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BAe 146-100
17th Mar 2009, 10:13
I was wondering if the 757-300 have any performance restrictions, because they rarely seem able to make climb restrictions when it's smaller brother the 200 has no problems at all. I guess that is due to the fact that it has a lot more weight and pax with the same engines as the 200? I guess it will also have problems in hot conditions with a full load of pax.

If so why wasn't there a higher powered RR turbofan made available on the a/c?

TinyTim2
17th Mar 2009, 17:06
Changing the engine would have made the certification process much longer and a lot more expensive.........

enicalyth
17th Mar 2009, 21:07
The 757-200 suffered "limitations" above 250,000lb TOW; the 757-300 which sold like pork sausages in a synagogue the day before Yom Kippur would have required a modest upgrade in engine rating to 42250lb-st (from 41000) to retain the same TOW/ST rating as the ostensibly replaced 727-200. But it did not happen. Meantime Northwest was a firm P&W lover and went as far as I know to be the only P&W buyer. At less thrust than the roller. The airline I then worked for would not look at a fuselage barrel that was 707/727/757 with a completely different wing to the 767 with no structural strength to go to thrustfuller engines. Yup I know the 757/767 have a common type rating. Nope I don't think the 757 was a good move apart from folks who lived in Renton. Yup I think the 737-900ER is a bag of prawns. Nope I do not work for company "A" any more. Yup I work for company "B". Nope I don't regret. But yup I remember it was difficult times and if I recall engine makers and air-framers were not exactly philanthropic enterprises. And nope, nobody buys my book. And yup I must stop talking like this and go in and have dinner with my family. But what I remember about the 767 is a) appalling number of gotchas but b) she flew rather sweetly for all that. Oh to be young again.

oceancrosser
18th Mar 2009, 00:16
A few incorrect things in the previous posts. A lot of airlines have P&W powered 757s. The 753 has higher thrust engines than the 752. A quick Google search gave the RB211 numbers 43.500 lbs as opposed to 40.200 for the 752.
As has happened with most aircraft being stretched, the wing did not change, power increase was modest, and the MTOW went up by 10 tons.
So inevitably, it needs more runway (higher speeds), climbs slower and the initial cruise altitude is 3-4000 feet lower at comparable load factor.

In some ways it is a dog, but it is economical on sectors up to 2000 nm, anything longer is not really worth it. Handles fine, but when you only fly it rarely, it lands a little bit earlier than little sister :ugh:

captjns
18th Mar 2009, 11:19
Meantime Northwest was a firm P&W lover and went as far as I know to be the only P&W buyer

Nope... Besides Northwest, Delta and TWA(RIP) had P&W motors installed on their jets too.

For the 757-300... Continental retained the Rolls, and Northwest kept the P&Ws

SOPS
18th Mar 2009, 12:44
Ok while we are on the subject (but with a little thread drift)...why did they stop making the 757 in the first place??

WHBM
18th Mar 2009, 13:16
A further 757-300 restriction is in extended turnround time that has to be allowed because of the sheer time it takes to get all those passengers out and in through one door at the front, and down one aisle. If full on both sectors it takes for ever.

757-300 which sold like pork sausages in a synagogue Like most of Boeing's recent stretches in the last 10-15 years. 737-900, 747-8, 757-300, 767-400. They seem to have lost their touch.

Rainboe
18th Mar 2009, 13:24
Can you be more specific on where the 737-900 starts to lose its touch? It seems to be getting the 737 more up to 707-type fuselage size. I'm interesting in understanding where it fails.

WHBM
18th Mar 2009, 13:50
Can you be more specific on where the 737-900 starts to lose its touch? It seems to be getting the 737 more up to 707-type fuselage size. I'm interesting in understanding where it fails.
Commercially the 737-900 initially failed on the following.

The 737-800 had been sized up to the maximum size for the evacuation provision (189 seats I believe), beyond that it needed substantial reworking of the exits. However Boeing identified that only charter-pitch 737-800s actually installed the full number of seats, and they could do a further stretch to allow mainstream carriers with F/Y seating, who typically put in about 150 seats in a 737-800, to have more seats, still without exceeding that 189 seat maximum.

