Our Coupe has the same takeoff RPM's about 2200. My climb rate at 1320lbs, 85HP, wooden climb prop, indicating 70 MPH is about 400 FPM on a cool day. At 75MPH my climb is about 300 FPM.
Jim N3439H 415C KFDK ----- Original Message ----- From: alanrayj To: [email protected] Sent: Monday, March 30, 2009 7:39 PM Subject: [ercoupe-tech] RPM at takeoff and cruise altitude Let me begin by saying I realize ercoupes and M-10's are not racing aircrafts, and I did not buy one for that purpose. I love vintage aircraft and it is a joy to fly an M-10, but the only aircrafts I have flown before have had 180hp Lycoming engines and I am wondering if what I am experiencing with my M-10 is normal. And this group is the perfect forumn to answer my questions being new to ercoupes and M-10's The M-10 has 850 hours since the last major overhaul and the annual was done in December with no problems documented. It still has the original Continental C-90-16F engine. My M-10 rpm's max out at 2000 to 2100 at take off.(redline for the rpm is 2475rpm) My field altitude is 600 feet and the temperature has been averaging around 40 to 70 degrees F with winds of 5 to 10 knt. This is enough power to become air borne (according to the original POH lift off or rotation should be at 50 mph) which is no problem. After I become airborne my Vx and Vy are only 100 to 200 feet a minute to reach pattern altitude at this max rpm of 2100 rpm. Is this normal. The problem is the aircraft seems sluggish (it sounds like a radial engine which I actually like, and I saw no visible problems with the exhaust) and the aircraft will not get above an rpm of 2100 to 2200 rpm. This is within the green arc of the rpm but seems sluggish at take off and climbing to pattern altitude. Climbing to cruising altitude of 2500msl to 3500msl the airplane will maintain rpms of 1900 to 2100 and climb at a rate of 100 to 500 feet per minute. Is what I am experiencing normal or do I have a problem that needs to be corrected. Any help with these questions will be appreciated. Alan
