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Helicopters and retractable gear
When lifting off or touching down in a helicopter with retractable landing gear would you normally have the wheel brakes ‘on’ so the aircraft cannot roll forward or back ?
Do helicopters with wheels, retractable or not always have brakes and is there a parking brake ? |
Normally OFF, we often want to perform a rolling landing to use less power. If you don't want to move on touchdown, press and hold the brake levers. A rolling landing with park brake ON can burst the tyres or at least cause a flat spot, and a boot up the bum from your boss.
I don't know of a wheeled machine that doesn't have brakes, though the early B47s looked like they didn't. Tricky to steer and stop if you don't have brakes. (Did the Wessex have a bicycle-type handbrake on the cyclic??) Park brakes aren't always that successful - the A109 early series used the hydraulic pressure (with engine/s running) which was stored behind a valve for parking when you pull out the park brake handle and press the brakes. Sadly, after shutdown the stored pressure would bleed away, and if the bird wasn't chocked, it might just roll off downhill. On start-up and when ready to roll, a touch of brake pedal would usually release the park brake, and then the pilot realises he has left the chocks in... Not such a problem if they aren't your chocks, just lift vertically and leave them there. |
Clear area departure/arrival, brakes off. Helipad/helideck departure/arrival, brakes on. |
Also brakes on for sloping ground landings
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Try applying the brakes in a Navy Wasp! |
Park brakes aren't always that successful - the A109 early series used the hydraulic pressure (with engine/s running) which was stored behind a valve for parking when you pull out the park brake handle and press the brakes. Sadly, after shutdown the stored pressure would bleed away, and if the bird wasn't chocked, it might just roll off downhill. The other "gotcha" on that aircraft is that the rotor brake pressure works in a similar way. Woe betide the pilot who starts his 109 with the rotor brake "on". If the pressure has bled away, the rotors will start turning as per normal - until the hydraulics re-pressurise, whereupon the rotor brake will re-apply itself. One pilot I know started his first A109 job in the morning, burned out the rotor brake, damaged the transmission and was out of a job early afternoon. Almost as silly a design as the SK76 where the aircraft can't be safely towed unless undercarriage locking pins are inserted. |
Thanks for the informative replies, while on the subject of helicopter landing gear what was the thinking with the ‘splayed out’ wheel configuration on the RN Lynx ? |
As far as I can gather this was so that it could be landed on the deck more or less into wind. The helicopter could then be pivoted around on its undercarriage so that it was pointing at its hanger, The wheels were then straightened, locked and the aircraft pushed in.
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Originally Posted by Fareastdriver
(Post 10347385)
As far as I can gather this was so that it could be landed on the deck more or less into wind. The helicopter could then be pivoted around on its undercarriage so that it was pointing at its hanger, The wheels were then straightened, locked and the aircraft pushed in.
skadi |
Originally Posted by stilton
(Post 10347290)
Thanks for the informative replies, while on the subject of helicopter landing gear what was the thinking with the ‘splayed out’ wheel configuration on the RN Lynx ? Pivoted outside allow for turning around the harpoon, which holds the helicopter on the deck, after castoring the nosewheel 90 degrees. Over land you can do a running landing, the „splayed out gear“ braking the helicopter, turning and leaving rubber. Autorotation onto grass would send piles of dirt through the rotordisk 😜 |
Originally Posted by ShyTorque
(Post 10347203)
Almost as silly a design as the SK76 where the aircraft can't be safely towed unless undercarriage locking pins are inserted.
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ISTR that on the CH 47 in the 80’s, we landed brakes off but held it on the toe brakes until the park brake was applied. |
Originally Posted by Sir Korsky
(Post 10347628)
They were only silly when you left one in :rolleyes:
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Originally Posted by Sir Korsky
(Post 10347628)
They were only silly when you left one in :rolleyes:
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Originally Posted by Sir Niall Dementia
(Post 10347689)
Not just me then :mad: |
I assume the brakes are on the top of the pedals, are these called rudder pedals on a helicopter? |
According to Wiki they are anti-torque pedals. Should you take off without your feet on them the person beside you shuts up.
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The brakes are usually on the wheels :E.
The brake pedals are usually incorporated into the yaw pedals. |
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