# Tag Info

61

When you are breathing, oxygen ($\mathrm{O}_2$) and carbon dioxide ($\mathrm{CO}_2$) are exchanged between the alveoli in your lungs and the environment. This gas exchange is based on diffusion, which means the partial pressures of each gas involved will move towards equalization: Henry’s law states that the amount of a specific gas that dissolves in a ...

60

I'm a controller, not a pilot, so I can only speak from my own perspective. What we are taught in ATC school is that many pilots are reluctant to use the word mayday because they feel it might escalate a situation unnecessarily and potentially create a lot of paperwork. I guess, mentally, it seems like calling mayday is a significant, irreversible step ...

42

To supplement Jimmy's answer, if they had to land right away, they could have; it just would've resulted in an overweight landing being recorded, and which on most airliners triggers a special inspection of the landing gear and its attaching structure, and if nothing is permanently bent or cracked or broken, you are good to go. An overweight landing in ...

34

Wake Island has had aircraft divert there before, as it serves as an ETOPS diversion airport. Per the remarks on AirNav and the NOTAMs: RSTD: VERY LIMITED OPERATIONS STATUS, AVBL FOR EMERG LDG AND MIN PRIORITY TFC. TRAN ALERT: SVCG FEES RQD. TRAN SVC HRS 2000-0400Z (0800L-1600L) TUE-SAT. CLSD SUN, MON, HOL. FUEL: FLIGHT CREW REQUIRED TO ASSIST ...

33

For the US, the FAA's Intercept Procedures list several things a pilot can indicate without radios: Acknowledge instructions: rock wings, flash nav lights Unable to land at indicated airport: flash landing lights Cannot comply: switch all lights on and off at regular intervals In distress: switch all lights on and off at irregular intervals

32

The answer is no, not totally, but it would really slow things down. I don't think anybody knows the precise answer because only flat water ditchings seem to result in the airplane stopping in the water in one piece (such as 1549 and a similar one in Malaysia) and flat water incidents (like Malaysia and some airport overruns) are usually in shallows where ...

26

Saying mayday or pan-pan is only recommended, and repeating it three times is merely preferable. That statement applies to USA, and ICAO in general, by referencing both the AIM and AIP; and ICAO's Annex 10 Volume 2, respectively. Let's begin with the basic (from the linked AIP): A pilot who encounters a distress or urgency condition can obtain ...

24

Where I work, we have to stay in the tower for 15 minutes after the last departure in case they need to return. To my knowledge, there are no international regulations about this, so the rules may well be different from place to place.

24

I think the characterization that it's "too heavy to land safely" is erroneous; the fuel burning is probably out of circumspection and to allow for a better safety margin. The runway length may also be beyond the landing field length and/or the brake energy limit of the heavy weight, so decreasing weight would add to the safety if immediate return to land is ...

23

Not just departures. Assume an emergency takes place en route, and that airport with the closed runway is the only one available within a big area. What now? There are two things to distinguish: Operating hours Temporary surface (runway) closure If the airport is already 24/7, the tower will remain staffed. If not, once the airport closes on schedule, ...

23

The situation in a high altitude depressurization is different because: The air in your lungs is now "FL500 air" - i.e. the pressure is about 0.1 atmosphere. This means that the partial pressure of O2 (ppO2) is about 0.021 atm, instead of 0.21 atm. Oxygen will rapidly diffuse out of your blood and into your lungs, and your brain will very soon not have ...

20

An interceptor can gain cooperation from an intercepted aircraft by means of a show of force ie forming up on the target’s 6 and 9 o clock position and attempting to contact them on the emergency radio channel. If the target remains unresponsive or refuses to comply, a fighter will often cut in front of its flight path in afterburner, causing the target ...

17

In theory, yes. In practice, no. FAA regulations (specifically, 14 CFR 25.801(d)) require that, under reasonable water-landing conditions, an airplane must remain afloat long enough for the occupants to evacuate. Most airplane manufacturers don't actually test the ditching performance of their aircraft, but instead rely on the clause of paragraph (c) to ...

17

Landing at a military base is not off limits to civilian aircraft but typically requires some pre-approval. In an emergency situation (and declared over the radio) most military facilities will be helpful. If you came diving in with out any radio announcements and on an apparent crash course the situation may not play out in your favor. But a stable glide in ...

15

Many years ago, I had an unexpected landing at a non-towered military base. I did not need fuel which made things easy. The base stored nuclear weapons, and we were escorted at all times, until we were able to depart. Security was annoyed, but polite. Since we did not leave the ramp, there was no paperwork that we needed, however we did provide the MPs ...

