View Full Version : Max RPM (N17N2)
alatriste
2nd Mar 2006, 09:35
Just curious.....
I would like to Know the max RPM ( N1 and N2) for different jet engines, I cannot find this data in any of the AFM of the airplanes Iīve flown.
Thanks for the info.
john_tullamarine
2nd Mar 2006, 09:43
? should be in the Limitations Section of ALL AFMs.
.. or is it a case of you have the limitation as a percentage and are after the actual RPM ?
alatriste
2nd Mar 2006, 09:56
Yes John, this data is not available in my manuals.
Limitations regarding power plant says N1 max 101.7 % and N2 102.5% for the JT8D-219, but what about RPM. I would like to Know if we are talking about 25.000 rpm, 15.000 rpm or 5.000 rpm.
For other engines I donīt even have this data (e.g IAEV2500 or PW4060) just ECAM red lines.
For sure max rpm will depend on engine BPR and I would like to know some max rpms for diferent jet engines.
thanks for your help
barit1
2nd Mar 2006, 11:21
The engine Type Certificate Data Sheet will give these numbers. It's on the FAA website I'm sure.
john_tullamarine
2nd Mar 2006, 19:28
Some data in the TCDS (http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgMakeModel.nsf/0/a917bb88f923ba338525670d0063152c/$FILE/E9ne.PDF). You could also contact Pratts .. they are generally pretty helpful (even if I'm still trying to get some specific PT6 performance data out of my local support organisation ...)
barit1
4th Mar 2006, 13:30
There is a bit of information you can extract from this TCDS (JT8D-219) if you know one additional detail:
The tachometer drives on older-vintage engines are all of a spec that says when the drive pad turns 4200 rpm, the steam gage reads 100%.
From the TCDS, the N1 tach pad is turning at 0.511 times fan rotor RPM. Thus when the pad turns 4200, the fan turns 4200/0.511 = 8219 rpm. This represents 100% on the N1 gage.
Similarly when the core turns 4200/0.343 = 12245 rpm, that's 100% on the N2. :8
I don't think many newer engines use the old-style tachometer system in this illustration, though...
alatriste
5th Mar 2006, 11:42
Thanks John and Barit1 for your time and interest. The info is good enough for this engine. Anyhow, I cannot find the TCDS for other engines in the FAA website.