Flight 3407 | What happend?

You can ignore the occasional errant eyewitness account. The problem comes when many witnesses report the same thing. The results of the neighborhood canvas by the FBI was that a large majority of the people who either saw or heard the plane said it didn't sound right.

www.airlinepilotforums.com...
A man who took photos at the site is talking with CNN over the phone. Says he talked to 9 adults who witnessed the crash and ALL said the aircraft was on fire before it hit the ground.

www.flyertalk.com...
A friend of a friend lives across the street from the crash site and saw the crash. He said the plane was on fire before it hit the ground.

lockportjournal.com...
Lockport Union-Sun & Journal contributing photographer Stephen Wallace was on the scene Thursday night and described a hole in the ground where the plane hit one or more houses that were leveled by the impact. He said he talked to seven eyewitnesses who told him that the plane was on fire before it crashed.

reply to post by starviego


What you need is facts..

I've noticed most posts are many layers of opinions and assumptions wrapped around a thin slice of fact..
That's a recipe for disinfo...

I agree a witness is not neccessarily credible, but when many share the same story it's a different scenario..
You are correct..You don't need to be a 40 year pilot to know what you saw and heard..

Pursuing the idea of a plane in mechanical trouble, one scenario is a failure in the propellor control unit(PCU), whereby the prop pitch flattens out to a very low angle. This would indeed create a combination of asymmetric drag and deficiency of lift over the affected wing, and would result in an uncommanded roll.

One of things that can lead to a failure in the PCU is a condition called propellor overspeeding, in which the propellor races out of control. Failure to immediately feather the prop and shut the engine down could easily lead to a crash, especially at that altitude.

Was there evidence of prop overspeed?

NTSB report of ASS flight 2311 on 4-5-91 pg21(an Embrear 120 turboprop aircraft similar to the Dash 8)
Over-speed experience with the Pratt&Whitney118 has indicated that if an engine has been subjected to propeller speeds greater than about 120 percent or maximum authorized speed, rub marks will occur on the power turbine shaft and the interior of the high pressure rotor shaft.

Well the Dash 8 is Powered by Pratt&Whitney150A engines, but if the symptoms are similar in these engine types, we find the same sort of damage on the crashed plane:

417219
No 1 engine-
Powerplant Group field notes
pg8of23
The outer diameter of the PT(power turbine) shaft exhibited circumferential rub mark from the fractured end to almost the shoulder of the shaft diameter changes.

And there's your evidence for mechanical problems.

reply to post by starviego


First of all....where is the source, for that post? (Because it looks a lot like it was a copy/paste).

Second, from the source (I assume) they said in part (and misspelled):

....(an Embrear 120 turboprop aircraft similar to the Dash 8)....

The Embraer 120 is nothing at all "similar" to a De Havilland Dash 8!! Unless you want to say,
"they both have two engines, and are powered by turboprop engines." And, they are both airplanes.

Embraer (EMB) 120:

[atsimg]http://files.abovetopsecret.com/images/member/81e0592f1fe3.jpg[/atsimg]


De Havilland (now Bombardier) DHC-8-Q400:

[atsimg]http://files.abovetopsecret.com/images/member/0fe5625a74a6.jpg[/atsimg]



(EMB 120):

Length: 20.00 m (65 ft 7½ in)

Wingspan: 19.78 m (64 ft 10¾ in)

Height: 6.35 m (20 ft 10 in)
......

Max takeoff weight: 11,500 kg (25,353 lb)

Powerplant: 2× Pratt & Whitney Canada PW118/118A/118B turboprops, 1,340 kW (1,800 shp) each ...

en.wikipedia.org...

Length overall: 32.84 m (107 ft 9 in)

Wingspan: 28.42 m (93 ft 3 in)

Height overall: 8.34 m (27 ft 5 in)
......

Maximum takeoff weight: 29,257 kg (64,500 lb)

Engines: Two Pratt and Whitney Canada Corp. PW150A

www.q400nextgen.com...

