DC-9-30 Won't Rotate

[Erik Ingram - HJG]

That pretty much describes it. I was using the -30 (JT8D-9 model, all FSX CFGs) in the PSA 1985 livery (don't think that makes a difference, but I don't know). I tried four takeoffs, all of which reached 180+ knots, but it WOULD NOT even START to rotate. The nose gear stayed firmly on the ground. The flaps were set normally for takeoff, but again, nothing would happen. So I took it to an extra long runway, got it up to 230 knots, but it still wouldn't lift off. Then I tried using slew to get it into the air, but even at nearly 300 kts, it just fell out of the sky and wouldn't pull out of the dive it was in.

Can anybody help? I've never had this problem with any of the other DC-9s.

Thanks, Erik

[aerofoto - HJG Admin]

Did you set a few degrees of TRIM "prior" to T/O ?

Failing that .... I'd say you're VR problem is hardware/control device based .... because we've never, ever, had an issue like this reported in relation to any of these aircraft .... or any of our other types too .... that I can immediately recall.

What panel are you using also ?

Remember .... the HJG supplied DC9 panels "ARE NOT" FSX compatible.

Mark C
BOG/CO

[Erik Ingram - HJG]

I'm using a default panel with it, but I never thought to adjust the trim (usually it's never a problem). I'll report again when I have a nother chance to try it.

[aerofoto - HJG Admin]

Have look at the trim recommendations, set out for each DC9 TYPE aircraft, per my DC9 FLYING GUIDE (although these recommendation apply more to when usiung our panels), which you'll find is the last chapter appearing in my extensive DC9 INSTALLATION & HANDLING NOTES posting .... on the DOUGLAS AIRCRAFT SUPPORT page.

Usually about 5-6 units of TRIM is desirable for T/O and for most of our DC9 SERIES aircraft .... but again .... you may still have a control device callibration issue to contend with there if your not getting any response at all when attempting to rotate.

Mark C
BOG/CO

[Herman]

Ok Erik, I did a couple of test flights in FSX with the DC-9-30 and these are the results. The aircraft was pretty well at its MTOW.

It was configured with 15deg flaps and the rotation speed was calculated to be 130knts indicated.
THere is a discrepancy between the flap indication on the dial indicator and the actual flap selection lever. 15deg on the dial indicator shows only 5deg. on the flap selection lever. A visual inspection showed that the dial indicator was more accurate.

1. With the horizontal stabalizer trim at its default setting it was above the green safe setting. At that setting I was able to rotate and lift off at about 155knts, but it required full backward positioning of the control yoke.

2. With the stabalizer trim set in the green safe position of "5" I was able to rotate at 130knts and lifted off at 145knts.

Don't know why you were unable to get airbourne at the speeds you mentioned even if you didn't trim properly or had your takeoff flaps incorrectly set.

Herman

[aerofoto - HJG Admin]

Dunno why you're seeing a discrepency between the flap lever and gauge indications Herman .... becausae in the case of my own installation of all of these DC9 aircraft and "our own panels" I'm not observing anything other than "perfect results".... which, unfortunately, are not FSX compatible

I just need to state this to alert folk that there "IS NOT/SHOULD NOT BE" any such problem in respect of this and with our own FS2004 HILMERBY/CARTY DC9 panel series.

Whether or not there's such a discrepency when using MSFS default panels .... I can't say .... and even if there was I probably wouldn't bother doing anything to fix it since I consider MSFS default panels to be "just a convenience only" rather than a definitive or intended solution for any of these aircraft .... in fact I don't even bother testing any of our aircraft with default MSFS panels.

I believe Erik is using a default MS FSX panel with his DC9 aircraft.

[Herman]

As mentioned, I only tested the DC-9-30 in FSX which is what Erik was using.

In FSX the DC-9 panel is aliased to the MS B737-800. I checked the flap operation again today and as far as I could see the flap lever on the pedestal and the position dial indicator are out of wack.

With the flap lever set at 15deg. I am showing 40deg. on the dial indicator and this also indicates full flap extention visually externally.

If Erik is setting his TO flap according to the pedestal lever then he will actually have full flap extention which may explain his inability to get airbourne??? I'll have do a test flight using that configuration to see if it is possible to get airbourne.

Then again I don't know what Erik's flying knowledge and experience is with large jetliners ie. does he know what the rotation technique is.

Big jetliners are not like a Cessna 172 that practically lifts off by itself when reaching 60knts.

Herman

Herman

[aerofoto - HJG Admin]

Feel free to test and report, if you wish, Herman .... but .... where default MSFS panel are concerned I really wouldn't bother .... and only for my reasons stated above.

Personally .... I've got no time for and bear no favour at all toward default MSFS panels .... or sounds either for that matter.

I can only say that the reported issue doesn't appear to be relevent in respect of our own HILMBERBY/CARTY DC9 panel series .... and which is my prime/only concern really.

Mark C
BOG/CO

[Falcon]

I have all versions of HJG DC-9's in FSX with stand alone panels, and I don't have a problem with rotation at the correct TO speeds. Can't imagine what the problem is there either.

[Herman]

Hi Mark;

OK, I hear what you're saying.....However,because the HJG DC-9's are certified to be used in FSX, and even though they have to use the default FS 737-800 panel, I still feel that if I can help with identifying the problem it is worth while my effort.

Fortunately I am in a position where I have the time to do this and I understand that others are unable to devote as much time because of other more important commitments.

Herman

[Herman]

Erik... if the other HJG DC-9's are working for you in FSX then I don't know why the -30 is not. It sure sees odd and a bit of a mystery.

The bird rotates and lifts off for me at GMTOW even with full flaps, stabalizer trim and CG out of range albit at somewhat higher speeds.

However, you should be striving to operate these aircraft in a realistic fashion by using the correct horizontal stabalizer trim setting, depending on the aircraft CG and correct TO flap setting,otherwise you will be using up more runway than you should.

Also note, as I mentioned to you before when using the default 737-800 panel the flap settings are out of whack because the HJG DC-9's have different values in it's aircraft cfg file. ie. when you select the 737-800 in FSX the flap settings on the pedestal handle agree and exactly correspond with the dial indicator.

PS. Please describe exactly what your TO procedure is with regards to you rotation tecknique.

Herman

[Erik Ingram - HJG]

Well, I tried it again a few days ago and aside from making absoultely certain the plaps were set to 15 degrees, I didn't do anything different, and it worked perfectly. Whatever it was seems to have fixed itself, as it hasn't happened in any of the flights I've done since. Thanks for the suggestions, though.

[Herman]

Glad to hear that you finally got her airborne. ;D ;D

Herman