Interesting Teterboro crash report

[SeenItAll]

Excerpt from The New York Times on preliminary NTSB reports concerning a Canadair CL-600 crash at Teterboro last February 2.

WASHINGTON, Oct. 31 - The corporate jet that went off the end of a runway at Teterboro Airport on Feb. 2, overweight and imbalanced, was tantalizingly close to being able to take off, according to documents released Monday. The crash was made worse, however, because the pilots delayed using the thrust reversers, according to investigators.
A sheaf of reports released by the National Transportation Safety Board found flaws in split-second decision-making in the New Jersey airport crash, which badly injured both the pilots and two men in a sedan that the plane hit after crashing through the airport fence,.
The reports also identified a variety of problems with the training of both pilots and of the "cabin aide," a 22-year-old woman who had previously worked as a model and as a "VIP waitress." Her brief training did not include handling a fire extinguisher or learning how to instruct passengers to assume a braced position before a crash, the reports said.

Complete story at: http://www.nytimes.com/2005/11/01/politics/01teterboro.html

[PaperTiger]

The report said the crew should have used "actual passenger weights."Yeah, right. You're going to ask the CEO of a F500 company how much he weighs ? :*

[tom de luxe]

Yeah, right. You're going to ask the CEO of a F500 company how much he weighs ?
"Is that in lbs or in US$?" :E

[Jetstream Rider]

Why on earth not? He's not God, all he does is move money around to certain rules - we move people around to certain rules and one of them is we have to know the weight. Don't like it, get off the aircraft.

That's not to say you can't use standard weights in the right circumstances. Have not read the report so cannot comment on whether this was one of those circumstances or not.

[NZLeardriver]

I believe the Platinum Ops Spec says they must use actual weights, and not standard or estimated.

[pigboat]

In a past issue of Business & Commercial Aviation there was an article about two rejected take-offs in SFO involving a similar aircraft. Both rejections were carried out at maximum t/o weight on an 11,000 foot runway. In the first instance, the aircraft accelerated to V1 and the PF rejected when he was unable to rotate normally. The aircraft was returned to the ramp and inspected by maintenance, no faults were found and the aircraft was released for flight. The second attempt resulted in a similar occurrence, except that when the aircraft returned to the ramp the fuse plugs melted and the tires went flat. No mechanical reason could be found why the aircraft could not be rotated normally. Some smart gent decided to re-weigh the aircraft. The basic operating weight was actually 1300 lbs over the stated number so the aircraft was actually 1300 lbs overweight and the C of G exceeded the forward limits. The galley furnishings alone were over 200 lbs above the stated weight. :ooh:

[westhawk]

Interestingly, there was another previous instance at KTEB involving a CL-600. In this one, a crew attempted takeoff on the longer of the two runways but were unable to rotate. A successful abort was accomplished and the aircraft was turned over to Mx personnel. Upon inspection, no discrepancies were noted and the aircraft was returned to service. Subsequently, a second crew attempted a takeoff and were also unable to rotate and so rejected the takeoff after Vr. This time, the shorter of the two runways was used and the aircraft came to rest in the mud beyond the departure end. This time it was inspected by Bombardier and again, no discrepancies were noted and the airplane returned to service. A crew then flew it out empty with no problems.

Details here:

http://www.ntsb.gov/ntsb/brief.asp?ev_id=20040108X00033&key=1


Best regards,

Westhawk

[Huck]

Under Part 135, are operators allowed to use reverse thrust in calculating required runway lengths? Not under 121.....

[Check 6]

Huck, under 135 TR's are not part of the equation, so they do not count, same as 121.

Check 6

[westhawk]

Not a decision I'd like to be faced with while barreling down a 6,000' runway (less than half of which remains in front of you) at 250' per second and increasing. By the time "rotate" was called, back pressure applied and the lack of aircraft response noted, at least 3 or 4 seconds must have passed since the V1 call. Decision time. At least 20 or 25 kts beyond V1 but the damned nose won't lift! Continue (as you've allways been taught after V1) and hope the nose comes up? Or accept she won't fly and try to scrub off some of this speed before the inevitable impact? Decision made. Take right hand off the yoke and slam the thrust levers back while moving feet up the pedals to stomp the brakes. Another second or two has passed. You're at least 1,000' (probably more) beyond the point on the runway where V1 was reached and doing at least 150 kts. Probably less than 2,000' of runway remains in the best case. Hell of a situation.

I will be interested to read the final report. I'd like to know what the empty and loaded CG locations really were. Along with the programmed and actual trim positions, this information might be instructive. Was there a possible failure mode or interferance in the control circuit or hydraulics system which might have acted to limit elevator travel during this takeoff? As yet, these things remain unknown to me. Speculation about the possible benefits of having used reverse thrust sooner do little to address the cause of the accident. Getting the simulator to stop once on the airport after practicing several times is a nice addendum to the story. So is briefing a pre-crash "BRACE" position to the PAX! I guess we wait for more information to be released before the crux of the matter may be addressed.

Best regards,

Westhawk

[Mad (Flt) Scientist]

From Westhawk's link to the NTSB report on the earlier Teterboro overrun

The aircraft manufacturer inspected the airplane, and did not find any discrepancies pertaining to the aborted takeoff. The manufacturer also computed two weight and balance calculations for the incident takeoff. Both calculations revealed that the airplane was above the maximum gross takeoff weight, and outside the forward center-of-gravity envelope.

Technically, I'd consider the loading a "discrepancy" and there was certainly a "reason" why the plane wouldn't fly, which the summary in the earlier post doesn't quite suggest.

