737 Engine failure on final approach

[CFMFan]

Tried to get an answer to this by bolting it on to a similar thread. No joy... any help would be much appreciated.

Our FCOM Part B states the procedure is -
"Retract the flaps to 15
Maintain high thrust. Increase approach to the speed tape generated speed of Vref +20 then adjust thrust to maintain this speed.

If the speed and approach path still cannot be maintained, or if a go-around is subsequently required:

CALL GO AROUND FLAP 5 AND CLIMB AWAY AT FINAL APPROACH SPEED.
ACCOMPLISH THE ENGINE INOPERATIVE GO AROUND PROCEDURE."

The Boeing Flight Crew Training Manual says - "If the approach is continued and sufficient thrust is not available for landing flaps, retract the flaps to 15 and adjust thrust on the operating engine. Speed should be increased to 20 knots over the previously set flaps 30 or 40 Vref. This is equal to at least Vref for flaps 15.

IF A GO-AROUND IS REQUIRED, FOLLOW THE GO-AROUND AND MISSED APPROACH PROCEDURES EXCEPT USE FLAP 15 INITIALLY IF TRAILING EDGE FLAPS ARE AT 30 OR 40. SUBSEQUENT FLAP RETACTION SHOULD BE MADE AT A SAFE ALTITUDE AND IN LEVEL FLIGHT OR A SHALLOW CLIMB"

As one of our regular posters said though, from a flap 40 approach Vref 40 + 20 represents the minimum speed for a one engine go around (V2 flap 1). So is there an objection to selecting flap 15 initially followed rapidly by flap 1 ?

[Port Strobe]

As one of our regular posters said though, from a flap 40 approach Vref 40 + 20 represents the minimum speed for a one engine go around (V2 flap 1). So is there an objection to selecting flap 15 initially followed rapidly by flap 1 ?

My 2c here only so don't take it as authoritative but I'd think the point of accelerating to Vref40+20 initially is to place you at F15 minimum manoeuvre speed for a OEI approach which allows you the full manoeuvre margin (because you may have had landing flap selected on base leg due to strong tailwinds on base near circuit height say and you may need to use the full 25* AoB to roll onto final). If you drift through the centreline for example and execute a missed approach you're starting from a familiar point so I'd guess "go around flaps 1" would be what's required as per OEI GA. However assuming you don't have a bug for Vref15 displayed, and in keeping with what you said re V2 F1, then you're in no place to assume you're above V2+15/Vref+15 and so I'd manoeuvre with care up to 15* AoB, you've just taken the LE slats in 1 stage after all. Once the initial turn is out the way then I suppose you could accelerate and clean up the last stage of flap. More than happy to be corrected if anyone knows otherwise however.

[RobinR200]

No objections here. It's our flying technique. But only when above 500'.

As a recap: engine out on final -> stabilize (rudder!) -> flaps 15 -> speed bug Vref +20 -> thrust to initially 80%N1 (rudder) -> All stabilized and above 500' and then GA? -> flaps 1 and follow EO GA.

All other case GA is made with flaps 15.

Don't try to retract flaps in the GA: u will stall almost instantly. (did it in the SIM once due to obstacle obstruction ahead. Will never try that again)

[Mrs-rodge-bless-her]

I've tried this in the sim... waiting for it to happen. Knowing it was going to happen, and still screwed it up trying to reconfig to land off it.

In my humble opinion (being newly rated on the 737NG) best thing is to just go around!

If in doubt.... there is no doubt!

Hope this helps.

[john_tullamarine]

Can't speak to the NG but for the Classics .. reconfiguring to land is straight forward .. but the above comments give the secret away - one needs to have practised the manoeuvre in the sim a few times to see the problems and get on top of them.

Problems include

(a) not being aware of the problem in the first place ie failing to recognise the failure (and that is an easy trap if you still are bleeding speed back to a stable final configuration) .. which sets you up for a (fairly rapidly) energy decaying situation prior to the obvious becoming blindingly so

(b) you don't have all day. If you aren't onto it very quickly you will find yourself in a difficult energy predicament fairly quickly and a small problem becomes a big one.

MORAL engine instrument scan needs to be integrated into the overall scan on final .. a lot of people take a while to learn this lesson.

However, several practice approaches in the sim and it becomes a bit of a doddle.

[RAT 5]

Just to complete the discussion, as the height of the failure was not mentioned. It is allowed, FCTM, to use discretion, maintain configuration and land. Increased thrust will be needed. naturally.

[Rainboe]

Ops manual B says that when an engine goes, you may not be able to maintain the profile. It recommends power up to GA on the remaining engine while you reconfigure. That is almost certainly bad news! In fact, you only need a small handful. If you are heavy, or hot and high, you may well need to reconfigure fairly rapidly, but putting on GA power will so disturb your approach you will probably end up too high to land.