GIV Runway Excursion on takeoff FXE 8/21
- Thread starter KLB
- Start date
Autothrust Blue
Welcome aboard the Washington State Ferries
knot4u
Repeat Offender
I've changed a bunch of those servo valves, I'm still not sure how one could fail and cause a hardover in the steering. But I barely get paid to think and I won't have much luck arguing with the FAA and Gulfstream. What doesn't make sense is there are two valves in series, one is activated by the on/off switch next to the tiller and the other is activated by the NLG WOW switch, they're basically just shut off valves, they simply supply pressure and a return path. All of actual "thinking" happens in the ECU and the manifold on the steering unit applies the muscle, the steering unit has two hydraulic connections, pressure and return. Changing those valves is a filthy, difficult mess of a job. It's one of those things that even though you can see it clearly removing and replacing it is an all day job. As far as the accident you referenced that flight had a lot of issues before it ever left Nice.I guess I am saying that if the accident was violent enough to rip the entire nose assembly off the airplane, chances are the torque links are also trashed. The pin could have sheared off?
Yea the steering looks straight enough you’re right.
Airworthiness Directives; Gulfstream Aerospace Corporation Airplanes
The FAA proposes to adopt a new airworthiness directive (AD) for all Gulfstream Aerospace Corporation (Gulfstream) Model G-IV airplanes. This proposed AD was prompted by reports of un-commanded nose wheel steering turns. This proposed AD would require replacing the nose wheel steering servo valve...www.federalregister.gov
Uncommanded Nosegear Steering a Factor in GIV Crash
T/O w/FSII
Well-Known Member
There have also been multiple close calls with aircraft nearly coming off the runway, enough so that they changed the checklist on the airplane to “feet off the floor” before landing and take off. That way you can reach the break. They also teach NWS hardcover during all initial and recurrent courses. It requires full rudder and full opposite brake. If the runway is less then 100ft wide you’ll probably end up on the dirt on landing.
They show us lots of pics of skid marks in school, but none I can easily find on google. Gulfstream keeps it pretty tight.
Yea, they had lots of issues in Nice, but the NWS hardover is what killed them.
knot4u
Repeat Offender
IF there was a hardover it was a contributing factor, you say you're trained to handle that issue. I'd venture a guess that not arming the ground spoilers was probably more of an issue. But you're a pilot and you certainly know the airplane better than me.
T/O w/FSII
Well-Known Member
Well, there was a hard over recorded. And that’s what sent them into the trees. Not arming the ground spoilers isn’t what killed them *this time*.
I’ll take 100 automatic ground spoiler failures before I’d take one uncommanded NWS event.
“Feet off the floor”
knot4u
Repeat Offender
I've repaired plenty of GIV steering systems, R/R steering units because they will inexplicably develop a leak overnight parked in the hangar, tillers that the pilot thought was a coffee holder, and sometimes an NLG wiring harness. The number one culprit in a GIV steering issue is the ECU. As far as I know there's two P/Ns available depending on the aircraft S/N. I've never dealt with an airplane that had a "hard over", I've spent rainy nights out on the ramp tuning the steering to alleviate an issue where it wouldn't taxi straight hands off. I'm not sure where this hard over rumor was generated.
Cherokee_Cruiser
Bronteroc
Hot dang the media won’t just STFU and let the viewer watch. It sounds like they are just salivating at this thing to go up in flames simply so they can say they brought this to you live.
Like that Dick Thornberg dude in Die Hard 1 and 2.
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T/O w/FSII
Well-Known Member
Maybe you didn’t read what I wrote.
Flight safety and CAE both show multiple case studies, photos, and FDR data BY GULFSTREAM of airplanes that have departed the runway on landing, during class, every 6 months. I’m not so sure why you think it’s a rumor. They have changed the checklist, it’s trained in the simulator and It’s even killed people. This isn’t a rumor. The damn parts have been recalled not once, but twice, and is currently covered by an AD.
