737 – S/E, when is additional go-around thrust required ?

[CaptainSandL]

In the 737 QRH, One Engine Inop Landing, Descent Checklist the following statement appears:

“If additional go-around thrust is desired, below 10,000 feet configure the pressurisation system for a no engine bleed landing:” It then goes on to configure the pneumatics panel accordingly.

My question is, how are we supposed to know when this is required? In the all engines case we have go-around climb gradient/weight tables, are these also valid for engine out?

S & L

[Slick]

Capt S&L hi, don't know what model you fly, on the 800 with 26k the increment to your go-around climb gradient pack off is 0.2%. At max landing weight 18 degrees SL packs on the single eng climb gradient is 5.15% so not that shabby anyway.

However to ans your qn think hot heavy maybe overweight and possibly high, apply a bit of common and, - you get the picture.

To get a little more scientific look at your A/C and what it will/can achieve, compare it you what you want it to achieve, run a few calculations into the fields you go to.

With your two eng case on the 800 packs off landing climb weight increase 1200kg. On previous older A/C I have flown some airfield briefs used to give a temp when a packs off approach/landing was mandatory.

All the best

[Centaurus]

I think that this was meant for really high altitude airfields, 7000 ft plus where SE climb is limited.

[Denti]

It is thought for heavy and hot conditions. Nevertheless we configure our 733 (okay, the sim, never had an engine failure in real life) every time for the additional thrust. The check-pilots think it's safer that way.

PS: They canceled our second LOFT per year (to cut the sim-costs), now thats safety-relevant...

[irvin]

As a suggestion, when landing single engine you could simply have a look at the performance tables for the airfield you're landing at (assuming you have them and not diverting into a completely unknown field).

If your weight is approaching the WAT limit (sometimes called climb limit) for the temperature at the field then consider a bleeds off landing. (You might also want to look at the figures from the "packs off" tables as well. If by any chance your weight is above that then bear in mind at that field, even bleeds off, in the event of a go-around your climb performance won't be what you expect!!

Hope that helps.

[grey-fox]

The reason behind this procedure is to enable you to achieve the maximum gradient on GA possible in the Engine out case. Say you are returning to the airfiled of departure having taken off at max TOW. Pansops minima (unless steted otherwise) require a 2,5% gradient for the miised approach. Lets say that Icing conditions are prevalent, the OAT is 8degrees or less, low pressure (1000hp) now calculate your GA gradient with corrections from your performance manual. This is of course an emergency situation and under those conditions it is not a requirment to check this prior to T/O but it would be prudent prior to committing yoursels to a 1eng approach in minima conditions. In the CATII/III case it is mandatory to satisfy this case at all times. On a 737 of course you can only make these approahces all engines. Have a look at BSL where the CATIII minima is based on 3% GA gradient, If you are flying a -300/-400 you might find that your performance limiting LW is interesting. Have fun!