Challenge for the MRJ is that the after market & support infrastructure doesn't exist. Few airlines would be ready to set that up completely them selves..
If the current operators, GE and Bombardier and a new owner would have a billion laying around.. https://www.airliners.net/forum/viewtopic.php?f=3&t=1422729
Only a billion? Much lower than my estimate. The Passport isn't ready for high cycle duty. Oh, it can be made ready, I see no issue. But besides I creasing the bypass ratio, the subsystems are not ready for 20,000 FC (flight cycles) and 30,000+ hours before the first overhaul.
The nacelle isn't going to survive 80,000 FC either. It is a great design for the Global, an aircraft with a limit of validity of 17,000 cycles:https://www.ainonline.com/aviation-news ... -certified
Seriously, if any Global sees 12,000 cycles, I would be shocked. CRJs are already passing 60,000 FC, hence the LOV expansion to 80,000 FC. A huge difference in design optimization...
The Passport claims 8% lower fuel burn than comparable engines (BMR-725).
Errr.... That sucks compared to a GTF. Now, it isn't built to compete. It is faster and cheaper. Just as RR did well taking the BMR 715 and putting in a durable BMR720, it still hasn't received the maintenance PIP (too few sold). Overhauls every 8,000 cycles vs. 20,000+ cycles between overhauls for commercial engines.
Oh, both the BMR720 or Passport could do 20,000, but neither has had that billion dollar PIP. Perhaps 2 billion. RR is trying for a lesser number at lower cost per contract with DL. I do not know the status.
Why yes Virginia, the Pearl could be adapted to commercial duty too. The core of both are excellent, they just need different high turbine blades for commercial duty, different turbine clearance control, sump back pressure regulator, low spool, compressor stator linkages, anti ice valves, fuel pumps (durability), a low turbine Clearance control valve (reduced fuel burn), LEAP variable turbine cooling (how the LEAP can compete with the PW1100G), and a totally different nacelles.
But yeah, otherwise ready.
Man. That put a damper on my enthusiasm for a CRJ800....From time to time, I've mulled the prospect over quietly to myself in the mornings while I sip coffee and watch the finches tend to their business from my patio. Just couldn't understand why Bombardier wasn't going to give it one last go in the 76pax space. I had no idea the Passport was 'that' unready for commercial service. I thought perhaps the fuel burn would be different in the CRJ at .78mach compared to the speed of a Global private jet... more to the plus side of 10%... However with the mods you mention to increase durability and service intervals, I suspect that would cut into fuel burn. Guess, I'd just like to see the last regional manufactured on the North American continent succeed. Will be a shame to see the CRJs just go away. Anyway, I'll follow Keesje's other thread on a proposed CRJ800, because I like the idea of it. But having been educated by PhotonSword (LightSaber I never cease to be impressed by your depth of knowledge... you know your craft!) on the matter, I concede it's just going to be a fun forum diversion for the K-man and I, probably nothing more. Bummer.
The mods I note would reduce fuel burn about 5%. Weight would increase, about 300kg per engine.
Business jets peak at 500 cycles for those who buy new. Quickly, within 7 years, they are sold to customers who do 250 or fewer cycles per year and so on down to 4th hand buyers typically do 50 or so cycles a year. This is why business jets almost never break 12,000 cycles. I'm not aware of any in fact. So spending an extra $500+ million of R&D and adding $350k+ to engine build costs make no sense. Also, production runs of a few thousand engines take many variations of the engine for multiple thrust levels.
Commercial jets typically do 2,000 to 3,000 cycles per year and are typically retired in the 40,000 to 70,000 cycle range (yes, MD-80s have done 98,000+). The only high cycle RJs are the CRJ where I believe (can anyone confirm?) That the fleet leaders are just passing 60,000 cycles. So the CF-34 missing 20,000 cycles because one regulator failed early annoyed airlines (now fixed). One little part, that met warranty but not promise, added 1/2% to the total cost of flying because of reduced overhaul intervals. So details matter.
Yeah, Island hopping airlines do exceed 5,000 cycles per year. No one engineers for small volumes.
So don't be discouraged. The 717 engines cost more per cycle, so the aircraft had a limited production run and found its way, excluding HA, into lower utilization duty. I could make a great CRJ engine off the Passport or Pearl, but both cores need new auxiliary systems, nacelles, and a full low spool. The current systems would require an engine overhaul every 10 to 15 months in the duty new aircraft are thrown into.
No one buys new for low utilization duty. There is a reason leasors have Allegiant, Volotea, and Delta are on speed dial for 12+ year old aircraft. (E.g., DL doesn't fly a third of their fleet Tuesday through Wednesday outside of surge events).
For RJs, the old aircraft serve the low utilization duty (fixed vs. variable costs favor old). New are flogged their first six years, basically the entire low maintenance life of the aircraft, as they have the lowest fuel burn too.
The MRJ is really an island hopper. Everything I know about the design shouts to the limit of validity (cycles and Hours) being dramatically increased (to almost MD-80 levels).
I'm amused by Photonsword in a good way.
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