Brakes Off? What's it all about?

[EGBKFLYER]

Idle discussion in the pub yesterday and we drew a blank - if any expert out there can help, we'd be very interested:

For most, if not all light aircraft, the first checklist item on the DW checks is 'Brakes off'. Questions are - why would you have the brakes on? Wouldn't 'Brakes - pressure check' be a more useful and appropriate item, since no one I know of ever puts the brakes on after take-off (save for the little dab to stop the wheels rolling before retraction)?

If anyone can throw any light on the reason for this item, we're all ears...

[Sassenach]

I was always taught "brakes set". Most of my flying is in a Chipmunk, which requires a couple of notches on the brake lever in order to give you differential braking. When landing with a crosswind, you need a small amount of differential braking to keep the aircraft straight during the landing run. You might sometimes also need brakes set for takeoff for the same reason - if there was no crosswind on the subsequent landing, then you would need to take the brakes off again.

[EGBKFLYER]

Very interesting - we thought reasons may come from ways certain 'classic' aircraft were operated. 'Brakes set' is obviously a really important item for DHC pilots then, but I'm still puzzled as to why they include 'brakes off' for say a C152 if it doesn't apply - after all, they don't ask you to check for 3 greens...

[Sassenach]

It's all about teaching pilots generic techniques that they can use no matter what type of aircraft they are flying. I learned to fly in a PA28 so setting the brakes was not relevant, but I didn't have to learn a different check when converting to the Chipmunk. PPL students are also taught to point the controls into the wind, which makes no real difference unless the wind is really strong; in the Chipmunk, it's very difficult to taxi unless the stick in pointing into the wind.

[Say again s l o w l y]

Brakes in the downwind check should be to check for pressure in the system first and then checking that the parking brake hasn't been set inadvertantly second. This can happen on certain types.

[EGBKFLYER]

Understand that and agree - our discussion yesterday was more along the lines of - if 'brakes off' isn't meaningful, should 'brakes-pressure check' be there instead as something that might be useful? It would be in the same vein as the undercarriage call of 'fixed' or 'down and green' - slight risk of saying the wrong thing in the wrong aircraft but reflecting the type of system in general.

Can you elaborate on which types may suffer from inadvertant park brake selection? I am familiar with Robin (knob and umbrella handle type), Cessna and Piper systems and struggle to see how, assuming you released the brakes properly on take off (which I take it you might notice from performance), you could select brakes on at a later stage.

[RodgerF]

Small point can we call them the 'pre-landing' checks please.

[pulse1]

There's a yarn in the current issue of Todays Pilot which describes someone in a PA28 taking off with the brakes partially on, then landing and taxying in with the brakes still on using lots of power - so it would seem to be a worthwhile check, at least in PA28 and 172 types.

[RodgerF]

Quote:

Can you elaborate on which types may suffer from inadvertant park brake selection? I am familiar with Robin (knob and umbrella handle type), Cessna and Piper systems and struggle to see how, assuming you released the brakes properly on take off (which I take it you might notice from performance), you could select brakes on at a later stage.


The reason why we do these things is the old airmanship adage 'don't assume, check'

[18greens]

Isn't there an aircraft you have to set the brakes on for aerobatics and spin recovery. (something to do with more rudder authority). After such an exercise it would be useful to have a reminder put them off again.

I guess it also acts as as a reminder to the student to put their heels on the floor incase in their tense exitement they have allowed their feet to ride up.

Either way landing with brakes on is usually expensive.

Having said that don't some jets fitted with anti locking systems land with their brakes on for decreased stopping distance.

[EGBKFLYER]

You should all have been in the pub on Sunday - some new ideas we didn't think of coming up...

Totally with you on the 'don't assume-check' thing - we were also concerned with making sure the 'check' is of something useful! Very interested on the aerobat angle - anyone know which type that is?

[Big Pistons Forever]

I have never seen a checklist that had brakes off as a prelanding check, I have always tought " brakes -- Pedals firm " as a quick squeeze on the pedal /brake handle in order to ensure the brakes are still there when you land. I once had a flight in a Seneca where the brakes worked fine on the ground but all the fluid leaked out in flight. I was more than a little surprised when I did a brake check and the pedals flopped to th floor:eek: . I informed ATC and put the airplane down at the very beginning of the runway at min safe airspeed and it still took almost 6000 feet to stop:( A final niggly point about the brakes -presure check call discussed in a earlier post. I believe the check calls should be what is actually checked. Since almost all light airplanes do not have a brake pressure guage you cannot check the brake pressure. Therefore the check should say what you are actually doing which is checking that the pedals are firm. The only exception I have encountered was a Nanchang CJ6 which had a brake airpressure guage directly showing the airpressure at the wheel brake bladders... and the Chipmunk of course with its goofy
system.

