tag:blogger.com,1999:blog-8118460937928958757.post4188899284585855838..comments2024-01-17T13:23:35.896-05:00Comments on aeroturbopower: A320neo engines comparedUnknownnoreply@blogger.comBlogger12125tag:blogger.com,1999:blog-8118460937928958757.post-7611546885488904882016-06-01T02:21:14.936-04:002016-06-01T02:21:14.936-04:001000lb / 500kg Payload shortfall is not a small nu...1000lb / 500kg Payload shortfall is not a small number. And it affects not only MTOW missions, but all TOW limited missions (e.g. Hot&High takeoff mission). Quite some operators chose the neo because of its better Hot&High payload capability compared to the classic/NG.<br /><br />According to AIRBUS info, 500kg transforms into 120nm Range on the neo(s).<br /><br />1000lb/500kg indeed results in ~0.6%-0.7% percent fuel burn on nearly every mission - for long legs the drawback is obvious - but also on short legs it hurts, because not only the fuel burnt is higher, but also the reserves you carry (which may double the fuel load on short legs).<br />How severe is 0.6%-0.7%? Well, engine manufacturers usually take several years to develop a PIP which give 1% sfc improvement - and A/C manufacturers & operators are starving for these PIPs. So it must be worth something.<br /><br />On the cash side - hum, depends. Fuel cost is 30%-50% of COC (depending on the carrier), so .6% of 30% seems ridiculous. On the other hand, for airlines operating at the edge of profitability (which are quite some) it may matter.<br /><br />What I'm asking is: Isn't that shortfall already compensated for? IF they got the weight increase from the bigger fan (and additional LPT stage) - well - the fuel burn goes down, even if you take into account the fuel burn impact of the heavier engine.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-8118460937928958757.post-28430921775795838452016-05-29T21:37:51.436-04:002016-05-29T21:37:51.436-04:00The fuel burn depends on the actual sfc of both en...The fuel burn depends on the actual sfc of both engines and other aerodynamic aspects that will be known only after the tests are completed at aircraft level. Weight is only one aspect. For the majority of meaningful missions the difference of 4 to 5 passengers mentioned in your article does not exist.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-8118460937928958757.post-34667020464718087782016-05-29T05:44:49.125-04:002016-05-29T05:44:49.125-04:00Sorry, but I don't get it - is this a question...Sorry, but I don't get it - is this a question? For the same fuel burn you can carry more pax on the GT powered aircraft. With the same payload you have more fuel burn with the LEAP powered aircraft. What is your problem?aeroturbopowerhttps://www.blogger.com/profile/17686461923667604678noreply@blogger.comtag:blogger.com,1999:blog-8118460937928958757.post-28035016006380634762016-05-25T09:12:13.846-04:002016-05-25T09:12:13.846-04:000.65% fuel burn difference. What's the reality...0.65% fuel burn difference. What's the reality today?<br />What about the 4 to 5 passenger difference? Gone?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-8118460937928958757.post-74892559328062284912016-05-25T02:51:30.345-04:002016-05-25T02:51:30.345-04:00The LEAP powered aircraft would burn more fuel the...The LEAP powered aircraft would burn more fuel then as it is heavier. 1000lbs are worth about 0.65% fuel burn. So the LEAP powered aircraft would need 0.65% more fuel for the mission.aeroturbopowerhttps://www.blogger.com/profile/17686461923667604678noreply@blogger.comtag:blogger.com,1999:blog-8118460937928958757.post-62703936599279282492016-05-24T22:52:27.131-04:002016-05-24T22:52:27.131-04:00You tell me.You tell me.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-8118460937928958757.post-24960041647430119592016-05-23T03:57:01.215-04:002016-05-23T03:57:01.215-04:00What would that change? What would that change? aeroturbopowerhttps://www.blogger.com/profile/17686461923667604678noreply@blogger.comtag:blogger.com,1999:blog-8118460937928958757.post-84365765172654743082016-05-20T14:10:12.344-04:002016-05-20T14:10:12.344-04:00Have you examined the case of a 900 nautical mile ...Have you examined the case of a 900 nautical mile mission at maximum passenger load and that is not limited by takeoff weight?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-8118460937928958757.post-22939882345669997472016-05-19T05:51:55.214-04:002016-05-19T05:51:55.214-04:00Why should it not be true?Why should it not be true?aeroturbopowerhttps://www.blogger.com/profile/17686461923667604678noreply@blogger.comtag:blogger.com,1999:blog-8118460937928958757.post-1709508085200622882016-05-18T09:36:18.542-04:002016-05-18T09:36:18.542-04:00"Or in other words: if both engines would hav..."<i>Or in other words: if both engines would have the same fuel burn (according to John Leahy the LEAP engine is not yet at spec fuel burn), a PW1100G-JM powered aircraft could transport 4 to 5 passengers more by burning the same amount of fuel for the trip.</i>"<br /><br />Is that always true?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-8118460937928958757.post-36148826120636182232016-05-12T15:06:38.656-04:002016-05-12T15:06:38.656-04:00Addendum
LEAP-1B fan diameter: 69.4"Addendum<br /><br />LEAP-1B fan diameter: 69.4"Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-8118460937928958757.post-20304307510006904392016-05-12T15:04:51.158-04:002016-05-12T15:04:51.158-04:00The weight data for the LEAP-1B was recently relea...The weight data for the LEAP-1B was recently released: "Weight of the dry engine, including basic engine equipment, will not exceed 2780 kg".<br /><br />So, in a worst-case scenario for the MAX, the difference in dry engine weight for the 81-inch diameter PW1100G-JM on the A320neo and 6.4-inch diameter LEAP-1B on the 737MAX is just 77.6 kg (per engine).<br /><br />https://www.easa.europa.eu/system/files/dfu/EASA%20E%20115%20TCDS%20issue%201%20LEAP-1B_20160405_1.0.pdf<br /><br />Rgds<br />OV-099Anonymousnoreply@blogger.com