Avmax’s experience in freighter conversions has allowed us to help with Aircraft Commerce’s April/May 2017 article about “Cherry picking CRJ100s/200s for P-to-F conversion”
The CRJ100/200 series is the only RJ type with active passenger-to-freighter conversion options. Key P-to-F feed-stock selection criteria for these aircraft are considered here. Operators should prioritize age and accumulated flight cycles.
Below are some highlights.
Canadian-headquartered leasing and maintenance, repair & overhaul (MRO) specialist Avmax is the world’s largest lessor of CRJ100/200 aircraft. It has converted five CRJ200s to PF status so far, all of which have been leased.
“The precise variant of CRJ100 or CRJ200 series aircraft is designated by the engines,” says Rick Pollock, business development manager, aircraft leasing, Americas, at regional aircraft leasing specialist Avmax. “Any gains realized by operating an aircraft with CF34-3B1s, rather than CF34-3A1s, may be minimal in the typical freighter environment. You could therefore argue that CRJ100s and CRJ200s are equally suitable for P-to-F conversions. The only reason a cargo carrier may prefer the CRJ200 is if a high percentage of its flying involves serving hot and high airports, or frequently needs to operate the aircraft at its maximum take-off weight (MTOW),” adds Pollock.
“LR variants have been more popular in passenger service, but it is quite possible that operators in the freighter segment may not need the extra 2,000lbs of MTOW that an LR offers, either due to freight loading considerations or shorter sector lengths,” says Pollock.
“Each task in the CRJ100/200 Maintenance Planning Manual (MPM) has an individual inspection interval,” explains Paul Draper, planning manager at Avmax. “The intervals are FH, FC or calendar based. There are a few that have a combination of the three.
“Despite this, many operators still group inspections into blocks and refer to them as A and C checks,” adds Draper. “The C check interval is 5,000FH, while the A check interval is 500FH. Some operators equalize A checks into 250FH intervals, but this is uncommon.
“At typical levels of utilization, most passenger operators end up performing C checks every two years,” explains Draper.
It is likely that CRJ100/200 freighters would be bridged on to the low utilization maintenance program (LUMP). “The LUMP must be applied to any aircraft that operates fewer than 1,500FH per year in accordance with maintenance review board (MRB) requirements,” says Draper. “Due to the average utilization of cargo operators, it is likely that most CRJ100/200 freighters will be maintained under the LUMP. The LUMP moves a large number of the 5,000FH and 10,000FH inspection tasks to intervals of 48 and 96 months. This will result in heavy check inspections taking place at 48-month intervals.”
One particular maintenance consideration that potential CRJ100/200 freighter operators should be aware of relates to structural inspection tasks that come due when an airframe has accumulated 40,000FC. These fatigue damage (FD) tasks require deep access and potential operators might be concerned about associated MH requirements and any costs linked to associated non-routine rectifications.
“The FD tasks require the removal of the passenger cabin interior and all flight controls,” says Draper. “About half the tasks have a 40,000FC repeat interval, while the rest are manageable during the routine inspection cycle as part of a block check.” According to Bombardier, seven CRJ200 aircraft have undergone the 40,000FC inspection with a minimum amount of findings. This suggests the inspection should not be a major concern for potential freighter operators.
Avmax’s Draper agrees, and suggests that the FD tasks should be manageable if incorporated within existing heavy maintenance inspections.
“The FD tasks that come due at 40,000FC need a fair amount of access, but if this is scheduled with a C check the additional access is not excessive by any means,” says Draper. “If the FD tasks are performed as a standalone event out-of phase with a heavy check, it is estimated they will require 1,280MH. This is for a passenger-configured aircraft, with 985MH for access and 295MH for inspections. Access requirements are far smaller for a freighter due to the simplified interior, with no seats, overhead bins or galleys to remove.” If the FD tasks are performed during a scheduled C check the required access MH will clearly be significantly reduced. Avmax estimates that avoiding the duplication of access would reduce the time required to complete the 40,000FC FD tasks by 250MH for a passenger configured aircraft.
Avmax has put three CRJ200s through the 40,000FC inspections so far. “Non-routine findings resulting from the 40,000FC FD inspections have been low for the three aircraft that have reached this utilization threshold so far,” says Draper. “On average they have required fewer than 200MH to rectify. We have found corrosion on airframes converted to freighters, but this was during standard heavy checks as a result of the calendar-based structural and corrosion prevention control program (CPCP) inspections.”