TristarSteve From Sweden, joined Nov 2005, 3855 posts, RR: 34 Reply 3, posted (7 years 11 months 3 weeks 4 days 23 hours ago) and read 3318 times:
You have picked a good aircraft. I like the B757. It has enough BITE to make it easy to troubleshoot, but not too much electronics to make it hard. There is no CMC, you have to go to all the boxes to do BITE, and they are all over the place. Fwd Equip, Fwd freight and Aft freight on some B757. An being a well developed aircraft it has a good MEL.
I see a couple every day.
Fr8Mech From United States of America, joined Sep 2005, 4741 posts, RR: 12 Reply 5, posted (7 years 11 months 3 weeks 3 days 14 hours ago) and read 3270 times:
Quoting HAWK21M (Reply 4): Hows the RB211s compared to the P&W 2040 Mx wise.
We have more suging problems with the RB211, but it's a stout engine. Very little trouble with FOD damage. The pnuematic system on the PW leaves a little to be determined, but the engine is OK. I believe the numbers will say the RB is more reliable.
MD11Engineer From Germany, joined Oct 2003, 13602 posts, RR: 63 Reply 8, posted (7 years 11 months 3 weeks 2 days 10 hours ago) and read 3221 times:
The PW2040 used to have some issues with the 10th and 11th stage HPC stator vanes (cracks) and the 5th stage LPT blades (blade clashing, rotor blades against moved stator segments), but due to mods carried out during engine overhauls (replacement of the offending stator segments with a redesigned version and replacement of the 5th stage LPT stators with a redesigned version), the problems have been fixed. Up to the mods, regular boroscope inspections (a bitch especially on the 11th stage HPC, since there is no normal boroscope access to this zone, you've got to go in from the 12th stage and carefully thread the probe through the 12th stage rotor and stator with a high risk of getting stuck, happened to me once, the tip of the probe tore off when I tried to remove it, resulting in an unscheduled engine change. But I've heard this is a regular incidence in these inspections, so I never had any problem with the airline about it) were mandatory to catch the cracks and blade clashing as early as possible and to pull the engine if necessary.
AFAIK, the RB211 gives a better performance in hot and high situations, but the PW2040 is a bit cheaper.
Fr8mech From United States of America, joined Sep 2005, 4741 posts, RR: 12 Reply 10, posted (7 years 11 months 3 weeks 1 day 16 hours ago) and read 3198 times:
Quoting HAWK21M (Reply 9): Damn. Wasn't there anyway to extract it out.Mechanical fingers.What were you thinking that night at home.
We've had it happen a couple of times. I found the T5 inspection harder to do than any in the compressir. You need to snake in between 2 stator sets and then look at the base for eveidence of clashing. Luckily you only need to do it at 2 points (180 deg) on the engine.
MD11Engineer From Germany, joined Oct 2003, 13602 posts, RR: 63 Reply 11, posted (7 years 11 months 3 weeks 1 day 9 hours ago) and read 3183 times:
I actually found the T5 inspection quite easy. You'll need a guide tube to deflect the boroscope probe aft and a real thin boroscope (I used an old Machida 4mm boroscope without camera). Then it is a piece of cake. Just don't forget to count the sets of blades and vanes you pass through to be shure that you are looking at the correct stage.
In the case of the torn off probe, maintenance control told me not to worry, since I wasn't the first person to whom it happened.
A few days after the engine change we had a specialist in from Pratt & Whitney, who opened a bleed duct and used another boroscope with an attached mechanical finger to recover the boroscope tip. We wrote the engine servicable and used it as a spare (we always had one engine for each aircraft type based on the station in stock, after all we were the European main base back then).
HAWK21M From India, joined Jan 2001, 31457 posts, RR: 57 Reply 12, posted (7 years 11 months 3 weeks 1 day 2 hours ago) and read 3173 times:
Quoting MD11Engineer (Reply 11): A few days after the engine change we had a specialist in from Pratt & Whitney, who opened a bleed duct and used another boroscope with an attached mechanical finger to recover the boroscope tip
Ok great.It was Extracted.I presumed it had to be sent for Overhaul to be dismantled sectionwise to retrieve the probe.