Making of the Integrated Standby Flight Display

The Integrated Standby Flight Display (ISFD) is used in all newer Boeing 737 jets. This instrument is thought to be a backup when all other (now digital) flight instruments fail. In the real aircraft it is a fully independent (in terms of power and sensors) and rather small replacement of the Primary Flight Display (PFD) with reduced amount of information. It will tell you altitude, attitude, bank, speed and heading. What do you need more? In the simulator, we can mimik its usefulness by e.g. turning off the PFD and keeping the ISFD on, simulating broken avionics. The ISFD has five buttons and a rotary encoder to set e.g. the barometric height, since its pressure is measured separately for the ISFD.

Original Image of the ISFD from http://www.b737.org.uk/flightinsts.htm#Standby%20Flight%20Instruments

SISMO Soluciones sells a very authentic “dummy” bezel of the ISFD for a good deal. However, as the description says, the buttons are just decorative. I have removed the button caps and have mounted real buttons behind those caps and a rotary encoder into the dummy bezel. Apart from destroying a few edges of the nicely painted ISFD bezel, the thing looks pretty nice and also works. The key is to use as little space behind the bezel for wiring and screws, since the EICAS monitor will have to fit closely to the plexiglas of the ISFD bezel. Oh, one note: the original plexiglas of SISMO Soluciones is a smoke glas, which looks nicely, but unfortunately “eats” too much of the monitor brightness. The solution was to simply cut my own transparent plexiglas. For those of you who would like to repeat my work, please be aware to buy an additional inputs daugther card and connect it to the SISMO Soluciones master card via the 10 pin downstream link since the ISFD needs a total of 8 inputs (5 buttons, 2 for the encoder and if you want, one for the encoder button).

In case you look for a low height rotary encoder that would fit your ISFD. I can recommend the ALPS EC11E18244A5, as for instance sold by Farnell.

Now have a look at the process and the result and compare to the original above …

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