Beginner's
Guide to Propulsion
Range
and Fuel Consumption Activity
If so instructed
by your teacher, print out a worksheet page for these problems.
Before you begin:
Airplane specifications
generally include pieces of information about the range,
cruise speed, and
fuel capacity
of a given airplane. These three items make it possible to calculate
fuel consumption, range, and cruise speed.
Equations:
-
To find the
time it takes to travel a given distance at a given speed, use the
following equation:
-
To find the
airplane's fuel consumption:
Note: Total
fuel is considered the total amount of fuel excluding any fuel reserves.
Reserves can generally be considered 10% of the total amount of fuel
capacity for the airplane. For airplanes that are able to fly by "IFR"
(Instrument Flight Rules), or with instruments, the reserves will
be higher. If this is the case, the specifications will show the IFR
quantity reserves. Total time is the number that you calculated in
Equation 1.
Directions:
-
Using these
two equations and the data from the Airplane
Information sheet on four types of aircraft, answer the questions
on the worksheet. (Ask your teacher if you can print the worksheet.)
-
Use the Conversion
Web site for assistance with speed, distance, and/or weight conversions.
Answer the following
questions:
-
You are an acrobatic
pilot getting ready to go to an air show. The air show is being
held at an airport 500 nautical miles (NM) away. Given the cruising
speed of the Extra 300 you are flying, how long will it take to
fly to the air show?
-
In the situation
above, will you be able to fly to the air show without refueling
along the way? Why or why not?
-
A Cessna Skylane
has a range of 820 NM and a cruising speed of 140 KTS. How many
hours will it take you to fly 820 NM?
-
Since the Skylane
has a fuel capacity of 88 US GAL (including 10% in reserve -- Don't
forget to subtract the 10% before figuring your consumption.), how
many gallons of fuel per hour does it use?
-
You are flying
a Cessna Skylane at a speed of 120 KTS. You are flying on a trip
that will take you 520 NM. How long will it take you to get to your
destination?
-
In the situation
above, given that your Cessna holds 88 US GAL of fuel (with 10%
held back as reserve fuel), how much fuel will you use? (Hint: you
will need your final answer from Question 4 to find this number.)
-
You are the
pilot of a Learjet 31A leaving Chicago's Meigs airfield under dense
fog conditions. You must fly using your instruments (IFR). How much
fuel do you have for this flight? (Don't forget about your reserves.)
-
You've been
flying the Learjet for 1.5 hours, at a speed of Mach .76 (Visit
the Conversion
page to convert Mach numbers into Knots.), under visual flight conditions
(VFR). How much fuel do you have left (excluding reserves)?
-
How much farther
could you fly on the fuel you have left from Question 8?
- You are a WW-I
Sopwith Camel fighter pilot chasing the infamous "Red Baron." You
are traveling at a speed of 115 KTS. You know that your enemy is 40
NM away from you. How many minutes will it take to reach him?