Mooney M20B Mark 21 Model Guide
Mooney M20B Mark 21 · Model Guide
Overview
The Mooney M20B Mark 21 is a four-seat, single-engine piston aircraft built from 1961 to 1963. Its 1961 owner's manual describes a 180 HP Lycoming O-360-A1A, a McCauley constant-speed propeller and a laminar-flow wing. The wider M20 family reaches up to 222 kt cruise and 1050 nm range. Those are family maximums, not figures for this variant.
- The 180 HP Lycoming O-360-A1A has a 750-hour normal overhaul life. Flying it longer needs a mechanic's approval.
- Minimum fuel is 91-98 octane. 100-130 octane is preferred because of its lower lead content. Never use a lower grade than 91.
- An aileron control link AD applies to all M20B serial numbers. It requires inspection within 100 hours and repeat checks at intervals of up to 100 hours.
- The weight and balance sheet in the file is for an M20C. Get this airframe's own weight and balance records before you buy.
Summary written by AI from the source document. Check the original before relying on it. See which parts of Sprinkle are written by AI.
Reference only, not for flight. Use the current approved manual for your aircraft. See terms, section 5.
Document
Source
Copy found at sprinkle.com. Sprinkle hosts a reference copy with an added summary, specifications and searchable full text.
Document details
- Type ·
- Model Guide
- Year ·
- 2026
- File size ·
- 48 KB
- Copy found at ·
- sprinkle.com
Specifications & performance
Extracted from this document.
Specifications
- Engine power (hp) ·
- 180
- Propeller diameter (in) ·
- 74
Weight & balance
- Original spinner weight (lb) ·
- 3
- Original mccauley propeller weight (lb) ·
- 59
- Alternative hartzell propeller weight (lb) ·
- 65
What engine does the Mooney M20B Mark 21 have?
The Mooney M20B Mark 21 has a Lycoming O-360-A1A rated at 180 HP, driving a McCauley constant-speed propeller 74 inches in diameter, per its 1961 owner's manual.
What fuel should the Mooney M20B Mark 21 use?
The Mooney M20B Mark 21 engine is designed for 91-98 octane aviation fuel. 100-130 octane is preferable because of its lower lead content. Never use a grade lower than 91.
How long can the Mooney M20B Mark 21 engine run before overhaul?
For the Mooney M20B Mark 21, the manual gives the FAA-approved normal overhaul life of the O-360-A1A as 750 hours. It can be flown longer only with a mechanic's approval.
Is there an airworthiness directive on the Mooney M20B Mark 21?
Yes. The Mooney M20B Mark 21 falls under the aileron control link AD, which covers all M20B serial numbers. It requires inspection within 100 hours and repeat checks at intervals of up to 100 hours, unless the improved links are fitted.
What is the Mooney M20B Mark 21 Model Guide?
The Mooney M20B Mark 21 Model Guide is a model guide for the Mooney M20B Mark 21, dated 2026.
What year was the Mooney M20B Mark 21 Model Guide published?
The Mooney M20B Mark 21 Model Guide — the Mooney M20B Mark 21 model guide on file — is dated 2026.
Common. One of the most common aircraft types we track.
Most owners only have the POH. Here's the essential set for the Mooney M20B Mark 21.
- Pilot's Operating Handbook / AFM
- Checklist
- Maintenance Manual
- Parts Catalog (IPC)
- Systems & Wiring
- Service Bulletins on file
- Type Certificate (TCDS)
Mooney M20B Mark 21 for sale now
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More Mooney M20B Mark 21manuals & documents
- AUTOPILOT SERVO INSTALLATION MANUALMaintenance Manual
- Mooney M20B Mark 21 Training ManualTraining Manual
- SCHEDULE OF AIRWORTHINESS DIRECTIVESService Bulletins
- Weight & Balance for Mooney M20B Mark 21Weight & Balance
- Weight & Balance for Mooney M20B Mark 21Weight & Balance
- Pilot's Operating Handbook for Mooney M20B Mark 21Pilot's Operating Handbook
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In this document
Engine and propeller
The Mark 21 has a Lycoming O-360-A1A rated at 180 HP, with a Bendix dual-magneto ignition and a starting vibrator. The oil system holds eight quarts. It runs safely on as little as two quarts, and the manual says to add one quart when the level falls below six. The McCauley constant-speed propeller is 74 inches in diameter. Check the blades for nicks and cracks before each flight.
