Questions tagged [descent]

Use for descents in general, else use [approach] or [landing].

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The role of accurate DES FORECASTS for descent planning in VNAV, during the latter stages of an approach

Giving an accurate set of criteria in the “DES FORECASTS” page of the FMC helps produce an accurate descent path. Typical Descent Profile, Vertical Path Adjusting the “TAI ON/OFF” (Thermal Anti Ice), ...
7 votes
2 answers
507 views

Is it realistic for a WW2 aircraft to dive to extinguish an engine fire?

In the film "Memphis Belle" there is a scene in which the titular plane is successfully put into a steep dive in order to extinguish an engine fire. This may have been the inspiration for a ...
1 vote
0 answers
46 views

Are Runway Profile Descent charts available to non-121 carriers? If so, where can I find them?

AIM 5-4-2(c) says: When crossing altitudes and speed restrictions are issued verbally or are depicted on a chart, ATC will expect the pilot to descend first to the crossing altitude and then reduce ...
0 votes
0 answers
95 views

IDLE Factor determination

The Flight Management System (FMS) utilises the Idle Factor to modify the computation of the vertical profile whilst descending. During this phase, the FMS calculates the vertical profile and ...
0 votes
3 answers
94 views

How does changes in Power vary the aerodynamic forces on an aircraft?

When we make changes to the Thrust by adding or removing power. In what way does it affect the other forces? As Power controls Rate of Climb or Descent of an aircraft, How is it acting on the other ...
8 votes
1 answer
2k views

How can a pilot fly a descent angle of 4° in an A320?

Would any A320 pilot be able to share any tips regarding maintaining a descent rate for final approach of 4°? Of course this is in case of manual flying. I know we can use a descent rate of speed*5 ...
1 vote
2 answers
192 views

LFLL LSE VOR 35L Visual Approach

Was wondering whether someone could help me understand how to perform a visual approach (not using the VOR) specifically if I look at RWY 35L at LFLL. Airport elevation is 821 ft. It's a 3° GS ...
3 votes
3 answers
675 views

PA/APV Glidepath Descent and Obstacle Clearance Slope's lowest point determination

I am studying the US Terminal Instrument Procedures manual (TERPS) and as I was skimming through the guidelines about Sloping Obstacle Clearance Surface, I came across the image below from section 2-1-...
7 votes
2 answers
501 views

Autorotation Index: The more gravity, the better?

I have been working on helicopter design and autorotation for a while. An Index used for this is the so-called "Autorotation Index" Evan A. Fradenborugh derives it in this work https://doi....
4 votes
0 answers
196 views

Why did this flight descend way below usual path?

I flew on UAL2086 last night which is a regularly scheduled flight from KIAH to KLAS, this particular plane was a 737-900 - N79402. We took off early and had no issues until we arrived in Arizona when ...
9 votes
2 answers
1k views

What is the minimum altitude over Egmond aan Zee when landing at Schiphol?

I live in Egmond aan Zee which is about 36 km flight distance from Schiphol. It seems that aircraft fly over Egmond when there is a southerly wind so they can make a landing approach to Polderbaan ...
1 vote
4 answers
763 views

How do pilots know when they have to start the descent?

I am trying to understand how pilots do know when to start descending, I have read that mostly it is from the FMS information and ATC clearances (Aviationvector.com). And on some other references, ...
6 votes
4 answers
18k views

What is the maths behind the descent rate calculation?

The descent rate calculation states that descent rate is calculated by 'groundspeed / 2 * 10'. Another document stated that the ground speed should be multiplied by 5 (or more accurately 5.2) to ...
14 votes
3 answers
760 views

Why would the U2 descend more quickly with its engine on than off?

I was talking to someone who got to fly in the U2. He mentioned that the pilot said that a descent from 70k' would take two hours with the engine working, or three hours without. I have every reason ...
12 votes
3 answers
2k views

Are there aeromedical reasons to avoid too-rapid descent in hypoxia?

I recently watched this video: When the controller realized the pilot was hypoxic (at about 9m47s in the video) they said, Kalitta 66 if able descend and maintain FL260 ...
0 votes
2 answers
1k views

Delays between "50", "40", "30", "20", and "10" cockpit announcements

When a large airplane is about to land, the following announcements are heard in the cockpit: "Fifty!" (delay) "Forty!" (delay) "Thirty!" (delay) "Twenty!" (...
2 votes
4 answers
343 views

What is the decrease in power when a drone is in descent?

