Official Aviation Thread...

[varg]

About what I'd expect from this situation in a developing nation.

Dronez, dawg.

I'm surprised there isn't an active model aviation thread considering the popularity of "drones." I fly RC planes, helicopters and quadcopters, and I build and modify quads for people as a side job.

[LateFan]

Lion Air Crash - Reuters :

"JAKARTA (Reuters) - Bureaucratic wrangling and funding problems have hampered the search for the cockpit voice recorder of a crashed Lion Air jet, prompting investigators to turn to the airline to foot the bill in a rare test of global norms on the probe’s independence."

"Weeks of delays in the search for the second ‘black box’ may complicate the task of explaining how 189 people died when the Lion Air Boeing 737 MAX crashed into the Java Sea on Oct. 29.

Indonesian investigators told Reuters budgetary constraints and the need for approvals had limited efforts to raise the main wreckage and find the cockpit voice recorder (CVR), thought to hold vital clues to Indonesia’s second-worst air disaster.

“We don’t have further funds to rent the ship,” a source at Indonesia’s transport safety committee (KNKT) said, in reference to specialized equipment needed for the search.

“There is no emergency fund for us, because there is no legal basis,” the source said, speaking on condition of anonymity."

“We have already asked the coordinating minister for the economy, but there is no regulation and it would need to be discussed by the parliament,” the source added.

The source said Lion Air’s insurers had been approached to pay the bill.

A source at Lion Air said its insurers had been reluctant to pay for the search and so the airline had stepped in.

The clock is ticking in the hunt for acoustic pings coming from the L3 Technologies Inc cockpit voice recorder fitted to the jet. It has a 90-day beacon, according to an online brochure from the manufacturer.

Safety experts say it is unusual for one of the parties to help fund an investigation. Under United Nations rules, such probes must be conducted independently to maintain trust in any recommendations made to prevent future accidents."

[tttoon]

Separate thread...

j/k

[TimeMachinE30]

What is that? Undesired aircraft state?

Dronez, dawg.

[flyboyx]

Any sUAS ? Or need a separate thread?

What is that? Undesired aircraft state?

[LateFan]

Unfortunately, the voice recorder is buried in the sea mud, it should answer those questions.

When are they going to find that thing? How deep can it be?

[TimeMachinE30]

Any sUAS ? Or need a separate thread?

[tttoon]

The 787 (FBW as well) has trim switches, just no trim wheel. In the air the trim works as a speed trim, so if you move the trim switches the computers change the reference speed. They'll streamline the stabilizer and elevators to achieve the minimum drag. There's a stabilizer non-normal checklist similar to the trim runaway checklist on the 737.

[ThatM20Guy]

That is wild! Never seen that picture before. Thanks for sharing!

[LateFan]

I don't want to change the subject, but I just saw this cool shot of the last Concorde flight, late November 2003. Photographer Lewis Whyld was hanging off the skid of a helicopter at 3000', the Concorde was at 1500'. He was moving, the plane was moving, it was very cold, he wanted the bridge in the shot, he had one chance.



And a cockpit for you pilots...



Now, back to discussion of trim and elevators!

[flyboyx]

I had never really thought of it in those terms, but yes it does. In all configirations: flaps, spoilers, climb, descent, auto thrust on or off......there is simply no electric pitch switch anywhere in the cockpit controllable by the pilot. As I mentioned above, this does actually bring up an interesting question if there were a trim runaway situation. I guess it's never happened in this plane.

[FLYNAVY]

Out of curiosity, do Airbii auto trim to 1G flight in the absence of autopilot usage? In the three FBW jets I have spent much time flying, the aircraft FCS software is designed to do that if not in landing configuration........in other words, you barely touch the pitch trim switch at all in flight. If you were to bring the throttle(s) to idle, the jet would simply remain pretty much in 0 VSI level flight as the jet slowed, got more and more cocked up/high AoA, the leading and trailing edge flaps would schedule down as you got real slow, and then after a bunch of angry tones, if you still didn't add power, it would ultimately settle while still trying in vain to seek 1G flight.

[LateFan]

Airplanes without trim would require constant force on the elevators at all but one speed, if that makes sense.

It does.

The trim must be adjusted based on configuration, speed, weight and balance, it is something that requires a wide degree of adjustment. Flaps and slats can change the center of lift/center of pressure of the wing, drag from landing gear can impart a moment on the airplane that must be countered, CG location can shift as the aircraft burns fuel....

Good explanations both, thanks.

[hoveringuy]

I instructed in a GlasAir GlaStar the other day. Cool little airplane with a stick and electric trim, except the trim switches were on the panel and I spent the entire flight wondering why the fart the trim switches weren't on the stick...

[flyboyx]

oddly, the airbus has no electric elevator or aileron trim adjustment in flight. the computers take care of all of it. you can only set elevator for takeoff based on the aircraft weight and balance loading. we do have a manual wheel for elevator but that is only if all the computers fail.

the only trim adjustment that is overridable is the rudder. the only reason why the pilot is allowed to fuck with that is in the event of an engine failure. the 1986 technology computer will adjust for it eventually, but the pilot can trim the plane up so much faster which would be critical in the event of an engine failure on takeoff.

we don't even really have a procedure for elevator trim runaway. I was sitting around the other day trying to figure out what I would do in that situation. the only thing I can come up with would be to reach up to the overhead panel and start shutting off computers.