Multi Engine First Start?

[AC560]

I fly little prop twins and when I got my multi add on I was taught to start the left engine first, as clearing the left prop gave you best visibility to not cut the head off of some unfortunate ramp rat. That being said I am not aware of any specific requirement to start the left side first, perhaps Avbug can add his special insight to this

 

[planejockey]

The 310's battery is closer to the left engine so more power is supplied for starting. Just my .02

 

[Sig]

Which side is the door on...

 

[avbug]

A number of reasons may exist for starting one engine over another, but most commonly it may be one engine having a hydraulic pump while another doesn't, proximity of the engine to a power source (hydraulic or pneumatic, etc), proximity of passengers to one side of the airplane (starting engine on side that doesn't have passenger entrance door), location of ground power attachments, etc.

In most light twins (this thread probably doesn't belong in the regulatory forum), while the battery may be closer to one engine than the other, the size of the starter cables from the battery mean that there's no significant voltage drop to either engine. You're usually best alternating your starts, all else being equal.

Alternating engine starts may accomplish a number of things, depending on the aircraft and the systems. It allows an independent test of your vacum pumps. If you have dual hydraulic engine driven pumps, it may be the only time you get to see each working separately, and it may be the only time during the flight when you can evaluate pump output. If you're doing a cross generator start (using the generator on the operating engine to start the second engine), it's a good time to evaluate the first start generator under a load. Other systems may be able to be tested at that time.

If your ability to see the propeller area favors one engine over the other, so be it. But remember, you're going to be starting that other engine some time...If you can't see it for the first start, you can't see it for the second, either...so is that really a good criteria for always starting one engine over the other?

While one engine may be farther from the battery than the other, they're both negative ground, and taking their power through ground...the truth is that they're both directly adjacent to the aircraft where they're bonded and grounded...the distance from the battery doesn't make a lot of difference. Further, the size of the battery cables and starter circuitry mean that the distance isn't that critical...unless you have a very low battery.

If your aircraft flight manual directs that one engine be started over the other, or if the aircraft manufacturer has established a particular policy of starting one engine first, then go with that. Otherwise, consider alternating your starts...try a little experimentation.

Whatever you decide, use your checklists, do clear the area, and fly safe.

 

[b350capt]

i second avbug. however when you get to turbine aircarft that are pulling upwards of 900 - 100 amps on start distance from the battery can become an issue. but like avbug said really only if you have a low battery. Visibility is a good consideration, as are the other thoughts by avbug. the door issue is another good point, especially if you ever have passengers who board late, or need to get if they forget something. on any light piston twin i've flown (duchess, seminole, baron, cessna 300-400 series) there have not been any explicit procedures. However, FlightSafety does teach in the 421 and King Air programs, that the engine closest to the battery be started first, except for a GPU start. So who knows

 

[avbug]

Particularly in a turbine airplane, alternating starts is conducive to extended engine and starter life, as well as battery life. First engine non-GPU starts will be hottest of the two, with greatest starter demand...alternating starts switches this effect and effort from engine to engine, meaning more equal wear and tear, less frequent first-starts, longer engine and starter life, and a more consistant repetitive load on the battery during first start.

 

[NoPax]

In the Twin Commander, we're told to start the right engine first, as the door is on the left side. Check the pumps (vacuum and hydraulic) on start (right engine), and when we shut down, we shut down the right engine first, and check the pumps on the left engine. Vice versa if you start the left first.

 

[MauleSkinner]

Personally, everything else being equal on piston twins (and it generally is), I start the right engine first...I find that it's easier to tell when the left engine catches if the right is running than it is to tell when the right engine catches if the left is running. Saves me a little starter grinding.

Fly safe!

David

 

[UndauntedFlyer]

It's all a matter of personal technique and therefore doesn't make any difference. Whatever you like unless there are special reason as have been stated by Avbug and others.

It is sometimes said to start one by sight and one by sound.

 

[Joshrk22]

I fly little prop twins and when I got my multi add on I was taught to start the left engine first, as clearing the left prop gave you best visibility to not cut the head off of some unfortunate ramp rat. That being said I am not aware of any specific requirement to start the left side first, perhaps Avbug can add his special insight to this

I had this problem the other day when I was sittin' in my 172.

 

[sstearns2]

In most light twins (this thread probably doesn't belong in the regulatory forum), while the battery may be closer to one engine than the other, the size of the starter cables from the battery mean that there's no significant voltage drop to either engine

There's actually a very significant voltage drop between the battery and the starter when you start the engine. That's why the battery cables are so large. If the battery is at 12 volts your lucky to get 10 volts across the starter during the start.

Scott

 

[PA31Ho]

on the pistons, i generally do right side first because of the ac running off the right side. but then again i live in florida where you get drenched just sitting ouside for 5 minutes

 

[Flyerjosh]

FWIW, the CRJ starts the right engine first since the outboard brakes are powered by the #2 (right engine driven) hydraulic system. This allows the aircraft to single engine taxi, and still have all brakes available.

I typically start the Citation right engine first since the door is on the left side of the plane, and we sometimes board up with one engine running. Or alternatively, I will look to see which side has more fuel and start that one first to avoid needing to crossfeed on the taxiout. (Fuel imbalances are common if you don't fuel on perfectly level ground or the valves aren't opened all the way).