Start-up clearance in SEP?

With having no ground power APU has to be started before turning on avionics.
APU in my plane has a propeller attached.

what_next wrote:

wastes fuel better used for flying.

Yes sure, but that’s mostly relevant for turbines that have almost no difference in fuel flow between ground idle and max power, and where every cycle counts towards maintenance.

With a piston engine, it’s no big deal. I’d start up anytime without clearance if operationally required (eg. to charge the battery). After all, you don’t ask for startup permission of your APU, do you?

Yeah, what exactly is the purpose of a start-up clearance?

One of its purposes is to allow ATC to check for the existence and correctness of your flight plan. Furthermore, the ground/delivery controller will be the one who will then actually print your FP strip and hand it to the next station (Ground or Tower typically).

This is mostly a concern for IFR flights, but where I live FPs are required for VFR flights to/from/through controlled airspace as well. So when departing from a controlled airport, you will always need to ask for startup.

Another purpose is to check you have the ATIS correct, or if you are unable to get the ATIS (e.g. ATIS on VOR but no VOR receiver in the A/C) to relay the ATIS to you. (Just say “negative weather”.)

In my experience, asking for startup never hurts. But starting up without clearance (if required) is frowned upon. We sometimes do it anyway – for instance after a cold winter night when we suspect the battery charge/current is going to be very marginal: Do the preflight checks without battery usage at all, start the engine and then ask for startup. (A useful trick: The alternator field also draws current. But it’s perfectly OK to start the engine with the alternator field switched off, and only turn on the alternator field when the engine is running properly. We also use the fuel pump to prime the system, but turn the pump off during the actual starting. Saves current too.)

After all, you don’t ask for startup permission of your APU, do you?

“My” plane doesn’t have one, but there are more and more airports which limit APU usage to 10 or 15 minutes (these things are really a big nuisance, especially on congested GA aprons, and often louder than the engines themselves). On such an airport, one should at least inquire about any startup delays before getting the APU going.

BackPacker wrote:

But starting up without clearance (if required) is frowned upon.

Frowned upon by whom and why?

Startup clearances certainly make a lot of sense for turbines, but it seems to me this procedure is quite mindlessly applied to 152s as well where it makes very little sense.

what_next wrote:

these things are really a big nuisance

Yes I know APUs have a noise issue. But compared to that, I’d claim that a typical SEP engine/propeller running at idle RPM is pretty harmless.

It isn’t always Ground. It even isn’t always the Delivery frequency… they like to keep you guessing

Forgive me but I dont get this.

As I mentioned earlier every where I have been you toddle off somewhere and pay your landing / parking / handling fee – so you ask do I need to request a start up clearance – seems simple enough to me. Every time I have asked they know – or know who to ask, and they will confirm the frequency on which to make the request.

Now I accept that you might forget to ask or whatever so everything else said is interesting and relevant, but I have found over the years this is the easiest solution – as well as being worthwhile asking if there are any special procedures or anything else of which to be aware.

For me it demonstrates you are just that much more clued up before faffing about in the aircraft.

Places like Southampton you actually pay your fees in the ops room – they know exactly what is going on.

Places like Gatwick where you know anyway they are going to want a start up call, they will call the tower for you on the landline and check.

Places like Manston (as it was) there was a dedicated phone in ops to call the tower to “book out” on.

It intrigues me how often one hears pilot’s go through the whole process to hear some “smug” :-) controller point out that he hasnt got your flight plan and cant give you a departure clearance – it happens all the time at L2K. So the pilot and passengers sit there waiting, engine running, getting hot and bothered, then shut down, then find the dear old Lycoming doesnt like a hot start, get even more hot and bothered, then miss their slot .. .. .. all very entertaining.

It usually goes something like this;

G-XXXX request start up.
Tower – G-XXXX you dont need to request start up, but you may start.
G-XXXX three POB, with India, 1012.
Tower – 1012, please pass your request.
G-XXXX – request taxi, as flight plan to Y.
Tower – I dont have your fight plan.
G-XXXX – well we filed out flight plan via EuroWorld traveller before we left.
Tower – well I still dont ’ave it.
G-XXXX – what do you suggest?
Tower – shut down and report to ops or standby as you wish.
G-XXXX – will shut down.
10 minutes later.
G-XXXX – cant start the engine please can you delay our flight plan by half an hour.

so it goes on.

Why didnt they ask “dispatch” when they paid their landing fee please, can you check with the tower if they have my flight plan! At my base they even provide a rather handy dedicated line to the tower.

Surely it is just all part of the process before you even get in the aircraft if you are unsure?

Mind you I hope not too many people read this – it would spoil the entertainment. I can almost guarantee at L2K you will follow something similiar 1 in 3 visits. I have done it myself I might add!!

Perhaps I am missing something or perhaps it is just part of the process of pilots feeling this compelling need to get on the radio at the first available opportunity and tell the whole world their life history :-).

The bit you might be missing is that a lot of pilots feel they should not have to make a phone call to check if their flight plan is in place, etc. I tend to do it when I can and have the phone number, but sometimes the number is unpublished / not in my phone book from a previous flight there, and the desk where you pay was not visited because e.g. you paid up the day before.

But then nearly all of my flight plans are Eurocontrol IFR and I don’t recall the last time one of these has not been received by the departure tower.

VFR flight plans often go missing.

@Fuji_Abound – and if they don’t have your flight plan, what is the best course of action? Refile? Contact whichever service you used to flight the flight plan? Just curious.

…dedicated phone in ops to call the tower to “book out” on.

“Booking out” and dedicated phones to talk to someone in the tower are kind of an UK extravaganza not easily found elsewhere. Anywhere else, I wouldn’t know who to call but “DELIVERY” or “GROUND” or “TOWER” (depending on the size of the airport) on their radio frequencies if I need to find out about the status of my flight plan. And for that, I need to have a powered airband radio.