Weird rumor right.
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knot4u
Repeat Offender
Okay.
gotWXdagain
Polished Member
I feel like the guy learned the importance of proper preflight without needing advice from some jackwagon in the peanut gallery.
knot4u
Repeat Offender
He blamed the airplane, I'm suprised he didn't blame maintenance. God forbid he owns up to his own dumb mistake. The first thing I was taught as a student pilot was a preflight, shiny jets are no different.
gotWXdagain
Polished Member
The phrase: “…and just how bad I screwed this up.” appears in that person’s very first post in this thread, so?
Old Boeing Driver
Well-Known Member
Video of the takeoff and runway excursion.
dustoff17
Still trying to reach the Top Shelf
You should read my post again, I never blamed the airplane!!
I looked at the pictures and scratched my head as to how the pin was in place and the "ears" weren't damaged.
Then I simply stated that I missed it on my plane and I understand (from this experience) that it's easy to do. Then, I stated that I was able to leave parking and make 3 turns, and, had I not been taxiing fast, would have been in a takeoff roll when it revealed itself. My statement was also that had I done THAT, I would have severely damaged the plane.
As an after comment (akin to an after thought), I commented on how the design is terrible....blah...blah...blah.... but I never blamed my plane!!
I did a preflight, actually crawled up in all three wheel wells and removed the pins! Coming from the Citation family for the last 12+ years, the scissor is new to me, I missed it, take (and took) full responsibility for it. I made that pretty clear in my post.
P.S. I've seen a lot of things in my day but I've never been "suprised" about anything; surprised on the other hand....
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Old Boeing Driver
Well-Known Member
If I recall.....there was a G-IV from a construction company in Louisiana that had the pin not correctly installed and it worked its way out during taxi or maybe takeoff.
I cannot find any reference to this incident.
I cannot find any reference to this incident.
dustoff17
Still trying to reach the Top Shelf
Here's an interesting parallel; involving a Citation X in July 2018.
In this accident, the crew had a total of 22,500 total hours (Almost 3x my total time) and 3,843 hours in type (427x my time in type). So, clearly not their first preflight...
They BOTH testified that they looked at the "scissor" pin to ensure that it was installed and that the safety button on the end was in the "out" position; indicating that the locking mechanism was in the locked position. Although they both verified that the pin was locked, NEITHER verified that the upper portion of the "scissor" assembly was actually attached to the lower portion!
Sooooo......slow taxi out, a couple of turns getting to the runway, and a discussion about the "mushy" feeling in the steering while turning onto the runway. Reached around 67kts for take off when the nose gear started to "shimmy" violently. Interesting read, the only thing missing is ending up in the grass.
I'm not feeling so bad about my experience now. Still feel a little stupid AND relieved that I didn't make it to the runway, but certainly not as bad!
P.S. I'll never miss it again....
In this accident, the crew had a total of 22,500 total hours (Almost 3x my total time) and 3,843 hours in type (427x my time in type). So, clearly not their first preflight...
They BOTH testified that they looked at the "scissor" pin to ensure that it was installed and that the safety button on the end was in the "out" position; indicating that the locking mechanism was in the locked position. Although they both verified that the pin was locked, NEITHER verified that the upper portion of the "scissor" assembly was actually attached to the lower portion!
Sooooo......slow taxi out, a couple of turns getting to the runway, and a discussion about the "mushy" feeling in the steering while turning onto the runway. Reached around 67kts for take off when the nose gear started to "shimmy" violently. Interesting read, the only thing missing is ending up in the grass.
I'm not feeling so bad about my experience now. Still feel a little stupid AND relieved that I didn't make it to the runway, but certainly not as bad!
P.S. I'll never miss it again....
knot4u
Repeat Offender
Wow, I'd like to retract my previous statements but I can't. There are two seperate devices other than the pin itself that are there to ensure the pin can't fall out.