This was not acceptable to owners, and more particularly leasers because it meant they were cutting out a significant aftermarket for the aircraft, in that they could not be moved on to charter/LCC type operators with high-density seating once the initial operator handed them back. Boeing have eventually realised this and done a rework of the exits for the 737-900ER, but they missed the market for some years and don’t seem to have got it back.

Capt Chambo
18th Mar 2009, 14:30
I am with WHBM on this, Boeing seem to have lost their way a little over the last ten years or so. They have "tweaked" a number of airframes which haven't proven commercial successes (B753, B764, & B736) and so far the B748 is looking doubtful, certainly in the passenger version. Similarly they have been distracted by things like the "Sonic Cruiser". In their defence the B777 is in a league of it's own and has probably contributed to the demise of the B747 passenger series as well as the B767-400.
The B737NG is selling well but one has to wonder at what price?

Can you be more specific on where the 737-900 starts to lose its touch? It seems to be getting the 737 more up to 707-type fuselage size. I'm interesting in understanding where it fails.
Again I would contend that Boeing took their eye off the ball here. The aircraft is supposed to compete with the Airbus A321, carrying c210 passengers on up to c2000+nm legs. However the B737-900 can only carry 189 pax due to the fact that the emergency exits don't meet present passenger evacuation requirements. To fix this Boeing have come up with the -ER version where they have had to install a pair of emergency exit doors (D doors?) behind the wing in addition to the normal pair of overwing exits. JetPhotos.Net Photo » PK-LFG (CN: 35680) Lion Air Boeing 737-9GPER by NGO Spotter (http://www.jetphotos.net/viewphoto.php?id=6507792&nseq=1)
By doing so they effectively lost a row of seats and so they had to re-design the rear pressure bulkhead, and make it flat, redesign the rear galley and toilets all so they could recover the "lost" row of seats, and presumably the empty weight went up too!

However back to the basic B737-900, we now have a 189 seat aeroplane which can only legally carry the same number of passengers as the B737-800 but of course the airframe weighs a couple of thousand pounds more. I fly the -900 with 24K engines and 188 passengers, and I used to fly the A321 with 215 passengers. In a straight head to head with the A321 with a full passenger load on a similar 4-5 Hr flight. They will both climb initially to approx. FL330-340. There the A321 will cruise at approx. M.79 whereas the B739 will be M.78 or less. The B739 will be burning about 3100-3200 lbs per hour for the first couple of hours, which if memory serves is similar to the A321 with V2500s. Granted the B739 will climb higher sooner than the A321, but it doesn't disguise the fact that it is slower than the A321, and carries less passengers. Basically it's not doing anything that the slightly smaller B737-800 isn't already doing, something the world's airlines have recognised and sales of the B737-900 have not been fantastic.

Now don't get me started on the shortfalls of the -NG series generally. :}

captjns
18th Mar 2009, 15:07
I do agree that Boeing has been in the habit of stretching their products rather than stretching their imaginations in aircraft design. I know, it's cheaper in the short term. The 737 cockpit for instance was originally designed in the 1950’s and is still just as crappy as they day the –80 was born.

I know that after the big turkey dinner is done, you can make turkey sandwiches the next day… turkey hash the next… turkey croquettes the next… turkey stew the next… turkey soup the next… and so on.

While very popular at the out set… people get board with leftovers.

On a side bar… and this is per Mr. Boeing’s rag.

www.newairplane.com - Boeing’s New Airplane (http://www.newairplane.com%20-%20boeing's%20new%20airplane/)


The -900 can carry 220 bodies... range up to 3200nm with extra tanks... and weighs about 10,000 lbs. less than that A321.

Capt Chambo
19th Mar 2009, 02:53
Sorry looks like my post 10 has crossed with WHBM's post 9.!
captjns I can't get your link to open.

boeing boeing.. gone
19th Mar 2009, 12:01
Boeing's New Airplane (http://www.newairplane.com/737/)

HAWK21M
29th Mar 2009, 08:39
Wasn't the RB211-535-E4-B2 developed for that very purpose.
regds
MEL.


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