PDA

View Full Version : The B737 MEL as a useful instructional tool


sheppey
24th Jun 2019, 14:09
The FAA approved Master MEL for the Boeing 737 Series. While most pilots rarely have reason to study its contents, it strikes this scribe as not only most instructive but a useful document for simulator instructors responsible for type rating of pilots or for recurrent training sequences. For example, it is permissible to dispatch (under stated conditions) with flight directors inoperative. One presumes this pre-supposes the pilot is certified competent at raw data flying. That's a big ask in todays Children of the Magenta Line piloting society.

Yet there are operators who are prone to penalize pilots via the QAR for turning off the FD even in good weather despite the pilot trying to maintain raw data competency. Most would agree that a ten minute raw data ILS in the simulator once every six months does not maintain any sort of serious instrument flying competency; despite the appropriate regulatory box being ticked.
Imagine the outcry if a pilot refused to accept an MEL departure on the grounds he lacked recency and/or competency at flying without the aid of a flight director.

yoko1
24th Jun 2019, 14:22
One of my personal pet peeves is that airline managers (often non-pilots) will on one hand insist that you always use some gadget on the grounds of safe and efficient operations but will gladly take it away under MEL authority to keep the metal moving. I've turned down a handful of aircraft over the years because I don't believe I should be practicing a skill for the first time on a revenue flight.

Goldenrivett
24th Jun 2019, 14:37
Most would agree that a ten minute raw data ILS in the simulator once every six months does not maintain any sort of serious instrument flying competency; despite the appropriate regulatory box being ticked.
Isn't that a bit like saying you won't accept the chance of an engine failure on take off because you only practiced once in the last 6 months?

gearlever
24th Jun 2019, 14:53
Not to forget:

The decision of the Commander of the flight to have allowable inoperative items corrected prior to flight will take precedence over the provisions contained in the MEL. The Commander may request requirements above the minimum listed whenever in his judgement such added equipment is essential to the safety of a particular flight under the special conditions prevailing at the time.

wiedehopf
24th Jun 2019, 15:57
Isn't that a bit like saying you won't accept the chance of an engine failure on take off because you only practiced once in the last 6 months?

No it's not.
It's more like not accepting a guaranteed EFATO.

For example on takeoff something else might fail, which is now harder to handle because the FD is already not working.
So while you are confident that you are able to fly RAW data if necessary, it's less error prone to use the FD.
That's why it is used in the first place.

Intruder
25th Jun 2019, 02:48
To address the subject line, the MEL, MMEL, or DDG is a VERY valuable training tool. Some pilots will only refer to it if they need to confirm they are legal to fly. However, comparing the DDG with the QRH non-normal procedures for a particular failure will give you a much better foundation for understanding the ramifications of any single system failure. Also, the DDG will likely alert you to any OTHER critical systems that must be operational to dispatch with a given system failure. When troubleshooting a system failure airborne (or doing refresher training on a long flight), the DDG often provides insight the QRH does not.

Judd
25th Jun 2019, 08:32
it's less error prone to use the FD That's why it is used in the first place. Not necessarily so. An FD has to be programmed and programming errors have led to fatalities. Fly the bloody FD is an impatient exhortation often heard in simulators and a typical example of poor instructional technique. The FD is purely an aid and nothing else

.On the other hand, raw data hand flying needs no programming just instrument flying ability. Refer to that classic Handling the Big Jets by D.B. Davies, first published in 1967. Chapter 11 Advice to airline pilots. Quote: The autopilot is a great comfort, so are the flight director and approach coupler. But do not get into the position where you need these devices to complete the flight. Keep in practice at raw ILS, particularly in crosswinds.

