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View Full Version : Are the MAXs now in 'Parc Ferme'..?


scifi
31st Mar 2019, 19:21
I just wonder if the grounded aircraft are in Parc Ferme, where they cannot be worked on by engineers.
If,.as has been suggested in other threads, there is some common AoA data transmission error. Then it would be nice is the fault could be found in some of the other Maxs. as the only two aircraft we know had the fault are not intact now.

DaveReidUK
31st Mar 2019, 19:30
I just wonder if the grounded aircraft are in Parc Ferme, where they cannot be worked on by engineers.

What makes you think that?

They will be getting the same attention given to any aircraft that aren't going to fly again for a while.

Uplinker
1st Apr 2019, 12:49
There are five Tui Max’s parked at Juliet 1 at Manchester, (making that intersection unavailable to traffic).

I would imagine that these aircraft can be worked on in the open to prepare them for short-term storage? Would they remove batteries, empty the fuel water drains and drain potable water? I am sure there is more to it than that. Maybe jack them onto blocks to prevent tyre flats?

They can change engines outside, (under a tent), so I would imagine they can work on Avionics and probes?

Flying Wild
1st Apr 2019, 13:01
TUI Max aircraft at TFS have had wheel bogies wrapped in plastic along with normal probe/engine covers

scifi
1st Apr 2019, 13:18
I was thinking that they would be a good source of information, and that an engineer could un-knowingly alter any evidence that would help pin-point the faults.
Were there not a few other aircraft that had similar captain side anomalies. These should be inspected by suitable FAA / CAA teams.

GordonR_Cape
1st Apr 2019, 16:05
I was thinking that they would be a good source of information, and that an engineer could un-knowingly alter any evidence that would help pin-point the faults.
Were there not a few other aircraft that had similar captain side anomalies. These should be inspected by suitable FAA / CAA teams.

I had that same thought, to test them every day until an AOA error occurs, but politics/liability/insurance would all get in the way.

scifi
9th Apr 2019, 11:53
Lets be quite honest, that airframe was never designed for those engines, and no amount of software is going to solve that problem.
If Boeing want to use the LEAF engines then they need to design a new aircraft to suit them.

DaveReidUK
9th Apr 2019, 14:30
Lets be quite honest, that airframe was never designed for those engines, and no amount of software is going to solve that problem.

To be fair, it was never designed for the engines on the Classic or NG, either.

Exup
9th Apr 2019, 15:20
Plenty of aircraft have been re-engined over the years not just the 737.

safetypee
9th Apr 2019, 16:05
Exup, its not just re-engining, it’s repositioning, wt, cg, and lift from the extended nacelles - proportional to AoA.

At least none have been sent to Tucson so far.

tttoon
9th Apr 2019, 16:09
Lets be quite honest, that airframe was never designed for those engines, and no amount of software is going to solve that problem.
If Boeing want to use the LEAF engines then they need to design a new aircraft to suit them.

Can we get some arguments to support this statement?

pineteam
9th Apr 2019, 17:13
Can we get some arguments to support this statement?

Just look at the size of the engines on the 737-200 vs 737-Max. The fact that they need to flatten the bottom part of the engine nacelle on the NG says a lot already.

DaveReidUK
9th Apr 2019, 17:59
The fact that they need to flatten the bottom part of the engine nacelle on the NG says a lot already.

Even before the NG the nacelles were flattened, albeit not by quite so much, on the Classic.

krismiler
10th Apr 2019, 01:00
The B737 fuselage design dates back to the 1950s, the later designed B767/757 are already obsolete and except for a few specialised variants, out of production. It should have been obvious to Boeing back in the 1980s that they needed a new airframe for their bread and butter narrowbody. Possibly they didn't see the new A320 as a threat and weren't willing to invest the money in a new design. Even at 30 years old the A320 is still a fantastic aircraft which is still able to be updated without mutating it into something the original designer wouldn't recognise. New sharklet wings and next generation engines have improved it's efficiency considerably, update the flight deck and there is no reason for it not to go on for another 20 years.

Boeing would need to spend billions on a new design which would be unlikely to offer significant improvements over the current A320 series, and the selling price would need to recoup the development costs. Margins at the economy end of the market aren't as much as at the higher widebody long haul end and it would take many years to get back into the black.

DaveReidUK
10th Apr 2019, 07:49
Even at 30 years old the A320 is still a fantastic aircraft which is still able to be updated without mutating it into something the original designer wouldn't recognise. New sharklet wings and next generation engines have improved it's efficiency considerably, update the flight deck and there is no reason for it not to go on for another 20 years.

Boeing would need to spend billions on a new design which would be unlikely to offer significant improvements over the current A320 series

You can't have it both ways.