[Divergent Phugoid!]

A few years ago I flew a mates Grumman A A 5. This had a terrible habbit of both wheels freewheeling in flight, causing a horrible whine and vibration too, albeit not too much vibration. To stop this... The parking break was applied... Problem solved...

Pre landing checks were "Brakes Off!" for that very reason.

Hope this helps.. DP.

[homeguard]

You apply brakes on a C150/152 by first pressing the pedals downwards with the feet. You then pull out a sprung toggle which, via the springs and attached chains, lift up clams (my word) which grip each brake master cylinders piston rod, both left and right. You release the brakes by pressing once more on the pedals and the clams fall away clear of the piston rods.

Should the toggle not return fully home then a tention is retained on the springs and chains. If in this condition the brakes are applied eigther deliberately whilst taxxing or inadvertently during flight then one or both brakes could become partially operative. The result on landing is obvious and most serious should just one brake be partially on.

The C150/152 brakes therefore, during the BUMPFH, should be checked for servicabilty by pressing with the feet but only after checking to ensure that the toggle is fully home.

I,m sure that we must all be agreed that the replies already posted show that checking the brakes ain't a bad idea. Re-invent the wheel if you dare!

[Big Pistons Forever]

I am not sure how the parking brake in a C150 could be inadverantly applied in flight and if it was on during the takeoff, surely the pilot should have realized something was wrong. :hmm: There certainly is not great amounts of thrust to overcome a dragging brake. I think checklists, particulary during high workload times like prelanding, should be as short as possible. I do not think it is worth while checking for something that is very unlikely to occur. Checking the brake pedals to ensure they are firm and thereby having reasonable certainty that the brakes are working does strike me as a worthwhile check. BTW I discourage the use of C150/152 style parking brakes because they do as you correctly point out , can jam on, and in any case it is hard on the disks if they are applied when the wheel is hot.

[Sassenach]

Regarding 18Greens' query about types that require brakes to be set for spinning and aeros, to the best of my knowledge the rule is always to set the brakes off. Taking the Chipmunk again as an example: as you bring the brake lever back, you get progressively more braking as you deflect the rudder bar. Since you are now pushing against the hydraulic pressure, the rudder travel decreases. When the lever is fully back, you can't move the rudder at all!. This is clearly not desirable if recovering from a spin or trying to make coordinated manoeuvres during aerobatics.

[EGBKFLYER]

Thanks for all the response on this one - very interesting to hear all the different views and I certainly learnt something. I'll post what the guy I discussed this with says on the subject of C150 brakes - he's an ATPL and a licensed engineer, so I'm sure he'll have a take on it!

[Say again s l o w l y]

I can't imagine putting on a C150 park brake inadvertantly. Since they are invariably useless it probably doesn't even matter that much!

The only a/c I've seen someone put on the parking brake during flight accidently, was in a Robin, but this was due to a complete brain dump on the part of the student.

Checking that there is pressure in the system is the main point in the brakes bit of the pre-landing checks.

[Divergent Phugoid!]

Come on BP get real... Next you will be saying lets not check carb heat or similar cos its unlikely to happen... And we all know the common regularity of this! Particularly in the hot summer months!


I will always make sure the brakes off item are on the pre landing checks and I suggest that if the workload is too high for the pilot to manage to check brakes off, I would seriously question if the individual should be in command of any Aircraft, and their ability to fly in the first place.

Safety must come first, and this is definately a safety item.

DP

[Big Pistons Forever]

Divergent Phugoid

While in the circuit I once had a wasp come out a C150 wing root airvent. Another time a student puked all over the instrument panel obscuring most of the instruments :sad: . Because of those incidents I did not subsequently add to my prelanding checklist

Wing air vents -------- close

or


Puke Bag -------------- give to student



So why would I put something on the checklist that has NEVER in 5000 hrs, happened to me. I think you have to be carefull about invoking the " safety " word. Safety does not come from mindlessly following a printed list , it comes from fully understanding the relavance of each checklist item and always maintaining the correct priority of actions at any given time throughout the flight.

[Chuck Ellsworth]

Divergent P :

Thank you for teaching me something new...

I guess I should not have been in command of aircraft all those years, any chance you could reprogram my thought pattern so I come up to your standards? :D :D

[Cypher]

Parachuting... Standard practice..

Airborne

Flaps Retracted
Power Set
Temps and Pressures in the greens

Parking Brake ON..

Them meatbombs love to climb over the gear on their way out or even stand on them now and then.. they get pi$$ed off when they stand on the gear and the wheel throws em off..

Hence landing with the parking brake on is not a good way to impress the boss...

