EK521 Atterissage sur le ventre à DXB

Vector a écrit:Bonjour C.Foussa,
Lorsque tu dis "Les autothrottle (Boeing) et autothrust (Airbus) sont largement autre chose que la simple gestion de la poussée des moteurs"  Est-ce que tu veux aussi dire que l'A/THR gère aussi la symétrie de la poussée ? Il est en effet tout à fait concevable que la montée en puissance des deux moteurs ne se fasse pas toujours selon la même courbe (réglages des FCU, etc.) et qu'il y a momentanément un certain déséquilibre qui ne peut que créer une déviation de l'avion pas forcément facile à contrer aux commandes.

As recorded by the Aircraft flight data recorder, the weight-on-wheels sensors indicated that the right main landing gear touched down at 0837:17, approximately 1,100 meters from the runway 12L threshold at 162 knots IAS, followed three seconds later by the left main landing gear. The nose landing gear remained in the air.
At 0837:19, the Aircraft runway awareness advisory system (RAAS) aural message “LONG LANDING, LONG LANDING” was annunciated.
At 0837:23, the Aircraft became airborne in an attempt to go-around and was subjected to a headwind component until impact. At 0837:27, the flap lever was moved to the 20 position. Two seconds later the landing gear lever was selected to the UP position. Subsequently, the landing gear unlocked and began to retract.

At 0837:35, three seconds before impact with the runway, both thrust levers were moved from the idle position to full forward. The autothrottle transitioned
Preliminary Accident Investigation Report № AIFN/0008/2016, issued on 5 September 2016 2
from IDLE to THRUST mode. Approximately one second later, a ground proximity warning system (GPWS) aural warning of “DON’T SINK, DON’T SINK” was annunciated.
One second before impact, both engines started to respond to the thrust lever movement showing an increase in related parameters.

As the ARFFS crew were fighting the fire, an explosion occurred approximately nine minutes after the Aircraft had come to rest. The explosion occurred in the center wing tank, causing a large section, approximately 15 meters in length, of the RH inboard wing upper skin to be liberated and blown several meters above the runway surface. The liberated skin landed near to the RH wingtip

Les poussoirs TOGA sont inhibés au toucher des roues, la poussée doit être appliquée manuellement.

The FCOM states that “Pushing  either  TO/GA  switch activates  a  go-around.  The  mode  remains  active  even  if  the  airplane  touches down  while executing  the go–around.”  In  addition,  the FCOM states  that “The  TO/GA  switches  are inhibited when on the ground and enabled again when in the air for a go–around or touch and go.”
(..)
The following is stated in the FCTM: “Although the FCOM/QRH does not contain a procedure or maneuver titled Rejected Landing, the requirements of this maneuver can be accomplished by doing the Go-Around Procedure if it is initiated before touchdown. Refer to Chapter 5, Go-Around after Touchdown, for more information on this subject.”

“(...)
If a go-around is initiated after touchdown but before thrust reverser selection,  continue  with  normal  go-around  procedures.  As  thrust levers  are  advanced  auto  speedbrakes  retract  and  autobrakes disarm.  The  F/D  go-around  mode  will  not  be  available  until  go-around is selected after becoming airborne.”

Go-Around after Touchdown
If a go-around is initiated before touchdown and touchdown occurs, continue with
normal go-around procedures. The F/D go-around mode will continue to provide
go-around guidance commands throughout the maneuver.
If a go-around is initiated after touchdown but before thrust reverser selection,
auto speedbrakes retract and autobrakes disarm as thrust levers are advanced. The
F/D go-around mode will not be available until go-around is selected after
becoming airborne.

Bounced Landing Recovery
If the airplane should bounce, hold or re-establish a normal landing attitude and
add thrust as necessary to control the rate of descent. Thrust need not be added for
a shallow bounce or skip. When a high, hard bounce occurs, initiate a go-around.
Apply go-around thrust and use normal go-around procedures. Do not retract the
landing gear until a positive rate of climb is established because a second
touchdown may occur during the go-around.
Bounced landings can occur because higher than idle thrust is maintained through
initial touchdown, disabling the automatic speedbrake deployment even when the
speedbrakes are armed.