The A320 certainly has significant advantages over the 737, which is no surprise given that it came along 20 years later.

So what makes you think that an all-new aircraft 30 years further down the road than the A320 wouldn't be able to offer a corresponding leap over it in technology and capability ?

Cows getting bigger
10th Apr 2019, 08:49
I'm not a tube driver so could someone please explain to me why the 757 was ditched, especially the -100 in favour of the 737? Was it due to the 'same type' argument that seems to pervade for the 737 Max? It seems to me that this was a good aircraft with plenty of space for bigger engines.

GordonR_Cape
10th Apr 2019, 08:59
I'm not a tube driver so could someone please explain to me why the 757 was ditched, especially the -100 in favour of the 737? Was it due to the 'same type' argument that seems to pervade for the 737 Max? It seems to me that this was a good aircraft with plenty of space for bigger engines.

Someone stated that the cost-per-seat-mile of the B757 was almost twice as high as the B737. Simple economics, airlines stopped buying it, end of story. Fuel efficiency is king in the low-cost market, and safety is a secondary concern, as long as the aircraft is FAA approved, and has a long flight history, and passengers are willing to step on board.

Cows getting bigger
10th Apr 2019, 09:40
You see, that's where I'm a bit confused. The only data I can find is that cost/seat mile for the latter 737s is in the region of 6-8 cents/mile; Boeing claim the Max is a 20% improvement on earlier models. The 757 appears to be about 7.5 cents/mile.

https://www.planestats.com/bhsn_2014sep

Wiki hits it from a different angle saying that a 737 Max has a Miles Per US Gallon of 102/seat with the 757-300 at 88 MPG.

For sure, the 757 appears to be more expensive but not in the order of twice as much. It would be an interesting theoretical exercise to number crunch a 757 with LEAF engines. :)

Bend alot
10th Apr 2019, 10:39
Same TDC S269C and S269D

Nothing like a good engine change and pretty much all the air-frame - only thing similar is being able to continue to use the magnesium.

compressor stall
10th Apr 2019, 11:26
You can't have it both ways.

The A320 certainly has significant advantages over the 737, which is no surprise given that it came along 20 years later.

So what makes you think that an all-new aircraft 30 years further down the road than the A320 wouldn't be able to offer a corresponding leap over it in technology and capability ?

It's a good question.

If Boeing can design an aircraft that offers superior safety / fly by wire characteristics / ergonomics to the A320 family of aircraft, they'd be on a winner.

Unfortunately for them, I think that technology has largely plateaued since the A320 introduction. The only major change is in engine efficiency. The 787 and A350 are certainly incremental improvements, but largely offer a refinement (albeit larger) of the A320 FBW concept.

For Boeing, shrinking the 787 into a new 737 replacement would need to do a lot more than the A320 to be a best seller. Size aside, the 787 and the A320 are largely equals in terms of technology and safety. If the tech was there, Boeing would have it on show already in the 787.

krismiler
10th Apr 2019, 11:58
So what makes you think that an all-new aircraft 30 years further down the road than the A320 wouldn't be able to offer a corresponding leap over it in technology and capability ?

A brand new design today could offer some small improvements over the A320 but it's doubtful that there would be the massive leap ahead which would be needed to justify the massive cost of a brand new aircraft and the necessary price increment over the A320. The Airbus can use the latest engines and with sharklets has a very efficient wing, the fuselage is the right size and with additional centre tanks range can be extended.

A few tweaks here and there and the A320 can easily go another 20 years, by then technology will have improved to the extent that it will be worth incorporating the advances in an all new design which will probably be all composite and use half the fuel of the present aircraft. The B737 should have been scrapped in the 1980s and replaced with a design using B767 level technology. Had this been done Boeing would have had an equal competitor to the A320 in the narrow body market .

DaveReidUK
10th Apr 2019, 17:10
A few tweaks here and there and the A320 can easily go another 20 years, by then technology will have improved to the extent that it will be worth incorporating the advances in an all new design which will probably be all composite and use half the fuel of the present aircraft.

OK, but I'm still struggling to understand why you should say there have been very few developments in the last 20 years, but there will be loads in the next 20. I'd have said that there's been slow, but consistent technological progress and it's likely to continue at pretty much the same rate.

A brand new design today could offer some small improvements over the A320 but it's doubtful that there would be the massive leap ahead which would be needed to justify the massive cost of a brand new aircraft and the necessary price increment over the A320.

