Beech 1900 article

[ultrarunner]

The AP actually wrote an intelligent article today regarding the Beech crash in CLT. It brought up some good points regarding weight, which has been mentioned here.... and that's..AVERAGE weights.

According to the paperwork, as reported, the feds determined the plane to be within 1% of the aft limit and within 100 lbs of gross weight. An experienced KA driver would have spun that elev. trim wheel up to the fwd marks.

We've got 19 pax and 31 bags. So, with this information, we know how much fuel was on board.

Lets figure that the men on board didn't come anywhere near the std 175 for winter, including carry-on. Heck, I'm pretty lean, and I JUST make that number. So, lets figure that 1/2 the men, 1/2 the woman and one kid fit the standard american weight profile of being obese. Yes, that true folks.

Being conservative, figure 210 for 1/2 the men: 1680
figure 200 for the other men, incl. carry on 1600

160 for half the woman 160
140 for the other one 140

200 lbs for the kids 200
_______

3780 for pax

What does Air Midwest allow for bag? Prly 25? Lets figure 35...ive seen these checked bags in the lines.

Baggage 1085
There's your payload 4865

Now add the fuel, and you have another estimated ramp weight.

Bow's run about 10700 or so, plus 4865 + 15565

So it's only a 70 mile flight or so, my guess is about a 700 lb burn, block to block?

For simlicity, lets figure the're tanking fuel and bring it up to mtogw....

Can someone plug this in that's a 1900 guy and see what you come up with on the CG? I wouldn't appear GW would be exceeded, but maybe not hard to go too far aft of the aft limit.

I'm just curious, as the article I previously mentioned did bring up some good points.

I suspect that it's possible the CG might have been slightly aft....using some realistic pax and bag weights, but IMO, it would have to be so far out the back as to be obvious, in order to cause this type of ANU.

If I recall in my previous life, the local GADO would give waivers to operate at 20% or more above certificated togw and several inched aft of the aft cg limit, for the purposes of atlantic ferry flights. Planes took off fine.

anyway, just some thoughts.

How about one of the 1900 experts here plug this in and see what weight and Cg location you get.

 

[KingAirer]

I dont think there is anyway that weight alone caused the crash. Being a few pounds overweight is not going to cause the airplane to nose up 52 degrees on climbout. It may have been a contributing factor, but in my opinion not the cause.

 

[CA1900]

That, and it's pretty hard to get the airplane beyond the aft limit unless you start using the cargo area rear of the net, and it's very rare that it ever gets used.

Extending the CG range is part of what all those extra fins hanging out on the tail are about. And even with the CG at the aft limit and the trim in the normal takeoff position, it's still very controllable, although you will need to push the nose down a bit. (And the manual trim is very quick and responsive.)

This plane was, at least on paper, 100 pounds underweight and forward of CG. I've flown many, many 1900s that were right at max gross weight, and it's not a problem at all. (And this is 19 people with big bags traveling to northern Maine in the middle of winter. And I'm sure they were all 175 pounds. Uh-huh. There isn't the slightest hint that it's anywhere near the edge of controllability or performance when it's fully loaded.

I'm curious what the NTSB will find, but I just don't see weight & CG being a significant factor in this accident.

 

[ultrarunner]

I agree....my thought is the cg limit was likely more aft than the paperwork indicated. How far is anyones guess, but was just wondering how far aft it may have been using some 'real world' weights.

But even several inches aft should not cause what happened, especially if trimmed 'nose down', and the crew knew the plane was at or near the aft limit and accounted for such during rotation. Which was likely the case with the exchange that occured regarding the loading.

On a related note, and this is going back a bunch of years, but back in my King Air days, an AD or SB came out which required that alingment marks be painted on the bottom of the elevator trim tabs and a corresponding alingment mark on the elevator actuator rod. A required item on the preflight was to position the elevator trim wheel at 'zero', then on the walk-around verify that the alingment marks lined up. This made sure that if some bozo didn't put it back together correctly, the crew would know.

Do the strech KA's like the 350 and 1900 have this setup?

 

[TriStar_drvr]

I read an article on CNN.com that said that the passenger load consisted of 16 men, two women, and one child. I believe the number of checked bags was 31. The topic of the article is that the assumed weights are probably below average. It said that Air Midwest used 175 pounds for the average winter pax (including carryon baggage) and 25 pounds for the average checked bag. I think these are standard for most carriers.

