What does HMV mean. I googled it and His Masters voice or High Maintenance Va***a isn't really helpful. You mean the big 3 airlines in China, or any western airline?
Not sure if you already found it, but it stands for Heavy Maintenance Visit
How does Lightsaber (who as far as I know is an American) know if any MA-60s never made it to a heavy maintenance check? Looking down through the list of operators, that' a lot of typically secretive third world countries.
Yes, I am an American. I work with stress engineers, many trained at Douglas. What has been found is they are all parked and the stress engineers were obsessing over why.
I personally worked on a bid for the ARJ-21 where cooling for engine parts had arbitrarily been cut in half to reduce fuel burn. I advised a no bid.
But who supplied the engines for the MA-60. Hmmm... Or the propellers? You really cannot produce an aircraft without Western content today.https://en.m.wikipedia.org/wiki/Xian_MA60
The engines go through overhaul prior to the aircraft heavy maintenance visit. If the engines and propellers cancel their service contracts...
Also, look at how all the early operators are storing ir scrapping the MA-60. The MA-600 was introduced to stop the cracking problem, at least that is what the stress engineers I personally know who were hired to fix the problem claim.
I work in an industry with thousands of contractors who I work with, they go off to another project, then I hire them back when needed. I have worked with over 1,400 contractors in my career. Since they want to be rehired, we occasionally meet up to chat where they ask for potential jobs and I chat aircraft design.
Since I am specialized in solving issues found in testing, I tend to interact with those people who are good at solving issues who are in demand (and command a pay bonus).
I also came out if flight test (I have kids, so I can no longer work those hours), so I know a lot of test pilots who like to drink and tell stories.
So unless the Western parts are ripped out, I or friends of mine have access to the maintenance data bases.
I also have friends at the component vendors including Moog and Meggitt (Aircraft valve vendors). Every aircraft ever built has at least one custom valve in it, usually built by the above two or Woodward (who isn't in Southern California, where I live), so when I go to a valve vendor, I always ask for a tour.
I also used to design aircraft regulators and bearings. So I have contacts in that small community.
When a heavy maintenance visit (HMV) is performed, it isn't just the maintenance provider (MRO) that is involved. All of the vendors are contacted for spare parts. By the HMV, everything that needs to be rebuilt must be rebuilt (excluding gear and engines, they work on their own cycles). So the vendors get parts in to rebuild.
As a turboprop part might cost $500 to rebuild or $1500 new, the vendors know how many spares are out there and if they have demand for rebuilds.
If the parts are not being rebuilt, aircraft are not undergoing HMVs.
So yes, I'm an American living where perhaps a quarter of the little vendors are located (SoCal) and Vendors always put up a poster for every aircraft they have parts on (to help sell future parts). So I ask.
So my vendors complain the MA-60 isn't getting parts rebuilt (EIS 2000, so 3 years past due), stress engineers tell me they were hired to fix a problem and performing examinations on those aircraft to try to make them fly again, and big vendors not being paid for overhauls...
I'm confident in my prior statements.
It is how I know the status of the MD-80/90 markets too.
Now trying to determine say a CFM-56 aircraft is doing is impossible for me as the shops are so overloaded when those parts are going through overhaul that I am politely asked to show up after they are done and the leads are so numb after overhauling so many parts, they cannot tell me DC-8, KC-135 vs. 737NG vs. A320 as it was just a flood of parts (and overtime). But all low production items, I get quite the earful when I go to a vendor, I particular the parts I designed.
So make no mistake, I can tell small batch aircraft utilization by frequency of overhauls. Now, the ARJ-21 is too new for a HMV, but eventually I'll find out if any are parked by the demand for component overhauls or if my contractors are hired (mind you, a very lagging indicator).
Flu+Covid19 is bad. Consider a flu vaccine, if not for yourself, to protect someone you care about.