B737-800 MEL 27-4

[rasper90]

I had a recent false snag that caused all my LED overhead panel lights to illuminate.All it's green and amber(transit) lights.All devices were extending and retracting normally.Forward panel lights were serviceable.

Maintenance released the A/c under MEL 27-4

1. Is that correct with all green and amber lights lit.

2.How do I complete my LE flaps transit NNC as regards 300 or 230kts as all the overhead annunciator lights are illuminated.

3.Why does MEL 24-4-5 not permit slats 3,4 and 5 slat light Inop dispatch.

Any inputs from 737 specialists would be welcome.

[rasper90]

Exactly my point.

MEL 27-4 states that fwd panel lts or annunciator panel maybe inoperative.It expands further regarding what to do in case the fwd panel lights are Inop.

MEL 27-4-5 talks about the leading edge slats indications .Maintenance says this MEL applies only in case fwd panel lts are u/s, then only one slat light maybe inoperative.It restricts level to 300/.65 and FL 280.

If either MEL applies, I am still unable to differentiate if one or more slats are extended.For one slat I am permitted 300/.65 ,for more than one I have to fly 230 kts as per the QRH.Since I am unable to differentiate I would have to fly 230kts in case of a LE laps transit light. Should I not cater for additional fuel as this is at dispatch.

My doubt with the MEL is would Boeing leave all this unsaid????

[ohreally]

First of all, check which revision of the Boeing DDG your MEL was derived from. Revision 50 (current) corrected a previous mistake in this entry as you pointed out.
In addition, I dont know about the ability to "see" the slats but the numbering of the slats does vary between variants due to the input to the stall warning computers. You can see this in the Maintenance actions.

[rasper90]

27- 4 Leading Edge Flap / Slat Position Light Systems

Interval Installed Required Procedure

C 2 1 (M)

Forward panel lights or annunciator panel may be inoperative. If forward panel lights are inoperative, annunciator panel must be used to verify proper LED position, and a placard must be installed to indicate proper positions for flap configuration in use.

5) Leading Edge Slat Indications

(- 800)

Interval Installed Required Procedure

C 8 7 (M) (O)

Indication lights on forward panel and in addition indication lights for one leading edge slat, except for slats 3, 4, 5 and 6 on overhead annunciator panel may be inoperative provided :

a. Normal operation is verified by flight crew before each takeoff and landing. b. Maximum speed is limited to 300 KIAS at/below FL 200 or .65 Mach above FL 200. c. All remaining indications on overhead annunciator panel operate normally. d. Stall warning operation of both systems is verified to operate normally.

Dispatch Deviations Procedures Guide (DDPG)

MAINTENANCE (M) PROCEDURES

With forward position indicator lights inoperative and one SLATS annunciator panel light inoperative :

1. Cycle the flaps.

2. Verify that the remaining LE DEVICES annunciator panel (P5) lights operate normally during flap extension and retraction.

NOTE: Dispatch is not allowed if the LE DEVICES annunciator panel FLAP TRANSIT lights do not illuminate properly and the forward panel light(s) are inoperative.

3. Remove the bulbs from the associated forward position indicator light(s) on the center instrument panel, P2.

[rasper90]

The MEL extract was posted before Oheally's post.Any one has DDG 50 or any idea what the correction that has been effected.The extract I posted is from DDG 49

[HOVIS]

From what you are saying and the info at hand, it looks like a no-go.

Fwd annunciator lts inop? Go-if.....O/head annunciator lts ok but one allowed inop.

O/head annunciator lts inop? Go-only if one inop and fwd lts ok...etc.

If all O/head annunciator lts inop? No-go.

I think..:confused:

[rasper90]

Still does not answer the NNC actions one slat 300kts two slats 230 limitation.I can't make out how many are extended?

[BOAC]

Does it matter? 230kts, and, I think F15 landing?

[rasper90]

That's my point , I would have to cater for the extra burn else on a long sector that could imply a diversion. I am being dispatched with an MEL that does not let me complete the QRH actions. Shouldn't the MEL sync with the NNC ?

[OwenMc]

I know this is an Old post but we had a similar complaint with maintenance.
They totally messed it up.
Certain LE slats are no/go (3,4,5,6) because they not visible from the cockpit to confirm position should they fail in flight and the load they take on generating lift. LE flaps are no/go. Period. No explanation needed for that.
When one of either slat 1,2,7 or 8 is inop, dispatch is allowed provided maintenance perform a few tasks and the stall warning test passes at flap 0, 1 and 10.
Airspeed limitations are due to cruise maneuvering capabilities. If a failed proximity sensor on the affected slat indication is the cause then the stall speed also rises as the FSEU input to the SMYDs is not accurate due to a slat "not" being in the selected position.
MEL 27-4-1 allows for a failed aft overhead annunciation panel only. Failed is considered not operating in the normal manner as designed.

Hopefully this helps. If not; club me.. Lol :ok: