Re the last two posts...
I say again; take a look at the photograph on p27 of the Interim Accident report. it shows the 'as removed' relay R2-5. Now take a look at the wiring diagram shown previously.
The wiring diagram shows two wires to each of the 4 contact groups of the relay. The photograph shows clearly that there are no wires at all on the C set of contacts; these would normally be occupied by the Rat Heater wiring. It would appear that these wires have been transposed elsewhere...
It looks as if the relay wiring has been substantially rewired in that;
The A contacts have one wire on A3, one wire on A2 and two wires on A1;
The B contacts have two wires on B3, one wire on B2 and one wire on B1;
The C contacts have no wiring at all;
The D contacts have one wire on D3 and one wire on D2.
The only reason I can think of for this rewire was to get around the possibility that on some previous occasion the Rat Heater contacts had burned out or become welded together and that a replacement relay was not available at the time...If this was the case however, no matter how well meaning the 'repair' it wasn't particularly well thought out.
The crimp tags are bent out of shape somewhat on all the contacts, and as is suggested in the Interim Accident Report, there is a possible short circuit between the X1 115vac contact and the A2 contact.
The effect of moving the Rat Heater wiring to other contacts, especially the TOWS contacts could be to overload the current carrying capability of the contacts themselves and cause all kids of problems to the associated circuits especially in view of the fact that the B and C contact groups work in opposite senses...
Looking carefully at the crimp tag retaining screws, I can see no evidence that this rework was recent ie., post accident. The wiring to the adjacent relay is also in a poor state.
Again looking carefully at the picture, there would appear to be some heat damage and scorching to one of the wires due, to my mind at least, to excess current draw.
At no point in the Accident Report is this hodge-podge of wiring mentioned, only the possibility of the accident being responsible for the possible short circuit between the adjacently mounted A2 and X1 contacts.
The judge handling the case is still holding under indictment the two mechanics who handled the snag when the aircraft returned to the stand after abandoning the first take off attempt; he is acting upon reports that the failure of R2-5 was due to the actions of these two mechanics who actually did no more than to pull the breaker for the Rat Heater.
Other reports have suggested that a third party may have been in the cockpit and interrupted the pre-take off checks; so much for the sterile cockpit!
Be that as it may, the second take off was started with the Flaps and Slats retracted and no Alarm sounded. That an MD-80 can still do this after the previous very similar accident is difficult to understand. Flaps / Slats are required to be set and checked I believe no less than three times between engine start and take-off and they still got it wrong for whatever reason.
This link however demonstrates that with Spanair this was not uncommon. Just one month before the accident a Spanair aircraft was filmed during a routine take off from Glasgow; in this instance the flaps and slats were not deployed until the engines were run-up at the end of the runway prior to take-off; could it be that a sticky nose leg switch had failed to operate the relay that energises the TOWS and that only cleared when the brakes were applied thus compressing the nose leg?
The Interim Accident Report appears to have been withdrawn from the CIAAIC website but I have a pdf copy if anyone would like to read it. PM me if so.
pp