exceeding POH take-off speed
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exceeding POH take-off speed
Good afternoon, all.
When flying a PA28, or even a PA38, rotation occurs at around 60kts IAS.
My question is this: Is it considered dangerous If you're traveling at say 75-80kts before rotating (assuming you have a long enough runway)? Apart from experiencing possible positive G, is this considered dangerous?
When flying a PA28, or even a PA38, rotation occurs at around 60kts IAS.
My question is this: Is it considered dangerous If you're traveling at say 75-80kts before rotating (assuming you have a long enough runway)? Apart from experiencing possible positive G, is this considered dangerous?
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Ha, sorry. I should have explained why I asked.. I saw a chap take off the other day and was clearly exceeding 60kts, he then proceeded to do a rather rapid climb and that's what made me ask. Apart from looking like a bit of a prat, I was just curious to know if there was actually some danger involved in doing such a stunt
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Personally I don't believe it's sensible. Firstly, why ask the tyres to do more than they need? Secondly, do you have to give the suspension and undercarriage such a hammering? Thirdly, the brakes will heat up unnecessarily (just with residual brake drag) and last of all, you are wasting climb-out and stopping distance. I also don't think there are improved V2 climbs for singles.
I don't understand.
I agree. To look impressive in a PA28 or PA38 you'd have to have full tanks and park either vertically or it in a tall building.
Apart from experiencing possible positive G, is this considered dangerous?
looking like a bit of a prat
Last edited by Jetdriver; 20th Jan 2014 at 02:03.
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If you need to stay on the ground longer to try and look cool during the climb the plane you are in will never live up to your expectations of awesomeness. Its a fact of underpowered single engine school/rental aircraft.
If on the other hand you are in something descent you don't need to push the designed speeds or in fact do anything other than fly it within its limits to have peoples jaws dropping.
Probably the most overpowered single engine prop plane in the world, the video drags on a bit but if you forward to 2:30.
If on the other hand you are in something descent you don't need to push the designed speeds or in fact do anything other than fly it within its limits to have peoples jaws dropping.
Probably the most overpowered single engine prop plane in the world, the video drags on a bit but if you forward to 2:30.
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When you start thinking about how it looks to the people watching, is generally when things start to go wrong.
The PA28 should get airborne at around 55-60kts, at that speed you can certainly feel it's ready. Any more will do the nose leg no good at all, and it will eventually develop nosewheel shimmy, and eventually fall off if you consistently hold it on the ground until 80kts. it was never designed to deal with such punishment.
The PA28 should get airborne at around 55-60kts, at that speed you can certainly feel it's ready. Any more will do the nose leg no good at all, and it will eventually develop nosewheel shimmy, and eventually fall off if you consistently hold it on the ground until 80kts. it was never designed to deal with such punishment.
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If I'm flying an SEP (172, PA28 etc) I will rotate at the correct speed and sometimes hold it in ground effect and gain speed then pull up for climb. I do this not to impress people but because I find it fun and I don't get a chance to do it during the day job. I don't believe that I am the only person that does this sort of thing for fun. I wouldn't recommend actually keeping it on the ground past Vr though just because of the previously mentioned reasons.
As indicated above, normal technique is to start raising the nose - a little -at around 55-ish, and let it fly off when ready. The only reason I can think of for not doing that is if you're in a crosswind takeoff, or expecting significant windshear of turbulence airborne. In such a case it would be normal to hold the aircraft nose-level to about 65-ish, maybe a little more depending on type/weight/severity of the weather, and then rotate positively to the climb attitude. 'Holding it on' to a much higher speed risks wheelbarrowing, and excess tyre loading. Wheelbarrowing in a gusty crosswind- or at any time, really - is quite undesirable.
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I saw a instructor prat try out his theory with the tommy once with an increase to 70knts before letting it fly. It was quite amusing as it was on grass and he couldn`t get it past 65knts. Then he hit a bump and it all ended in tears and brown pants very lucky not to go off the end or have a prop strike.
Just set your trim and let the plane fly you off when its ready. Because there is only one speed which is for mtow. So unless your at that it will usually go before the book speed. If it goes after the book speed you will be over loaded.