[Tinstaafl]

I once saw a student in a PA28 apply parking brake instead of 1st stage of flap... :ooh:

[Snigs]

Slight tangent, but what about (in a PA28) leaning the mixture instead of carb heat hot. That's scarey if you haven't noticed it!!:{

[Big Pistons Forever]

Cypher

Your checklist is short, to the point , and meets the unique needs of your operation, sounds like good airmanship to
me. Although I always thought the objective of every splatter
enabler was to get the #@^%$#^&$ jumpers gone as fast as possible, hence wouldn't be it be better to leave the brake off:E

Snigs

If the student whips the mixture back instead of the carb heat , I don't think you will need to wait for the pre-landing checklist to find out ;) . The Last time a student did that to me I screamed
" OH MY GOD WE ARE GOING TO DIE , GET THE ENGINE GOING, GET THE ENGINE GOING !!! " To his credit he did the engine failure checklist, figured out what he did , got everything thing squared away and said. "That was mean you freaked out to get me rattled". I replied "thats right you were rattled but you still remembered to do the drills and fixed the problem". He learned two big lessons.
1. Think before you push/pull/turn anything in the cockpit
2. The importance of having the emergencies drills down cold, because when bad things happen your brain initially freezes solid, Having the drills to give you a place to start is a big help to get the thinking process working.

I guess it was a bit mean but the the expression on his face was priceless
:D

[juggernaut]

The reason for the brakes off check on the likes of c152 and pa28 is to check the pressure and ensure they are not on for landing, also take note that on some aircraft activating the parking brake decreases rudder deflection which may hinder spin recovery, the grob 115 comes to mind!

[fireflybob]

Remember also that if you land a tail wheel aircraft with the brakes on the results are likely to be much more catastrophic compared to doing same with a tricycle undercarriage (i.e you might end up upside-down having tipped the aircraft up on its nose!). On a tricycle undercarriage you might blow the tyres or damage them but not a lot more.

And yes, they are "Pre-Landing Checks" because you might do a straight in approach and never fly downwind.

I too have observed a student place the brake lever to park in error for applying the first stage of flap!

Incidentally, I teach never to set the park brake having lined up - it's too easy to forget, especially if you are taking off on ice or wet grass and the resulting poor acceleration is not good for performance! I believe it was at Alaska many years ago where a DC8 attempted take off on an icy runway with the brake brake set to ON with dire consequences and hence, in my experience, the park brake is never set to ON after lining up with most airlines etc.

[flyby_kiwi]

Have to go with Cypher on this one - I was always taught brakes off (Re Parachute Ops) and Check for Px. (No px in the brakes we wont be landing on any short strips).

[FlyingForFun]

What about (in a PA28) leaning the mixture instead of carb heat hotOk, I'll admit it - I did that. On a solo cross-country, with about 35 hours. :eek:

My ear caught the engine starting to run rough, and my instinct was to undo whatever it was I'd just done. The mixture was full rich again before the engine had a chance to cut out. I confessed to my instructor when I got back, but there's no real advice he could give except for being more careful next time. I know the 300-odd hours I've logged since then isn't a huge amount in the big scheme of things, but I've never moved the wrong lever or knob in any aircraft in those 300-odd hours.

FFF
--------------

[Tinstaafl]

I've put the park brake on in an Islander instead of L.H. carby heat. The lever is next to the C/heat AND moves in the same direction and locks with a similar sideways detente. Realised what I'd done & corrected it but you never know, there's always next time....

[Divergent Phugoid!]

Well, what a response from Big Pistons...

All I can say is that BP, thank god I didn't learn to fly with you!

I had an instructor who taught me how to be a professional pilot.

If you think that the correct course of action towards your student was to lose control of the situation and start screaming and shouting then shame on you. I would recommend you seriously consider a career change! Something more suited to your outbursts under pressure!

It seems from your own words, after 5000 hrs, its not going to happen to you. Well then Mr Invincible, when you do eventually land with the brakes on either by your own negligence or a students, just think back to this thread as you burst your tyres and skid off the runway...

Who was it that said,' When flying, always expect the unexpected?' He must have been a wise man and a professional Pilot that leaves little to chance.

If the worse is going to happen, lets reduce the risk.

Oh and Chuck, glad to have been of assistance and if you want a refresher to come up to my level of ability you only have to ask!! ;) ;)

Happy flying!! :ok: :ok: :ok:

[Field In Sight]

If you think that the correct course of action towards your student was to lose control of the situation and start screaming and shouting then shame on you. I would recommend you seriously consider a career change! Something more suited to your outbursts under pressure!


