In Response to Pam's inquiry into the Catalina's cruising speeds, I've decided to post a little guide to cruising operations in the Catalina.
First, engine operation. During normal flight, the Mixture should always be set to either Auto-Lean or Auto-Rich. This boundary is determined by the operating power of the R-1830-92's. Above 700 brake horsepower is the Auto-Rich zone, and below is the Auto-Lean zone. Practically, this is determined by engine speed and Manifold pressure.
- If Engine speed is less than 2150 RPM, Mixture is always Auto-Lean
- At 2150 and above 29.5" hg, is the lower boundary of the Auto-Rich Zone
- At 2550 and above 27.0" hg, is the upper boundary of the Auto-Rich Zone
Cruising Speeds. These speeds assume a 30,000lb Cat at 4,000ft at 15 Deg C; and of course, a well mannered engine.
Very Slow Cruise: 105KTAS (Auto-Lean)
Slow Cruise: 120KTAS (Auto-Lean)
Moderate Cruise: 130KTAS (Auto-Rich)
Fast-Cruise: 140KTAS (Auto-Rich)
I hope this helps, and please feel free to ask any further questions.
Kind Regards,
John
First, engine operation. During normal flight, the Mixture should always be set to either Auto-Lean or Auto-Rich. This boundary is determined by the operating power of the R-1830-92's. Above 700 brake horsepower is the Auto-Rich zone, and below is the Auto-Lean zone. Practically, this is determined by engine speed and Manifold pressure.
- If Engine speed is less than 2150 RPM, Mixture is always Auto-Lean
- At 2150 and above 29.5" hg, is the lower boundary of the Auto-Rich Zone
- At 2550 and above 27.0" hg, is the upper boundary of the Auto-Rich Zone
Cruising Speeds. These speeds assume a 30,000lb Cat at 4,000ft at 15 Deg C; and of course, a well mannered engine.
Very Slow Cruise: 105KTAS (Auto-Lean)
Slow Cruise: 120KTAS (Auto-Lean)
Moderate Cruise: 130KTAS (Auto-Rich)
Fast-Cruise: 140KTAS (Auto-Rich)
I hope this helps, and please feel free to ask any further questions.
Kind Regards,
John