Iae V25 Engine
Thread Starter
Join Date: Feb 2006
Location: london
Age: 66
Posts: 42
Likes: 0
Received 0 Likes
on
0 Posts
Iae V25 Engine
From all your expieriences how would you describe the perforamce of this engine ie
-Fuel efficency.
-oil usage.
-Compressor stall/surge.
-EGT margin.
-Noise levels.
-Have you every experienced an N1 Reversion.
-High Vibrations.
-Fuel efficency.
-oil usage.
-Compressor stall/surge.
-EGT margin.
-Noise levels.
-Have you every experienced an N1 Reversion.
-High Vibrations.
Join Date: Apr 2008
Location: Here,There,Everywhere!!!
Posts: 73
Likes: 0
Received 0 Likes
on
0 Posts
Granard, first of all I would like to ask....whats the context of your question??? do you want specific figures or general info?? is it for flying knowledge, commercial, engineering or some research??? Might be able to help if things are a bit clearer 
Join Date: Oct 2003
Location: Gweriniaeth Cymru
Posts: 577
Likes: 0
Received 0 Likes
on
0 Posts
Granard,
from a general perspective I would describe the V2500 A5 as:
- Oil Usage - very low compared to the CFM - quite often less than 0.1 qt/hr
- Compressor stall/surge - only a few issues - seen 1 surge in 4 years
- EGT margin - still in positive territory when the engine is removed time-expired
- N1 Reversion - not seen it used as often as I have on the RB211 or Trent 700
- Vibes - Fan is good with routine relubes, core vibes low - only issue is monitoring for N2 vibe shift indicating a particular component failure - haven't seen one here yet
Noise and Fuel Eff - no comments to make.
Regards,
N1 Vibes
from a general perspective I would describe the V2500 A5 as:
- Oil Usage - very low compared to the CFM - quite often less than 0.1 qt/hr
- Compressor stall/surge - only a few issues - seen 1 surge in 4 years
- EGT margin - still in positive territory when the engine is removed time-expired
- N1 Reversion - not seen it used as often as I have on the RB211 or Trent 700
- Vibes - Fan is good with routine relubes, core vibes low - only issue is monitoring for N2 vibe shift indicating a particular component failure - haven't seen one here yet
Noise and Fuel Eff - no comments to make.
Regards,
N1 Vibes
Join Date: Dec 2005
Location: E.Midlands
Posts: 92
Likes: 0
Received 0 Likes
on
0 Posts
V2500
Engine is subject to repeat boroscopes on the HPC due clapper problems (stg3) and suffers from core bleed valve problems from time to time (valves or the solenoids) - am not referring to the pneumatic system PRSOVs. VSVs are subject to periodic lubrication requirements covered by the Maintenance Schedule. Problems tend to manifest as stalls which can lead to surges if unrectified. You'll then most likely be looking at a new motor as the surge tends to make the HPC blades look like sharks teeth - don't know why but especially stage 6. There is test set available for checking out the engine core bleed system
Ref the N1 reversion, the engine is EPR rated, ie the controlling factor is px in-to px out of the engine, with a backup N1 indication. When the EPR sensors either fail or lose their heating supply the indication will either switch to rated or unrated N1 mode as necessary
Think the CFM is the marginal engine of choice with operators but no real complaints with the V2500. Not too bad to work on either
Right, far too technical for a Monday. You ain't seen me right..........
Ref the N1 reversion, the engine is EPR rated, ie the controlling factor is px in-to px out of the engine, with a backup N1 indication. When the EPR sensors either fail or lose their heating supply the indication will either switch to rated or unrated N1 mode as necessary
Think the CFM is the marginal engine of choice with operators but no real complaints with the V2500. Not too bad to work on either
Right, far too technical for a Monday. You ain't seen me right..........
Last edited by North Stand Tier3; 27th Apr 2009 at 13:39. Reason: Yet again poor use of the England language
Join Date: Feb 2002
Location: The Sandpit
Posts: 555
Likes: 0
Received 0 Likes
on
0 Posts
At a guess you're looking at 'bus options.
Oil consumption is very good. Whereas you may put 2 cans into a CFM on a TFS-UK flight the V2500 will do several before a whole can will go in.
However they (used to? (there may be mods now to cure it)) suffer from rotor bow, due to the relatively long shaft and this can be exacerbated by not allowing the engine to thermally stabilise before shutting down or applying take-off power. The problem manifests itself by causing massive vibs during start.
They're also a little underpowered and require the use of bump on short or high airfields. The number of bump take-offs is limited before the engine needs to come off (bump provides additional turbine case cooling to improve efficiency but as a result increases tip rub and reduces EGT margin and life)
If you plan to use short, high or hot airfields you should consider this carefully.