There is more but go read it for yourself.

yoko1
25th Jun 2019, 13:01
Not necessarily so. An FD has to be programmed and programming errors have led to fatalities. Fly the bloody FD is an impatient exhortation often heard in simulators and a typical example of poor instructional technique. The FD is purely an aid and nothing else



Absolutely correct. The Flight Director is another one of those garbage in/garbage out devices that will be helpful only if it is set up correctly for the conditions and the intentions of the pilot. Granted, most of the time it is, but I've seen my share of pilots who couldn't put the aircraft where it needed to be without some bloody needles pointing the way. Some maneuvers must be flown immediately without waiting for the FD to catch up, so practicing without it is an essential part of maintaining your airmanship skills.

gearlever
25th Jun 2019, 13:41
Some years ago 737 on T/O roll (major EU carrier) WX: VMC, rwy 4.000 m.

At about 100kt junior FO was yelling "STOP".
CPT aborted.

CPT: What was wrong?
FO: We had the FD OFF

Greek God
25th Jun 2019, 14:03
Have a read of the BA 320 loss of eng cowlings incident wrt handling the emergency and ability to use manual thrust.
AFAIR BA prohibit manual thrust flying on line.
Not pretty!

tdracer
25th Jun 2019, 22:19
It's worth remembering, the MEL is the Minimum Equipment List. What Boeing publishes is actually the MMEL - Master Minimum Equipment List - individual operators use that as the baseline - they are free to make their MEL more restrictive than the MMEL, but are prohibited from making it less restrictive.
As noted above, the pilot gets the final determination - if they decide they don't want to fly an 8 hour flight without a functional autothrottle, they don't have to accept the aircraft.
When we were getting ready for first flight of the 747-8, we were having problems with the engine FADEC/FMC interface (which meant no functional autothrottle). The Chief Pilot (who, BTW, I liked and had considerable respect for) told us in no uncertain terms that he needed a functional autothrottle for first flight - and he didn't care if it was on the MMEL - so figure it out. Fortunately we did.

john_tullamarine
26th Jun 2019, 00:31
and he didn't care if it was on the MMEL - so figure it out

Absolutely not a problem. The MMEL would not have had the permission for the consideration of initial flight testing, one opines ? In general, the Commander knocks back the MEL permission when the specific circumstances pertaining to the specific, individual flight so warrant. On occasion, of course, one observes inappropriate/cavalier/petulant rejection but that is a different animal altogether ...

industry insider
26th Jun 2019, 09:36
Yoko wrote

One of my personal pet peeves is that airline managers (often non-pilots) will on one hand insist that you always use some gadget on the grounds of safe and efficient operations but will gladly take it away under MEL authority to keep the metal moving. I've turned down a handful of aircraft over the years because I don't believe I should be practicing a skill for the first time on a revenue flight.

As a pilot, I did the same and as a Manager 100% supported crews who did the same on many occasions.

mnttech
26th Jun 2019, 14:13
It's worth remembering, the MEL is the Minimum Equipment List. What Boeing publishes is actually the MMEL - Master Minimum Equipment List - individual operators use that as the baseline -.
In the US, the FAA publishes the MMEL, not the OEM.

Banana Joe
26th Jun 2019, 14:29
I think the FAA just approves it? Just like the other NAA's around the world.

mnttech
26th Jun 2019, 18:20
I think the FAA has a pretty large part in it, never have been there. From:
FSIMS Document Viewer (http://fsims.faa.gov/PICDetail.aspx?docId=8900.1,Vol.8,Ch2,Sec2)

