washingtonflyer
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Weight/balance Issues On Regional Craft?

Thu Sep 26, 2013 6:26 pm

Had two interesting weight/balance incidents yesterday on a trip.

First was a Q400 hop from DCA-EWR. Flight was not more than 1/2 full. Three passengers from the front (rows 6-8) had to move back to rows 12-15. Later in the day...

On a quite full CRJ-200 (booked 48/50) two passengers had to move from the front 3C and 3D to the back - one to row 8 (the exit) and one to row 12.

How sensitive are these regional aircraft to weight/balance given that the Q400 seems (IMHO) to be a decent sized plane, and the CRJ was booked to nearly full anyhow?



[Edited 2013-09-26 12:25:18]
 
lhcvg
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RE: Weight/balance Issues On Regional Craft?

Thu Sep 26, 2013 7:17 pm

Anecdotally (from a friend who used to be an OH ramper), RJs can be VERY sensitive to W&B issues. Part of the issue is that each person in this example is 2% of the theoretical total pax weight load, instead of say .5% on a 200-pax plane. So yes that's definitely an issue for small planes.
 
PGNCS
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RE: Weight/balance Issues On Regional Craft?

Fri Sep 27, 2013 11:05 pm

Quoting LHCVG (Reply 1):
Anecdotally (from a friend who used to be an OH ramper), RJs can be VERY sensitive to W&B issues.

Agreed. Speaking as a (would be) jumpseater that has been left behind due to balance issues by 50 seat CRJ's more times than I'd like to remember, potentially very sensitive.
 
Alias1024
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RE: Weight/balance Issues On Regional Craft?

Sat Sep 28, 2013 2:40 am

The CRJ-200 can be a pain when it comes to weight and balance. It is usually no big deal where the people are seated when it is under about 40 passengers. It's only when it is nearly full that you often have to make sure the empty seats are toward the front. The CG envelope narrows considerably as the plane gets heavier. That of course also depends on how many bags we have in the cargo bin. Lots of bags and we're ok. Only a few, like often happens on routes with lots of business travellers on day trips, and people are going to have to move. May even need ballast in the cargo bin.

When we are full with someone in the torture chair, oops, I mean jump seat, ballast is more likely than not, again depending on the bag count in the cargo area.
It is a mistake to think you can solve any major problems with just potatoes.
 
Goldenshield
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RE: Weight/balance Issues On Regional Craft?

Sat Sep 28, 2013 3:11 am

Quoting PGNCS (Reply 2):
Agreed. Speaking as a (would be) jumpseater that has been left behind due to balance issues by 50 seat CRJ's more times than I'd like to remember, potentially very sensitive.

A nose-heavy plane, plus jumper a long arm ahead of CG is bad deal if the ramp can't find, or doesn't have, 250-300 lbs of ballast to offset it. I much prefer the -700 and -900 better. They're much less sensitive.
Two all beef patties, special sauce, lettuce, cheese, pickles, onions on a sesame seed bun.
 
N353SK
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RE: Weight/balance Issues On Regional Craft?

Sat Sep 28, 2013 4:50 am

The problem is that the cargo bin is all the way aft instead of spread out underneath the entire passenger compartment. This means that too many or too few bag will cause a massive center of gravity shift.
 
MSJYOP28Apilot
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RE: Weight/balance Issues On Regional Craft?

Sun Sep 29, 2013 2:16 pm

Another issue that creates problems for the CRJ200 is that the max landing weight structurally is 47,000 lbs. Max structural takeoff weight is 53,000 lbs. The maximum zero fuel weight is 44,000 lbs. Most of the stage lengths flown by the CRJ200 are nowhere near a 6,000 lb burn. Many of the legs it does are 3,000 lbs burn or less. Thus it gets weight limited by the max landing weight.

For fuel legality purposes, the 45 min FAR reserve is about 1600-2200 lbs, depending on what measure you are using to determine 45 min FAR reserve. This is fuel that must be planned to be landed with for weight and balance. Thus you get to within 1,500-1000 lbs from max landing weight exceeded if you added max zero fuel weight and FAR reserve. If you need an alternate, you add another 500-2000 lbs depending on what kind of alternate is available and legal.