The economics of a 737 replacement are a different story, I think you're right about that. Even without the aircraft's current problems, Boeing are between a rock and a hard place. If they try to squeeze even another decade out of the 737, Airbus will eat their lunch.

scifi
10th Apr 2019, 22:09
It's going to be interesting to see what type of old school engineering goes into the Chinese Comac 919. It will use the same LEAP engines, but without having to dent the bottom of the cowling to get them to fit.
Might be worth buying one of their aircraft, to study what their design department has come up with.

https://www.youtube.com/watch?v=rfGy9fnqAVo
. (https://www.youtube.com/watch?v=rfGy9fnqAVo.)

tdracer
10th Apr 2019, 22:46
I'm not a tube driver so could someone please explain to me why the 757 was ditched, especially the -100 in favour of the 737? Was it due to the 'same type' argument that seems to pervade for the 737 Max? It seems to me that this was a good aircraft with plenty of space for bigger engines.

There never was a 757-100. Shrinking an existing aircraft and still having it economical is close to impossible. The wing is going to be way too big, manufacturing costs will only be slightly less than the baseline, and seat mile costs will be higher due to too much wing and structure. The 737-500 was a slow seller, the similar sized 737-600NG even worse, the A319 remains a slow seller and the A318 was a major flop. The 747SP was moderately successful, but that was a different time and no other aircraft offered that kind of range (and as the saying went, all they did on the 747SP was remove all the empty seats).
What really killed the 757 was it was expensive to build, as compared to the 737. When the 737-900 came out, it's capabilities were very close to the 757-200 (aside from range) and it cost a lot less to buy. Boeing tried to save the 757 with the stretched -300, but it flopped, in large part because when you make a single aisle that long it takes so long to load and unload that your turn times go to hell and it remained expensive to build and hence expensive to buy.

krismiler
11th Apr 2019, 02:09
OK, but I'm still struggling to understand why you should say there have been very few developments in the last 20 years, but there will be loads in the next 20. I'd have said that there's been slow, but consistent technological progress and it's likely to continue at pretty much the same rate.

Speed hasn't increased, we're still up against the sound barrier. M0.78 is about the right speed for the range of the current narrowbody fleet as over typical distances flown, bumping up to say M0.83 isn't going to make a huge difference on a 2 hour sector where as it would on a 14 hour leg.

180 seems to be about the right passenger load, some variants offer more and some less. Interior capacity for hand luggage needs to be increased as people are tending to carry on rather than pay to check a bag in. The A320 is ahead in this area at the moment but there is still room for improvement.

A new generation flight control system and EFIS would be a welcome addition on the A320 as it currently lags behind the latest generation of flight decks. It's adequate rather than class leading, but as it was designed fly by wire in the first place, improvements should be easy to incorporate. Bringing a B737 up to modern spec would be like trying to incorporate the last 50 years of advances in motoring technology into a 1960s VW Beetle body. As a previous poster stated, things plateaued since the A320 was introduced. Aviation went from the Wright brothers first flight to Concorde in less than 70 years but exponential improvements seem to have died off a bit.

There have been advances in the last 20 years particularly in engine technology (which the A320neo enjoys), composite materials and flight control systems. Due to the expense of aircraft design, a product cycle is much longer than in the automotive industry as manufacturers need to recoup development costs and can't afford to introduce new types every 5 years. Add up the improvements over the past 20 years with the likely advances over the next 20 years and a significantly improved clean sheet design could be offered around 2040 which would probably be all composite material with unducted fan engines and the latest avionics which would be essential given the growth in air traffic density.

Airbus can keep the A320 going until then with a few tweaks here and there where as Boeing needed a B737 replacement a long time ago.

MCDU2
11th Apr 2019, 09:24
Read an article a while back that Airbus was looking to develop the wing of the A321LR, presumably to reduce fuel consumption, increase range and bump up the speed. I would expect that if they can achieve this then the A320 family as a whole could see the benefit down the line.

HarryMann
22nd Apr 2019, 11:09
I thought someone said a good while ago this was a field length /field performance issue... Vs provincial airports?
The 737 Vs 757 debate that is. Wing size /wing loading

bizdev
22nd Apr 2019, 11:42
As I understand it - the problem of engine fit on the 737 is due to the height of the undercarriage which Boeing have resisted lengthening due to a major redesign of the wing and fuselage centre section. This was coupled with not wanting to raise the height of the fuselage so that the baggage loaders did not need specialist loading equipment - a key consideration for short turn round LCCs. However that hasnít stopped easyJet from operating the A320!

groundbum
22nd Apr 2019, 12:03
Boeing delayed replacing the B737 with a new type as they knew if they asked their big 737 customers to transition to a new type, then those same customer would rightfully take the opportunity to conduct an open market competition as to which aircraft to choose, which would include the Airbus A320/A321. Boeing really didn't want their biggest and most loyal customers to start looking around for the best plane.

Most large airlines have a mixed Boeing/Airbus fleet, so 787 and A350, 737 and A321. This way both manufacturers offer their best prices to keep the business and hopefully steal some from the competitor.

G