Aimpoint shifting down the runway
Mission 10: Landing From A Base Leg Position Using The
Instruments
Figure 10-1
Figure 10-2
The other important part of the HSI is the CRS (Course) knob, which allows you to set a course in 5° increments into the course window. The course window sets a course that is shown on the dial by the CDI (Course Deviation Indicator), which is a needle that deflects to show your position from the selected course. Figure 10-3 shows this needle along with another important indicator, the bearing pointer, which points to the selected TACAN station. Along with the bearing pointer needle is a
corresponding tail of the bearing pointer.
In the center of the HSI are a series of dots that show how many degrees the needle is deflected from the desired course. Each dot represents either 5° or 2.5°, depending on which mode the HSI is in.
When the needle is fully deflected, the aircraft is 10° or greater from the selected course.
To the left of the course window is the range window, which shows nautical miles to the selected TACAN station or navigation steerpoint, whichever is selected. One fundamental feature of the HSI is that it does not exclusively display TACAN data. The HSI also displays navigation steerpoints and ILS (Instrument Landing System) information. The F-16 pilot can navigate using TACAN stations or INS
Figure 10-3
(Inertial Navigation System) steerpoints. INS steerpoints are specific places in the world that are loaded into the aircraft's INS. The INS uses a laser gyroscope to determine where the aircraft is at all times. The pilot can then put steerpoints into the ILS pattern system and get steering to those destinations in the HUD and HSI. The HSI displays this information in the same way that it displays TACAN data. ILS data can also be displayed on the HSI. The ILS is used for precise azimuth and glide slope steering to the runway during night or adverse weather. The ILS signal radiates from a series of antennas located near the runway. Figure 10-4 shows the ILS antenna radiation pattern. Aircraft use onboard equipment to pick up this radiated signal and steer toward the intersection of the radiated pattern. This creates a path in the sky down toward the runway.
Figure 10-4
When the ILS is selected, ILS steering appears in the HUD to match the HSI. One limitation of the ILS is that you must be close to the airport (approximately 20 miles) and near the antenna pattern in order to receive ILS steering. For this reason, it is best to use the TACAN first and then switch to the ILS when you are within 20 miles and near the inbound course. In summary, the HSI can display course information along with aircraft position from a selected TACAN station, navigation steerpoint or ILS course. Several combinations of the above data sources can be selected and displayed on the HSI.
Below the HSI is the Instr Mode knob, which has four settings: NAV, NAV/ILS, TCN (TACAN) and TCN/ILS.
You will practice intercepting a final approach course and landing the aircraft, starting 15 nm out positioned on a base leg. This base leg is where the jet is heading 90° to the final approach course.
This training mission is designed to teach you how to fly an ILS approach using the HSI as a primary reference.
Figure 10-5
z Airspeed: 200 knots
z Altitude: 2,000 AGL
z Throttle setting: Mid-range
z Configuration: Gear up and clean
z Position from the runway: 15 nm out, 90° from the runway centerline
z Weapons Mode: NAV
When the mission starts, the jet is approaching the final approach course from a 90° angle. You will already be in ILS mode, but when you are returning from a real mission, you may have to navigate back to the runway using TACAN and then switch to ILS. The HSI will have the runway heading dialed in and will show your position approaching the inbound course. Figure 10-5 shows you an overhead view of your position from the runway. Perform the following steps to fly the approach:
1. Load training mission
"10 Instruments Landing"
from the Training section.2. Ensure the flight path marker is on the level line (0°) line in the HUD.
3. Set the fuel flow to 1,200 - 1,300 pounds/hour. Figure 10-6 shows the correct position with the fuel flow gauge set. This fuel flow will keep the jet at approximately 200 knots with the gear up in
Initial Conditions
Mission Description
level flight.