I flew 19 pax airplanes for several years, and used to watch rampers struggle to load those supposed 25 pound bags on the airplane. I 've also seen the size of some of those standard 175 pound passengers that get on the airplane. Here are my own estimates of what could have been on the Air Midwest flight.

The official paperwork:
19 pax X 175 = 3325
31 bags X 25 = 775
Total "official" payload = 4100

My estimate:
16 men X 200 = 3200
2 women X 140 = 280
1 child X 100 = 100
31 bags X 35 = 1085
Total realistic estimated payload = 4665

I now work for an airline that does a lot of charter work for the military. Whenever we carry troops we use actual weights. It's interesting to note that the actual weights are always significantly higher than what the estimated weight would be had we used the assumed weights for the same number of pax and bags.

Even if the investigation doesn't find that aircraft loading was a contributing cause to this accident, I wouldn't be suprised to see the NTSB recommend that changes be made to the use of assumed weights for pax and bags.

If this is the case, you can bet that the airlines will be screaming when they find out that because their pax ate one too many Big Macs, their 19 pax aircraft is now limited to 17 or 18 passengers.

 

[chperplt]

We just started an FAA required 7 day test program. All pax and bags are weighed and then logged. So far, actual weights have been 3-5% higher than "standard" weights. This is only after 2 days (5-6) flights..

Not sure if any procedure will actually change when they analyze this info..

 

[Salty Dog]

Just read a recent article on how fat we Americans are getting. Was actually surprised the wts were so low:

Avg Dude: 180 lbs
Avg Chick: 150 lbs

Considering that more than 50% of the American population is chick, (so much for their vaunted minority status) it would appear that the 170 lb avg pax is a little conservative.

Not that I immediatly believed that after strolling around town and noting how many disgusting lard-a$$es are out there, but dem's the latest facts. Must be that I just don't notice the little twerpy guys (tom cruise, etc.) pulling that bell curve to the left.

 

[dmspilot00]

I am kind of surprised at this "one-size-fits-all" approach to average weights. You would think that they would actually do a little research before using such an arbitrary number. For example I'm sure they would get better estimates if they used the average weight of a person traveling a particular route (the average weight of a passenger on a NY->Chicago may be significantly different than someone on a Seattle->Vegas flight).

If you want exact, why not have passengers stand on a scale at the gate or check-in and have a computer transmit the weight to dispatch (no one ever has to know who weighs what)? And it wouldn't be very difficult to automatically weigh checked luggage...

 

[Dieterly]

Most companies will restrict it's use to crew bags only.

How many have you worked for?

 

[skyslug]

DMSpilot00, you talked about weighing pax before they get on a plane. While I was working ramp in IFP we watched the pax who were boarding a 737 all get weighed, their bags weighed and then carefully loaded on the plane. Several folks didn't make it. IFP is rather toasty (Laughlin, NV) and if I recall the plane was an older 737 for Viscount (scheduled charter service "sponsered" by several of the casinos). They did this all the time to maximize the "casino cash" flow.

We watched this plane take off and use every inch of the runway - rather creepy to watch. That baby was climbing soooo slowly I think a wee little 150 would have out climbed it.

 

[jetdriven]

AMW uses an index and estimated weight for the manifest.

175 Lbs for pax (including carryons) in winter and 25 lbs for bags.
Actual fuel weight. Regardless of the ACTUAL weight she was legal to depart, and in the end thats what counts.

The pitch jammed right when they rotated and they could not push the yoke forward. thats what kiled them.

 

[enigma]

I am kind of surprised at this "one-size-fits-all" approach to average weights. You would think that they would actually do a little research before using such an arbitrary number. For example I'm sure they would get better estimates if they used the average weight of a person traveling a particular route (the average weight of a passenger on a NY->Chicago may be significantly different than someone on a Seattle->Vegas flight).

If you want exact, why not have passengers stand on a scale at the gate or check-in and have a computer transmit the weight to dispatch (no one ever has to know who weighs what)? And it wouldn't be very difficult to automatically weigh checked luggage...

