Batteries and icing
 

Stapleford told me they had no Cessna 152s available today as "all the batteries are flat due to the icing problem".

I found this a bit strange as they have a large fleet. Does icing cause batteries to go flat?

Not directly. In fact, cold batteries are supposed to keep their charge better than hot ones. But that's only when you don't use them.

When you use them, the chemical reaction, which releases the electrons in the battery, goes slower so less current is available for the starter motor. In addition to this, the oil in the engine is thicker when cold, so it's harder to turn the engine over. And fuel evaporates slower which, combined with less than perfect starting technique, causes more difficult starts. To the point that people drain the battery easier.

So yes, you'll find more flat batteries all over the country when cold. Just this morning I had to get external power to start - battery didn't have enough juice left to pull the engine through its first compression.

[Cue discussion about correct priming and starting techniques]

Sounds a good excuse though to not have all the hassel of de-icing all the planes at great expense

I wouldn't buy that at all. Far more likely to be because of MJ's suggestion.

It wasn't that cold.

I agree with mad-jock. It's nonsense - unless the batteries are totally knackered in which case the thicker oil might prevent the starter turning the engine.

Yeah but the whole fleet?

Possibly.. as I just phoned up out of the blue. If I had been at the airfield no doubt they would have sorted something.

It took nearly an hour to get the old 0-200 going this morning so there was nothing wrong with the battery. After normal priming (accelerator pump), the engine would fire and run for about 5 seconds, apparently on all four. There didn't seem to be any way we could keep it going any longer with extra priming.

Once it did start and run we realised that we had carb icing as the engine would not run below about 1100 rpm. It seemed as if we were getting carb icing even before the engine fired. It took about 15 minutes with intermittent carb heat to get it to run normally. After that, a nice problem free trip to Sandown and back.

I think that, next time, I will preheat the carburettor rather than the mags.

I had the same problem yesterday. After running at medium to high revs for a few minutes it didn't cut out again.

Cold start Cessna
 

Leave primer out and push in as engine is firing and often this is all that is required to get some momentum going, also pump throttle if necessary.

Some still hand swing before flattening the battery and/or pull the prop through before trying to start at all.

Care with flooding potential and fire, if fire keep cranking if possible and have extinguisher ready!!!!!!!!!

In short know your aircraft if possible, take advice and demo in cold wx...

Edit: Could fit heavier duty battery to prevent most winter starting problems.

It didn't take me quite that long - about 25 minutes with the 0-200. She would fire run for a bit then cut out after about 5 seconds or quicker if we tried to increase power. In the end starting with no throttle worked a treat.

I reckon it was simply that the carb was so cold there was b*gg*r all evaporation for the fuel and it needed time to warm up before she deigned to fire.

In the end it was a grand day out to Bembridge - even with frost on the wings.

In the end it was a grand day out to Bembridge - even with frost on the wings.

Steady on lads. Engine starting problems then an open water transit to Sandown/Bembridge - with frost on the wings?????!!!!!

Remind me not to go flying with you lot!

Couldn't agree more. One should not fly with frost. Especially not to such relatively short runways. I spent a while cleaning the stuff off today, and some days ago I just gave up - it was too thick and solid.

I doubt very much that robin was daft enough to go flying with frost on the wings.

A few lines on a website that could mean anything, don't make someone a fool or a bad pilot.

Get a bit of a grip please and don't go down the idiotic route of hanging and drawing someone due to comments on here about a situation you weren't part of and have absolutely no knowledge of.

silvereagle,

Not for me. Straight out of the hangar, ergo no frost on my wings.

Batteries are spec'd to perform in minus God awful temps, if they don't do the job then they're knackered. Sounds like an excuse TBH...

Sounds like crap customer service, lousy maintenace or a lame half-arsed excuse to me. Must be a bit frustrating. If you appreciate that bad wx is bad for business then surely when it is flyable, flying schools/clubs should try their best to deliver the goods/service.

Clear blue skies and half decent vis should be taken advantage of surely. It makes business sense to sort out deicing facilities and make preparations for cold wx problems.

The C85 in our C140 is cold blooded and prone to carb ice. I've taken to leaving the carb heat on during taxi when conditions warrant, and I don't push the carb heat in until I've got the throttle all the way in on the takeoff roll. We do have the luxury of a heated hangar.

-- IFMU

Today I found out what it's all about!

I had an Cessna 152 booked for 10:30. The aircraft started with no problems at all. I used car de-icer to clear the windscreen and was happily filling up with fuel (one has to do this a Stapleford as there are no fuel dipsticks in the aircraft) when I asked an instructor if it was ok to fly. The reply was negative as there was frost on the wings and he suggested I speak to the "hanger guys".

What happens is that the planes are de-iced by rolling them into a hanger for 10 minutes thus saving the "great expense" of spraying. It works quite well except that it was poorly organised and everyone was looking out for themselves and no one else.

Although the "hanger guys" knew that another plane as well as my own was waiting for the "service" they all suddenly disappeared around lunch time. A PA-28 crew decided to do an "A" check in front of the hanger - blocking access. When I pointed out that there were planes waiting to be de-iced I was ignored.

Scouting around I found a young man washing a car and asked for help. He and I opened the hanger doors and pushed both aircraft inside.

After about 5 minutes both planes were free of ice but the crew of the other larger aircraft had gone off to the cafe for lunch. I offered an incensed examiner (who was waiting for an aircraft trapped at the back of the hanger so that a student could do her skills test) to search them out and we managed to persuade the pilot to come and move the aircraft.