4. Press SHIFT
-P
to freeze the sim.5. Now you need to set your TACAN channel. In the Balkans this is Lecce. If in Korea it is the Kunsan TACAN. There are two ways to set the TACAN: the Upfront Controls (UFC) or the Backup system. We will use the UFC controls for this mission. Setting the TACAN channel and other navigational information is done thru the T-ILS page. Push the '1' button on the UFC to change to the T-ILS page. On the DED display to the right, you see the data entry section, the so called 'Scratchpad', enclosed by two asterisks. Using the properly numbered buttons, enter
the Tacan channel appropriate for the airbase into the scratchpad and push the ENTR key on the UFC. In this case, the channel is "075X" for both Lecce or Kunsan. Verify the TACAN Band is 'X'. If it's 'Y', input a '0' into the scratchpad followed by ENTR to change the TACAN Band.
Verify the TACAN mode is TR (Transmit Receive). Use the SEQ mode of the Data Command Switch (DCS) to change the TACAN mode if neccessary.
6. Look down in the cockpit by pressing
2
on the numeric keypad. Switch the Instr Mode switch to TCN/ILS. Next, set 320° (Lecce) or 340° (Kunsan) as the inbound course for the Kunsan ILS.You can get the TACAN channel and runway information from the appendix on Airport Maps, or look down from the main cockpit view until you see an airbase chart. Use the course dial (CRS) to change the numbers in the window. I know this is a lot of work, but you wanted real and you got real. This is just the way it is in the jet, so hang in there.
7. Unfreeze the simulation by pressing SHIFT
-P
. 8. Watch the CDI (Course Deviation Indicator) onthe HSI. As soon as it starts moving toward the aircraft symbol, start a 30° bank turn toward the runway. The bearing pointer in the HSI will be pointing toward the runway. To make this turn precisely, use the ADI (Attitude Direction Indicator), the round ball in the center of the instrument panel. It displays aircraft pitch and roll information. The ball represents the earth, and the horizontal line through the ball is the horizon line. The wings of your aircraft are represented as a fixed line in the center of the display. The line remains fixed when you roll or pitch the aircraft. The tick marks on the side of the ADI represent degrees and are a backup to the HUD. In addition, the ADI is the only precise way of setting a bank angle when you cannot see the horizon. Figure 10-7 shows the ADI displaying a 30° banked turn.
9. Roll wings level when the CDI needle is centered in the HSI display. The bearing pointer should be centered at 12 o'clock, with the runway on your nose. Figure 10-8 shows the HSI as you roll out of the turn. If you turn too fast or too slow, you may not be aligned with the runway.
Remember that in the mode we are using, the HSI bearing pointer points to the runway. Make small roll inputs to get lined up with the runway final approach course.
10. After rolling out on final, you are now between 10 - 12 nm out. At this point, lower the gear by pressing
G
. You must be below 300 knots or you will damage the gear. In the HUD, the ILS steering cue consists of a horizontal pitch bar and a vertical roll bar in the HUD. When the ILS is called up, these lines will direct you to the ILS glide path. To get on the ILS glide path, you must center these bars.Figure 10-6
Figure 10-7
Figure 10-9
11. The first bar that should be centered is the vertical bar that displays your course deviation. Make small roll inputs toward the vertical bar to center it in the HUD. Do not chase the vertical steering bar. Lean into it slightly and change your heading approximately 15°. As the vertical bar centers, you can lean back to the runway heading to keep it centered. Remember, the runway heading is 320° (Lecce) or 340° (Kunsan). The pitch bar will be above the flight path marker as you
approach the runway. Do not climb to center the bar. Let it come down to you as you approach the glide path. In addition to the HUD ILS steering bars, the HSI also displays ILS deviation via the CDI needle and the glide slope indicator on the left side of the round HSI dial.
12. Now that the gear are down, you will slow rapidly to 160 knots. As you approach 160 knots,
Figure 10-8
set the fuel flow to about 2,000 pounds per hour. This will stabilize the airspeed at approximately 160 knots with the gear down and the speed brakes closed in level flight.
