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Posted
“glide distance under active control after second engine flame-out was 125nm (230km) which favours a no active control scenario” . To a pilot this is very confusing because I don’t understand what they mean. (Boeing would be stunned that a B777 with both engines flamed out could glide so far while in a practically stalled condition.)

All of the above story sounds credible, but when I got the the 'glide distance' comment, I also was a bit confused.

However, I was confused at the author's questioning of the statement, as from the airline flying I've done (as a passenger), I would happily accept the implied glide ability of a B777.

 

In my earlier years of travelling from Perth to Sydney and back, in the old B727's, it was not uncommon to hear the engines go to flight idle around Goulburn (90nm) at 30,000ft, and even then it was not unusual to see the speed brakes come out to avoid overspeeding in the glide.

 

These days in the wide bodies, tending to start from closer to 40,oooft, and trying to be as efficient as possible (no wasting energy with speed brakes, no dropping below glidepath and no lowering of gear 30 miles out and 'driving' the plane toward the airport), it is not uncommon to hear the engines go back to flight idle passing Canberra (130nm) and not be touched till approaching the threshold.

 

As such, I would think a 125nm glide to be quite reasonable.....

 

 

  • Agree 1
Posted

I'm no expert but when power is reduced for descent in large jets I don't think it is to complete idle and some thrust is still being produced and even at idle there is a small amount of thrust compared to a flame out when there is none.

 

 

  • Agree 1
Posted

I wouldn't question the author on any technical issue as he is thoroughly experienced on type. He has also published it for all the world to see including all the aviation experts and his peers.

 

From an energy point of view the glide distance is probably easily verified. Normally you don't get to do an all engine out glide, but no doubt it could be done in a simulator of the aeroplane specific type

 

The B727 has to be partly spooled up below 3,000 feet as flight idle on the P&W JT 8 D gives a slow throttle response, and it's a safety requirement to be above it at that stage of the approach.

 

Normally one doesn't drop the gear way out unless a change of runway is offered and you use it to lose height if you are set up for a runway with more track miles to threshold, you will be too high for a straight in on 06. Nev

 

 

Posted
I'm no expert but when power is reduced for descent in large jets I don't think it is to complete idle and some thrust is still being produced and even at idle there is a small amount of thrust compared to a flame out when there is none.

Which is why it's called 'flight idle' as opposed to 'ground idle', but yes, flight idle probably produces enough thrust to overcome the drag of the engines, and avoid the risk of a flame out.

Dead engines would produce a bit more drag.

 

 

  • Caution 1
Posted

Two distinct different programmes. in the engines. that suits the particular situation. Leg switch actuated I think. Flight idle is fairly minimum fuel flow.. Some airlines use more critical ones than others. The engine can take more than 5 seconds to get full power from ground idle and still be considered serviceable.. Ground idle on 3 engines is enough to need brakes to stop it going too fast when taxiing so usually one engine is shut down during taxy after landing.Nev

 

 

Posted

Well, if you follow the links in the ATSB "correcting the media buzzards bad reporting" link in the previous page, that article is refuted.

 

The plane did NOT circle the pilots home island. Noone has said if the flaperon was up or down, or speculated in an official capacity, that is media wishful thinking. The engine flameout scenario envisioned and calculated for is one flaming out, followed by the other in close order due to fuel exhaustion. The articles author refutes the official calculation on the basis of one engine flaming out but the other continuing to run, not what they say would happen.

 

 

  • Agree 1
Guest SrPilot
Posted
It could of course be something that is unmistakably from an aircraft (tail section, wing section) and after all he is a pilot!

And when have we ever known a pilot to be mistaken? 074_stirrer.gif.5dad7b21c959cf11ea13e4267b2e9bc0.gif075_amazon.gif.0882093f126abdba732f442cccc04585.gif

 

 

Posted

It's not really correct to talk about big jets in terms of "flight idle" and "ground idle". These are turboprop terms related to blade angle and governing, and are distinctly different from how idle thrust is controlled in big jets.

 

On the ground and in flight, a jet has but one "idle" setting, with two exceptions. When the thrust levers are at "idle" (there is only "idle" position on the throttle quadrant) so too are the engines. There is always residual thrust in this position in the air and on the ground. It is quite considerable, on most modern jets at least. Certainly enough to get you moving on the ground without touching the throttles at all but the heavier weights. In the air it makes your glide distance longer than if you had them shut down.

 

Exception 1: In both Airbus and Boeing aircraft, when certain conditions are satisfied to indicate that the aircraft is on approach, the engines will automatically switch to an "approach idle" mode. This is a higher idle setting, to allow for less spoolup time in the even of a go-round with idle thrust selected.

 

Exception 2: Idle setting increases automatically with the anti-ice/de-ice systems turned on to compensate for bleed air demand. In the case of the Boeing aircraft (including the B777), that setting is the same as the "approach idle" setting.

 

Other than those cases, idle is pretty much idle.

 

 

  • Helpful 1
Posted

MH370 sonar vessel torn from Fugro Discovery after crashing into underwater mud volcano

 

BREAKING: A sonar deep tow scouring the southern Indian Ocean for missing Malaysia Airlines flight MH370 has been lost after crashing into an underwater volcano.