For a quad-copter, or a fixed-wing drone with quad-rotor formation, how much would the power of the motor decrease when a constant speed descent is needed to bring the drone back to the ground? Does ...
13 votes
1 answer
1k views

Does this Hawaiian Airlines descent look routine?

I was on flight HA 30 from Kahului to Seattle on Dec 19 2021 (Dec 20 Zulu time). FlightAware track log FlightRadar24 track log The descent looked anything but familiar. As you can see it reached over ...
2 votes
1 answer
483 views

How do flights fly on some special days when there are firecrackers bursting near the source/destination airport? [duplicate]

I mean there might be festive nights like New Year eve, when there is spectacular display of colorful firecrackers in the sky, but when there are flights descending or ascending near a city with an ...
5 votes
2 answers
969 views

Can the energy dissipated in a power-off descent be calculated and expressed in horsepower?

If the weight in pounds of an aircraft is known along with its sink rate in feet per minute at best power-off glide conditions, can the horsepower being dissipated by drag as the plane descends via ...
0 votes
0 answers
43 views

Assuming a descent at 250kt IAS and idle thrust, will the resulting ROD be higher at a higher GW, or lower? [duplicate]

I was recently told by a pilot that it works in inverse order: Keeping indicated airspeed steady, and using idle thrust, the rate of descent will be lower with a higher gross weight (and a higher rate ...
13 votes
5 answers
11k views

Why did my plane descend nose down?

I was on a flight recently and the plane started to descend normally etc. However one cabin crew member randomly announced "remember if we have an emergency landing please leave all your ...
3 votes
4 answers
693 views

What descent rate would be a "hard" landing in a Huey or similar helicopter with skids?

I would like to know what vertical descent rate a Huey or other helicopter with skids can land safely at. What would be considered a "hard" landing that would require air frame inspection? ...
4 votes
1 answer
567 views

Does the A320's FMC automatically adjust the rate of descent on a non-precision approach?

Does the A320's FMC automatically adjust the rate of descent on a non-precision approach? Like a back course approach for example if the distance to altitude is (or can be) programmed in?
0 votes
3 answers
855 views

What would the altitude profile for a typical airline flight look like?

It's hard to appreciate an aircraft's rates of change in altitude, in particular with respect to its travel through the mass of air, rather than over the ground, since the latter is affected ...
4 votes
2 answers
290 views

Are there more refined rules-of-thumb for Top of Descent calculation, than the simple FL x 3?

Forgetting the excellent capabilities of VNAV for a moment and reverting to simpler days, is there a rule of thumb to further refine the FL x 3 rule for Top of Descent calculation, when there are ...
1 vote
2 answers
405 views

Why is airspeed different in climbs and descents although the AoA doesn't change?

Here are the background facts: This excercise has the objective to familiarise the student with the slow flight characteristics. The steps are: 1)Establish straight and level, 90% RPM, 15 units AoA, ...
1 vote
1 answer
127 views

What would be the expected approximate ROD when descending at 250 kt IAS using LVL CHG at 10,000 ft, assuming a GW of 60t?

The question refers to a B737NG but I suppose most similarly sized airliners would show a similar ROD under the circumstances.
1 vote
1 answer
459 views

How does deploying flaps change the gradient and rate of descent?

My understanding is: Using the gradient formula "(T-D)/W x 100", we can see that with the deployment of flaps, the gradient would reduce (due to the drag added). And since Rate of Descent (...
2 votes
1 answer
4k views

What are the various thrust modes in the Airbus A320?

I was going through A320 AFM and came across Thrust modes. I was not able to understand why thrust is in thrust mode during climb and descent because we climb or descent with a constant speed. So ...
0 votes
1 answer
150 views

Descent of Light attack aircraft to loiter altitude

How do Light Attack Aircraft (LAA) such as the Embraer Super Tucano descend from their cruise altitude to their loiter altitude to be on-station above ground troops? I want to know the way these ...
6 votes
2 answers
2k views

Are there certification requirements for an emergency descent?

In case of emergency, an aircraft may have to descend very quickly. Is there some performance (L/D ratio with full spoilers, descent rate, ...) to be proven in the certification process for such ...
9 votes
4 answers
7k views

Is the descent performance of the PMDG 737-800 accurate?

I often fly the PMDG 737-800 (with winglets) in my home simulator and most of the time, I find it hard to slow the aircraft down for landing when I descend. Most of the time, I need to deploy the ...
1 vote
1 answer
502 views

Does a VNAV PTH descent need the Forecast Descent winds?