I finally got to taxi out more than three hours after arriving at Stapleford. Just enough time for a two hour cross-country before sunset.

Does anyone know of a do-it-yourself de-icing kit?

Wow. That is customer service of the best kind..............And people wonder why this industry is on its knees.:rolleyes:

If I'd been that examiner, someone in the club would have had a foot up their a*se. Poor, very poor.

What sort of bo**ocks is that?

Just because the temperature is 0. Doesn't mean you are in icing condiitons. I assume you've been up at altitude on a summers day. Ever noticed what the OAT gauge might be reading.

Good grief!

Errr. No. I have a feeling I might understand the concept of icing and it's definition.

So Icing conditions are purely to do with temperature are they?

I'd like to. Any chance of a relevant reference?

Ice doesn't melt in a hurry even when the temp is way above 0 degrees. You have to have moisture to form ice else all our little aircraft would be hurtling earthwards when the OAT was below zero. Today that would have been at less than 1000 feet. Everyone was flying today - no one came to grief!

Too much Champagne me thinks, mate.

Oh dear. How about you think about what you are posting and I'll just use the definitions that are correct.

If you can't back up a statement, don't make it.

It seems that the lunatics are running the asylum.

If this is your response to a question, which you clearly have little or no knowledge of then why ask in the first place?

I thought the Muppet show ended years ago... I obviously was wrong! All the cast are alive and well in the private flying forum!

Maybe if we ignore him he'll just go away;)

Guess we'll just have to accept your superior knowledge then!

Oh b*gger, if only you'd let us know that thirty years ago, I for one would have turned out to be a responsible pilot!

Priceless. It is possible that there are people on this forum who do have a wee bit of knowledge. Some of us even fly for a living too.

I promise you. I'm not worried about my level of knowledge on this subject.

Thank you SAS
As it happens it was not an open water crossing. The frost was only on the wings for a very short time and disappeared quickly in flight. I would never have made the trip if I was at all concerned about airframe icing and carb icing was never a problem.

Being a natural-born coward I probably have less desire to put myself at risk than many and will (and have) abandon(ed) flights if I am not convinced it is safe to continue.

You took off with frost on the wing though.....................:eek:

Shame some of the comments are being deleted so quickly, as there's clearly a large gap in knowledge here. Maybe a gap I could've addressed today: flying with a reasonably high aspect & thus critical wing in -5 or so. Or maybe a few weeks ago, across the Irish Sea at FL105 on a lovely winter's morning with an OAT of -18? Both utterly clear of ice on the wings or the engine intake, and with a piston engine cleared down to fuel temps of -30 on Jet A-1. Or a couple of times getting through cumulus clouds at rather higher OATs with anti-icing systems switched on to control the buildup of ice and allow me to get to clearer air - in a twin rather than a single, fortunately.

Icing conditions are not purely defined by temperature - it does take a certain amount of humidity to actually create the ice.

Are you saying that you need both cold temperature and moisture to form ice?

Well blow me down with a feather!!;)

Welllllll, it's only a guess from the last few years flying in UK winters with no ice :E Shame some people need prompting to make them think. Just like the people who assume that commuting in -6 on 2 wheels means an automatic death wish, or that a balmy summer's day means no carb heat checks are required. Ah well...

Couldn't agree with you more!

There's something rather amiss with this thread - as has been noted, so many posts have been deleted it makes it very difficult to get any sense of context. For whatever reason, the Pprune forum software no longer supports the 'quote' button which provided an easy means of quoting an existing post, complete with attribution; however, for future reference, opening a manually crafted quote with quote=Username will at least provide the attribution, but still means you have to manually cut and paste whatever muppetry has boiled your wee for it to make any sense.

It was, however, distinctly brass monkeys this morning. My cunning plan of priming the Pitts and then allowing *three* minutes for the fuel to evaporate initially worked a treat as it started immediately, but then my fundamental Baldrick nature kicked in, opened the mixture too quickly, rich cut, splutter, stop, and that was all the battery had to offer. The Yak started without much protest, but de-icing the airframe was like de-icing my freezer - I only do it once a year, it takes sodding hours and all the crap that was nicely deep frozen mysteriously transfers itself to my clothing.

Still, I did manage to aviate three days in a row, a decent enough way to round off the Christmas and New Year break. Office tomorrow....on reflection, it still be rather de-icing the Yak than stuck in an office in Slough.

Excellent - it gets scary sometimes how many misconceptions are out there, whether from people being lucky once (a PPL reval stude who attempted to barrel roll a PA28 on me, on the grounds that he'd messed up an unusual attitude recovery badly enough once that the FI he was with decided to continue the roll round, so it must be a safe manoeuvre), or simply those who take caution to a level that actually reduces their own safety (those on this thread who would probably descend close to terrain/down a valley to escape freezing temps on a clear day!). Sadly, there's a limit to how much people who don't want to listen can be educated. The reasons for why they won't listen are a whole different thread though!

I'm surprised you have a freezer eharding. I fail to understand how even the smallest morcel of food would survive long enough in your house to be frozen. May I suggest you throw out the freezer and in it's place install a heated hangar for your pitts?

An even better technique is to hit the REPLY button on the post which has 'boiled your wee' and you will get something like this in your browser address bar
http://www.pprune.org/newreply.php?d...7697&noquote=1


now just replace the noquote=1 with noquote=0, hit enter and voilà you have your quote!

No airliner would ever fly anywhere if that was true (apart from low level hops around the tropics)! There's a bit more to icing conditions than that which has been quoted.