A320 Manual Engine Start

The Actual Procedure for a Cold and Dark Manual Start

The A320 manual engine start is the procedure you use when the aircraft has no electrical power and you need to light off an engine without relying on the full automated sequence. It lives in the QRH and the FCOM supplementary procedures. You are essentially doing by hand what the EEC would normally do automatically. Here is how it works on the ground with a depleted battery. You first establish 28V DC from the ground power unit or the APU generator if the APU can be started first. If you truly have nothing, the battery alone will barely keep the ECAM and essential busses alive long enough for the procedure to complete. That is tight. In my experience, a single healthy battery can do it once, but two starts in a row on battery alone is pushing it hard.

A320 Manual Engine Start

Move the engine master switch to MAN. Turn the mode selector on the overhead panel to MAN START. Set the ENG MODE selector to IGN/START. Push and hold the ENG MAN START pushbutton. The starter valve opens, the N2 begins to rotate, and when N2 reaches about 15 to 20 percent depending on the specific FMA configuration you are seeing, you move the FADEC mode knob to NORMAL and the fuel valve opens automatically via the EEC in alternate mode. Monitor N2,EGT, and fuel flow. Once EGT rises and N2 approaches the idle cutoff point, release the MAN START button. The starter cuts out around 50 percent N2 normally, though the exact point depends on whether you are using the normal or alternate starter cutout logic. What is not obvious is that the EEC in manual start mode runs on alternate law with limited protection. It will still fire the igniters, it will still regulate fuel, but it has shed some of the soft limits like transient stall protection. You need to watch EGT closely. It climbs faster than in an automated start because the EEC is not being as aggressive with fuel scheduling.

I had a situation a few years back where a manual start on engine 1 resulted in a hot start scare. EGT was creeping up past 725 and the fuel flow had not dropped. I cut the fuel by moving the master switch to OFF and the starter to STOP, then motored the engine dry for about 60 seconds before trying again. The root cause turned out to be a sluggish fuel metering valve on the DDFA. On the second attempt I held the MAN START button until N2 reached 25 percent instead of the usual 20, and the EGT spike disappeared. That extra 5 percent gave the combustor pressure enough time to build before fuel was introduced. It is a trick not written in any manual, but it is real and it works when the metering valve is slow to respond. Another thing people miss is the relationship between the N3 parameter and manual starting. You do not have N3 on the manual start display the same way, and the EGT limitation is still 725 degrees for a normal start and 750 for a maximum start duration of 120 seconds. But here is the part nobody warns you about: if the engine has been soaking overnight in cold weather and you attempt a manual start without preheating, the EGT rise can be delayed by up to 15 seconds compared to a warm engine. You will see fuel flow climbing and N2 turning but no EGT response right away. This is not a hung start. It is just thermal mass. Hold steady. Wait for the needle to move. Do not cut fuel immediately on an apparent flatline. There is also a quirk with the fuel crossfeed. If you are starting on battery alone with the AC ground cart disconnected, the fuel pump on the opposite wing tank is unavailable. The center tank cannot supply either engine during a manual start unless the AC bus is powered. So if you only have battery power, verify that the tank feeding the engine you are starting actually has fuel pressure. A common mistake is assuming the main pump is running when the transfer valve has closed due to low bus voltage.

One more practical note. Manual start is not a reliable long-term strategy. It requires someone at the overhead panel or a very well rehearsed PF/PM split. If you are down to battery power on both sides with a total electrical failure scenario, you have maybe one engine start attempt before you risk deep discharging the battery below the minimum threshold needed for the flight controls. In that case, calling ground crew for a GPU hookup is the better option. It usually takes 10 to 15 minutes to connect a GPU and switch over, and it eliminates most of the uncertainty around the manual start sequence. The A320 manual engine start is a fallback, not a preferred method. It works. It has edge cases. Know your limitations before you need it.