Emergency Descents

[Bernoulli]

I am working on a lesson plan for emergency descents for both the Cessna 172 and the Piper Arrow II. I know the FAA no longer tests for emergency descent but there are a few select reasons why a pilot might want to get down ASAP. So I'd like to teach the proper technique to my future students if they are interested. For most of my flight lesson plans I have been referring to the specific airplane's POH's and the FAA Airplane Flying Handbook. This has worked well so far... but not with Emergency descents. The FAA Airplane flying handbook does not cover emergency descents. The Piper Arrow II POH does not cover them either. The Cessna 172 POH only covers emergency descents THROUGH CLOUDS... not in VFR which is how I plan to teach them. I have found that there is a wide variety of ways pilots have been taught. Here are five of the most common I have heard about:

1. Chop power, slow to Vfe, get dirty & make a steep turn maintaining Vfe

2. Chop power, slow to Vfe, get dirty and stay level while pitching for Vfe.

3. Chop power, stay clean, slow down and make a steep turn

4. Chop power, stay clean, pitch to stay just below Vne but only do this in smooth air.

5. Chop power, stay clean, slow down and put plane into a forward slip.


My question is, if you were taught how to do an emergency descent in either a Cessna 172 or a Piper Arrow II how were you taught, because I sure can't find any real documentation on the subject from the legitimate sources... maybe that is why the FAA no longer tests for it. Oh yeah... I do have an old PTS that has the maneuver in there but it does not indicate anything about how to perform the maneuver. Any comments would be greatly appreciated, and as always, I thank you in advance.

 

[BoDEAN]

Power to idle
Pitch for the bottom of the green arc, no more than 30 degree bank, and start a turn.
Once you get down to say 2000 or 3000, recover, and do your ABC's and prepare to put her down in a field.



You're saying FAA doesn't test on this anymore?

 

[Timebuilder]

If the plane is on fire at a good altitude, I'll push the nose over and stay below vne to snuf it, and slip to about 2,000, looking for the field on the way down, complete the checklists, and get it on the ground.

 

[Bernoulli]

From what I can tell the FAA does not test for the emergency descent on any checkrides. If you do have a procedure that you use for either a Cessna 172 or a Piper Arrow II please specify which aircraft. Cheers.

 

[BoDEAN]

150/172 was what my response was refering to.

 

[Northern Lights]

There was a great article in "Aviation Safety" a couple of years back on E- descents. If I find it I'll scan it and send it to you.

The main point was "GET DOWN. RIGHT NOW!" If you delay, that extra minute might be the difference in crashing or walking away.

In the Arrow, put Gear down, pitch for Vle and bank it to 45 to get it started down. The bank will help you dump the vertical lift component and get you going down hill faster. Spiral down or roll out and hold Vle 'till you need to transition to landing.

Also consider combining emergencies.

For example in the arrow:
Give an electrical fire. Since there is/was a fire you need to initiate an emergency descent. Because you have turned off the battery and alternator for the elec. fire, you now need to do an emergency gear extension.

So there you can do 3 emergencies in 1!

 

[huncowboy]

I am not a CFI yet but tha way we do it in a PA44 and the 172RG:

Power to idle
Extend gear (slow down to limit if needed)
Verify Flaps Up and Cowl Flaps Closed
Mixture Rich
Prop Forward
Pitch down to Vno
Make shallow bank turns as you descend to avoid traffic and announce your position, and make a simulated emergency call on the radio.

Engine fire for us is different. Cowl flaps would stay open and the checklist would concentrate on cutting the fuel.

On the 172 or 150 I guess it would only be:

Carb heat on
Throttle to idle
Mixture Rich
Verify flaps up
Pitch to Vno
...annuonce, call emergency shallow turns etc.

I think flaps would always(?) stay up because your priority is to get down ASAP, tuhs you do not care how much you travel forward while doing it. With flaps down you can not overfly Vfe which is slower than Vno. I think flaps up will get you down faster.
But I am not a CFI yet and I only have some 200TT.

 

[Bernoulli]

I think flaps would always(?) stay up because your priority is to get down ASAP, tuhs you do not care how much you travel forward while doing it. With flaps down you can not overfly Vfe which is slower than Vno. I think flaps up will get you down faster.
But I am not a CFI yet and I only have some 200TT. [/B][/QUOTE]


That is a good point. I would think the opposite though. Flaps allows you to be only as fast as Vfe. The slower you are going the less overall lift that wing is generating. If you were dirty and put the plane in a 30 to 45 degree bank the vertical component of lift would decrease and you would sink like a rock. If any one else has an opinion on whether an emergency descent should be done with or without flaps please comment.