Zebulon84 a écrit:Toujours selon cette page 15 du rapport, FCTM chapter 5.69 dit :

“(...)
If a go-around is initiated after touchdown but before thrust reverser selection,  continue  with  normal  go-around  procedures.  As  thrust levers  are  advanced  auto  speedbrakes  retract  and  autobrakes disarm.  The  F/D  go-around  mode  will  not  be  available  until  go-around is selected after becoming airborne.”

Toujours en lisant vite, « continue  with  normal  go-around  procedures. » peut être interprété comme « un simple appui sur TOGA switch suffit »


FCTM = flight crew training manual

The Long Landing Monitor function offers the pilot increased runway awareness and complements the RAAS Distance Remaining callouts. The function advises the crew of their position during a landing when the aircraft has not touched down in a nominal amount of time and/or distance. Existing EGPWS protection and operation is unaltered by the addition of the Long Landing.
The Long Landing function adds two new distance remaining annunciations to enhance crew awareness of aircraft along-track position relative to the runway end. If the aircraft has not touched down before a configurable threshold, the EGPWS will activate an aural message. In addition, airborne only aural annunciations of current distance from aircraft to the runway end can be enabled.
The Long Landing function is enabled using the RCD. When enabled, the Long Landing function operates automatically, without any action required from the flight crew.
In addition to the aural annunciations provided, visual annunciations can be activated in the form of caution indications if the annunciations are considered cautions. Visual text annunciations can also be configured to be overlaid on the terrain display for a period of time when the condition is entered. System inoperative messages may be indicated as required using existing GPWS inoperative indications or dedicated RAAS INOP indications (MKV-A EGPWS, or MKV/MKVII EGPWS -236-236, -057, -006 software versions and later) if supported by aircraft. The Long Landing inoperative status will be indicated during the EGPWS Self Test if the monitor is enabled via the RCD and the status indicates the function is inoperative. Inhibition of the Long Landing function via an external cockpit selection may be configured.

8.2.1 Annunciation Criteria
The Long Landing and airborne only Distance Remaining alerts are generated when the following conditions are met:
Aircraft is within 100 feet AGL, past a customer specified distance from the runway end (see below); Aircraft is airborne above 5 feet AGL, or weight on wheels is false
The callout triggers are defined by several RCD items:
1) Base callout activation relative to approach or departure end of runway
2) Percentage of runway remaining to trigger callouts (used for shorter runways – see section 8.2.2 for an example)
3) Fixed distance from threshold end (or departure) to trigger the calls (used for longer runways – see section 8.2.2 for an example)
Using these RCD selections, a flexible enabling threshold method is provided to allow the calls to be based on a fixed distance from departure end or a fixed distance from approach end, and a percentage of runway length. To allow for short runways and long runways, the two computed thresholds are evaluated and the threshold that provides the longer distance from the departure end of the runway is used for the trigger point.
Long Landing callouts are disarmed once the on-ground condition is met (radio altitude or weight on wheels depending on aircraft configuration). This prevents a second Long Landing callout in the case of a touch-and-go landing.

Poncho a écrit:Est-ce qu'on est posé avec un train sur la piste ?
On commence à ralentir qu'avec les deux trains sur la piste ? ou avec les  3 trois ?
Le TOGA est-il inhibé avec un train sur la piste ou deux ?

Dans le cas d'EK521, de toute manière le second train était sur la piste 1 s après l'annonce "long landing" et probablement simultanément à l'énoncé de l'annonce...

Cas où le système d'aide a causer une réponse inapropriée ?

Vector a écrit:Bonjour C.Foussa,
Quelle est la référence et la méthode de détection du point initial de la piste. Comment le système peut-il établir la corrélation avec le WOW ? 
Deuxième cause d'interrogation profonde : quelle est la logique d'avoir une voix masculine pour les altitudes et une voix féminine pour les distances ? Y a-t-il une convention ?
Comment ces systèmes ont-ils réagi dans le cas particulier le l'A340 d'AF à Toronto. J'imagine que l'aquaplaning a joué un rôle important, mais n'était-il pas évident qu'encore en vol à la moitié de la piste, il fallait faire une RDG.