BP Said.
" OH MY GOD WE ARE GOING TO DIE , GET THE ENGINE GOING, GET THE ENGINE GOING !!! " To his credit he did the engine failure checklist, figured out what he did , got everything thing squared away and said. "That was mean you freaked out to get me rattled". I replied "thats right you were rattled but you still remembered to do the drills and fixed the problem". He learned two big lessons.

I think he was just pretending to be an out of control lunatic to rattle his student.

I'll have to try that on my students :}

FIS

[Divergent Phugoid!]

FIS

And you consider this is the correct way to train your students?? I feel sorry for them.
With the cost of flying today I would have thought they would expect professional instruction, not some childish behaviour in the cockpit.
If I were your student I would not tollerate such behaviour.

[Say again s l o w l y]

DP, I think there was a bit of sarcasm in FIS' post.

BPF, why did you tell him that the engine had failed? Normally an unexpected silence from the donk causes enough of a heart flutter. Surely recognising the problem quickly is the most important reaction, since the emergency drills should be well ingrained.

The technique of putting people under as much pressure as possible does work well as you can never tell exactly how someone will react in a real emergency.
I don't see anything wrong with what BPF did, my job is to teach people to fly safely, not to win popularity contests and to be honest at times if my students like me, then I'm not doing my job correctly.
They usually understand why you've seemingly been an a*se when you explain the reasons down the pub.

[homeguard]

If anyone still wishes to argue that to check the brakes prior to landing is superfluous then they should read this months Pilot magasine "I Learned About Flying From........" and the report published within the latest GASIL.

Anyone else wishing to re-invent the wheel, write on I can't wait to hear the nonsense!

[Big Pistons Forever]

This will be my last words on this subject as I think this post has run its course.

With respect to my pretending to wig out in the cockpit , I thought ( and still think ) that for that student at that time, it was a good teaching tool and at the end of the exercise I truly beleve he gained a measure of confidence in his ability to handle emergencies,( not to mention paying more attention to what knob he is pulling! ) that he would not otherwise had. Nevertheless it is situationally dependant and there would be only be a limited set of circumstances this scenario would be appropriate for.

With respects to the brakes off check I have heard nothing which will cause me to change my mind that this check is unnecesary
in the context of post number one, which is the operation of your typical light flying club type aircraft. I still believe that the call

brakes ------ pedals firm

provides a sufficent check of that aircraft system and is likely to catch any likely system abnormality. Since it is obviously impracticle to have a check list that would cover every possible abnormality I think particularly in the high work load environment of the phase of flight where the prelanding checklist is done, the checks have to strike a balance between covering the essential items but not being so involved and lengthly that it detracts from flying the aircraft. Therefore I came to the opinion in I say again the operation of your typical light flying club type aircraft ,the brakes off check is not required.

As it happens I have yet to fly an aircraft or aircraft operation where this check is necessary. However it is entirely possible that in future I may add the brakes off check for valid operational reasons.

So Divergent Phugoid et al if your have thought through the issue and come to the conclusion that this is the best way to operate then good for you. I must note that over the years when I have challenged pilots on why the did something ( the run up mixture check is a good example ) often the best they could offer was because "I always did it" or " somebody told me to " and really had no idea why they were completing th action.

But you know what the best part of this forum is ? It has made me think about things. I can guarentee, I never would have put this level of thought into this one issue if it had not been brought up and for that reason I intend to contribute to and learn from this forum:ok:

[lady in red]

I know this post has nearly run its course, but why do we check our brake pressure first and then lower the undercarriage? Surely it would make sense to check the brakes after the undercarriage was down??? As an aside I did suffer brake failure once in a twin, on one side only! By checking downwind as part of the pre-landing checks, I knew I had the problem and therefore was able to deal with it by landing as slowly as possible and as short as possible to maximise available runway for my asymmetric barking deceleration...

[eyeinthesky]

Lady In Red:

Good question, and that's why when I'm teaching or flying a twin or any retractable I change the order to be:

Undercarriage Down
Brakes off and pressure checked.

It would be unfortunate if, in the process of the gear lowering, one of the hydraulic lines had been ripped off or punctured and the first you know about it is when you head off to one side of the runway with only one brake working!

The replies so far have just about covered it. The BUMPPFICHH or whatever are taught for generic checks to ensure that when we fly different types later the seeds are sown to prevent missing something. If we adjust those basics correctly then safety is improved.

Of course to be certain we should use a printed checklist to ensure we miss nothing, but we all know that most of us do pre-landing checks from memory, so something memorable drilled in at the student stage is useful.

[Chuck Ellsworth]

I just can't resist.

So here goes.

Divergent P.

If I decide to take you up on that offer to retrain me. what do you charge for the training? :O

And will I be able to up my rates with this new found skill? :O

Chuck