Cherokee 6 Weight and Balance Calculator

Ensure a safe and compliant flight for your Piper PA-32 Saratoga, Cherokee Six, or Lance.

Flight Parameters

Item	Weight (lbs)	Arm (in)	Moment (in-lbs)
Enter values and click Calculate.

What is a Cherokee 6 Weight and Balance Calculator?

A Cherokee 6 weight and balance calculator is a specialized tool designed to help pilots and aircraft owners of the Piper PA-32 series (which includes models like the Cherokee Six, Saratoga, and Lance) determine if their aircraft is loaded within safe operational limits for a given flight. Proper weight and balance is not just a regulatory requirement; it's a critical safety factor that directly impacts an aircraft's stability, maneuverability, and performance. This calculator simplifies the complex calculations needed to ensure the aircraft's Center of Gravity (CG) remains within the acceptable envelope throughout the flight, from takeoff to landing.

Who should use it? Any pilot operating a Piper PA-32 series aircraft, including:

• Private pilots flying for recreation or personal travel.
• Commercial operators conducting charter or ferry flights.
• Flight instructors supervising training operations.
• Aircraft owners managing their maintenance and operational safety.

Common misconceptions about weight and balance include believing that if the total weight is below Maximum Takeoff Weight (MTOW), the aircraft is automatically safe. This overlooks the crucial aspect of CG placement. An aircraft can be within the weight limit but still be dangerously tail-heavy (aft CG) or nose-heavy (forward CG), leading to control difficulties or even an unrecoverable stall. Another misconception is that weight and balance calculations are only needed for long or heavily loaded flights; they are essential for every flight, regardless of duration or payload.

Cherokee 6 Weight and Balance Formula and Mathematical Explanation

The fundamental principle of aircraft weight and balance involves distributing the aircraft's mass such that its CG falls within a specified range. This ensures the aircraft remains stable and controllable.

The core calculations involve:

1. Calculating Individual Moments: For each item loaded onto the aircraft (empty weight, occupants, baggage, fuel), its moment is calculated. The moment is the product of the item's weight and its horizontal distance from a reference datum (usually the aircraft's nose).
   Moment = Weight × Arm
2. Calculating Total Moment: All individual moments are summed up to find the aircraft's total moment at its current configuration.
   Total Moment = Σ (Weighti × Armi)
3. Calculating Total Weight: All individual weights are summed to find the total weight of the aircraft.
   Total Weight = Σ Weighti
4. Calculating the Center of Gravity (CG): The CG is determined by dividing the Total Moment by the Total Weight.
   CG = Total Moment / Total Weight
5. Checking Against Limits: The calculated CG is then compared to the aircraft's allowable CG range (Forward CG Limit and Aft CG Limit) for the calculated Total Weight. This range is typically defined in the aircraft's Pilot's Operating Handbook (POH) or Aircraft Flight Manual (AFM).

For the Cherokee 6 series, specific arms for various seating positions and baggage compartments are provided in the POH. These values are crucial for accurate calculations. The calculator automates these steps.

Variables Table:

Variable	Meaning	Unit	Typical Range (PA-32 Series)
BEW	Basic Empty Weight	lbs	~2000 – 2600 lbs
BEW Moment	Moment of the Basic Empty Weight	in-lbs	~75,000 – 105,000 in-lbs
Occupant Weight	Weight of persons in seats	lbs	~150 – 250 lbs per person
Occupant Arm	Horizontal distance of occupants from datum	inches	~38.5 (Fwd), ~70-80 (Aft)
Baggage Weight	Weight of cargo in baggage compartments	lbs	~0 – 200 lbs (Total for both compartments)
Baggage Arm	Horizontal distance of baggage from datum	inches	~90 (Bag 1), ~125 (Bag 2)
Fuel Weight	Weight of usable fuel	lbs	~0 – 480 lbs (Full tanks: 80 gal * 6 lbs/gal)
Fuel Arm	Horizontal distance of fuel tanks from datum	inches	~40 (Main tanks)
Total Weight	Sum of all weights aboard	lbs	~2500 – 3800 lbs (MTOW)
Total Moment	Sum of all individual moments	in-lbs	~100,000 – 150,000+ in-lbs
CG	Center of Gravity location	inches from datum	~75 – 85 inches (Typical operating range)

Practical Examples (Real-World Use Cases)

Let's illustrate with two common scenarios for a Piper PA-32-300 Cherokee Six:

Example 1: Short Weekend Trip with Family

Scenario: A pilot is flying with his wife and two children to a nearby city for the weekend. They are carrying moderate baggage.

