ce650

I asked this question in the photo section yesterday and still no response so I will go right to the people in the know! There is a cockpit photo of a dc9 in the photo section, (your window thread) and I was wondering what the rectangular thing with the arrows is just to the right of the gear handle, also duplicated on the left side of the panel also. Thanks in advance to the "9" pilots for this one.

ExAF

It's called a "comparator" or something like that. It looks at the approach instruments for each side of the cockpit and compares them to ensure they are both reliable. If it detects a problem, it is supposed to direct a ga/ma and give you an indication of which portion (CA/FO side, course, glide path etc.) of the instrumentation is unreliable. Its been a while, but that is the best way I can describe it without getting too deep.

8CherryGarcia

Without seeing the actual photo in front of me, but having the image burned into my brain from thousands of hours staring at it around the midwest, my guess is it is the instrument comparator.

The comparator monitors both stations' flight instruments and flashes when they are in disagreement. (ie. bad Vertical Gyro). The arrows will illuminate green or red and point at the good or bad side respectively. Most useful when shooting Cat II approaches with a 40 year old autopilot (and a 40 year old co-pilot for that matter!)

Works good, lasts long. Bang it fit, paint it to match...it's a -9!


8Cherry

III Corps

What they said...

Note the last flap positions have been blocked so this is probably NOT an -80 but your basic -9. Also note the wonderful blue theme that is also found on most Russian aircraft.

Now for a small quiz. look at the photo and see if you can find the required mag compass. Don't spend a long time at it however.

The -80 is the ONLY airplane I have ever flown where with an engine loss, the landing lights retract.

ExAF

Just flip up the little mirrors on the dash (above the landing light switches) and you'll see the mag compass right behind you.

gripen

... and I always thought those were for checking out the cute girls walking down the aisle!

8CherryGarcia

notes on the "Instrument Warning Panel"....I always called it a comparator...they had one on the early Lears as well


DC-9 34.20.42
NAVIGATION
Controls and Indicators
NAV/INST Warning Display (some aircraft)
Location
A NAV/INST (navigation/instrument) warning display is located on the captain’s and first officer’s instrument panels.
Function
The NAV/INST warning displays assist the flight crew in the early recognition of some navigation equipment disagreements and flight instrument failure conditions.
1.Comparator lights
Illuminate to indicate that a difference exists between two identical systems. (some aircraft - GP EXT position is blank.)
2.INST (instrument) warning lights
Illuminate red to indicate that an instrument has a failure warning flag in view. The red INST light points toward the crew position where the failed instrument is located. The opposite INST light will illuminate green to signify that the instruments at that crew position are not affected. (The GA warning lights will illuminate in conjunction with the INST warning lights.)
3.GA (go-around) warning lights
Illuminate red to indicate that an instrument failure has occurred (INST warning light will also be illuminated) and the failed instrument is not to be used during a go-around. Illuminates green to indicate that an instrument failure has occurred but the failure does not affect go-around capability. The red GA light points toward the crew position where the failed instrument is located. The opposite GA light will illuminate green if the instruments at that crew position are not affected.
Note:The INST and GA lights will illuminate in conjunction with each other.
J340132C42153THROTTLELOCRADALTMONITORHDGHORIZONGPA/P
Aug 1, 2005
DC-9 34.20.43
NAVIGATION
Controls and Indicators
NAV/INST Warning Display (some aircraft) (continued)
4.THROTTLE light (some aircraft)
Illuminates to indicate the autothrottle engage lever has returned to the OFF position for any reason.
5.A/P (autopilot) arrow
The A\P arrow can illuminate either red or green.
Functions:
A\P GREEN - Illuminates to indicate a navigation instrument failure that does not affect autopilot operation. It is reset by pressing the INST WARN RESET button adjacent to the instrument failure warning annunciator.
A\P RED - Illuminates to indicate that the autopilot has been disconnected by any means other than the control wheel auto pilot release switch(es). It is reset by pressing either control wheel autopilot release button.
(-50) Flashes instead of steady illumination. It is reset by pressing either control wheel autopilot release button.
J340132C42153THROTTLELOCRADALTMONITORHDGHORIZONGPA/P
Aug 1, 2008

sorry for the format, I don't know how to upload a Pdf
[IMG]file:///C:/DOCUME%7E1/Owner/LOCALS%7E1/Temp/moz-screenshot.jpg[/IMG][IMG]file:///C:/DOCUME%7E1/Owner/LOCALS%7E1/Temp/moz-screenshot-1.jpg[/IMG]

Larry in TN

It's a DC-9-50 series. It has the digital RAT/EPR gauge instead of the analog one.

What's the only switch on the DC-9 were "forward" is "off"?

RichieAshburn

I may misunderstand your question, but no. The TCI is push button, it is just to the right of the standby by attitude indicator. This advance in technology is much more user friendly!

After re-reading your question, I see I did misread it, sorry. But to answer it...Alt hold.

1234

Now that is funny, Alt hold on a dc-9......