Flaps up or flaps down??

[Robert1968]

I'm confused,


As all us modellers are aware ( those who build aircraft kits wheather it be from WW1, 2, Cold War and to the present we have all come across the option in some detailed kits of "flaps up or flaps down" and I may be picky here but after surfing the Internet and reading many of reference books and even listening to some actors who play pilots etc the view of the aircraft is always " flaps up" Sometimes I have seen the rudder to one side and maybe the tail flaps draped down but actual wing flaps they can't be down unless the aircraft is switched on as are thesenit hydraulically operated?


The wing surface is enlarged by deploying the flaps to gain more lift? Deployed down to create drag. So when we model say a Spitfire is it correct to show the flaps on the wing down? Unless we are modelling with a pilot in the aircraft ( I know I say flaps and there are tech names like airalons etc )


But is this true, does a pilot leave flaps down and walk away or is it just for visual aids in the modelling world?

[Guest]

To gain more lift, the slats are deployed. This was mostly a Luftwaffe feature. Flaps were seen to be fully drooped on the ground, but for RAF aircraft, they were normally retracted once the aircraft was shut down. Yes, it does look good, if deployed, but historically it was incorrect.


Cheers, John

[takeslousyphotos]

I think Spitfire flaps were pneumatically operated ......... As for up or down when parked ??? I believe it is common practice for the flaps to be retracted. Although someone will no doubt correct me on that.

[Guest]

I think Spitfire flaps were pneumatically operated ......... As for up or down when parked ??? I believe it is common practice for the flaps to be retracted. Although someone will no doubt correct me on that.

I agree with you. As said in my earlier post, when parked RAF aircraft had flaps up.


John

[Guest]

Flaps could be hydraulic or electric and could well be open or closed on the ground. It would be normal practise to have flaps retracted however there could be maintenance reasons for having them down or there may be some modellers who would like to portray thier model just after landing or during take off for instance. Sometimes in cases of very fast turn around such as very fast re-arming and refuelling it would not surprise me if the pilot did not bother to retract them.


Some modellers simply like to display as much internal detail as they possibly can with gun bays open engine covers off, flaps down etc for nothing more than to see as much as possible. There is certainly no right or wrong.

[Guest]

Flaps could be hydraulic or electric and could well be open or closed on the ground. It would be normal practise to have flaps retracted however there could be maintenance reasons for having them down or there may be some modellers who would like to portray thier model just after landing or during take off for instance. Sometimes in cases of very fast turn around such as very fast re-arming and refuelling it would not surprise me if the pilot did not bother to retract them.
Some modellers simply like to display as much internal detail as they possibly can with gun bays open engine covers off, flaps down etc for nothing more than to see as much as possible. There is certainly no right or wrong.

Completely agree with you mate, but if one is a historical accuracy fanatic, with a Spitfire, the flaps would be up.


John

[flyjoe180]

It all depends on the aircraft type you are replicating. Flap systems could/can be pneumatic, hydraulic, electric, or plain old manually operated.


On some types it is common for wing flaps to be retracted after landing to prevent damage to the undersides when taxiing. Discussions have been had about Luftwaffe ground crew pushing slats back into the wing after shut down to prevent damage or the ingress of debris. On some aircraft it is desirable to leave the flaps down to enable evacuation over the wing.


The most common type of flap system is hydraulically actuated and electrically operated. Over time hydraulic pressure can reduce causing wing flaps to slowly extend over time. Some aircraft do this over a matter of hours, some days. it really comes down to researching your type and determining how the flaps and other items are positioned for the state you are modelling your replica in.

[Guest]

On the Spitfire (and others) the Pilot's Notes were specific in their instructions that, on landing, the flaps must be retracted, and the aircraft was not to be taxied until they were up. Props throw up mud and stones, and wheels can go into hidden holes, dropping a wing and damaging the flaps; erks didn't appreciate digging lumps of mud out of hinges, either. Forgetful pilots tended to be fined, by the C.O., with the money going into the mess fund.


A friend of mine is an ex-Hunter pilot, and he said that the same system of fines still applied to them.


Probably the only time you'd see flaps down is during a pre-flight check, with cockpit open, and an erk peering under the wings to check the flaps.

[rickoshea52]

From my experience flaps and slats are retracted as soon as possible after completing a landing but the actual instruction for when this should happen will be contained in the pilots checklists.


During Nimrod operations the flaps would be fully extended during the start and pre-taxi checks and then returned to the take off flap position. On landing the flaps would be fully retracted. They would be fully extended for washing and any maintenance as the situation required but never towed with full flap without justifiable cause.


Every flight I take now on civil airliners the flaps and slats are retracted as the aircraft exits the runway after landing.


Flaps and slats are used to change the cross sectional shape of a wing to increase the surface area and therefore lift at lower speeds for landing. They are also extended to a lesser degree at take off for increased lift. And there are different types - plain, split and slotted - Nimrod has split and plain flaps, I think that most WW2 fighters have split or plain flaps.

[stona]

All the above is true. Not all flaps were operated by the same method nor was their travel the same. A Spitfire flaps (pneumatic/spring operated) could either be up or down, many others (usually hydraulic or electrically operated) had variable or various degrees of deflection selectable. On some aircraft the flaps and ailerons were linked so that as the flaps went down the ailerons drooped proportionally. This system was fitted to the Bf 109 for example.


Next you will need to worry about other moveable systems. How will you pose your radiator or oil cooler flaps? These too are seen in various positions on parked aircraft of different types!


You really have to try and find a decent reference for your aircraft, if you are very concerned about posing your model in a historically accurate way. Otherwise pose it how you like, it's your model after all


Cheers


Steve

[Guest]

Same with the gear doors on P-51's, they droop (unevenly) when pressure starts going down.


Theuns

[Dave W]

When I was a crew chief on a Saudi Tornado squadron our aircraft would be parked over night with flaps and slats extended. Pilots would taxi in with flaps retracted.But before shut down they would extend them for the ground crews post flight inspection.So when I get round to building another Tornado it will have the flaps and slats extended.

[stona]

Same on the P-51. The flaps were lowered by hydraulic pressure, in fact in the manual for the P 51 D it warns that if there is less than 800psi in the system the flaps can't be lowered. If the flaps are down, then the pilot lowered them after parking. Some late version P-51 pilot's notes ask for this to be done


On late model P-51s, after landing, a valve was operated to release pressure in the hydraulic system to the fairing doors. This would cause the fairing doors to droop, but protect the hydraulic circuit from 'thermal expansion'. Most importantly this action would place a mechanical lock on the undercarriage to prevent retraction whilst the aeroplane was on the ground.


Cheers


Steve

[Guest]

Also allot easier to get onto the wing walkway with the flaps down ;-)


Theuns