Inputs:

• Basic Empty Weight (BEW): 2250 lbs
• BEW Moment: 88,000 in-lbs
• Forward Occupant (Pilot + Wife): 360 lbs at 38.5 in
• Aft Occupants (2 Children): 200 lbs at 74.5 in
• Baggage 1: 120 lbs at 90 in
• Baggage 2: 0 lbs at 125 in
• Fuel: 64 US Gal = 384 lbs at 40 in

Calculation Results:

• Total Weight: 2250 + 360 + 200 + 120 + 0 + 384 = 3314 lbs
• Total Moment: (2250*38.5) + (360*38.5) + (200*74.5) + (120*90) + (0*125) + (384*40) = 88000 + 13860 + 14900 + 10800 + 0 + 15360 = 142,920 in-lbs
• Current CG: 142,920 in-lbs / 3314 lbs = 43.12 inches from datum
• Status: Within limits (Assuming typical Cherokee Six limits for this weight)

Interpretation: With this load, the aircraft is well within its maximum takeoff weight (typically 3800 lbs for a PA-32-300) and the CG is safely forward. The pilot should monitor fuel burn, as this will shift the CG aft.

Example 2: Ferrying Aircraft with Maximum Baggage and Fuel

Scenario: A pilot is ferrying the aircraft to a new owner, carrying maximum allowable baggage and full fuel tanks, but no passengers.

Inputs:

• Basic Empty Weight (BEW): 2400 lbs
• BEW Moment: 95,000 in-lbs
• Forward Occupant (Pilot only): 180 lbs at 38.5 in
• Aft Occupants: 0 lbs at 74.5 in
• Baggage 1: 150 lbs at 90 in
• Baggage 2: 50 lbs at 125 in
• Fuel: 80 US Gal = 480 lbs at 40 in

Calculation Results:

• Total Weight: 2400 + 180 + 0 + 150 + 50 + 480 = 3260 lbs
• Total Moment: 95000 + (180*38.5) + (0*74.5) + (150*90) + (50*125) + (480*40) = 95000 + 6930 + 0 + 13500 + 6250 + 19200 = 140,880 in-lbs
• Current CG: 140,880 in-lbs / 3260 lbs = 43.21 inches from datum
• Status: Within limits (Assuming typical Cherokee Six limits for this weight)

Interpretation: Even with maximum baggage and full fuel, the aircraft's weight (3260 lbs) is below MTOW (3800 lbs). The CG is also well within the typical forward limit, which is common when carrying heavy fuel loads forward. The pilot must be aware that as fuel burns off, the CG will move aft. They should check the POH for the CG envelope at the expected landing weight.

How to Use This Cherokee 6 Weight and Balance Calculator

1. Gather Aircraft Data: Obtain your specific aircraft's Pilot's Operating Handbook (POH) or Aircraft Flight Manual (AFM). You will need the aircraft's Basic Empty Weight (BEW) and its corresponding moment, along with the arms (horizontal distances from datum) for all seating positions, baggage compartments, and fuel tanks.
2. Find Your Current Load Data: Determine the weight of each person, baggage item, and the amount of fuel you plan to carry. Remember that 1 US gallon of aviation fuel weighs approximately 6 lbs.
3. Input Data: Enter the values into the calculator fields:
   • Start with your aircraft's Basic Empty Weight (BEW) and its BEW Moment.
   • Enter the weight and arm for all occupants (forward and aft cabins).
   • Enter the weight and arm for any baggage loaded in compartment 1 and compartment 2 (if applicable).
   • Enter the total weight of usable fuel and its corresponding arm.
4. Calculate: Click the "Calculate" button. The calculator will process your inputs.
5. Review Results:
   • Primary Result: The calculated Current Takeoff CG (in inches from datum) will be displayed prominently.
   • Intermediate Values: You'll see the Total Takeoff Weight, Total Moment, and a Status indicator (Within Limits / Out of Limits).
   • Table: A detailed breakdown of each item's weight, arm, and calculated moment will appear in the table.
   • Chart: A visual representation shows your current CG point relative to the aircraft's forward and aft CG limits across its weight range.
6. Interpret Status: If the status is "Within Limits," your aircraft is loaded safely for takeoff. If it shows "Out of Limits," you must adjust the load (remove weight or shift it) to bring the CG within the acceptable range before flight.
7. Decision Making: Use the results to decide if your planned load is safe. If it's borderline, consider reducing baggage or fuel, or ensuring passengers are distributed appropriately. If you are near MTOW, pay extra attention to the CG, as even small shifts can move it outside the limits.
8. Reset: Use the "Reset" button to clear all fields and start fresh.
9. Copy: Use "Copy Results" to save the calculated values for your flight log.

