Autopilot 727 and DC9

[nac]

I'm just getting back into flight sim.

Can both the 727 and the DC9 use the altitude hold selection that I set? Example, if I want to cruise at 20,000ft can I select that.

[aerofoto - HJG Admin]

Using each of our B727 panels ....

A "target altitude value" can be dialed up/selected on these panels .... BUT .... the actual "altitude capture" must still be performed manually by flicking "ON" the AP ALT HLD switch as the ALTIMETER needles intersect the precise target altitude value. There is no automatic altitude capture function built into any of these panels. The earlier type of B727 AP is what is represented in each of these B727 panels. When a target altitide value is set/selected .... it should be interpreted as "a reminder" (only) as to what particular altitude has been actually been targeted or the aircraft cleared to. An ALTITUDE ALERT tone will activate, automatically, at approximately 700 FT prior to passing the selected target altitude value .... and again .... within approximately 500 FT of passing the selected target altitude value. In order to avoid writing at length .... here´s a copy an paste from the AUTOPILOT section of our forum based/online B727 panel manual ....

AP PANEL

The AP system featured in these B727 panels is engaged by selecting "UP/ON" both paddle switches. The left paddle switch influences Aileron setting. The right paddle switch influences Elevator setting.

Disconnecting the AP system will trigger a red flashing lamp on the main panel. It will .... intentionally .... not then be possible to re-engage the AP system until this red lamp is manually extinguished .... per a simple mouse click.

The AP System can also be disconnected using the AP System knob .... but .... it should not be used to do so. This knob is knob is used only to select between the hydraulic systems used by the AP to assist controlling the aircraft during AP controlled flight modes

Inflight, and when the AP engaged, the large AP Pitch & Roll knob is used to roll the aircraft left or right, and also, to trim the aircraft up or down .... per mouse clicking either its extreme left, right, top, or bottom edges. Clicking the left side of the AP Pitch & Roll knob turns the aircraft left .... and .... clicking the right side of the AP Pitch & Roll knob turns the aircraft right .... but only when the small AP Roll Mode Selector knob is set to "MANUAL". Clicking the extreme top side of the AP Pitch & Roll Knob trims the aircraft down .... and .... clicking the extreme bottom side of the AP Pitch & Roll Knob trims the aircraft up .... but only when the AP ALT HLD switch is not engaged.

"HDG HLD" and "VOR/LOC" are both engaged using seperate switches on the AP. Only 1 of these 2 modes can be engaged at any time. The HDG HLD switch will .... intentionally .... disconnect when the VOR/LOC switch is engaged. Once captured both HDG HLD and VOR/LOC intercepts are confirmed by illuminated green lamps on the FD mode anunciator panel .... but only when the FD switch is set to either of these 2 modes.

The B727 panel AP is capable of fully ILS coupled approaches to landing, but, speed must be set .... and maintained .... strictly in accordance with the computed V-REF data. Excessive speed during AP controlled ILS approaches will force the aircrafts nose down, and, insufficient speed will cause the nose to drift up .... possibly to the extent of obscuring RWY vsibility during approaches to landing.

Almost of everything one needs to know about our PROBST/CARTY B727 panels is available per my "B727 PANEL INSTALLATION & HANDLING NOTES" posting .... which is located on the "ABOUT HJG AIRCRAFT" forum page, or, per the following link ....
tonymadgehjg.proboards.com/index.cgi?board=hjgaircraftlistings&action=display&thread=2382


Using each of our DC9 panels ....

Again ..... a "target altitude value" can be dialed up/selected on these panels too .... BUT .... there are actually 2 altitude capture options available. The first option allows for "altitude captures" to be performed "MANUALLY" by, once again, flicking "ON" the AP ALT HLD switch as the ALTIMETER needles intersect the precise target altitude value. An ALTITUDE ALERT tone will activate, automatically, at approximately 700 FT prior to passing the selected target altitude value .... and again .... within approximately 500 FT of passing the selected target altitude value. Unlike the B727 .... each of these DC9 panels also has an "AUTOMATIC" altitude capature mode .... which requires the target altitude value first being set .... on the AP itself .... and the the appropriate AP mode switches then activated in order to fascilitate the altitude capture. In this case the Main Panel altitude selecter should still be set as a reminder. Once more .... and in order to avoid writing at further length .... here´s a copy an paste from the AUTOPILOT section of our forum based/online DC9 panel manual ....

3.0 AUTO-PILOT PANEL

Starting from the left quadrant and working across to the right and then down the Auto-Pilot sub panel ....

The entire upper quadrant of the AP sub panel features AP Pitch Mode Selector knob, AP Vert Speed Control thumb wheel, AP Turn/Roll knob, AP Heading Hold switch, AP System engage/disengage paddle switch, and the AP Mode Selector knob.

Moving down to the bottom right quadrant the AP sub panel ....