13. Keep the jet in level flight with the ILS vertical steering bar centered. The ILS glide path indicator will start to descend as you approach the glide path. As the horizontal bar gets to the center of the ADI, deploy the speed brakes by pressing
B
and start down the glide path. Figure 10-11 shows this position on the ILS glide slope. You do not need to make a very big power change because 2,000 pounds/hour will hold 160 knots with the gear down and the speed brakes out with the jet descending between 2° - 5°.Figure 10-11
14. Once you have the ILS steering bars centered, use the throttle to control your airspeed and keep the AOA scale at 11°. This scale is just to the left of the ADI.
Figure 10-10
15. When you reach 300 feet, press
P
to pause the simulation. Now, press1
on the top row to switch to the HUD Only view. The runway should be in front of you. This is the point where you stop flying with your instruments and start flying a visual approach to the runway.16. As the jet moves down to 100 feet above the runway, it is time to flare. As you recall from the previous training mission, use a flare to decrease your sink rate in order to place the jet on the runway gently and safely. To flare the F-16, slowly pull back on the stick and shift your aimpoint from the threshold down to the opposite end of the runway. As you shift your aimpoint, bring the power all the way back to idle.
17. Once you touch down and hear the tires screech on the runway, fly the nose gear down onto the runway and press
K
to engage the wheel brakes.18. Park up as before and get yourself a cold one at the 'O' club.
Flight Attitude Gear Position Speed Brakes Position Airspeed Fuel Flow Setting
Level Up Closed 200 knots 1,200 pounds/hour
Level Down Closed 160 knots 2,300 pounds/hour
2° - 5° down Down Fully opened 160 knots 2,000 pounds/hour
Picture this... you're flying home from a successful mission. You have long since forgotten about that pesky warning from the jet's voice warning system when suddenly you notice that things are getting very quiet. You are shocked to notice that the motor is not, well, motoring. You are a glider. Your heart sinks into your stomach as you realize that you should have paid attention to that Fuel Low warning.
Your only options now are to jump out or crash... right? Wrong. Depending on your altitude, you may be in a position to make a flameout landing on a nearby runway. The F-16 can land without the engine if you are within gliding range of a suitable airfield.
This type of landing in a jet is frequently called a "dead stick" landing, but is not an accurate term for the F-16 because you must have electrical power to land the aircraft. The FLCS (Flight Control Computer System) needs power along with the hydraulic/electric servo actuators that move the flight control surfaces. The hydraulic power that you need to make a flameout landing comes from the EPU (Emergency Power Unit). The EPU is a generator that produces both electrical and hydraulic power when the engine fails. What all this mumbo-jumbo means is that the stick is not really dead. However, the EPU has only a limited amount of its own fuel, so you make all haste to get on the ground.
Since FalconAF provides very accurate flight modeling, it is possible to make a flameout landing (just like in the real jet). How well does the F-16 glide? Like a brick. Actually like a brick with wings. The wings help cushion your fall somewhat, but the only way now is down.
The F-16 Dash-1 manual says the F-16 will go 7 nautical miles over the ground for every 5,000 feet of altitude you lose. This makes gliding calculations hard for most fighter pilots, so figure 1-for-1. To see how far you can glide, just take your altitude in thousands of feet and convert it to miles and that is how far you can go. For
example, if you are 20,000 feet up, you can glide 20 miles. This number is only good if you fly 6°
AOA - your best glide angle. This AOA can be achieved by flying at approximately 210 knots plus 4 knots per 1,000 pounds of gas and external stores with the gear up. (If you lose an engine, you should jettison your external stores immediately.). If you can't make the fuel
calculations in your head, just fly 210 - 220 knots.
That will put you close enough to 6° AOA with the gear up. With the gear down, this airspeed changes to 200 knots.
Landing is the next step, and it really is just about the same as a normal landing except for the glide path. A normal glide path is 2°-3°, while a
flameout glide path is 11°-17° (as seen in Figure
11-2). Fly the jet on this glide path to maintain the proper airspeed throughout the approach and landing. Because of your steep approach and lack of thrust, you will need the increased airspeed to execute a flare and slow your descent rate. Remember that our normal flare for landing is at
approximately 11° AOA, whereas this flare for a flameout landing starts at 6° AOA. Since this is a 50 knot airspeed difference, it takes some practice.