Understanding_Specifications
Decode performance metrics, tradeoffs, and real-world implications of aircraft specifications
⚠️ The Performance Triangle
Every aircraft operates within a performance triangle. You can optimize for two of three variables, but never all three simultaneously:
RANGE
Maximum distance
PAYLOAD
Passengers + baggage
SPEED
Time to destination
Example: Maximum range requires reduced payload. Maximum payload reduces range. Maximum speed increases fuel burn, reducing both range and payload.
[1] Range Specifications
What "Range" Really Means
Manufacturer range specifications always include specific conditions. Never assume maximum range applies to your mission.
Example: Phenom 300E Range Specification
"2,010 nm with 5 occupants, NBAA IFR reserves"
This means:
- 5 people onboard (not 10 max capacity)
- NBAA fuel reserves (not minimum legal reserves)
- Standard atmospheric conditions (ISA)
- Optimal altitude and speed for maximum range
Factors Reducing Published Range
Additional Passengers/Baggage
Each 200 lb reduces range by ~50-100 nm (varies by aircraft)
Headwinds
50 kt headwind can reduce range by 300-500 nm
High/Hot Conditions
ISA+15°C reduces range by 5-10%
Increased Speed
Flying high-speed cruise reduces range by 200-400 nm
Aircraft Age/Condition
Engine deterioration can reduce range by 3-7% over time
The 75% Rule of Thumb
For real-world mission planning, expect practical range to be approximately 75% of published maximum range when operating with typical passenger load and reserves.
Example: Praetor 600
Still sufficient for transcontinental US or NYC-Europe routes
[2] Speed Specifications Decoded
Three Speed Ratings Explained
Most fuel-efficient speed for maximum range
✓ Best for: Long legs, payload-limited missions
Balance of speed and fuel efficiency
✓ Best for: Most missions, normal operations
Maximum certified speed, significantly higher fuel burn
⚠ Reduces range by 15-25%
Speed vs Fuel Efficiency
The relationship between speed and fuel consumption is not linear—it's exponential. Small speed increases cause large fuel burn increases.
| Speed Setting | Time Saved | Fuel Penalty |
|---|---|---|
| LRC → Normal | +5-7% | +8-12% |
| Normal → High | +3-5% | +15-20% |
[3] Cabin Dimensions & Comfort
Height Matters Most
< 5'0" (60")
VLJ category - seated only
5'8" - 6'0" (68"-72")
Light jets - crouch/limited stand-up
> 6'0" (72"+)
✓ Full stand-up cabin
Width & Volume
Cabin width determines seating configuration and comfort:
Cabin Volume: The True Comfort Metric
Total cabin volume (length × width × height) is a better comfort indicator than any single dimension.
400 ft³
Light Jet
Adequate for 4-6 pax
600 ft³
Midsize Jet
Comfortable for 6-8 pax
1,000+ ft³
Super Mid/Large
Spacious for 10+ pax
[4] Operating Cost Breakdown
Cost Per Flight Hour Components
Fuel Consumption Rates
Fuel is your largest variable cost. Understanding consumption rates is critical for budgeting:
At $5/gallon: Light jet fuel = $750-1,000/hr | Midsize = $1,000-1,400/hr
✓ Key Takeaways
- 1.No single specification tells the whole story. Always evaluate performance in context of your specific mission profile.
- 2.Practical range is ~75% of published maximum. Account for payload, weather, and reserves in mission planning.
- 3.Speed costs fuel. High-speed cruise increases hourly operating costs by 15-25% while saving minimal time.
- 4.Cabin volume matters more than any single dimension. Total cubic footage determines true passenger comfort.
- 5.Operating costs vary by 3-4x across aircraft categories. Annual operating budget should drive aircraft selection.