Key Factors That Affect Cherokee 6 Weight and Balance Results

Several factors significantly influence the weight and balance calculations for a Cherokee 6:

1. Payload Distribution: Where you place passengers and baggage is critical. Heavier items placed further aft will shift the CG aft, while heavier items placed further forward will shift it forward. The Cherokee 6's multiple seating rows and two baggage compartments offer flexibility but require careful planning.
2. Fuel Load: Fuel is a significant weight component. The fuel tanks are typically located forward of the main cabin, meaning a full fuel load will tend to keep the CG forward. As fuel is consumed during flight, the aircraft becomes lighter, and the CG shifts aft. This shift must be accounted for, especially on longer flights where significant fuel burn occurs.
3. Aircraft Configuration Changes: Any modifications, equipment installations (like avionics upgrades), or repairs that change the aircraft's empty weight or its moment will alter the baseline BEW and BEW Moment. These changes MUST be incorporated into the aircraft's official Weight and Balance records via an FAA Form 337 and updated records.
4. Passenger and Cargo Weight Variations: Actual passenger weights can vary significantly from estimates. Always use the actual weight of occupants and cargo, or the maximum allowable weight specified in the POH if actual weights are unknown. Overestimating occupant weights slightly is safer than underestimating.
5. Datum Selection: While the datum is fixed by the manufacturer, understanding its location relative to the aircraft's structure is key. All arms are measured from this point. A common datum for the Cherokee 6 is the leading edge of the wing.
6. Maximum Takeoff Weight (MTOW): The total weight of the aircraft cannot exceed its certified MTOW. Exceeding MTOW compromises performance, structural integrity, and controllability. This calculator checks your loaded weight against MTOW implicitly via the CG limits, which are often tied to specific weight ranges.
7. CG Limits and Envelope: Each aircraft type and model has a specific CG range (forward and aft limits) that is dependent on the aircraft's weight. These limits are published in the POH/AFM. The calculator visualizes this by plotting your current CG against the aircraft's acceptable CG envelope.

Frequently Asked Questions (FAQ)

Q1: Where do I find the official Arms for my Cherokee 6?

A1: The specific horizontal arms (distances from the datum) for the seats, baggage compartments, and fuel tanks are published in your aircraft's official Pilot's Operating Handbook (POH) or Aircraft Flight Manual (AFM). Always use the values from your aircraft's specific documentation.

Q2: What is the datum and why is it important?

A2: The datum is an arbitrary vertical line or point used as the zero reference for all horizontal measurements (arms) in the aircraft's weight and balance calculations. It's typically located at or near the aircraft's nose. Consistency in using the datum for all measurements is crucial for accurate CG calculation.

Q3: How much does fuel weigh?

A3: Aviation gasoline (Avgas) weighs approximately 6 pounds per US gallon. Jet fuel weighs approximately 6.7 pounds per US gallon. For the Cherokee 6, assume 6 lbs/gal for planning.

Q4: What is the Maximum Takeoff Weight (MTOW) for a Cherokee 6?

A4: MTOW varies slightly by specific model (e.g., PA-32-260, PA-32-300, T-32, 6X, 6XT). For many common PA-32-300 models, it is 3800 lbs. Always consult your aircraft's specific POH/AFM for the definitive MTOW.

Q5: Can I carry more weight if the CG is within limits?

A5: No. You must satisfy BOTH the maximum weight limit AND the CG limits. The CG limits are often dependent on the current weight, meaning the acceptable CG range may narrow as the aircraft gets heavier or lighter.

Q6: What happens if my CG is outside the limits?

A6: Flying an aircraft outside its CG limits can lead to serious control problems, reduced stability, and potential loss of control. If your calculated CG is out of limits, you must rearrange or remove weight before flight. Generally, a CG too far aft is more dangerous than one too far forward, as it can lead to stall/spin characteristics that are difficult to recover from.

Q7: How does fuel burn affect CG?

A7: Since fuel is typically loaded forward of the CG datum, as fuel is consumed, the total weight decreases, and the CG shifts aft. This is a critical consideration for long flights. You may start within limits, but end up outside the aft limit if not properly planned.

Q8: Do I need to update my W&B records after using this calculator?

A8: This calculator is a tool for pre-flight planning. For official records, any permanent changes to the aircraft's weight or balance (e.g., installing new equipment) require updating the aircraft's Weight and Balance sheet, which must be done by qualified personnel and documented according to FAA regulations.

Q9: What are the typical CG limits for a Cherokee 6?

A9: Typical operating CG limits for a PA-32-300 range roughly from about 75 inches to 85 inches aft of the datum, but this range often varies with weight. For example, the forward limit might be 75″ up to 3400 lbs, then move forward slightly to 73″ above 3400 lbs, and the aft limit might be 85″ up to 3400 lbs and move forward to 83″ above 3400 lbs. ALWAYS refer to your specific POH/AFM for exact limits.

Related Tools and Internal Resources

TOTALS

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