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While I was reading news, I came across this image of Marine One:

This is Sikorsky UH-60 Black Hawk

Marine One Citation of Image 1 enter image description here Citation of Image 2

On a closer look, I see there are two big exhausts just under the blades at the top of Marine One. And there is also a big wing at the end of Marine One.

I know I would be wrong, but I am not sure about it: I thought these two things are inter-related to each other in case of rotor failure, i.e if the rotor fails then the exhaust would pump out air backwards like a blast giving it forward thrust, and the wing at the end would help it in direction or upward/downward thrust balance (just like in F1 racing cars). Essentially making it work like a plane for some time until it lands safely.

I tried searching about it, but could not get information about it. I did come across an older Marine One image whose exhaust is too small and is at the side rather than at the back and this does not have a wing at the back:

This is Sikorsky SH-3 Sea King

enter image description here

Citation of Image 3 enter image description here Citation of Image 4

I have 3 questions:

  1. Why is the exhaust at the back of new Marine One so big now?
  2. Why is there a wing at the back of the new Marine One ?
  3. What would happen if rotor blades of Marine One fail ?

Citations

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    $\begingroup$ Welcome to Aviation.SE! If the rotor blade fails (comes off/breaks), the helicopter will crash. The exhaust nozzles do not provide lift and the tail doesn't either. I think somebody should be able to give you a good answer in detail. $\endgroup$
    – Ron Beyer
    Jul 17, 2017 at 17:35
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    $\begingroup$ See en.wikipedia.org/wiki/…. $\endgroup$
    – Fred Larson
    Jul 17, 2017 at 18:05
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    $\begingroup$ Meaning if the rotor of Marine One fails, the presidential line of succession comes into effect. $\endgroup$
    – Fred Larson
    Jul 17, 2017 at 18:14
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    $\begingroup$ This helicopter is a (slightly modified) black hawk. You can now search what you want about this helicopter and ask questions about specific parts of it (either the regular version or the one for the US president) $\endgroup$
    – Manu H
    Jul 17, 2017 at 18:25
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    $\begingroup$ You might get some info on the "big wing" here: aviation.stackexchange.com/q/25308/520 $\endgroup$
    – Fred Larson
    Jul 17, 2017 at 18:56

3 Answers 3

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No helicopter can fly if the blades fail. The overwhelming majority of the lift produced, required to counter gravity, is from the blades. There is some lift from lots of other parts of the helicopter but all combined, nowhere near enough to keep it flying. The blades are also required to manoeuvre the helicopter.

It is also most probable, and this what usually happens, that if one blade fails, or is lost, the resulting imbalance in the heavy, fast rotating rotor assembly leads to instant breakup of the aircraft.

The wing at the rear is called an horizontal stabiliser and its job is to push the tail up or down, depending on the load and speed of the helicopter, to keep the fuselage more or less level throughout the operating range of the craft.

Marine One would simply plummet if the blades failed.

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    $\begingroup$ Okay.. Thank you. My question has gained some negative feedback. How can this question be improved so as to help the community ? Or shall I delete it because this is just another stupid duplicate question. $\endgroup$
    – GypsyCosmonaut
    Jul 17, 2017 at 20:21
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    $\begingroup$ Neither. I don't know why it's been downvoted and it's not a duplicate. Quite simply, no-one has asked this "obvious question" before so it belongs here. I am very much of the school there are no stupid questions; perhaps not right time, right place but if this is not a place where someone who does not understand can ask these questions, then where is? +1 from me to help the natural balance of the interwebs. $\endgroup$
    – Simon
    Jul 17, 2017 at 20:36
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    $\begingroup$ Blade failures are one thing that is not trained, discussed or thought about since every helicopter pilot knows, unless they are slow and close to the ground, that they are dead if it happens. Not nice reading, but this is typical of what happens. P.S. you really need to edit your question to provide the attribution to the images. We are big on crediting sources here and it's possible some people might downvote because of that. $\endgroup$
    – Simon
    Jul 17, 2017 at 20:40
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    $\begingroup$ @FreeMan Ah, yes, I was only reading the summary. I think this accident report is accessible without restriction. $\endgroup$
    – Simon
    Jul 17, 2017 at 20:59
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    $\begingroup$ @Cloud Engine failure and rotor (or blade) failure is not at all the same thing. $\endgroup$
    – user
    May 22, 2018 at 12:59
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To answer the other questions...

Why is the exhaust on the Blackhawk so much larger than the Sea King? One reason is - the Blackhawk has larger engines, 1500hp as opposed to 1200hp. The primary reason, though , is dispersing the exhaust heat, making the Blackhawk a harder target for heat seeking missiles. Note the fairing above and around the exhausts, also part of the heat disperson system.

Why does it have a wing on the back? This Q/A thread suggests it is tied to airspeed, not the cyclic, for stability reasons.

As for a main rotor blade failing... yes, you're pretty much dead if that happens. One reason helicopters cost so much more per hour to operate than aircraft is the more rigorous maintenance and inspection schedule, especially on the main rotor and blades. Fortunately, main rotor failures outside of the blades hitting something due to pilot error are extremely rare.

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    $\begingroup$ (o.O) Ohhh..., heat dispersion..., I see... Nice.. $\endgroup$
    – GypsyCosmonaut
    Jul 18, 2017 at 14:13
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    $\begingroup$ According to Wikipedia, the current generation UH-60L's have two General Electric T700-GE-701C turboshaft engines, producing 1,890 hp each. en.wikipedia.org/wiki/… $\endgroup$
    – SnakeDoc
    May 22, 2018 at 16:00
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I served as a Helicopter Crew Chief on a Sikorsky H-34 helicopter in Vietnam and I agree that blade failures are incredibly rare on properly maintained aircraft.

On most helicopters the main structure of the blade (spar) is hollow and contains pressurized gas — usually nitrogen. Before each flight, the Crew Chief and Pilot check a gas pressure indicator on each blade. If a crack develops in the blade, the gas will leak out and likely indicate a problem before there is a failure.

Military helicopters are designed to work very hard and handle a great deal of stress. Marine One probably has a very easy life compared to its counterparts in the rest of the world. I’d say it is a very safe aircraft.

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