 

[hydroflyer]

Likely the reason why you have not found anything specific is because the type of descent will be dictated by the emergency and landing area. If you have a nice field/landing area directly under you, a forward slip wouldn't be the best choice because it would take you in a straight path away from the site, in that case a steep spiraling dive would be better. Of course if you were lined up on a "final" for a nice site but high, then the forward slip may be best. A combination of a steep spiral trasitioned into a forward slip is also an option. I used to teach both, along with the high speed clean dive for engine fires, as it all depended on the type of emergency calling for the descent.

As far as flaps go, you may just have to try out different methods of descents with and without flaps to see which will produce the greatest descent rate while keeping withing V-speed limits. I can't remember for sure, but I thought you could descend faster in the 152/172 without flaps, however recovering to a speed that would permit you to lower the flaps for landing could be a little harder. I thought in the RG we would use 10 degrees of flaps since they could withstand higher speeds in that setting, yet still cause enough drag to let the rest out when it came time to set up for landing.

One word of caution when you are practicing emergency descents in the Arrow or Seminole, remember your max gear up speed! You can fly at a much faster speed with the gear down then you can when you are retracting it, so when you and your student go to recover from the descent, watch that carefully.

 

[flytheblue]

BoDean-
The FAA took out the emergency descent from the PTS back in 2002, when they changed the Commercial standards and tweaked Private. The ED is still required for multiengine though. I still teach the ED because it's still handy and you might need to use it as a way to get down quickly if you have a fire or something.

 

[VNugget]

Engine fire for us is different. Cowl flaps would stay open and the checklist would concentrate on cutting the fuel.

On the 172 or 150 I guess it would only be:

Carb heat on
Throttle to idle
Mixture Rich
Verify flaps up
Pitch to Vno
...annuonce, call emergency shallow turns etc.

Why mixture rich? If you want to cut off the fuel, wouldn't you select idle cutoff? Not surprisingly, that's what my 172N POH calls for.

 

[huncowboy]

Engine fire for us is different. Cowl flaps would stay open and the checklist would concentrate on cutting the fuel.

On the 172 or 150 I guess it would only be:

Carb heat on
Throttle to idle
Mixture Rich
Verify flaps up
Pitch to Vno
...annuonce, call emergency shallow turns etc.

Why mixture rich? If you want to cut off the fuel, wouldn't you select idle cutoff? Not surprisingly, that's what my 172N POH calls for.

Actually I was not referring to the fire scenario in that list. I just continued with how the ED would look like in the 172 and the 150. It is confusing in my post because I put that comment inbetween the two about engine fire. That list in the quote is the ED checklist for the 172 and 150 not the engine fire checklist.

You are correct, engine fire would start with:

Fuel selector (or valve) off
Mixture cut... etc

my bad

 

[VNugget]

Oh.

 

[Bernoulli]

BoDean-
The FAA took out the emergency descent from the PTS back in 2002, when they changed the Commercial standards and tweaked Private. The ED is still required for multiengine though.

Does anyone know why the FAA stopped testing for the emergency descent for the private?

 

[Clancy]

no clue

 

[COOPERVANE]

I noticed several people saying to "lower the gear and pitch for Vle"

but if you are on fire $CREW vle. Get it down and worry about tearing up the gear doors later.

 

[TZRav8r]

Right on! To heck with Vle. If I truly had an emergecy in a single and wanted down as fast as possible, the gear doors can fend for themselves! In a 172, I would guess a flaps up, power off slip would be the best bet. Give it a try though. Flaps up, flaps down, Vfe, Vle, Vne, (refer to your POH) whatever, give it a shot and see what gives you the highest descent rate (VSI). The Slips and higher banked turns will give you greater descent rates than straight and level, however newer pilots, especially in IMC will most likely get themselves in more trouble. Strait ahead may be a better option, given I'd rather crash wings level at40-50 knots than 45 degress bank at 70 plus! Knowing your capabilities and limitations and having a plan before you need one is the key!

 

[Alchemy]

I was given an emergency descent situation on by my private and commercial checkrides.

On the private, when the examiner told me to execute an emergency descent, I pulled the power to idle, put on carb heat, put full flaps in and descended at about 2000 fpm at Vfe.

The examnier didn't like this. He took the controls and said, "No, this is how you do it". Raised the flaps and pointed it toward the ground at Vne. Luckily he didn't have enough contempt for my technique to bust my checkride over it.


On the commercial, I was given "smoke in the cockpit". So I pulled the power applied carb heat, kept gear and flaps up, pitched down to Vne and turned toward a nearby airport. The examiner didn't have any problems with this.

