737 flap inhibit and fire Fault light

[Pete the Pilot]

Questions, questions, questions!!!

1 Why use flap inhibit on a single engine approach, the book says landing flap is between 15 to 40 degrees so there would be no warnings from this or would there?

2 If in flt the FAULT light comes on indicating that the fire detection system has failed in 1 or both engines what do your company procedures instruct you to do? Land or whatever?

[Propellerhead]

Answers, Answers, Answers!

Flap inhibit relates to the GPWS system.
This will call 'Too Low Flaps' if flaps not in 30/40 position. Flap 15 is only ever used in non-normal situations - eng. fail, flap problems etc. Therefore, the GPWS stops you landing without landing flap in normal situations.

If the fire loops fail you continue to your destination, but I believe it would have to be fixed before any further flights.

[Pete the Pilot]

Yep, that makes sense, but in vol 2 it mentions flap 15 as being normal ldg flap. Obviously it isn't !

[Checkboard]

I suppose it depends upon your definition. The aircraft was certified for flap 15 landings to cover the abnormal cases - so the manufacturer probably considers it "normal" in the sense that the aircraft is certified to perform the manoeuvre.

Our Ops Manual had a passage that said something like "Flap positions certified for abnormal operations such as an enigne inop, shall not be used for normal line operations." This clarified things when coming across recomendations such as "use minimum flap when landing in gusty conditions."

[ 01 October 2001: Message edited by: Checkboard ]

[HighSpeed]

just out of curiosity, is there a special maintenance procesure to be done after a flap 15 landing? i am referring to the b737 classics. not sure about the NG though.

[tjslice]

Flaps 15 landings are done to improve your approach climb angle. In any condition where you cannot meet the required approach climb limit flaps 30/40, you would do a flaps 15 landing. It is a common requirement at high altitudes in the summer in a -200. You do have to check your brake cooling limits as well.

According to our operations manual, flaps 30 is normal. Flaps 40 is at the pilots discretion, but recommended for tailwinds and wet runways. Also, a flaps 30/bleeds off landing is preferred over a flaps 15 landing if that improves the approach climb suffieciently.

[Combi]

To the best of my knowledge, only the APU fire detection system has a warning light if it becomes inop. The only way to check for proper operation of the engine fire detection system is to conduct a system test. On the -200 advanced, if an engine fire loop has failed the test we can switch the fire warning system to the overheat detection system. Provided this tests OK it's just a quick note in the book and away we go.

[steelbird]

On our B737-400 BOTH engine & APU detectors have their respective fault lights.However only the APU DET INOP light triggers the Master Caution annunciator.
On the Q of to go or not go with both detectors failed, we had an incident a couple years ago on the 747-400 where both detectors on an engine had failed in flight.The commander elected to return to base, the company however wasn't too pleased with his decision & convened an inquiry.
To keep it short, the question of appropriate response to this problem was directed to Boeing in the course of the inquiry.Boeing's response after some technical gobbledygook was "at commander's discretion".
Cheers! ;)

[ 06 October 2001: Message edited by: steelbird ]

[flapsforty]

Flaps40 is at the pilots discretion

Interesting............. ;)

[Denti]

I had the problem with an inoperative fire detection loop the other day during my fire check (we have to check all fire detecting devices before we start our first flight of the rotation).
Loop A on engine nr. 1 was inop. Our MEL (737-31S) says about Engine Overheat and Fire Detection System: One Loop (A or B) per engine may be inoperative. According to the Dispatch Deviation Procedures Guide: Except for ER operations beyond 120 minutes, one loop (A or B) per engine may be inoperative.

Denti

[goblin]

Hi there
In summer we regularly have to do flap 15 landings, the old 200 needs all the help it can get when she's heavy into JNB. The only change in procedure is to use the 'flap inhibid' switch, otherwise you wake up quickly with the GPWS screaming at you. We do no special checks or anything afterwards, it does not even get mentioned in the teg log, but one obviously have to keep an eye on brake cooling. She also uses quite a bit more runway than with a flap 30.

[kriskross]

When we were doing the HUD testing for the NG 737 in Mojave 3 or 4 years ago, we were specifically asked to do Flap 15 approaches and landings, to cater for the user airline's requirements for approach/climb into Denver and other high altitude airfields. Being a European operator, we only did Flap 15 landings on non-normal procedures and in Europe Flap 30 or 40 seem to be the norm. I agree that the switch referred to is operated in connection with the GPWS or EGPWS.

[ 10 October 2001: Message edited by: kriskross ]

[dan296]

Oh my god!your all so lucky!The majority of you fly 737's as a job!I really want 2 become a pilot when im older.Theres something about the 737-400 that makes me want to fly it!Whats the best way to the flight deck then guys??im doing a-levels at the moment in maths,physics,geography and computing.Degrees helpful or not??