immediate power but it’s hard to determine airspeed, because the rolls affected the sensors and they’re bouncing all over the place, but they appear to indicate slowing to about 100, then seem to show a gradual increase to around 150. The ground speed shows below 100 and as low as sixties in the middle of the rolls. The rolls were -45, +105, -35, +100, coming back to 25 all in a period of 23 seconds. Pitch went up 30, then back level, a couple of bumps, then down 45, then a partial recovery to 30. AOA readings started cycling immediately, and reached 40 at a couple of points during the rolls.
So, it appears the pusher didn’t activate before he started that sudden pitch change, probably in response to the shaker, which is consistent with the two step warning process you outlined, and explains why the pusher never actually pushed the nose down.
The radio altimeter shows him at 1600 when the stall shaker activated. The pressure altimeter, as you indicate, has him at 2400 because it’s not taking the altitude of the field into consideration.
??? Just wondering, where did you get the info about the ice warning activating 2 seconds before the stick shaker?
Take a look at
http://www.ntsb.gov/Dockets/Aviation/DCA09MA027/417236.pdf
Page 15. Shakers are at the top, ice detection’s half way down the page.
The entire document’s eerily detailed. You can see the last 110 seconds in moment to moment detail.
Thanks, I wasn’t sure what the aircraft’s altitude was at the time of the accident.
A very detailed display of recorded parameters, certainly.
If anything the fact that ice was detected on a probe only a few seconds before the stick shaker reinforces the theory that icing had nothing (directly) to do with this accident. The anti-ice and de-ice systems were already selected on, and were on continuously from about 11 minutes after takeoff. All they had to do was fly through a cloud for the probe to pick up icing.
I say directly since with the anti/de-icing systems on the stall warning comes a few knots sooner, as a safety feature.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.