At take-off power the engine has a buzzsaw like sound as the fan blade tips get near supersonic but it's not noticeable inside the cabin.
I've yet to see a case of N1 reversion.
Fuel efficiency I'm not able to say but similar fuel loads are used for both CFM and V2500 a/c going to the same destination.
Hope this helps.
Oil consumption is very good. Whereas you may put 2 cans into a CFM on a TFS-UK flight the V2500 will do several before a whole can will go in.
However they (used to? (there may be mods now to cure it)) suffer from rotor bow, due to the relatively long shaft and this can be exacerbated by not allowing the engine to thermally stabilise before shutting down or applying take-off power. The problem manifests itself by causing massive vibs during start.
They're also a little underpowered and require the use of bump on short or high airfields. The number of bump take-offs is limited before the engine needs to come off (bump provides additional turbine case cooling to improve efficiency but as a result increases tip rub and reduces EGT margin and life)
If you plan to use short, high or hot airfields you should consider this carefully.
At take-off power the engine has a buzzsaw like sound as the fan blade tips get near supersonic but it's not noticeable inside the cabin.
I've yet to see a case of N1 reversion.
Fuel efficiency I'm not able to say but similar fuel loads are used for both CFM and V2500 a/c going to the same destination.
Hope this helps.
Join Date: Mar 2009
Location: Peterborough
Age: 60
Posts: 6
Likes: 0
Received 0 Likes
on
0 Posts
Internally from a borescope point of view the combustion chamber degrades very quickly.
Lots of edge burnback, lining erosion, fuel nozzle surround degredation, NGV wear and cracking and this happens very quickly.
High cycle engines are very scary when you look in the combustion chamber and really do need to be very thorough when inspecting this area.
Lots of edge burnback, lining erosion, fuel nozzle surround degredation, NGV wear and cracking and this happens very quickly.
High cycle engines are very scary when you look in the combustion chamber and really do need to be very thorough when inspecting this area.
Join Date: Feb 2008
Location: Abu Dhabi
Posts: 294
Likes: 0
Received 0 Likes
on
0 Posts
WRT the rotor bow, someone told me once that the blade clearances at the 9 and 3 o clock positions would be higher because of the effect of the aircraft turning in the holding stack.......
RR were never happy with the rotor shaft arrangement.
RR were never happy with the rotor shaft arrangement.
Join Date: Jul 2007
Location: UK
Posts: 186
Likes: 0
Received 0 Likes
on
0 Posts
Rotor bow and bearings have been a probem, due mainly to the position of the number four bearing compartment inside the combuston section and the thermal effects on the component.
The number four bearing was initially prone to break-ups due to it being squeeze-film type and the oil pressure on start-ups not being sufficient. This problem was rectified by IAE with longer FADEC auto start schedules raising the pressure before and during light up.
One surge in four years is extremely lucky, especially in a climate such as Hong Kong. Surging and surging msgs have been a problem with the engine. Fuel is used as a servo medium in the core airflow system components, spurrious msgs were produced on transient fuel px during accel/decel.
Bleed schedules such as this are an on-going problem but IAE have introduced numerous mods to iron out the problems, such as; bleed valve solonoids and bleed valves(prone to sticking) and FADEC software upgrades improving schedules and reliability. P3 ice ups are not so common anymore also, these also produce the infamous 'FADEC 1(2)' ECAM msg.
Credit to IAE, they take note of cutomers and the problems and do offer great support. The engine continues to be upgraded with the new 'Select One' efficient type engines entering service.
My experience is Airline line and hangar based, but im sure the guys at Rolls-Royce will be helpful on your assignment. East Kilbride is the overhaul facility for this engine.
The number four bearing was initially prone to break-ups due to it being squeeze-film type and the oil pressure on start-ups not being sufficient. This problem was rectified by IAE with longer FADEC auto start schedules raising the pressure before and during light up.
One surge in four years is extremely lucky, especially in a climate such as Hong Kong. Surging and surging msgs have been a problem with the engine. Fuel is used as a servo medium in the core airflow system components, spurrious msgs were produced on transient fuel px during accel/decel.
Bleed schedules such as this are an on-going problem but IAE have introduced numerous mods to iron out the problems, such as; bleed valve solonoids and bleed valves(prone to sticking) and FADEC software upgrades improving schedules and reliability. P3 ice ups are not so common anymore also, these also produce the infamous 'FADEC 1(2)' ECAM msg.
Credit to IAE, they take note of cutomers and the problems and do offer great support. The engine continues to be upgraded with the new 'Select One' efficient type engines entering service.
My experience is Airline line and hangar based, but im sure the guys at Rolls-Royce will be helpful on your assignment. East Kilbride is the overhaul facility for this engine.