Actually, the "one size fits all" program came from decades of weighing bags and pax. Believe it or not, the Feds do really try to maintain an acceptable level of safety. As Chprpilot said, they are doing a test program and the actuals are coming very close to the average weights. One of my previous employers had to weight bags to satisfy our POI that FAA standard weights were adequate, and we found the average weights to be almost exact. I think that they might want to use a slightly higher average on a small plane because the effect of one subject who was way outside the curve would affect a small plane much more than say a 767, but the system is actually time tested and fairly safe.

Yes, I too think that we probably have the technology to improve the system, and this accident may be the catalyst for developing such a system; but I'd be VERY surprise to find that either weight or aft CG caused this accident.

regards,
8N

 

[N215CJ]

Jet Driven thank you for your post...
God all the speculation and from professionals...If you do not agree with the index method go petition the FAA, Until then that is the method used at AMW. I too have been on a big jet that used up all and I mean ALL the runway at Jeddah in Saudi Arabia and real weights were used there it was the pilgrimage. JT8D-17 had three.... we came in way under MTOW but still used up a bunch of real estate..
I would venture a guess that it was control surface failure AND NOT a weight and balance problem
again Thanks JetDriven
...my 2 cents

 

[mar]

Average bag weights suck

I agree. We probably shouldn't be speculating and I won't but it's human nature. That's one way people cope with things they perceive to be out of their control.

And speaking of things out of our control: Average bags weights on an airplane the size of a 1900 or Metroliner (for example) is a complete sham.

I flew the Metro for three years and after a couple really bad loads I complained to the company. They told me the average weight thing was signed off by the FAA and besides that, the weights are really close.

I don't believe it.

If one good thing comes from this accident I hope it's the elimination of average bag weights on "commuter" sized airplanes. As my esteemed fellow poster Enigma commented, it may work fine for larger airplanes that can absorb the occasional spike in the weight but it's inappropriate for smaller airplanes.

I'm on the record and I'm out.
Peace.

 

[ALPO]

My first thought after seeing the reports was C.G. This crash is completely consistent with that. I'm sure a lote of you guys have a lot beech time and have never had a problem, but you wouldn't be here today if you did. Who knows how much weight was in the back and once the center of lift crosses the CG (which would happen at high loadfactor and slow airspeed, right at liftoff) the plane pitches straight up with the elevator completley usesless.

 

[jetflyer]

Jammed Elevator

Do you guys that are speculating C.G. and weight remember that the plane had MAINTENANCE on the Trim tab 3 days before the crash!!!??????? HMMMMMMM and that the flight data recorder said that the elevator had been moving eratically for the previous seven flights out of maintenance.

The FAA will find that the elevator jammed, cable slipped a pulley, etc. Most likely though the truth will never be known.

An aft c.g. or being overweight might just be pure coincidence.

 

[jetdriven]

the elevator donwspring wasnt connected and the cable was off the pulley. explain how weight and balance caused that.

Did you know these airplanes have 35,000 hours some of them? Mesa has had 22 years without a crash and AMW has had 37 years without a fatality?

it was not weight and balance. it was only incidnetal.

 

[jetflyer]

Jetdriven,

I agree with you that it was something like the elevator downspring not being connected.

But do you know for sure this is what it was, or are you speculating?

Jet

p.s.
There's no way possible an aft c.g. can't be overcome by pushing forward on an "OPERABLE"<-----KEY WORD controle yoke. At most the plane would be longitudinally unstable and look like a dolphin jumping in and out of water. This plane didn't look like that at all, it went straight up.

 

[ceo_of_the_sofa]

Now they want to weigh the bags...

As per CNN

Read all about it

 

[Beechball]

Jet Flyer,

Look at the accident that occured about 7 years ago in Miami when the cargo of a Fine Air DC-8 shifted on takeoff. The DC-8 went nose up to an extreme deck angle and did a tail slide onto Main St. How come they didn't recover based on your assumption?

For those that fly the 1900, you will probably agree with me that with a full load of people and bags, the aircraft is already tail heavy requiring almost neutral "0" elevator trim to keep it from jumping off the runway. Couple this with large people sitting Row 7 and aft and heavy bags....anything's possible.

Just remember when you guys are speculating....WE WEREN'T THERE!!! The only two things that survived to tell a story are the CVR and the FDR...neither of which we are privy to...so until the actual transcript and data are made public....IT'S ALL SPECULATION!!