Located across the center of the AP sub panel is the AP "ALTITUDE PRESELECT" system, and the KLN90B NAV System.

Located across the bottom of the AP sub panel are both COM1 and COM2 Radios, and below these are both the NAV1 and NAV 2 radios.

The DC9 panel AP functions in almost precisely the same manner as that of the HJG DC8 panels, but, the DC9 AP is also equipped with an automatic altitude capture mode which the DC8 panels do not feature.

The AP system is engaged, inflight, by setting the AP paddle switch to the "SERVOS ENGAGED" position.

The AP system can be disengaged, inflight, by setting the AP paddle switch to its "SERVOS DISENGAGED" position .... or by selecting the keyboard "Z" command. Deactivating the AP will trigger AP disconnect warning/alarm and will also cause the red "AP" annunciator lamp on the Main Panel Bowtie gauge (located above both the Altimeter and ROC/ROD gauges) to illuminate and then flash constantly. This warning lamp can be canceled/extinguished by clicking ("once only") on the main Panel "INST WARN RESET" knob (located beside the Bowtie gauge).

Disconnecting the AP will result in all previously coupled AP flight modes being canceled. The aircraft must then be controlled manually.

The AP cannot function if both the "L GEN BUS" and "R GEN BUS" on the OH panel have not first been selected "ON".


3.1: AUTO-PILOT PANEL - AP CONTROLLED CLIMB/DESCENT

During AP controlled climb/descent the aircrafts ROC/ROD can be adjusted by clicking the Vert Speed thumb wheel. Mousing the bottom of the Vert Speed thumb wheel ("CLIMB" position) will control ROC. Mousing the top of the Vert Speed thumb wheel ("DESCEND" position) will control ROD .... both in proportion to mouse input. Each individual mouse click over the Vert Speed thumb wheel corresponds to an approximately 100 FPM adjustment to any established ROC/ROD.

The AP Vert Speed thumb wheel can also be used to engage the AP altitude hold mode. The aircrafts ROC/ROD should first be set at no more than 500 FPM .... less during the last few hundred of climb/descent towards any target altitude. Clicking on the center of the Vert Speed thumb wheel as the altimeter needles indicate on the desired altitude will engage the AP ALT HLD mode. The aircraft will then begin to maintain the selected altitude. The aircraft may, at first, drift slightly above or below the selected altitude .... this is quite normal. The aircraft will eventually settle into a perfect altitude capture after a few moments. Care should be taken to engage this ALT HLD mode precisely .... paying close attention to both the altimeter and the ROC/ROD is essential !

Adjustment to any captured ALT HLD altitude value is possible by clicking the Vert speed thumb wheel. Mousing either the bottom or top ("DESCEND") or bottom ("CLIMB") of the Vert Speed thumb wheel disengages the AP ALT HLD function without disengaging the AP and allows any new ROC/ROD to be established.

The Vert Speed thumb wheel will not, intentionally, function in manual flight mode. In manual flight mode the ROC/ROD must be set manually. In this case it is recommended that the keyboard "HOME" and "END" commands (Windows XP) be used in order to adjust Trim and to establish the desired ROC/ROD. In manual flight mode the Trim warning horn will triggered, automatically, in response to significant Trim adjustment. The Trim warning horn will not be triggered when Trim is adjusted using the Vert Speed thumb wheel and during AP controlled flight modes.

3.2: AUTO-PILOT PANEL - AP IAS/MACH HOLD MODES

The AP Pitch Mode Selector features both "IAS HOLD" and "MACH HOLD" options. The "IAS HOLD" option should not be engaged below 290KTS or above FL250. The "MACH HOLD" option should only be used above FL250.

When either "IAS HOLD" or "MACH HOLD" modes are engaged the AP will adjust the aircrafts pitch attitude, automatically, and in accordance with power setting, in order to maintain a particular speed. The AP will always endeavor to hold whatever speed was acquired when either of these modes is first engaged. If more power is then applied the AP will respond by increasing the aircrafts pitch attitude to maintain speed. If power is retarded then the AP will respond by decreasing the aircrafts pitch attitude. This will also result in automatic AP controlled ROC/ROD adjustments during climb/descent.

"IAS HOLD" and "ALT HOLD" cannot be engaged together. Either one or the other mode only can be engaged at any time.

"IAS HOLD" is not an AT system and should not be used as such.


3.3: AUTO-PILOT PANEL - AP TURN/ROLL MODE

A large "TURN" knob is located in the center of the AP. This can be used to roll the aircraft left or right during AP controlled flight modes. This action is available only when the AP Mode Selector knob is set to the "TURN KNOB" position.

It has been observed that the AP "TURN" knob will not roll the aircraft through perfectly smooth turns during FS panel view mode. During FS external view mode the aircraft may also be seen to slowly roll-over and dive when the AP "TURN" Knob is selected to its maximum axis. This is a known FS bug associated with these, and some other, panels and which we can do nothing whatsoever about. It is recommended that the AP "HDG SEL" mode be used to ensure perfectly smooth turns during AP controlled flight and in conjunction with the HSI HDG SEL bug.


