22
$\begingroup$

I'm pretty sure that there are no aircraft equipped with a brake on its nose wheel, however two of my colleagues think there might have been. Are there?

Aircraft with retractable gear of course have devices to stop the wheels from spinning when retracted, but I'm asking about brakes used to stop or slow down the aircraft. Please don't consider aircraft with a tail wheel, gliders, experimental aircraft, or aircraft used for flight testing (certified aircraft only).

$\endgroup$
24
$\begingroup$

There are quite a few 727 that actually had nose wheel braking, however they utilized it only for maximum braking power. (Also they were proven to be ineffective and unreliable, so a service bulletin was written to remove the system).

Saab Gripens use nose wheel brakes to stop as well, the main gear sits farther aft than most planes, so there is quite a bit of weight on the nose gear, which makes it effective for stopping.

$\endgroup$
20
$\begingroup$

The Messerschmitt Me-262 had nose wheel braking as well. Back then, with the high landing speed of jets and no thrust reversers, the engineers wanted to give pilots as much stopping power as possible.

Here is a picture which shows the brake line running down to the wheel:

Abandoned Me-262 after the war

Abandoned Me-262 after the war (picture source)

$\endgroup$
  • 3
    $\begingroup$ Really interesting picture. My guess would be a forward deployment and that airplane was being cannibalized for parts. $\endgroup$ – Terry Jun 10 '15 at 19:47
  • 3
    $\begingroup$ @Terry: My guess is it has been taken by US forces when they discovered an abandoned makeshift airfield next to an Autobahn. Straight stretches of the Autobahn next to a forest (for hiding the planes and buildings) were used by several Me-262 units in 1945. Note the shattered windshield: I guess this particular plane had been damaged on the ground and was then cannibalized, as you said. $\endgroup$ – Peter Kämpf Jun 10 '15 at 22:53
  • $\begingroup$ Please provide proper attribution of the photo as required by SE $\endgroup$ – CGCampbell Nov 24 '15 at 0:37
  • 2
    $\begingroup$ That is a really odd picture. There are jack-stands under the forward fuselage and left wing. What looks like an engine or bomb hoist holding up the right wing. It appears that there is some sort of wooden structure holding up the tail. The main gear look to be partially retracted, while the right gear wheel seems to be missing (hard to tell). These all strongly lead to the cannibalization theory, yet there are piles of ammo and a bomb under it, as well, indicating a hasty de-ordancing (is that a word?) prior to field repairs. $\endgroup$ – FreeMan Nov 24 '15 at 13:20
  • $\begingroup$ @FreeMan: Given that the engines are also missing, I would strongly guess cannibalisation. $\endgroup$ – Sean Jun 15 '18 at 20:28
5
$\begingroup$

Good question. With regards to mainstream commercial jets it might not do much and quite possibly be counter-productive.

Most (all?) Boeing and Airbus have about 95% of weight on the main landing gear (MLG), and thus the nose brake wouldn't be very heavily weighted, so not very effective. And for reasons of rotation, you don't want to load the nose very much, but rather have it pivot around the wings: where your lift is coming from.

You can then design the nose landing gear (NLG) to be quite light because it doesn't see a lot of load, nor take large braking reaction forces. And doesn't have any brakes/hydraulics etc. And the same with the fuselage strength: it's okay if the MLG take all the load: they are already in the "beefy" section of the plane, and there is no moment arm (torque) due to a big displacement from the centre-of-gravity (CG).

However if you started to have large forces on the NLG, you have it a long way from the CG, and thus a big moment: you'd need to take that into account when you designed the fuselage, making it stronger, and thus heavier. At the moment with no lift on the front fuselage section, nor any forces from braking, you can make it pretty light.

Having the MLG at the CG and also centre-of-lift from the wings (drag from spoilers) makes for a very stable system. Inherently stable too: the faster you go, the more drag from the wings, and thus more weight on the MLG, which they need.

I think this will be the case for all planes with propulsion from the wings: regardless if props or jets. If you have a prop on the nose it's a bit different because you need to beef that up anyways, so you don't mind the braking loads from a nose-wheel. But I don't see a lot of advantages for it. You add all the extra weight of the hydraulics and brakes, plus the weight from making a much stranger assembly. More complexity, more to service and go wrong.

$\endgroup$
  • $\begingroup$ Nose gear does have hydraulics for steering (except on small aircraft with free-castoring nose gear where differential braking is the only way to steer). $\endgroup$ – Jan Hudec Nov 24 '15 at 8:32
  • $\begingroup$ Braking force on nose gear won't have any larger moment than braking force on main wheels, because braking force is horizontal, so only the vertical distance from CG matters and that is the same. $\endgroup$ – Jan Hudec Nov 24 '15 at 8:34
  • 2
    $\begingroup$ Very interesting and useful information, however it doesn't actually answer the question of "are there any planes with NLG brakes?" $\endgroup$ – FreeMan Nov 24 '15 at 13:23
  • $\begingroup$ Once the brakes on the main wheels are engaged, the load on the NLG goes up, making a brake there rather effective. Only if the breaking is done by a chute or spoilers will the NLG see litte load through the deceleration. $\endgroup$ – Peter Kämpf Mar 20 '16 at 11:38
4
$\begingroup$

Ahaha!! There IS in fact a non-ultralight aircraft out there that has its ONLY brake on the retractable nosewheel. That aircraft is the Verhees Delta. Uniquely, that aicraft has only two wheels (tandem, or bicycle undercarriage) and they are in line, one wheel at the front, retractable, and another, same size, 9 feet further aft, at the rear of the aircraft. There is a small bumper wheel at the tip of each wing.

The aircraft lands on the rear wheel - (the nose is very high, during landing as this is a delta wing aircraft). When it has slowed down enough the nosewheel leg makes contact with the runway and it can begin braking.

$\endgroup$
  • 3
    $\begingroup$ Welcome to Aviation.SE! Interesting airplane -- can you provide a link that shows us what this machine looks like? $\endgroup$ – Ralph J Mar 20 '16 at 6:04
  • 1
    $\begingroup$ Good catch! but it looks like it is an experimental (home built) airplane with a single one built, so it doesn't actually answer the question. $\endgroup$ – mins Mar 20 '16 at 10:48
  • 1
    $\begingroup$ Well, I think the U-2 falls into this grou, and likely the B-47 and B-52 as well. $\endgroup$ – Maury Markowitz Jun 11 '18 at 23:50
0
$\begingroup$

50+ B727-200 were equipped with nose brake systems. I have a B727 nose wheel cap with anti-skid. I have no idea what it is worth but it's a great conversation piece.

$\endgroup$
  • $\begingroup$ Hi Mark. The 727 was already mentioned in the accepted answer. Kindly take the tour and do stick around. $\endgroup$ – ymb1 Jun 7 at 2:56

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.