Propeller options and records
The original type-certificated propeller on M20A and M20B models is a McCauley, listed at 59 lbs with a 3 lb spinner. An older Hartzell option is listed at 65 lbs. A Hartzell HC-C2YR-1BFP/F7497 STC propeller is approved for the M20B. Its tachometer marking is a 2700 RPM red line with a 2100-2700 RPM green arc. Confirm any propeller swap is in the logbooks with a Form 337 and updated weight and balance.
What to check before buying
Ask for proof that the aileron control link AD (Mooney SB M20-264, FAA AD 98-24-11) was done. Check for a reinforcement gusset, or for repeat inspection records. Ask for engine hours since overhaul against the 750-hour normal life. Look at the blue band on the cylinders, which the manual says marks the newest O-360-A1A version. Review the generator, vacuum pump and propeller governor condition.
Summary written by AI from the source document. Check the original before relying on it. See which parts of Sprinkle are written by AI.
Safety notes
- Aileron control link failure could cause loss of aileron control. The AD requires inspection within 100 hours and repeats at intervals of up to 100 hours.
- Never use fuel below 91 octane in the O-360-A1A. The manual gives 80 octane as red, 91 as blue and 100 as green.
- Do not rely on the M20C weight and balance sheet in the file. Load the aircraft only from this airframe's own approved data.
Summary written by AI from the source document. Check the original before relying on it. See which parts of Sprinkle are written by AI.
Full document text
Mooney M20B Mark 21 Model Guide The Mooney M20B Mark 21 is a four-seat, single-engine piston aircraft built from 1961 to 1963. Its 1961 owner's manual describes a 180 HP Lycoming O-360-A1A, a McCauley constant-speed propeller and a laminar-flow wing. The wider M20 family reaches up to 222 kt cruise and 1050 nm range. Those are family maximums, not figures for this variant. • The 180 HP Lycoming O-360-A1A has a 750-hour normal overhaul life. Flying it longer needs a mechanic's approval. • Minimum fuel is 91-98 octane. 100-130 octane is preferred because of its lower lead content. Never use a lower grade than 91. • An aileron control link AD applies to all M20B serial numbers. It requires inspection within 100 hours and repeat checks at intervals of up to 100 hours. • The weight and balance sheet in the file is for an M20C. Get this airframe's own weight and balance records before you buy. Engine and propeller The Mark 21 has a Lycoming O-360-A1A rated at 180 HP, with a Bendix dual-magneto ignition and a starting vibrator. The oil system holds eight quarts. It runs safely on as little as two quarts, and the manual says to add one quart when the level falls below six. The McCauley constant-speed propeller is 74 inches in diameter. Check the blades for nicks and cracks before each flight. Propeller options and records The original type-certificated propeller on M20A and M20B models is a McCauley, listed at 59 lbs with a 3 lb spinner. An older Hartzell option is listed at 65 lbs. A Hartzell HC-C2YR-1BFP/F7497 STC propeller is approved for the M20B. Its tachometer marking is a 2700 RPM red line with a 2100-2700 RPM green arc. Confirm any propeller swap is in the logbooks with a Form 337 and updated weight and balance. What to check before buying Ask for proof that the aileron control link AD (Mooney SB M20-264, FAA AD 98-24-11) was done. Check for a reinforcement gusset, or for repeat inspection records. Ask for engine hours since overhaul against the 750-hour normal life. Look at the blue band on the cylinders, which the manual says marks the newest O-360-A1A version. Review the generator, vacuum pump and propeller governor condition. Safety notes: • Aileron control link failure could cause loss of aileron control. The AD requires inspection within 100 hours and repeats at intervals of up to 100 hours. • Never use fuel below 91 octane in the O-360-A1A. The manual gives 80 octane as red, 91 as blue and 100 as green. • Do not rely on the M20C weight and balance sheet in the file. Load the aircraft only from this airframe's own approved data.