Just set your trim and let the plane fly you off when its ready. Because there is only one speed which is for mtow. So unless your at that it will usually go before the book speed. If it goes after the book speed you will be over loaded.
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See SOP
Hi y'all,
How to fly the aircraft is printed in the SOP, which is based on the POH. Do not ever try to think that you know the aircraft better than the people that designed it. If you think the POH is wrong, tell the manufacturer so they can correct it.
Taken from the Standard Operating Procedures from South Sweden School of Aeronautics, a school that only trains professional pilots, following POH and Pans-Ops:
TAKE-OFF:
- While entering runway, apply "Spin-Up", 1500 RPM.
- Do not stop on runway unless instructed to do so. When "Cleared For Take-Off", ATC expects immediate departure.
- Softly apply full power. Hand behind throttle.
- On hard runway, keep slight forward pressure on steering wheel, maintaining positive nose wheel contact with runway.
- On soft runway, offload nose wheel.
- On Vr (normally V2-10) rotate aircraft (normally 10 deg nose up).
- Speed V2
- Half runway AND Positive Rate Of Climb, Gear Up. Hand off throttle.
- Not lower than 400 feet AGL, Flaps 0. Turning allowed.
- Speed V2+10
- Not lower than 1500 feet AGL, lower nose so to obtain climb speed, trim while accelerating, when on climb speed set climb power.
- Perform AFTER TAKE OFF checklist.
- On altitude, lower nose so to obtain cruise speed, trim while accelerating, when on cruise speed set cruise power.
C-172:
Flap setting TO: 0 (Soft runway, 10 deg)
Flap setting landing: Full
Vr: 60 kts
V2: 70 kts
Vcl: 90 kts
Vapp: 70 kts
ON HARD RUNWAY ONLY:
- To accelerate flying on the ground effect will give a longer Take-Off distance as compared with accelerating rolling on the runway, the increased angle off attack produces resistance.
- Resistance of rolling a tire on a hard runway is negligible.
...and, by the way...
Maximum tire speed is printed on the tire, normally 120 MPH = 105 KTS.
I personally try to impress any onlooker by flying safe and consistently.
How to fly the aircraft is printed in the SOP, which is based on the POH. Do not ever try to think that you know the aircraft better than the people that designed it. If you think the POH is wrong, tell the manufacturer so they can correct it.
Taken from the Standard Operating Procedures from South Sweden School of Aeronautics, a school that only trains professional pilots, following POH and Pans-Ops:
TAKE-OFF:
- While entering runway, apply "Spin-Up", 1500 RPM.
- Do not stop on runway unless instructed to do so. When "Cleared For Take-Off", ATC expects immediate departure.
- Softly apply full power. Hand behind throttle.
- On hard runway, keep slight forward pressure on steering wheel, maintaining positive nose wheel contact with runway.
- On soft runway, offload nose wheel.
- On Vr (normally V2-10) rotate aircraft (normally 10 deg nose up).
- Speed V2
- Half runway AND Positive Rate Of Climb, Gear Up. Hand off throttle.
- Not lower than 400 feet AGL, Flaps 0. Turning allowed.
- Speed V2+10
- Not lower than 1500 feet AGL, lower nose so to obtain climb speed, trim while accelerating, when on climb speed set climb power.
- Perform AFTER TAKE OFF checklist.
- On altitude, lower nose so to obtain cruise speed, trim while accelerating, when on cruise speed set cruise power.
C-172:
Flap setting TO: 0 (Soft runway, 10 deg)
Flap setting landing: Full
Vr: 60 kts
V2: 70 kts
Vcl: 90 kts
Vapp: 70 kts
ON HARD RUNWAY ONLY:
- To accelerate flying on the ground effect will give a longer Take-Off distance as compared with accelerating rolling on the runway, the increased angle off attack produces resistance.
- Resistance of rolling a tire on a hard runway is negligible.
...and, by the way...
Maximum tire speed is printed on the tire, normally 120 MPH = 105 KTS.
I personally try to impress any onlooker by flying safe and consistently.
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There's no such thing as 'rotate speed' with a SEP. When it's ready to fly, it will.