This further puts pressure on landing weight and thus your maximum allowable takeoff weight. If the dispatcher and pilot see a need for extra fuel above what is legally required, this further restricts the plane.

There are many tricks to make the weight and balance work out. If extra hold fuel or a distant alternate is the cause of the weight issue, you can see about moving the not required hold fuel to taxi fuel and burn it off on the ground or at a lower altitude, check if a closer alternate is legal to use and move to a closer alternate thus freeing up the excess fuel to be burnt off in taxi fuel or at a lower altitude. You can also check the destination weather and if the destination weather has changed since the dispatch release was sent, you can drop the alternate and move the fuel around to taxi or to enroute burnoff at a lower altitude.

The one downside to moving gas around is that it can cause CG issues. If is a short leg and you cant really get much of a burn difference flying lower then you have to burn the gas in taxi to make the weight and balance work. Moving the gas around to taxi changes the takeoff CG. Thus ballast is needed to get the plane within balance limits.

On the CRJ200, longer legs can be very tricky as well. If you file the CRJ200 above FL300 you have less of a burn and thus become limited by max landing weight. If you file lower, you are better on the max landing weight but the extra gas carried to fly lower brings up against structural MTOW. FL280-FL320 are the most optimal altitudes for the CRJ200 in terms of the weight and balance on longer legs.

As mentioned before, the CRJ200 gets nose heavy at higher weights and the cargo bin placement doesn't help the CG situation.
 
PGNCS
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RE: Weight/balance Issues On Regional Craft?

Tue Oct 01, 2013 1:20 am

Quoting Goldenshield (Reply 4):
Quoting PGNCS (Reply 2):Agreed. Speaking as a (would be) jumpseater that has been left behind due to balance issues by 50 seat CRJ's more times than I'd like to remember, potentially very sensitive.
A nose-heavy plane, plus jumper a long arm ahead of CG is bad deal if the ramp can't find, or doesn't have, 250-300 lbs of ballast to offset it. I much prefer the -700 and -900 better. They're much less sensitive.

I completely understand all of that; there have been plenty of times that the crew couldn't add ballast due to weight, but I was being general. I have had crews that just didn't want to (Captain's prerogative,) didn't have the time to get the ballast and stay on time (I get it,) or a station that couldn't find the ballast (just not my day.) It's all part of the day in the life of someone trying to commute on a CRJ. I never saw that issue on the -700/900, and was (relatively) thrilled when that showed up rather than the dreaded 50-seater. I don't have to ride on the CRJ-200 much anymore, and am thrilled to see them being relegated to the dustbin of history.
 
Goldenshield
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RE: Weight/balance Issues On Regional Craft?

Tue Oct 01, 2013 12:31 pm

Quoting PGNCS (Reply 7):
I don't have to ride on the CRJ-200 much anymore, and am thrilled to see them being relegated to the dustbin of history.

They've had their time in the lime-light, much like the Convairs, Martins, and Older DHC planes (Like the Dove and Heron.) They all fit their niche, but time and technology has moved on.
Two all beef patties, special sauce, lettuce, cheese, pickles, onions on a sesame seed bun.
 
srbmod
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RE: Weight/balance Issues On Regional Craft?

Tue Oct 01, 2013 8:04 pm

I can only recall a handful of times when I worked at ASA in which we were given a bag max on a CRJ-200 and supposedly it was so they could load extra fuel because of bad weather along the flight path. Normally, we'd run out of bin space before hitting any sort of bag max on the CRJ-200s (We'd have to leave room for the bags checked at the stairs, which were factored into the weight & balance as a separate item. The load sheets we gave to the pilots only covered passenger bags, mail, cargo and COMAT.) We'd hit the bag max on the EMB-120s (before they started to convert them to the ER standard) and often hit the bag max on most flights.
 
FlyASAGuy2005
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RE: Weight/balance Issues On Regional Craft?

Thu Oct 03, 2013 3:31 am

Quoting N353SK (Reply 5):
The problem is that the cargo bin is all the way aft instead of spread out underneath the entire passenger compartment. This means that too many or too few bag will cause a massive center of gravity shift.

Usually don't ever see much of an issue with "too many" bags as far as weight and CG. Usually too few.