3.4: AUTO-PILOT PANEL - AP COURSE/HDG/NAV/ILS MODE

Setting the AP "HDG SEL" mode switch to the "ON" position allows the aircrafts heading to be controlled by manipulating the heading Bug on the Main Panel HSI. Manually controlled turns (per Joystick or Yoke input) during AP controlled flight are possible prior to this mode being engaged. It is not possible to manually adjust the aircrafts heading (per Joystick or Yoke input) when the AP "HDG SEL" mode switch is engaged.

Setting the AP mode selector switch to the "VOR LOC" position allows the aircraft to engage and track along the radial emanating from any pre-tuned and captured VOR beam.

VOR radials should be intercepted at less than a 20 degrees to the intended beam. Engaging the AP "VOR/LOC" mode at too acute an angle of intercept will result in the aircraft constantly weaving as it endeavors to capture the intended VOR beam. It is recommended that the "HDG SEL" mode be used to first align the aircraft with the VOR beam .... then "VOR/LOC" mode engaged once the aircraft is established on the intended beam. The aircraft may still weave slightly over the beam at first .... this is a normal FS response. The aircraft will settle into to perfectly smooth tracking after a few moments.

The AP mode selector switch also features an "ILS" mode. This allows coupled AP controlled ILS intercepts during approaches to landing on any ILS equipped RWY. The AP should be selected "OFF" and all landings then performed manually when passing 100 FT.


3.5: AUTO-PILOT PANEL - PRESELECT ALTITUDE

Altitudes can be preselected and then automatically captured using the AP "Altitude Preselect" mode.

This mode is available only when the AP system is activated.

The small white AP "ALT INCR" button must first be clicked ("once only") in order to render this mode active. Altitude values can the be entered into the gauge window by clicking this button. Mousing the right of the "ALT INR" button (roughly on the "INCR" label) increases the Preselect Altitude value. Mousing the left of this "ALT" button (no visible label) reduces the Preselect Altitude value.

Preselected altitude values can be set in units of 1,000 FT only.

Upon setting the desired Preselected Altitude value the AP "MAN/AUTO" switch (located to the left of the "ALT button) must then be set to the "AUTO" position in order to enable the automatic altitude capture mode to function.

The aircrafts actual ROC/ROD to any Preselected Altitude must then be carefully monitored and adjusted using the AP Vert Speed thumb wheel.

Upon acquiring a Preselected Altitude the "AUTO/MAN" switch will automatically disengage and reset itself to the "MAN" position as the Preselected Altitude value is captured. The AP will then be observed to level the aircraft to maintain the Preselected Altitude. The aircraft may, at first, be observed to drift slightly above the Preselected Altitude value, but will, after a few moments, settle into a perfect altitude capture.

For smooth altitude captures it is recommended that the aircrafts ROC/ROD should always be reduced, manually, to less than 1000 FPM within the last 1000FT of climb toward any target altitude .... or .... reduced to less that 500 FPM within the last 500FT of climb toward any target altitude .... or reduced to less than 200 FPM within the last 200-100 FT of climb toward any Preselect Altitude. The lower the ROC/ROD within the last few hundred feet of climb towards any target altitude then the better/smoother the altitude capture.

Adjustment to any captured Preselect Altitude value is possible. The small white "ALT INCR" button must first be clicked (it will not be possible to select another altitude value until this has been done) in order to reactivate the system. A new target altitude value must then be entered by mousing the left or right sides of the "ALT INCR" button. The automatic altitude capture mode must then be reactivated by resetting The AP "AUTO/MAN" switch to the "AUTO" position. The aircrafts progress toward the new Preselected Altitude must then be carefully monitored and adjusted using the AP Vert Speed thumb wheel in order to ensure smooth altitude captures.

Almost everything one needs to know about our HILMERBY/CARTY DC9 panels is available per my "DC9 PANEL INSTALLATION & HANDLING NOTES" posting .... which is located on the "DOUGLAS AIRCRAFT SUPPORT" forum page, or, per the following link ....
tonymadgehjg.proboards.com/index.cgi?board=chat&action=display&thread=3435

"IF" one is new to these simulations then a good, long, thorough read of these notes/manuals is "ESSENTIAL" in order to be able to understand, use, and get the best enjoyment possible.

FINALLY ....

Using either panel/simulation .... to aid smooth altitude captures the ROC/ROD should always be "reduced" to no more than 1000 FPM within 1000 FT of any selected target altitude .... then to 500 FPM with 500 FT of any selected target altitude .... and then to 200 FPM within 200 FT of any selected target altitude .... as stated within manuals for these simulations. It´s possinbly needless to say this .... BUT .... the lower the ROC/ROD then the smoother the altitude capture.

Mark C
BOG/CO