777kicksass
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Any Point In Having The 737 -800 & -900?

Sun Mar 18, 2001 1:37 am

I heard that they have the same number of emergency exits so they can only carry the same amount of people. Considering the -900 is longer does that mean that more fuel is used so those passengers are paying more???

Thanks
Max
 
EIPremier
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RE: Any Point In Having The 737 -800 & -900?

Sun Mar 18, 2001 1:59 am

It is true that they have the same number of emergency exits. I believe this limits both aircraft to 189 seats.


However, in order to install 189 seats in a single-class configuration on a 737-800, you would need a 28 inch seat pitch, which is tighter than even most charter carriers use. 189 seats on a 738 just isn't practical. A typical one-class configuration might feature 174 seats, with a 31-32 inch pitch. A typical two-class plan would be 12F/150Y (162 seats). American only puts 134 seats on their 738s (20F, 114Y)

A 737-900 could accomidate 189 passengers in a single-class configuration, with a 31-32 inch seat pitch and a full galley. However, a charter/low cost carrier might want to push below a 31-32 inch pitch, and remove galley space, so the 737-900 wouldn't make as much sense. The 737-800 would be the most economical choice for such a carrier.

The 737-900 makes sense for carriers using a two-class configuration.

Also, the 737-800 does have a greater range than the 900, and I believe greater cargo capacity in relation to the number of passengers.
 
OPNLguy
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RE: Any Point In Having The 737 -800 & -900?

Sun Mar 18, 2001 2:13 am

http://www.boeing.com/commercial/737-800/product.html

http://www.boeing.com/commercial/737-900/product.html

Your fare should be the same, irrespective of whatever 737 version is used. The -900 will indeed burn more fuel, but that's not how fares are determined. (If I ever find the alchemist down in the secret sub-basement that *does* determine how fares are calculated, I'll let you know..  Big grin

Pax seats aside, the -900 provides about 300 cu. ft. more space for cargo/bags than does the -800, with only a small decrease in range. Presumably, this was important enough to Alaska, given their niche market between SEA and Alaskan points.

ALL views, opinions expressed are mine ONLY and are NOT representative of those shared by Southwest Airlines Co.
 
EIPremier
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RE: Any Point In Having The 737 -800 & -900?

Sun Mar 18, 2001 2:15 am

According to Boeing's website:

The 737-900 has more cargo capacity than the 738, and more passengers in a two-class configuration. BUT...

The 737-800 and 900 have the same MTOW (174,200 lb)

The 737-800 and 900 have the same fuel capacity (6,875 U.S. gal)

The 737-800 and 900 have the same General Electric CFM56-7B engines with the same maximum thrust
 
EIPremier
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RE: Any Point In Having The 737 -800 & -900?

Sun Mar 18, 2001 2:21 am

I don't know enough about the engines to say what I just did. But, they are both GE CFM56-7B.

My question is: How will the MTOW of the 737-900 impact it's ability to carry passengers and cargo? Under what conditions will the plane NOT be able to carry BOTH a full load of passengers and a full load of cargo?
 
tupolev154b2
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RE: Any Point In Having The 737 -800 & -900?

Sun Mar 18, 2001 2:23 am

Doesn't Boeing wan to put a type 1 exit behind the wing on the 739 to increase capacity to 207?
 
OPNLguy
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Misc 737 -800 & -900 Stuff

Sun Mar 18, 2001 3:30 am

From a Boeing press release back from 2/99...

"Since the 737-800 and 737-900 airplanes are both
limited to 189 passengers, the additional passenger space will be particularly useful in a dual-class passenger configuration," said Jack Gucker, Boeing Commercial Airplanes vice president - 737/757 Derivative Programs. "This model also will offer more comfort for all-tourist cabin arrangements."

Boeing could of course cut another exit, but perhaps it wasn't cost-effective from a manufacturing or certification perspective to do so. Also, going to 207 means another (5th) F/A..

As far as engines go, the CFM-7B engines are just the *general* designation, and actually come in specific -7B20, -7B22, -7B24, -7B26, and -7B27 variants (ranging from lo-hi max thrusts). Depending upon which engine option the airline customer orders (Alaska is getting the -7B24 on their 900s, same as their 700s), max takeoff weight for the 900 will vary. Continental is getting their 900s with the more powerful -7B26, so their max takeoff weights will be different than Alaska's...

Someone asked..
>>>My question is: How will the MTOW of the 737-900 impact it's ability to carry passengers and cargo? Under what conditions will the plane NOT be able to carry BOTH a full load of passengers and a full load of cargo?