I've bulked the bin out more than I can count. Anything norem of 70 bags and you're going to run out of room fast depending on how big they are and how many valet bags. I've personally loaded 90+ on a 200 excluding gate checks to OAJ. On those flights we really make a big deal out of getting as many valet bagsto remain onboard as possible.

Quoting srbmod (Reply 9):

As one of the posters pointed out. We would have a bag max a lot of times if it's a short flight AND there's extra fuel because of weather/an alternate, etc. Pretty much anything under 300 miles. All of Georgia and the surroundign states.

Only flight on the 700 that had a max was ATL-EYW. Everything else, you would bulk out the bin before you got close to your bag max. Then there's those flights to LIT that would have 120 bags checked or to GRK with about the same.
What gets measured gets done.
 
MSJYOP28Apilot
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RE: Weight/balance Issues On Regional Craft?

Thu Oct 03, 2013 7:13 pm

The biggest variable with the CRJ200 is the personal comfort level of the PIC and dispatcher. Some pilots dont want to deal with possibly taking delays for loading ballast, burning extra gas off on the runway or flying lower, and some done want to take less fuel and deal with a diversion. Pilots can get in trouble for taking extra delays for weight and balance especially if it is to take a jumpseater or non revs. It wont likely get a pilot fired but some pilots dont want to deal with getting a call from the Chief Pilot. Also, some pilots commute themselves and sitting around burning extra fuel or sitting in a diversion station behind a bunch of mainline planes means they themselves wont make it home. Pilots also can easily have their schedules screwed up by diversions and delays.

Dispatchers have their tolerances as well. Some dispatchers are min fuel types and give the legal or company minimum fuel. Other dispatchers dont want to deal with changes in weather and dont trust a closer alternate with stay legal for the FAR required time for an alternate to maintain alternate mins so they will use a farther out alternate even if legal alternates are still available closer. Some dispatchers also dont want to deal with diversions since they likely will have as many as 20 diverting at once so putting on the gas eases the workload.

Most pilots and dispatchers are in the middle. They try to work to get as much on while taking an acceptable medium on fuel.

Thus if a station by chance gets a lot of min fuel dispatchers and pilots that want to take everyone and dont care about possibly diverting then that station will see far fewer weight issues on the CRJ.

But for every airline, there are days where the closest legal alternate will be 200-300 miles away from the destination and thus for the regional airlines payload will undoubtedly need to be bumped.
 
747fan
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RE: Weight/balance Issues On Regional Craft?

Sun Oct 06, 2013 3:37 pm

ERJ-145's are similar to the CRJ-200's. If there's anything more than about 45-50 combined checked/gate-checked bags then we're usually fine. But when I have a flight with only 15-20 checked bags and 9,000lb fuel then several passengers in the first few rows are going to be moving to the back or worst-case scenario, 200lb+ of ballast is going to be necessary.
On American Eagle flights all the weight and balance is done by the ops agent using an online program (Electronic Weight and Balance System/EWBS).
 
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exFWAOONW
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RE: Weight/balance Issues On Regional Craft?

Tue Oct 08, 2013 7:08 pm

Anybody remember the SAAB 340a ?
Every Comair station had a bag cart (or several) filled with sand bags you had to load into the rear compartment if you didn't have enough checked bags. What a PITA.

IIRC, the 340b had some dorsal strakes (the only visable change I could see) that seemed to help nose-heavy handling and rarely needed ballast.
Is just me, or is flying not as much fun anymore?
 
srbmod
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RE: Weight/balance Issues On Regional Craft?

Fri Oct 11, 2013 10:18 pm

Quoting FlyASAGuy2005 (Reply 10):
As one of the posters pointed out. We would have a bag max a lot of times if it's a short flight AND there's extra fuel because of weather/an alternate, etc. Pretty much anything under 300 miles. All of Georgia and the surroundign states.

When I worked on the ramp for EV at ATL in 2000, bag maxes were very rare on the CRJ-200s. Procedures must have changed after I left.

Quoting FlyASAGuy2005 (Reply 10):
Only flight on the 700 that had a max was ATL-EYW. Everything else, you would bulk out the bin before you got close to your bag max. Then there's those flights to LIT that would have 120 bags checked or to GRK with about the same.

The 700s came into the fleet after I left.

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