Subject

Date: Sun, 27 Dec 1998 22:23:21 +0800
From: John Sampson <sampson@iinet.net.au>
To: JOHNDKING King <jking1@mediaone.net>, Patrick Price <PAPCECST@aol.com>,
"PEddyXX@aol.com" <PEddyXX@aol.com>, Ross Coulthart <RCOULTHART@ninenet.com.au>,
Ader <ader@compuserve.com>, "naefw@dial.eunet.ch" <naefw@dial.eunet.ch>,
"swissair_crm@e-mail.com" <swissair_crm@e-mail.com>,
"Babin, Jacques" <Jacques.Babin@bst-tsb.x400.gc.ca>
CC: Omega Systems Group Vernon Grose <omega@omegainc.com>, Edward Block <EdwBlock@aol.com>,
David Evans <devans@phillips.com>, Bob Rowland <rwroland@aol.com>

FROM http://pprune.org/ubb/NonCGI/Forum1/HTML/002015.html

Author: Nightflyer
Topic: 737 Power Loss

posted 26 December 1998 20:54 UTC

On December 15, 1998, about 1216 eastern standard time, a Boeing 737-232, N327DL,
registered to Wilmington Trust Company Trustee, operated by Delta Air Lines Inc.,
flight 2461, as a 14 CFR Part 121 scheduled domestic passenger/cargo flight,
experienced a reported total loss of electrical power on approach for landing at
Orlando International Airport, Orlando, Florida. Visual meteorological conditions
prevailed and an IFR flight plan was filed. The airplane sustained minor damage. The
airline transport-rated pilot-in-command (PIC), first officer (FO), 3 flight attendants,
and 51 passengers reported no injuries. The flight originated from Boston,
Massachusetts, about 3 hours 6 minutes before the incident. The PIC stated they
were cleared for a visual approach to runway 35 at Orlando International Airport. The
FO was flying the airplane. All descent and approach checklists were completed. The
APU was started on base leg. The FO called for the gear and flaps 15. The airplane
experienced a total loss of electrical power as the gear and flaps were extended. The
APU did not start, and the battery indicated between 17 to 18 volts. The normal
checklist procedures were accomplished followed by the quick reference procedures.
Electrical power was unable to be restored. A go-around was initiated to continue the
checklist. All communications and electrical equipment failed. The flap indicator
indicated an asymmetrical setting. A flight controllability check was accomplished with
no anomalies. The flight was continued and landing was made to runway 35. A left
main landing gear tire blew out on rollout. The airplane cleared the runway, stopped,
and was towed to the ramp.

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yaverona
posted 27 December 1998 11:00 UTC

Why they did not land before go around ?

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Juan To Go
posted 27 December 1998 11:54 UTC

If it wasn't immediately life threatening, such as fire or smoke, it gave them a chance
to check what shape the airplane was in for landing (control check etc), brief the
passengers for an emergency landing and get the emergency services fired up and out
to the runway. Also, it sounds as though they did not have time to complete the drills
before an immediate landing so there was a possibility that they could restore power if
they finished the checklist.

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pterodactyl
posted 27 December 1998 12:10 UTC

As above. The person in the situation at the time is best able to decide a course of
action. For example the approach may have been on a short runway compared with
others which may have been available. Anti-skid would be affected without normal
electrical power as seems likely in which case hastening to land on a short runway
would not be prudent especially if a more satisfactory control configuration might be
achieved.Wait for all the facts and don't assume one line of reasoning as I have just
demonstrated.A little knowledge is always dangerous.Just think of non flying airline
management who leap to conclusions based on scant aviation knowledge.Don't
emulate them.

[This message has been edited by pterodactyl (edited 27 December 1998).]

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Zippo
posted 27 December 1998 13:10 UTC

yaverona, For starters, how would they know if the gear was down? What flap
settings they had and speeds to use! Sounds to me like they did the only thing they
could, Go-around and sort it out.They're all still alive aren't they? Job well done.

___________________________________________________________________________________________

Sampson Comment:
A Kaptonitis smoking gun? At that voltage (17 to 18V) it sounds as though my theory on SR111 just came to life. They'd have been history if it had happened at night or IMC conditions (or both). The "normal checklist" (I assume) would be all about checking CB's and attempting to reset Generators. After that (logically) would come the (second?) APU start attempt. It sounds as though they probably had a dead short in the electrics (i.e. wiring) associated with the GEAR or FLAP extension (however it may have had something to do with the switchover priority between the APU gen and Gens 1 & 2 - wonder why they start APU on base leg?). With a dead short to the batteries I just don't think you are going to get a Gen reset (i.e. relevant to SR111 crew rotating Smoke/Elec switch - deselecting one generator and never getting the one associated with the next selection because of the dead short to the battery caused by the wiring fault). This was a very lucky planeful.

To jog your memory about my SR111 theory, go to:

switcher.html and

solution.html

then think about:

virgin.html

Appreciate any further definitive tech info on this one if someone comes across any.

regards

John Sampson

Subject: Re: For INFO:- B737 - Total Electric Power Loss on Approach
Date: Sun, 27 Dec 1998 13:36:37 EST
From: PAPCECST@aol.com
To: sampson@iinet.net.au, jking1@mediaone.net, PEddyXX@aol.com, RCOULTHART@ninenet.com.au,
avanderwal@compuserve.com, naefw@dial.eunet.ch, swissair_crm@e-mail.com,
Jacques.Babin@bst-tsb.x400.gc.ca
CC: omega@omegainc.com, EdwBlock@aol.com, devans@phillips.com, RWROLAND@aol.com

The 737-200 model is an earlier model and was wired with BMS 13-51 wiring,
which is KAPTON wire. UAL insisted that NO MORE KAPTON wire for their 737 &
757 models, and that was the reason Boeing developed TKT wiring (BMS 13-60
wire) so Boeing could sell a large production order to UAL for 737 & 757 model
airplanes back in 1991.

They had to have had a MAJOR electrical short (FLASHOVER). Someone has to
find out the age of the airplane, total hours and cycles logged by the plane
and when was the last major maintenance cycle performed on the airplane.

At least ONE MAJOR circuit breaker had to have TRIPPED and possibly more. To
find out: Did the F/O try to re-set any circuit breakers? A MAJOR SHORT had
to have occurred in the major power buss. Inspection of the wiring would
determined how much wiring was damaged. A complete check of associated wiring
must be completed to prevent a FUTURE SR 111 from happening before the plane
is returned to service.