So.....I would say clean up the airplane and descend at an airspeed close to Vne in calm air, Vno in rough air. Don't bother with the turning/spirals unless you're directly above the place where you're going to land.

Corrected to replace "Vso in rough air" with "Vno in rough air".

 

[avbug]

How about a different perspective?

Everybody gets trained to run screaming into the hills when they see fire. It's almost pavolvian in nature. Fire = panic. How many who flip out and make a blind rush for the ground with one of these heroic emergency descents has ever really had an emergency that requires it? How many have just been told that's the way to go, and decided to blindly accept it? How many who train this way have ever had an engine or cockpit fire, or other structural fire? Very few hands, I'm willing to bet.

Rush to the ground. Get down right now. Land in the middle of a big wheat field, set it on fire, too. Burn to death in a grass fire...the leading killer of people who die by actual fire (as opposed to asphixiation and smoke inhalation). Force a landing, away from help, away from medical support, away from crash rescue, just to get to the ground and check that box. Great idea, don't you think?

I don't.

Then again, based on experience with cockpit fires, structural fires, structural failures, etc...I think there's a lot of benifit to be had in dealing with the problem, flying the largest piece left (as they say), and getting to help. The chances of being in a situation that requires a downing of the airplane right HERE and right NOW are very small, compared to the liklihood that you really ought to get the airplane to a place where you can get help.

One of my favorites is what people want to do if someone has a heart attack. Get to the ground, he's having a heart attack. Let's make an emergency descent, land in that field or that parking lot, right over there! What a hero. Got her to the ground. No way to call an ambulance, no ambulance nearby. Passenger dies, anyway. But a real hero for getting to the ground quickly.

Most inflight fires can be put out. Few are nearly as bad as you might think. Fire is NOT a panic button. It's a chemical process. It has rules. It can be dealt with. It is not the four horses of the apocalypse come to get you. Calm down. Sit on your hands, remove the fuel source if you can, and think about it for a few minutes. Point the airplane toward help, and go there. Certainly some circumstances may occur that warrant landing right here and right now, but a much, much greater chance exists that you can do better by flying to help. Use that speed and altitude to get somewhere useful.

I had a suicidal person who ended up next to me when I was flying a trip in a light twin, once. Didn't find out until we were enroute and far from anything. I had a passenger riding in the right seat of a twin experience a heart attack one night, while we were flying in a fairly remote area. Last night I had a passenger that became a little nutty, and got arrested. In between I've had wings crack completely through, engine fires, fires in the cabin and cockpit, an onboard explosion that removed approximately 20' of the underside of the airplane, etc. I've had the cockpit fill with a thick hydraulic mist. Complete hydraulic losses. Various other structural failures, etc.

One common thread among all of them...rushing to the ground wouldn't have accomplished a darn thing. Each was something that was best dealt with in an orderly fashion, as best could be managed at the time...not any of them required an "emergency descent."

Certainly a pressure loss at altitude should be considered a candidate for an emergency descent. With a TUC that could be as low as a few seconds, getting down ASAP is warranted, and makes sense. Because it's the altitude loss to denser air that's the goal. Not so with emergencies or problems at lower altitudes. Getting lower serves no great purpose; the only real priority is getting to safety. If that means planting the airplane on a rocky flat or into a hillside, the effort becomes counterproductive. Especially if the airplane really does have a fire or medical emergency. My perspective, as a firefighter (one hat), and a pilot who has experienced these things...all of them.

When I was just out of high school, I went to work in Kansas doing ag work. A pilot there experienced a burst hopper ferrying enroute to a field. He had 9 lb parathion on board; nasty stuff. An organophosphate similiar in nature to Vx and other such agents, but potentially a whole lot more potent and concentrated in it's liquid form. A single drop on the tongue can kill, in concentrate, before mixed. As an ag pilot, he understood this, and knew the implications. Good a cause as any for an "emergency descent," right?

At a grand altitude of 500', he made such a descent, successfully getting stopped on a narrow two-track road atop a dike. Adjacent to the dike was a ditch full of water. He needed to get on the ground, get out of his clothes, and get in the water to minimize absorption. He did get landed safely, and got the airplane stopped. He pulled the emergency canopy release handles and bailed out. He made a beeline for the ditch. He would have probably made it if he hadn't been killed by the spinning propeller.

Fast hands kill, and there's no sense making a bigger emergency for yourself than already exists. Rushing to the ground sounds very heroic...but before you do that, stop and think. What is it that you hope to accomplish, and what is it that you're really accomplishing? If the two are the same, then continue. If not, if using that altitude and forward speed to get to help is truly a better option (it almost always is), then don't throw away the opportunity.