And, en.wikipedia.org...


The engines/propeller combinations are quite different, too. Yes, the basic engines are based on a Pratt/Whitney design....the PW-150 is just a "larger, beefier more horsepower" variant of the entire PW100 "series" of engines.

PW 150A

versus the

PW 118A


The propellers on the Dash-8 Q400 are SIX-bladed, built by GE, under the "Dowty" trade name. However, "GE" is only the "parent company", having acquired Dowty Rotol at some point. Dowty is a long-established propeller manufacturer:
en.wikipedia.org...

and, found this informative lnk:

www.geaviationsystems.com...

The EMB-120 propellers are built by Hamilton-Standard (also a long-established propeller manufacturer, BTW):
en.wikipedia.org...


NOW...what was your source, again? Oh, and...where in the NTSB report, the DFDR and CVR are any indications of the propellers causing a problem before the accident sequence started?

(I call the "start" of the accident sequence the point where control of the airplane was lost. As I said earlier, during the unusual attitudes the sort of forces encountered certainly could have caused the propellers to suffer mechanical damage...and even, perhaps, would have resulted in the presence of flames. BTW, "flames" from a turbine engine does NOT mean it is "on fire". The way an engine works means, there is a fire INSIDE all the time....visible flames can, under certain circumstances, be seen to emit from the exhaust system. A phenomenon called "compressor stall" will cause this, for one. Bad/disrupted airflow into the intakes, for example....).


Oh, and BTW: How does any (IF it is even found to be true) mechanical failure in the propellor or enigne fit in to this "conspiracy"?? Wasn't the original point of this thread to allege some sort of "hit" on the 9/11 widow??

You may as well claim it was a "hit" on the off-duty Colgan Air Captain who was riding as a passenger, in the cabin!!!!

It needs to be remembered that the very first indications(before censorship could be imposed) pointed to mechanical problems:

www.buffalonews.com...
(Erie County Executive Chris)Collins said that .... crew members had reported mechanical problems as they approached Buffalo Niagara International Airport.

More cites pointing to a problem with propeller 'overspeed' as the cause of the upset:

A pilot experienced on this type posted this(about problems with the Q400), before the Colgan3407 crash:
www.pprune.org...
There has been, and contiue to be, problems with just about any system on this A/C....More interesting, we have had more than a few prop overspeeds in the last year - This results in shutting the engine down (in the case where you are able to regain some control with the propspeed) which is obviously not always a desirable thing to do in the Scandinavian winters !
Very, very interesting aircraft indeed, and we are way beyond the "infant illness" period ....


Other cites:

www.flightglobal.com...
SHK found SAS Q400 pilots had experienced six propeller overspeed incidents in the preceding two years...

The Kalmar Incident
4-6-06
The crew of a SAS Dash 8 Q400 nearly lost control of their aircraft on approach to Kalmar's runway 16, when the right hand engine suffered a propeller overspeed. The commander decided to leave the engine in flight idle instead of shutting the engine off and feathering the prop. This caused the prop to still remain perpendicular to the airflow and produce a lot of drag, so that the left hand engine had to compensate producing power beyond the maximum permitted. The approach was unstable and very low.


Anyway for such a mysterious accident, it appears the investigators were in a hurry to make it go away:

en.wikipedia.org...
On February 2, 2010, the NTSB adopted its final report into the accident. This was the first time in 15 years that a report had been adopted by the NTSB in less than a year from the date of the accident. It concluded that the cause of the accident was pilot error.

More confirmation that flt 3407 had mechanical issues, from the wife of one of the victims:

www.facebook.com...#!/groups/311338878882815/320186051331431/?notif_t=group_activity
Jennifer West's husband called her from the plane that night, saying they were fixing the plane, to date..no records have been produced.

No where in the NTSB documents is there any evidence that they talked to the mechanics who serviced the plane before it took off. I'll bet they were working on the engines.