14
votes
A plane is flying at constant velocity in equilibrium, then pitches up. What happens?
A step increase in elevator (which is then held) will first upset the pitching moment equilibrium of the aircraft -- the pitching moment will be non-zero. It will pitch nose up, increasing angle of ...
- 5,659
11
votes
Accepted
PoH says airplane climbs steeper at higher weight. Why? How?
There are three stages to a short field takeoff over an obstacle- the ground roll, where the airplane accelerates to the minimum airspeed necessary to leave the ground, a period of further ...
- 10.1k
5
votes
PoH says airplane climbs steeper at higher weight. Why? How?
This is a very interesting question involving an amphibious aircraft, the Super Petrel LS.
Building on the answer by Chris, we see that take-off from water would involve "muddy/soft" field ...
- 18.7k
4
votes
What would the effect be of flap deployment on a UAV such as the Reaper or Predator?
the climb performance is usually worse with flaps extended
That depends which parameter needs to be maximized. If you want to climb as steeply as possible, flaps will definitely help. If, however, ...
- 228k
4
votes
Does cruise speed depends on rate of climb?
Rate of climb and cruise speed are unrelated.
Once a climb is completed, and an aircraft levelled out, speed will be increased until the desired cruise speed is reached and then thrust adjusted to ...
- 31.1k
3
votes
Does optimum IAS for climb vary with altitude?
Your equations aren't quite right. For example, you use IAS where CAS is intended. And drag power is V D, not V D / W. (Energy is force times distance and power is force times velocity.) Additionally, ...
- 31
3
votes
A plane is flying at constant velocity in equilibrium, then pitches up. What happens?
The increase in angle of attack increases the lift and drag. The airplane will begin to climb. If the elevator control is small enough, and the pilot continues to hold it in without adjusting, the ...
- 10.1k
3
votes
Accepted
After the phugoid mode subsides, in the steady state, why is there a small increase instead of decrease in the flight path angle?
Before the step change of the elevator the aircraft was in quasi-static stable flight: flying at a constant horizontal flight path angle ($\gamma = 0$) and no logitudinal acceleration.
After the step ...
- 81.7k
2
votes
Helicopter total power required: zero wind speed while climbing --vs-- down wind speed while hovering
Yes, the power required to hover in a 100 ft/min downdraft is the same as the power required to make a 100 ft/min climb in calm air, all other things being equal. And yes, the helicopter that's ...
- 12.8k
2
votes
A plane is flying at constant velocity in equilibrium, then pitches up. What happens?
No weight (mass) is added. Assuming the elevator deflection is constant, this is what will happen.
AOA will increase, causing an increase in Lift and Drag.
The increase in Lift, (greater than the ...
- 5,556
1
vote
Accepted
Determine Vx and Vy from other climbing rate datas
Since you have only one data point and no other information about the airplane, it is impossible to calculate the climb rates exactly. It seems your data point is neither at best climb angle nor best ...
- 228k
1
vote
Determine Vx and Vy from other climbing rate datas
While there may be only a few degrees difference in angle of climb between Vx and Vy, let's see what those few degrees mean.
The easiest way to determine climb rate at Vx and Vy is to actually fly it.
...
- 18.7k
1
vote
How is Vx speed and Vy affected when climbing?
Both Vx and Vy vary somewhat by density altitude. Check your POH. It should have a table.
It doesn't vary much, though. Somewhere in the neighborhood of 7 kts per 10,000 feet.
- 27
1
vote
How is Vx speed and Vy affected when climbing?
I assume you ask for a piston-powered airplane with constant speed propeller. Next, I assume you want those speeds as IAS, so you need not correct for density effects. Then the grah below shows the ...
- 228k
1
vote
How is Vx speed and Vy affected when climbing?
Yes the speeds would change-- because they must converge at the aircraft's absolute ceiling, where no more climbing is possible. Vy (best climb rate speed) decreases more than Vx (best climb angle ...
- 21.4k
1
vote
How to calculate the climb performance of an A320
Most airlines have the NavBlue FlySmart software on a pilot tablet to calculate performance.
A rough way to calculate this is to use the MCDU. Convert your ft/min climb requirement to ft/nm.
$$ \frac{...
- 11
1
vote
How to calculate optimal flight climb angle?
Did I do something wrong?
No, if you have no thrust limitation, your result of a vertical climb is correct. Rockets ascend that way initially while air is dense to minimize the energy expended.
On ...
- 228k
1
vote
How to calculate optimal flight climb angle?
The optimal flight rate of climb angle can be derived from Vy.
Basically, at Vy, one flys the plane at optimal angle of attack and optimal thrust output.
As we have learned, lift is less than weight ...
- 18.7k
1
vote
Is the Common Route, either of a SID or a STAR, related to the Runway Transition (climb phase) or the Enroute Transition (enroute phase)?
This took some digging.
There seems to be some mixing of the terms in the question, using different publications, mixing between STARS and SIDs, and maybe neglecting to read the textual route ...
- 2,574
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