What's the trick to slowing the MD-82 down on approach?

[Wise87 1,286]

I've flown the Maddog  10 times and with the simplified checklist I've gotten to the point were I haven't missed any steps. My last 5 flights have been flawless. One thing I have noticed was getting the Maddog to slow down below 250 speed. I have tried speed hold and FMS override. I even deploy the spoilers earlier than required and deployed slats. During my last two flights I  just disconnect the AT and manually control the speed. I feel like I am missing something. What's the best way to use AT and slow it down?

Edited February 26, 2018 by Wise87

[Xiropillo 14]

+1

[thibodba57 462]

3 minutes ago, Wise87 said:

I've flown the Maddog  10 times and with the simplified checklist I've gotten to the point were I haven't missed any steps. My last 5 flights have been flawless. One thing I have noticed was getting the Maddog to slow down below 250 speed. I have tried speed hold and FMS override. I even deploy the spoilers earlier than required and deployed slats. During my last two flights I  just disconnect the AT and manually control the speed. I feel like I am missing something. What's the best way to use AT and slow it down?

Haven't missed anything, spoilers along should help slow the aircraft down. VNAV is really not your friend in this bird, so plan WAY ahead, keep up with a 3:1 descent maybe add another 10-15NM above 10,000' for your deceleration.  Try 240IAS at 10,000 and slow your descent rate to 8-900 ft/min if you can alllow for it in the distance remaining.  Otherwise check the placarded speeds for the flaps and get down and dirty with her.  Sorry couldn't help myself.  If ATC needs you steeper its just gonna take a configuration change to make that happen.  But I would definetely toss VNAV out the window atleast below 10k.

[Wise87 1,286]

4 minutes ago, thibodba57 said:

Haven't missed anything, spoilers along should help slow the aircraft down. VNAV is really not your friend in this bird, so plan WAY ahead, keep up with a 3:1 descent maybe add another 10-15NM above 10,000' for your deceleration.  Try 240IAS at 10,000 and slow your descent rate to 8-900 ft/min if you can alllow for it in the distance remaining.  Otherwise check the placarded speeds for the flaps and get down and dirty with her.  Sorry couldn't help myself.  If ATC needs you steeper its just gonna take a configuration change to make that happen.  But I would definetely toss VNAV out the window atleast below 10k.

Thanks for the info Brian. I will give your steps a try. 

[bjratchf 80]

Configure early- use flaps/slats to slow, they are drag devices!

[Meekg 86]

Read the FAQ please, if you see LOW LIM you might not be completely at IDLE

Edited February 26, 2018 by Meekg

[Wise87 1,286]

8 hours ago, Meekg said:

Read the FAQ please, if you see LOW LIM you might not be completely at IDLE

I read it but my throttle settings are not the problem. I stated that I was using the autopilot and I don’t get a LOW LIM light. I will follow Brian’s suggestion.

[Omaniac 3]

If your throttles go all the way to idle you need to increase drag. At 250 kts you can select FL 11 or use speed brakes. Or slats and speed brakes.

[Omaniac 3]

If your throttles go all the way to idle you need to increase drag. At 250 kts you can select FL 11 or use speed brakes. Or slats and speed brakes.

AND, if you are used to VNAV with other aircraft and wait for the speed to reduce the same way, you will wait for a long time. I suspect that is what you mean when you say the speed will not go below 240. Select Vertical Speed and set the desired speed. If below the GS, use 500 ft/m. Add drag if requred.

[roland_lfor 249]

I've read somewhere that IAS HOLD mode switch throttle to idle and then adjust speed with pitch angle only, maybe something to try?

[RyInTheSky 22]

I suggest spoilers to 280 then slats to 250 with spoilers and then go to flaps 11 and retract the spoilers, reduce your rate of descent or level off to decel to flaps 15 and then 210 knots from there on in to make up for the distance you ate in the level off and from there you can catch your profile up in VS mode generally speaking. If that does not work, once you are at flaps 15 you can throw the gear out early and that generally helps. You really have to fly this airplane to get the best performance out of it.  The airplane is slippery by design. In the real Maddog the landing lights are good for 200 fpm descent alone in terms of drag without acceleration but I have not experienced that as reflected in the FSX model.  They designed the slats and flaps 11 to come out at much higher speeds to make up for the fact that the airframe design is like a wet salmon in your hands. 

[Omaniac 3]

IAS HOLD in the Maddog puts the throttle in CLAMP. You control the throttles manually and speed with the thumb wheel. It can cause confusion if you have a different speed in the auto throttle speed window. The moment you level off it switches to ALT HOLD and the throttle kicks in to maintain the speed in the window. Lets say you are in IAS HOLD and 220 kts. You forgot to change the speed in the speed window and left it at 300 kts. You level off and the throttles go to max to get you to 300 kts.

Yes, you can use IAS HOLD, but you need to know what you are doing. And it is NOT the same as Level Change in 737. That mode includes autothrottle.

[roland_lfor 249]

It looks like I have still a lot of home work to do, but that's also why I bought this aircraft, to learn new stuff

[Omaniac 3]

It will bite you in the xxx if you don’t fly it right. Just as the real thing.

Good luck!

[richcam427 29]

Spoilers are your friend. If you've ever flown on the Delta -88s into Atlanta, you'll notice that pilots keep them extended to some degree pretty much to the glideslope. Of course, it has a little to do with the way traffic is handled at Atlanta (basically, get down, get in, and get your butt off the runway as quickly as possible), but also because the DC-9/MD-80 series all have (relatively) tiny wings that create very little drag, which makes slowing down without flaps and slats a challenge. In addition, the autothrottle system on the MD-80 is, quite frankly, garbage, so try and think a step ahead of it during the descent. If you don't, you'll probably hate your life and end up about 50 knots faster than you need to be.

Edited February 26, 2018 by richcam427