Ignition smell engine start 738

[TheGlide]

Hi Guys

Does anyone have any idea what the ignition sort of smell is and where it comes from after engine start that enters the flightdeck on the 737-800.
Someone maybe has a technical explanation?

I have had it numerous times it has always been shrugged off as it dissipates within a matter of seconds.

Bear in mind the packs are off and in standard starting configuration with the Air Cond panel.

Many thanks

[framer]

I don't think I've ever noticed it. I've noticed the APU with a tailwind of course, you're not thinking of that are you?

[Golden Rivet]

Is it a new aircraft ?

[DevX]

It would be impossible to smell the igniters even if they did make a smell during use, are you perhaps referring to cabin odour from burnt oil? That is quite a common occurrence on many different engines during the start up procedure.

[TheGlide]

It depends on the A/C I don't think it is a question of whether it is new or old
Most A/C are not that old.

I never thought of the APU but thinking now I'm not sure that is it as it tends to be after startcut out of the number 2 then quickly dissipates.

I had asked an engineer and he said it may me some oil on the engine but I'm not so sure,

How is that air entering the flight deck if the packs are off?

All the best

[chimbu warrior]

How is that air entering the flight deck if the packs are off?

Your RECIRC FANS should still be turned on........

[Fullblast]

In some wind conditions that smell comes in from the outflow valve, fully open on the ground during start.

[Skyjob]

Fullblast is correct, as well as the outflow valve there can also be ingestion into Air Conditioning System in certain wind conditions of fumes from an idling engine after start when ISOLATED PACK OPERATION ON GROUND from SP is applied.