Bad airmanship to hold it on the ground after it wants to fly. Also shows poor mechanical sympathy on the part of the 'driver' (think of those forces on the noseleg it was never deigned to take!). Nosewheel should be unloaded early in the t/o run (and while taxying)... and actually held off ASAP on a rough or muddy field.
Sometimes (muddy field) one drags it into the air before it's ready to fly to get the wheels out of the gloop, however, and accelerate just above the surface in ground effect before climbing away (know your aeroplane before doing this).
A party trick in the Yak was to get the gear up ASAP but hold the aeroplane down just above the runway, accelerating all the time and requiring more and more forward stick to hold it down. When the trees at the upwind end were starting to fill the windscreen, ease back and up she went like a rocket, almost vertical. For about 350 feet! Then a very careful push-over to level flight! Why? Because it was fun and because one could!
Bad airmanship to hold it on the ground after it wants to fly. Also shows poor mechanical sympathy on the part of the 'driver' (think of those forces on the noseleg it was never deigned to take!). Nosewheel should be unloaded early in the t/o run (and while taxying)... and actually held off ASAP on a rough or muddy field.
Sometimes (muddy field) one drags it into the air before it's ready to fly to get the wheels out of the gloop, however, and accelerate just above the surface in ground effect before climbing away (know your aeroplane before doing this).
A party trick in the Yak was to get the gear up ASAP but hold the aeroplane down just above the runway, accelerating all the time and requiring more and more forward stick to hold it down. When the trees at the upwind end were starting to fill the windscreen, ease back and up she went like a rocket, almost vertical. For about 350 feet! Then a very careful push-over to level flight! Why? Because it was fun and because one could!
A word of caution about didactic statements regarding what to do 'when it's ready to fly'.
For example.
The Rans S4 (& I hear the old Aeronca Champ.) will fly off at a ridiculously slow speed and be completely uncontrollable.
In these a/c one has to hold them down to gain a few more mph (say ~15% extra) judged by feel. So that in the initial climb, even when in ground effect, the thing doesn't float off, or sideways if any cross wind, with little P1 can do.
I do know !
mike hallam
For example.
The Rans S4 (& I hear the old Aeronca Champ.) will fly off at a ridiculously slow speed and be completely uncontrollable.
In these a/c one has to hold them down to gain a few more mph (say ~15% extra) judged by feel. So that in the initial climb, even when in ground effect, the thing doesn't float off, or sideways if any cross wind, with little P1 can do.
I do know !
mike hallam
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What I find is that the Vr in the POH is typically quoted in the context of short field performance. At that speed you've got to put the nose on the horizon (or something like that) and when it's ready to fly, it will. You then accelerate in ground effect until Vx, or something close to that, and then start the climb.
That may all be best for short field performance, but requires excellent flying skills and might be pretty uncomfortable for your passengers, with all the pitching up and down. It also means that you are initially flying at a very slow speed, and hardly able to compensate for crosswind and gusts.
At a long enough runway, holding the aircraft on the deck until you reach a speed maybe halfway between the published Vr and Vx, and then pitching smoothly into a climb at Vx, might give you a longer ground run but feels much smoother and controlled.
But keeping the aircraft on the deck beyond Vx (or maybe Vy when doing flapless take-offs) doesn't sound healthy to me.
That may all be best for short field performance, but requires excellent flying skills and might be pretty uncomfortable for your passengers, with all the pitching up and down. It also means that you are initially flying at a very slow speed, and hardly able to compensate for crosswind and gusts.
At a long enough runway, holding the aircraft on the deck until you reach a speed maybe halfway between the published Vr and Vx, and then pitching smoothly into a climb at Vx, might give you a longer ground run but feels much smoother and controlled.
But keeping the aircraft on the deck beyond Vx (or maybe Vy when doing flapless take-offs) doesn't sound healthy to me.
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Having done lots of cross wind take offs in a PA 28 under very gusty conditions I can tell you that a conventional still air approach is positively dangerous. Under those conditions you can safely hold the aircraft down by slight forward pressure and the rotate at about 75 KIAS confident that the aircraft will then leave the ground more or less instantly and stay up.