 

The Australian Transport Safety Bureau released a statement from the Joint Agency Coordination Centre this morning detailing the incident, which resulted in the loss of the Fugro Discovery’s sonar towfish.

 

“Yesterday, while conducting search activities in the southern Indian Ocean, Fugro Discovery lost the sonar vehicle deep tow (towfish) being used to search the ocean floor,” the JACC said.

 

“The towfish collided with a mud volcano which rises 2200m from the sea floor resulting in the vehicle’s tow cable breaking. The towfish and 4500m of cable became separated from the vessel and are now resting on the sea floor.”

 

Thankfully there were no injuries to crew during the incident and it’s believed it will be possible to recover the towfish at a later date.

 

The JACC said Fugro Discovery was making its way back to Fremantle where a replacement cable will be installed on the vessel. During the journey, the spare towfish on board Fugro Discovery will be readied for future search activities.

 

The vessel is expected in Fremantle on January 30 or thereabouts, the agency said.

 

Malaysia Airlines flight MH370 disappeared on March 8, 2014 en route to Beijing from Kuala Lumpur with 239 people on board.

 

A flaperon that washed up on a beach in Reunion last July is the only debris confirmed to have come from the plane that has ever been found.

 

At the weekend, a barnavle-encrusted panel found off the coast of southern Thailand set off a frenzy of speculation that it might belong to MH370.

 

The large, curved piece of metal washed ashore in Nakhon Si Thammarat province, where villagers reported it to the authorities to help identify it.

 

It was quickly established that the debris was unlikely to have come from the Boeing 777 and had probably come away from a Japanese H-IIA rocket, a liquid fuelled launch system used to transport satellites and space probes..

 

http://www.news.com.au/travel/travel-updates/incidents/mh370-sonar-vessel-torn-from-fugro-discovery-after-crashing-into-underwater-mud-volcano/news-story/d0ebd3474959dbbec388575c01c186d6

 

 

Posted

Sorry Dutch. The Airbus A-300 and the Boeing 727 both had these terms used, and the settings varied sometimes if problems arose with stability..Later stuff may not have. I wouldn't know, having not been endorsed on them. Nev

 

 

  • 2 months later...
  • 3 months later...
Posted

Sixty Minutes report tonight saying that MH370 was glided into the sea under full control. Senior air crash investigator Larry Vance told Channel 9’s 60 Minutes program, a flaperon found on Reunion Island last year and handed over to France for analysis was the strongest clue yet the aircraft was “glided” into the ocean. See report:

 

The evidence MH370 ‘glided’ into ocean: 60 Mins

 

 

Posted

Wouldn't surprise me Peter - we've seen this before with the Germanwings flight 9525.

 

Having said that, nothing much surprises me these days and it may turn out to be a totally different cause.

 

 

  • Agree 1
Posted

Is this new? A wing part found in Tanzania.

 

Wing found in Tanzania 'highly likely' from missing MH370

 

MH370: Wing part found in Tanzania 'highly likely' from missing Malaysia Airlines plane

 

A piece of aircraft debris found in Tanzania is "highly likely" to be from missing Malaysia Airlines flight MH370, Australia's Transport Minister Darren Chester says.

 

The wing part was brought to Canberra for analysis after it was found by locals on Pemba Island off the coast of Tanzania last month. .....

 

 

Posted

I've always had the opinion that it was a quite deliberate act by one of the pilots. You can't get a big modern jet to change course like that and fly for hours without very deliberate pilot intervention.

 

 

  • Agree 3
  • Informative 1
Posted
I've always had the opinion that it was a quite deliberate act by one of the pilots. You can't get a big modern jet to change course like that and fly for hours without very deliberate pilot intervention.

I fully agree, dutchroll! I haven't swerved from that opinion either.

 

 

Posted
I've always had the opinion that it was a quite deliberate act by one of the pilots. You can't get a big modern jet to change course like that and fly for hours without very deliberate pilot intervention.

Dutch

 

You have a much more in depth knowledge of the systems on board large modern passenger jets than I ever will (I have a couple of theories but am not prepared to air them on a public forum due to my lack of knowledge of those systems), my question is why would you want to take seven (7) hours to commit suicide, just to be sure that is what you wanted to do, obviously there comes a PNR and you can't change your mind after that? Still too many questions - hope they eventually find the flight data recorders.

 

Aldo

 

 

Posted
why would you want to take seven (7) hours to commit suicide

To be sure you'd never be found.

 

 

  • Agree 3
Posted
To be sure you'd never be found.

Red

 

Don't buy that, know a couple of people that have committed suicide, they wanted to make a lasting statement.

 

Aldo

 

 

Posted

Like the Mary Celeste, this flight will be part of history.

 

Are you tired of trying to make your mark by doing the right thing? Do you want to achieve instant fame, your name and picture shown around the world?

 

It's easy; just do something rally nasty. The world's media will make you famous.

 

 

Posted

Suicidal people are not rational during the time they're preparing and committing it.

 

I have no idea why he'd never want to be found, except that it seems he didn't. Maybe he wanted to frustrate the hell out of his company? Or certain other people?

 

 

  • Agree 2

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