[westhawk]

Technically, I'd consider the loading a "discrepancy"

I agree with the intended meaning of your comment. However, it should be noted that the word "discrepancy", used in this context, would generally be understood to mean a problem with the function or physical characteristics of any part or system on an aircraft. None were noted by either of the technical inspections performed by maintenance personnel. In short, no discrepancies noted = airworthy aircraft. Airworthy aircraft operated outside AFM limitations = crew actions (PIC) are cause of incident. This was the probable cause finding issued by the NTSB. It appears that since the Captain could not produce a W&B sheet and the mx personnel reported no discrepancies following their inspection, the W&B calculations performed by Bombardier were accepted as the only real evidence to consider. Since nobody was injured and the aircraft was not substantially damaged, it was only an incident not an accident. As such, NTSB did not perform a full investigation as they are doing with regard to the subsequent accident of last February.

A great deal more independently verifiable information will be available to consider in the investigation of the February accident than in the earlier incident. In the accident case, actual CG location, elevator travel limits, trim position, hydraulic system performance and myriad other details will be determined to a much higher degree of certainty than in the minimal investigation of the earlier incident. If no reason other than CG location is found to be causal in the February accident, then some operators had better get their W&B control straightened out. If you can't load your cabin full of pax without exceeding the fwd limits, then use some ballast! Also, galley supplies, manuals and heavier than standard flightcrew are often not properly accounted for in W&B determination. Because of the forward location of these items, The effect on CG location is magnified. Of course until the final report is released, we don't yet know what, if any other factors might have been at work.

Best regards,

Westhawk

[Mad (Flt) Scientist]

If no reason other than CG location is found to be causal in the February accident, then some operators had better get their W&B control straightened out.

I'd probably phrase it more strongly than that; given the apparent common factor in all the events recounted in this thread, UNLESS the W&B is actually discounted, I don't think another contributing factor, whatever that might be, should stop people having serious pause about the state of W&B control. Even if all W&B mismanagement does is degrade margins to "barely acceptable" rather than result in an unsafe condition, routinely using all the design margin for a manageable condition leaves aircraft wide open to whatever the next failure might be. Few accidents are single cause, after all, but the idea should be to try to survive as many cumulative "causes" as possible without mishap.

[westhawk]

I'd probably phrase it more strongly than that;

And I probably should have too! Originally, I was going to say something harsher, having to do with FAA enforcement, but toned it down. On reflection, perhaps the most effective solution would for the FAA POIs to encourage operators to review their W&B control methods and then conduct follow-up audits on operators who seem, in the opinion of the inspector, to have compliance or competency issues. Emphasis should be placed on the following items during review:

1) Accuracy of empty weight/CG and completion of realistic BOW worksheets. At least the crews would know they have an accurate starting point for their part of the W&B control method.

2) The use of either permanent and/or portable ballast on aircraft which may be expected to exceed W&B limits with any payload and fuel load that might reasonably be expected to be carried.

3) Crew training and checking on the use of W&B control methods. Use real scenarios that require load re-distribution to bring the CG within limits. Dovetails nicely with the subject of performance planning. (another weak area in some outfits)

The job of charter captain requires signifigant planning and anticipation of problems if you are to avoid being forced into corners by circumstances which should have been recognized. Ensuring that crews have, and know how to use the necessary tools is the least that an operator can do if they want the job to get done safely, every time. Whether they know it or not, operators count on their captains to draw the lines that won't be crossed and enforce the safety standards. The really good ones are able to solve problems and modify plans as needed and still get the job done within the constraints somehow. The best do all this without making enemies!

It occurs to me that the Challenger might be appropriately (if somewhat ironically) named! Seems to be one of those aircraft that is a little less forgiving of any "lack of capacity, carelessness or neglect" than many other popular bizjet types. Less of a problem for some than for others, I guess.

Best regards,

Westhawk

[Astra driver]

The Gulfstream II that I fly recently had it's 3 year W&B done and when I checked the new BOW I found that it had increased by approximately 940 lbs !
Digging a little deeper I noticed that the empty weight had actually been decreased by about 10 lbs; the 950 lb increase was due to accurate weighing of all the galley supplies we had on board and some rather over zealous estimating of the weight of Jepps and AFM's as well as incorrect assumption of cabin attendant weights. (our gals' are no where near 180 lbs!)
After getting together with the cabin attendant and doing some serious house cleaning we managed to reduce the BOW by 450 lbs or so. None the less it was sobering to find that what I had always thought was an accurately derived BOW was off by almost a 1,000 lbs!
At another operator that I had previously worked at, I had always known that the BOW's where way too optimistic. Operations was not pleased when, upon takikng command of the aircraft, I recalculated the BOW's to a more realistic number and reduced the full fuel payload to just 4 passengers and bags, and informed them that a seats full payload calculated with standard weights was not possible as it would be out of forward CG.

[westhawk]

Hi Astra driver. Nice to see you online. Hope all is well.

It took me a while to figure out why it ran out of up trim on final too! The one I fly now has been re-checked and found to be accurate. (especially with my favorite 100 lb. co-pilot!) 250 lbs. in the tail (shot bags and water) brings it into the CG range with a full boat (canoe?) of big boys. We must remember to move that stuff forward for the empty leg though.

Wow, a 1,000 lbs. Did the boss misplace some of his gold bars? If so, I'll bet you saw to it that they were properly disposed of!

I've been aware of operators like your former employer. Builds character. And some characters too.

See ya 'round the patch,

Westhawk