08 may ae
#641
#642
Gets Weekends Off
Joined: Apr 2011
Posts: 5,816
Likes: 5
From: retired 767(dl)
Thats nothing! I was a T-34C instructor in Pensacola and that plane would go to full aft stick, power to idle and full rudder - almost as if it was trying to enter a spin on purpose. Once in said spin it would aggressively recover by pushing full forward stick and anti-spin rudder.
Did I mention that full aft stick would sometimes hit the IPs harness buckle (especially the short rotund types) and unlock it? Did I also mention that said IP would now (due to full fwd stick and no harness) get pressed overhead into the canopy? Well if I didn't mention it lets now consider it.
All is well so far, you are pressed against the canopy directly over the control stick but you are Ok because you are negative Gs. Ahhhhh, but what about the recovery when the plane goes abruptly to positive G's and you are impaled on the stick? Could be trouble. Bummer for the IPs with short arms as they were pressed against the canopy the control stick mere inches out of reach of their short T-rex like arms.
Then again I am not sure that this story counts because the automation was your student Naval Aviator trying to turn you into a human shish kabob.
Totally true story debriefed by the IP (not me) in training. After a prolonged effort that must have seemed liked minutes but was in reality a few seconds he was able to reach the control stick with his fingertips while yelling "I have the controls, I have the controls!"
The look and expressions on his face as he was debriefing this story was priceless.
Scoop
Did I mention that full aft stick would sometimes hit the IPs harness buckle (especially the short rotund types) and unlock it? Did I also mention that said IP would now (due to full fwd stick and no harness) get pressed overhead into the canopy? Well if I didn't mention it lets now consider it.
All is well so far, you are pressed against the canopy directly over the control stick but you are Ok because you are negative Gs. Ahhhhh, but what about the recovery when the plane goes abruptly to positive G's and you are impaled on the stick? Could be trouble. Bummer for the IPs with short arms as they were pressed against the canopy the control stick mere inches out of reach of their short T-rex like arms.
Then again I am not sure that this story counts because the automation was your student Naval Aviator trying to turn you into a human shish kabob.
Totally true story debriefed by the IP (not me) in training. After a prolonged effort that must have seemed liked minutes but was in reality a few seconds he was able to reach the control stick with his fingertips while yelling "I have the controls, I have the controls!"
The look and expressions on his face as he was debriefing this story was priceless.
Scoop

#643
When they fix the brakes, the FMC, the spoilers, the flight controls, the standby instruments, the autopilot, get the lower nav display out from behind the yoke, finish documenting the stall characteristics, put E C's on the JT8, discover what effect Type !V has on trim tabs, undo the Dial-a-Flap nonsense, nail down the trim range, stop using flaps 11 (15 makes no difference), take the thrust reversers off and throw them in the river, put GPS on it, replace the DC10-30 hydraulic boost pump with something sensible that fits the application, wire the yoke light so it does not catch fire and scorch the wedding tackle, and fix the nosewheel steering, it could be a certif'able design, maybe. Anyway, that's the short list.
#644
And that is the truth.Denny
#645
New Hire
Joined: Apr 2013
Posts: 5
Likes: 0
From: EMB-120 CA
The perception is much worse than the reality. As a former LCA on the 88/90 I had lots of guys turn to me during a line check or OE and ask what's going on after the plane did something they weren't expecting. But I never saw the airplane do something they hadn't just told it to do.
I've had it do something I didn't tell it. Flying across Texas at FL330 in VNAV LVL, we were BS'ing with the jumpseater. The airplane spun the altitude down to FL320 and then started a descent on it's own. We caught it and flew it back up to FL330 before we had to file an ASAP. My best guess is that the altitude select knob wasn't in a detent and clicked over 1000 feet. But that doesn't explain why it started a descent 500+ miles from the TOD.
#646
Gets Weekends Off
Joined: Feb 2008
Posts: 467
Likes: 0
From: SLC ERB
The ER does this as well. It is part of the FMS programming when the 1st fix is an at or above. Long story short, the plane thinks it's already on the path and will maintain the path until it needs to start down to make the restriction. I flew with the LCA who wrote the FMS book (on the ER) and he set up an artificial example just to show me this behavior. Plane slowed to about 3 knots above slats extend speed at 35k' then eventually recovered itself. Didn't descend until what should have been TOD. I have never flown the maddog so I could be talking out my butt, but this could be a case of the plane doing exactly what you told it to do. I am NOT disputing that the 88 will occasionally pull a crazy Ivan on its own accord.
Hmmm, guess I didn't get the memo. "Don't use descend now when the first fix is an at or above" should be a memory limitation
The MD90 just doesn't have enough wing for those kind of shenanigans
Been on the ER for a bit now and haven't seen it there...so I'm happier just saying it's a Mad Dog thing
Having said that, I've also never seen the ER just blow off an altitude capture...so there is that...
#647
Gets Weekends Off
Joined: Dec 2005
Posts: 4,047
Likes: 20
From: 7ER B...whatever that means.
Hmmm, guess I didn't get the memo. "Don't use descend now when the first fix is an at or above" should be a memory limitation
The MD90 just doesn't have enough wing for those kind of shenanigans
Been on the ER for a bit now and haven't seen it there...so I'm happier just saying it's a Mad Dog thing
Having said that, I've also never seen the ER just blow off an altitude capture...so there is that...
The MD90 just doesn't have enough wing for those kind of shenanigans
Been on the ER for a bit now and haven't seen it there...so I'm happier just saying it's a Mad Dog thing
Having said that, I've also never seen the ER just blow off an altitude capture...so there is that...As far as the going to idle at TOD without descending while in VNAV PATH, I believe that is specific to a couple of arrivals out west. I've seen it for sure going into SEA and I think there was a memo about it. Something to do with how the restrictions on the arrival were coded into the FMS. But I think it's an anomaly that only occurs if certain stars align.
#648
That thing's been missing restrictions by 300-350 feet since 1981. It's a honey badger when it comes to restrictions. And ATC don't care.
That's why I don't sweat a few hundred feet here or there.
#649
Gets Weekends Off
Joined: Feb 2008
Posts: 467
Likes: 0
From: SLC ERB
Its not the VNAV crossing restrictions I was talking about. I was talking about it blowing right through the altitude set on the MCP without showing any sign of trying to level off - even though it went into altitude capture mode....can't say I've seen the ER do that one.
#650
Its not the VNAV crossing restrictions I was talking about. I was talking about it blowing right through the altitude set on the MCP without showing any sign of trying to level off - even though it went into altitude capture mode....can't say I've seen the ER do that one.