If VNAV PTH, contrary to VNAV SPD, maintains a given path angle, depending on the CI chosen, and not a given Speed, then in my mind winds shouldn't affect it, since they would only cause the Vertical ...
-5 votes
3 answers
333 views

How can I communicate an emergency de-pressurization descent to the cabin as a passenger?

Hypothetical scenario. I'm on a commercial airliner (A320) as a passenger, sitting by the wings. We are cruising at 32,000. The oxygen masks suddenly drop down and the nose pitches down heavily, ...
4 votes
3 answers
2k views

How far from the runway should a small plane start its descent from 5000ft?

I don't fly, don't have a clue. But one of the main characters in my book DOES: it's a Cessna 152, just him at 14 stone and a couple of small bags, all conditions are perfect and he's flown from about ...
0 votes
3 answers
888 views

What rate of descent would kill you?

I was watching a video where a plane an MD-82 descended 18,000 feet per minute and crashed into a mountain. The plane was not upside down/on its side/spiraling- it had about a 5 degree pitch up the ...
4 votes
1 answer
5k views

What is the difference between Level Change and ALT INTV during VNAV descent?

I'm confused between the two. During descent for 737 PMDG, I usually start a descent via ALT INTV, but sometimes the plane doesn't response to ALT INTV but responds to LVL Change instead. I need help ...
22 votes
6 answers
8k views

Is it practical to intentionally stall an aircraft to execute a fast, controlled descent?

An MD-11 had an onboard fire, but had to request more flying distance at least partly to execute a safe descent (and to dump fuel). It ended in tragedy. In another accident, an A330 descended 30,000 ...
1 vote
2 answers
425 views

Descend via STAR, after getting crossing restriction previously

The ATC issues "Cross BHAWK at FL240" initially. After few minutes, the ATC instructs "Descend Via FYTTE5 arrival". Should we comply with the crossing restriction at BHAWK, or the ...
1 vote
2 answers
513 views

Mushing glide vs forward slip sink rate

Source: Wolfgang Langewiesche - Stick and Rudder; An Explanation of the Art of Flying I ran across a mushing glide in Wolfgang Langewiesche's - Stick and Rudder; An Explanation of the Art of Flying ...
2 votes
2 answers
939 views

Can the VNAV Path angle be modified in a Boeing 737 NG?

In the Boeing 737 NG series, can the usual 3 degrees Path angle used for VNAV Descent be modified through the FMC to another angle?
1 vote
1 answer
900 views

What profile will a Boeing 737 NG follow after pushing the ALT INTV button?

If one uses the ALT INTV button during a Climb or Descent in the Boeing 737 NG on the MCP, what profile (Speed/Path) will the AP follow in such a climb and/or descent? Is it the same as programmed in ...
19 votes
5 answers
39k views

What is a rule of thumb for when to begin a descent?

What rule of thumb would you use for your airplane insofar as how far from your destination you would begin your descent given an expected straight-in approach and landing in no-wind conditions and no ...
18 votes
2 answers
5k views

Why does an airliner have a shallow descent when heavier, opposite to gliders with ballast?

Gliders utilize water ballast to, among other things, descend faster: But sometimes you need to get down fast: This is when water ballast is added. In airliners however, the heavier the plane, the ...
42 votes
8 answers
31k views

Why would a glider have water ballast? If it is trying to stay aloft without an engine, wouldn't it be better to be as light as possible?

So I was looking at the description of a ASW 27 B glider and ran across this statement: Two water tanks in the wing plus a further 35 liter tank in the fuselage enable the ASW 27 B to carry more ...
2 votes
1 answer
1k views

What is the physical experience of passengers in the cabin during an Emergency Descent?

I am not a pilot so please forgive any misuse of aviation terminology; I'm merely a person who is working hard to overcome a sudden and intense fear of flying. While working through a course to ...
7 votes
2 answers
329 views

When to start descent entering a racetrack under NORDO?

Scenario: I am flying in IMC, and communications fail completely. IMC persists up until destination, where I will be conducting the following instrument approach: I am flying direct to ZUNAD from the ...
1 vote
1 answer
208 views

Why might an instructor in a small aircraft choose to descend with a substantial yaw on a first lesson?

Many years ago I took an introductory free (+fuel) flying lesson in a dual-control small aircraft (instructor in right seat) at a small city's municipal airport. There was a third passenger in the ...
1 vote
1 answer
155 views

Does airspeed come into play with vertical speed, in terms of who will reach the ground first?

So let’s say there’s two aircraft, which are the same, and both are cruising at 28,000FT, the only difference is one plane is doing 260 knots and the other is doing 280 knots. If they both pitched ...