Does anyone know the significance of the 10,600 lb / 4,800 kg MTOW of many planes?
Several planes are advertised as having an MTOW of exactly or extremely close to 10,600 lbs / 4,800 kg. I am interested in understand why this weight is so popular. Aircraft with this MTOW spec include but are not limited to:
* Cessna CitationJet / CJ1/ CJ1+ / Citation M2
* Beechcraft King Air C90 and C100 variants
* Embraer Phenom 100
* HondaJet HA-420
I understand that there are regulatory thresholds at 12,500 lbs and 19,000 lbs but I cannot find evidence of any regulatory thresholds at 10,600 lbs (or through foreign regulators, anything at the equivalent 4,800 kg). Furthermore I don't think that the limit is attributable to a shared engine or other component because all of the planes I mentioned have different engines and they all vary substantially in their design and performance.
There is a kind of industry conventional definition of a "VLJ" as having an MTOW of up to 10,000 lbs, however that doesn't explain the CitationJet which was developed before the "VLJ" moniker, nor the Beechcraft which isn't a jet, nor why they all exceed the 10,000 lbs conventional definition by a suspiciously consistent amount (600 lbs).
The only theories I have are either:
1. 10,600 lbs MTOW has some significance to insurers for single pilot operations, so even though its not a mandatory regulation, planes that are heavily marketed to single pilot owner-operators might keep that in mind
2. Its a complete coincidence and is a popular MTOW only because "it feels like 1 full step down from a 12,500 lbs MTOW" and a 12,500 lbs MTOW has logical basis as a significant limitation in FAA Part 23 certification.
The second theory is somewhat hinted by the fact that the Beechcraft King Air line and the Cessna CitationJet line each included a model one tier higher than my listed planes with an MTOW of 12,500 lbs. So if you are an airframer that is developing a line of aircraft in this general weight class, you are probably going to build one with an MTOW of exactly 12,500 lbs that maximizes the weight allowed under the simplest certification rules, and then if you build one smaller it has to be "enough smaller" to justify having 2 different models.
I am not thrilled by that explanation, the plethora of planes certified at almost exactly 10,600 lbs just seems too coincidental for there not to be a basis in regulations, insurance, or something like that.
Does anyone know the answer?