The Apollo 11 flight was the first landing on the moon, July 20th, 1969.
This EL3D mission has two unique features not present in
other missions. During the P64 flight
there was a program alarm which is modeled in EL3D. In addition the short flight (P66) has a
special sound file option. Please see
the Special Function sections for
There are two EL3D scenarios for this landing:
short flight is the default flight for non-registered versions of
EL3D. It starts at about 500’,
just east of West Crater. Eagle is
descending at about 17fps and moving forward at about 70fps. The AGC program is P66. The Primary Navigation Guidance System
(PGNS) switch is set to Attitude Hold.
This is allows manual control of the LM attitude. The throttle is set to Automatic and
the computer handles all of the throttle functions. The astronaut may click the Rate of
Descent (ROD) switch up or down to initiate 1fps per click commanded
changes in descent rate. On the
actual mission Neil Armstrong pitched forward and landed farther
downrange. Obviously he clicked
the ROD switch ‘up’ to reduce his descent rate. He kept a high forward velocity until
he cleared the West Crater and began slowing down to land. Pressing F3 will show the historic
landing site. A large arrow sets
over the top and a green outline of a LM is on the surface. The large horizontal velocity near the
ground caused the Altitude and Velocity lights on the DSKY light display
to come on. This meant the radar
could not provide reliable velocity information but since Neil was flying
visually it didn’t matter.
Function Before starting the
flight there will be a check box that becomes visible when you have selected
the Short Flight P66 scenario. This
check box is called Test-11 and is in the Sound Settings section. If you check this box the sound you will hear
is a continuous stream of real-time audio from the actual Apollo 11
landing. The ‘triggers’ of altitudes and
speeds no longer applies and this sound plays the audio non-stop. This option allows you to try to mimick the audio altitudes and speeds with your own
flight. See how close you can get your
flight to the actual flight.
longer flight begins farther up range and at about 8000’. The LM is moving at about 500fps and
descending at 140fps. The AGC
program is P64. The Primary Navigation Guidance System (PGNS) switch is
set to Auto.
That means the autopilot is engaged. The DSKY display is flashing indicating
it is expecting a PRO command.
Pressing PRO (keyboard ‘*’) stops the flashing and allows for
manual redesignation of the landing site. The angle to the computed landing site
is displayed in the right two digits of Register 1 on the DSKY. Aligning this number with the Landing
Point Designator (LPD) on the window will show the intended landing
point. If this is not acceptable
one can nudge the controller in the desired direction and the computer
will recalculate the landing site, issue commands to the autopilot and
display the new angle on the DSKY.
As the LM slow pitches forward the LPD angle will change a little
bit. Also, very near the landing
site the LPD angle will be so far below the window that the LPD angle
will go off scale. The two digits to
the left on Register 1 of the DSKY indicate the time left for LPD redesignation.
Function On Apollo 11 there
was a little trouble during the P64 flight segment. Apparently the rendezvous radar was trying
track the CSM even though it wasn’t needed for this stage of flight. This additional processing overloaded the
computer and caused several program alarms to occur. Two of them occurred in the previous flight
segment (P63) but one more occurred during P64.
When this happened the DSKY blanked and the alarm code showed in
Register 1. During P64 a 1201 alarm
occurred. It was easily ‘fixed’ by
resetting the computer. In EL3D just press the “.” Key on the Numpad. The
computer will restart. Note: For those
that may have seen the HBO mini-series From the Earth to the Moon, you may
recall this part of the story. However
they “hollywooded” it up a bit with alarm bells and
the Master Alarm light. In actuality the
AGC program alarms were not connected to the Master Alarm. Of course the LMP was intensely scanning the
DSKY so it really wasn’t necessary.