VOLUME 8 GENERAL TECHNICAL FUNCTIONS
CHAPTER 2 TECHNICAL GROUPS, BOARDS, AND NATIONAL RESOURCES
Section 2 Aircraft Evaluation Division
8-41 AEG ASI RESPONSIBILITIES. An AEG ASI has a variety of responsibilities, which includes, but is not limited to, the following:
C. Operations ASIs.
6) Develop and revise the Master Minimum Equipment Lists (MMEL).
7) Serve as the MMEL Industry Group (MMEL-IG) co-chairperson. This position will serve as the FAA liaison between the MMEL-IG and the FAA to coordinate reviews and approvals of MMEL Policy Letters (PL).
8-45 AFS-100 BRANCHES. The AFS-100 branches and their functions are as follows:
A. Propulsion and Auxiliary Power Unit (APU) Branch (EA-67), Burlington, Massachusetts. This AEG is responsible for aircraft engines and propellers certificated under Title 14 of the Code of Federal Regulations (14 CFR) parts 33 (javascript:openPage('/Regulatory_and_Guidance_Library/rgFar.nsf/FARSBySect?OpenView&count=-1&RestrictToCategory=Part++33','')) and 35 (javascript:openPage('/Regulatory_and_Guidance_Library/rgFar.nsf/FARSBySect?OpenView&count=-1&RestrictToCategory=Part++35','')).
B. Rotorcraft and Powered Lift Branch (SW-25), Fort Worth, Texas. This AEG is responsible for rotorcraft certificated under 14 CFR parts 27 (javascript:openPage('/Regulatory_and_Guidance_Library/rgFar.nsf/FARSBySect?OpenView&count=-1&RestrictToCategory=Part++27','')) and 29 (javascript:openPage('/Regulatory_and_Guidance_Library/rgFar.nsf/FARSBySect?OpenView&count=-1&RestrictToCategory=Part++29','')), and vertical lift.
C. Small Aircraft Branch (CE-60), Kansas City, Missouri. This AEG is responsible for those airplanes certified under 14 CFR part 23 (javascript:openPage('/Regulatory_and_Guidance_Library/rgFar.nsf/FARSBySect?OpenView&count=-1&RestrictToCategory=Part++23','')), including commuter category airplanes and Special Federal Aviation Regulation (SFAR) 41 airplanes, some small airplanes certificated under 14 CFR part 25 (javascript:openPage('/Regulatory_and_Guidance_Library/rgFar.nsf/FARSBySect?OpenView&count=-1&RestrictToCategory=Part++25','')), and gliders and airships.
D. Transport Aircraft Long Beach Branch (NM-17), Long Beach, California. This AEG is responsible for part 25 (javascript:openPage('/Regulatory_and_Guidance_Library/rgFar.nsf/FARSBySect?OpenView&count=-1&RestrictToCategory=Part++25','')) airplanes, such as Bombardier and Gulfstream.
E. Transport Aircraft Seattle Branch (NM-15), Seattle, Washington. This AEG is responsible for part 25 (javascript:openPage('/Regulatory_and_Guidance_Library/rgFar.nsf/FARSBySect?OpenView&count=-1&RestrictToCategory=Part++25','')) airplanes, such as Boeing and Airbus.
NOTE: FAA certification of foreign-built aircraft is handled by the AFS-100 branch responsible for that particular aircraft (e.g., SW-25 for foreign-built helicopters).

tdracer
26th Jun 2019, 18:39
I think the FAA just approves it? Just like the other NAA's around the world.

That's correct - the airframer (Boeing) submits a proposed MMEL to the FAA, who then either approves it, or rejects it asking for changes and/or additional information. The FAA simply lacks the resources or detailed knowledge to develop the MMEL from scratch - you need the airframer Subject Matter Experts to determine what their system needs or doesn't need to operate acceptably. I helped develop and reviewed several preliminary MMELs over the years.
However, once it's FAA approved, making changes becomes a royal PITA - especially if the intent is to make it less restrictive.

Judd
27th Jun 2019, 13:26
At about 100kt junior FO was yelling "STOP".CPT aborted.
A classic example of the bone-headed foolishness of a company procedure of encouraging any flight crew member to order "STOP" simply because in his personal opinion the aircraft is in danger if the takeoff is continued.
A high speed rejected takeoff for real is probably among the most critical instantaneous decisions a pilot will make in his career. To entrust that power to call "STOP" without giving the captain the opportunity to evaluate the veracity of that decision, defies logic.