That'll be driven the usual variable things (as always), like runway length/slope, field elevation, temp, pressure, flap setting, (and all the others) and the existence of any restrictive MEL/CDL items or runway clutter. Gassed to the gills for a SEA-DCA flight would probably work, but one shouldn't expect to operate the same flight/load from a 6,000' runway at 6,000' elevation, or with close-in obstacles like terrain off the end of the takeoff runway.

ALL views, opinions expressed are mine ONLY and are NOT representative of those shared by Southwest Airlines Co.
 
LJ
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RE: Any Point In Having The 737 -800 & -900?

Sun Mar 18, 2001 3:47 am

I think KLM will be one of the few having both the -800 as the -900. Anyway according to news I received from KLM, they will use a 178 configuration (mix unknown but siome say that World business may be installed in the -900, allthough I think this is unlikely) in the -900 and they have currently a 158 (C47M111) configuration in the -800. Thus the -900 generates an additional 20 seats.

Regards
Laurens Janssen
 
EIPremier
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RE: Opnl

Sun Mar 18, 2001 4:01 am

Thanks for the additional info on the engines. That was exactly what I was looking for. I know that the CFM-7B is a generally designation, which is why I was quick to correct what I said.

I'm aware of the factors which influence an aircraft's range. That wasn't really my question, but thanks for going into detail.

Essentially, this is where my head is at.

It does seem that it would be much easier to put a 737-900 overweight, than a 737-800, because the MTOW is more-or-less the same, but the 739 can carry more passengers and freight. So, I was wondering if the figures Boeing gave were really realistic. In other words, can the plane be operated with a full load of fuel, cargo and passengers in most situations?

I know Alaska has expressed displeasure concerning the 737-900 cargo capacity. The strange thing is, Boeing claims the 737-900 can carry MORE cargo than either the 800 or the 757-200. So, why is Alaska not pleased? It seems to be the only answer is that the plane isn't going to be able to carry a full load of passengers and cargo at the same time.

Any comments??

Regarding the DCA-SEA flight, it does seem that using a 737-900 would be pushing it a bit, especially with a full load of passengers fuel and luggage (if that's even possible). DCA has a short runway, and the plane would also be working against headwinds.

 
OPNLguy
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RE: Any Point In Having The 737 -800 & -900?

Sun Mar 18, 2001 4:35 am

http://www.cfm56.com/engines/cfm56-7/tech.html

More on the engines.. Forgot there was a -7B18, but it's so low-powered in comparison with the rest that nobody's ordered any. The only -7B20s that are flying are on the 600s.

DCA-SEA? Hey, I never said they'd make it *back*...  Big grin Just picked that city-pair as a WAG, but you already have the concept. Sorry I misunderstood your question.

>>Essentially, this is where my head is at. It does seem that it would be much easier to put a 737-900 overweight, than a 737-800, because the MTOW is more-or-less the same, but the 739 can carry more passengers and freight. So, I was wondering if the figures Boeing gave were really realistic. In other words, can the plane be operated with a full load of fuel, cargo and passengers in most situations?

OK, got you know. Yes, it would be easier to put a -900 overgross than a -700 (AS doesn't show any -800s on order). Since their -700s and -900s share the same engine variant, it's reasonable to assume that the takeoff performance will be similar. The big difference will come to play in the operational empty weight (OEW) of the two aircraft. I don't know the precise difference between the respective OEWs, but assuming it was, say, 6,000 lbs, that's 6,000 in payload that the -900 can't carry, at least at the max range of the aircraft. If Alaska was to operate their -900s on shorter (2000nm versus 3000nm) flights, they'd probably be able to do it and take that 6,000 lbs. I have no specific performance numbers, so these are just theoretical examples.


>>>I know Alaska has expressed displeasure concerning the 737-900 cargo capacity. The strange thing is, Boeing claims the 737-900 can carry MORE cargo than either the 800 or the 757-200. So, why is Alaska not pleased? It seems to be the only answer is that the plane isn't going to be able to carry a full load of passengers and cargo at the same time.

The 757 is truly an icredible performer, and according to Boeing's website info, the -900 does have more space than the 757-200. BTSOOM as to why AS is unhappy--maybe they just expected a 757 at a 737 price... Be curious to see how the -900s do once they get into actual service...
ALL views, opinions expressed are mine ONLY and are NOT representative of those shared by Southwest Airlines Co.
 
EIPremier
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RE: Opnl

Sun Mar 18, 2001 7:59 am

Hey, thanks for the info and the link!
 
raggi
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RE: Any Point In Having The 737 -800 & -900?

Sun Mar 18, 2001 9:18 pm

Korean Air will also operate both the 738 and 739.


raggi
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