10

ICAO describes the following distress signals in Annex 2 (Rules of the Air): The following signals, used either together or separately, mean that grave and imminent danger threatens, and immediate assistance is requested: a) a signal made by radiotelegraphy or by any other signalling method consisting of the group SOS (. ...

10

The jet fighters could harass the small plane, to the point of making it very clear: You will not get much farther on this path! Note what happens when the F-14s fly under the Zeroes here: The Zeroes aren't waggling their wings. This is an upset - they are being flipped over by the wake vortex from the Tomcats. The ...

9

The simple answer is no, there are no "subclassifications" of emergency or urgency calls in standard aviation phraseology. In terms of priority, they are all the same; however, in terms of actions taken, there can be differences based on what caused the aircraft in question to make the emergency or urgency call. There's mayday (emergency), pan-pan (urgency),...

9

The hook is for emergency use at airports that have Runway Arrestor Systems. Lots of non-naval fighters have arrestor hooks for that purpose. Now, there is nothing stopping someone from landing an F-16 or any other fighter on a carrier deck and using its arrestor system, which works the same way. The main issues are the proficiency required to do it and ...

9

It is the advice of the FAA that you should be looking out the window quite a bit when VFR in the pattern. According to this AC related to traffic patterns: Collision Avoidance. The pilot in command’s (PIC) primary responsibility is to see and avoid other aircraft and to help them see and avoid his or her aircraft. Keep lights and strobes on. The use ...

8

Actually lost a tail rotor. On a UH-1 in 1971. Slung a blade, ripped off the gearbox, destroyed the driveshaft. Occurred at about 80 knots. Aircraft has a tendency to nose forward and obviously no yaw control. Control was very tenuous. Since you won't know exactly what's going on back there, suggest you autorotate. That's what I did. It was a normal ...

8

In the USA, when an airplane is in the air, it is governed by Title 14 of the Code of Federal Regulations, also known as the Federal Aviation Regulations (FARs). FAR 91.3(b) gives the pilot in command authorization to deviate from any flight rule necessary to meet an emergency: if that pilot needs to land on a road to meet an emergency, it is certainly legal ...

8

If you are confused somehow about your situation over an airport, and there are other aircraft around, head for empty sky away from the airport beyond the pattern/circuit and get reoriented. By empty sky, I mean if you think somebody might be nearby and you aren't sure where they are and don't have them in sight, identify a patch of sky where they're not, ...

7

Let's assume you started exactly with ICAO minimum fuel required (as explained in What are the ICAO fuel reserve requirements?): Taxi fuel Let's assume you used all of it at your departure airport. Trip fuel Used for the flight to the destination airport. Contingency fuel Let's assume this was used in a holding pattern at the destination. Alternate fuel ...

7

"Mayday, Mayday, Mayday" tells ATC (and everyone else on frequency) that you have an emergency, but it gives them exactly zero information about the nature of the emergency or what you need other than getting their attention and time on frequency. If you're in a portion of flight where you don't already have the attention of the controller, then adding "...

6

I can imagine a couple of reasons why ATC could tell the pilots to please land somewhere else even if they have an emergency All runways are closed, e.g. they are repaving the runway surface or when the snow trucks haven't yet cleared a thick layer of snow or the instrument landing system is inop and the visual conditions are not good enough, runway flooded ...

6

One example of a helicopter bailout that I am aware of was the ditching of a USAF Sikorsky HH-60G during the infamous "Perfect Storm." After several failed attempts to refuel from a tanker in the extreme weather the pilot decided to ditch. He hovered to allow the other occupants to bail out, but he was unable to bail out himself as the engines flamed out ...

6

The F-111 capsule was great and I always felt glad to have it, especially at high speed. However in my 8 years flying in it, I'm not sure that the ejections I knew about were much different statistically. The fatal outcomes were late, upside down in a rapid roll or otherwise outside the parameters and the successful ones were mostly okay with a few non-...

6

No, the F-16 cannot "carrier land", even with the tail hook. The Air Force jets (aside from any that are shared with the Navy) have tail hooks only for emergency purposes during landing, or securing the aircraft during engine run-up testing. The tail hooks are not designed to arrest an aircraft like it would for a carrier landing, the land-based arresting ...

6

Yes the F-16 would be able to land on a carrier however it would most likely break/damage the landing gear and other components because it's not built for it. I am only assuming this, but I believe the net as shown in the picture could catch several non-naval aircraft including a F-16.

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