If things are really so serious that you need to be on the ground right NOW, then you don't need an emergency descent. You need a parachute.

 

[mar]

As usual: a thoughtful post, but...

Avbug--

Sir, I'm with you on *most* of your thoughts here, but I must disagree on one point.

The longer you're on fire the more you've compromised the strength of the airframe structure.

I'll submit three accidents. Each a different category of airplane. Each event took less than 15 minutes to turn critical.

--NAC DC6: Number 3 engine fire over Russian Mission. Six minutes from fire bell to right wing separation while on base leg.

--Canadian Metroliner: Wheel well fire. Twelve minutes from first wing-overheat light to wing separation on final approach.

--Swiss Air 111: Electrical fire. Less than 15 minutes from first detection of smoke in the cockpit to loss of all flight instruments over North Atlantic while dumping fuel.

The bottom line is you may not have the luxury of making a traffic pattern. That airplane needs to be on the ground.

Of course every situation is different but that's why we study different accidents.

 

[avbug]

No arguement, Mar. But we're not talking about the nicities of the traffic pattern. We're talking about having an emergency and getting on the ground right now...vs. getting to a runway with crash rescue, or close to shore...etc. Chances are that had each of those aircraft simply put themselves on the ground directly underneath the point where the emergencies first occured, or were recognized, they wouldn't have fared any better.

Radial engines are unique in certain aspects, in that fires can start which cannot be put out. That's typically true of most oil fires. Bust a governor base, rupture an oil return line, punch a hole in the case or lift a jug and shed oil to the collector, and you may have a fire that can't be extinguished. A really hot one, and not one with a few pints of fluid, but 50 gallons or more. Certainly something to be considered serious.

You can certainly understand, however, the potential ramifications for getting your DC-6 stopped in the terrain you typically overfly, vs. getting to help. You're also in situations personally where help may be hours, days, or weeks away...something not generally experienced in the lower 48. In many cases, there really is nowhere for you to go. The same may apply to a transoceanic operation.

Still, the fact remains that to get down, one has a certain amount of time. One can use that time getting to a spot directly beneath the airplane (seldom a wise choice), or one may point the airplane in the direction of help and get there.

The basic rule of thumb on a burn (and this is very general) is that it doubles in size every minute. That's with no intervention. Alter the burn conditions and the rule is changed. Cut off fuel, alter airflow, etc, then the rules change.

While it's dramatic to think that a fire could become unmanagable in 15 minutes, it's also realistic...but it's also worth remembering that in many such cases, the outcome would have been the same no matter what course of action was taken. Therefore, in such situations, there's no value in pointing to the event as a need to do something different than they did...if nothing would have saved them (and chances are, nothing would), then we can only look at the best options for the next time around. In virtually all cases, the best option is getting close to help.

One needn't fly a traffic pattern; one might land downwind straight in. One might even belly in short of the runway, being closer to crash rescue than one would have been before...but anything that can be done to enhance survivability and a successful outcome is important, and necesary. It's just that very seldom is that "anything" an emergency descent to a forced landing.

Pilots have had it drilled into them time and time again, and in most cases, it's unwarranted and wrong, and based not in reality.

When looking at examples of hot wings going bad fast, look at the transcripts for the last Shuttle failure. A rather extreme example...but there's not a darn thing they could have done to mitigate that, including trying to get down any faster. It really wouldn't have mattered what they did. In such a case, the crew actions become a mute point; the outcome was decided in many of these cases long before the crew took action.

The situations to which I refer assume that the crew still has a fighting chance.

 

[mar]

I gotcha now

I understand your point better now.

You're saying if you're on fire the first thing you should do is point the airplane towards the best chance of having CFR...rather than just dive for the ground and crash there anyway.

It's a good point.

It reminds me of a story I heard when I first got out to the bush.

A new pilot gets caught outside the Class Echo surface area in the fog and freezing rain. He's icing up pretty bad but the tower isn't reporting the required 1sm visibility for SVFR ops. Thus, the new pilot diverts to a nearby village and crashes due to airframe icing. He broke his back and is paralyzed.

The moral of that story is: If you're gonna crash an airplane do so at an airport with CFR and a hospital--regardless of the legality.

Perhaps the secondary lesson is: This was another accident that could've been avoided by simply declaring an emergency and making the SVFR approach anyway.

I admit I digressed but the thread sort of drifted into using our best judgement. I hope it's useful to someone.

 

[huncowboy]

Avbug,

I am sure we all appreciate you sharing your knowledge with all of us who are not experienced, or not as experienced as you are. I sure do and sometimes I just don’t know where the hell you get all this info from. Like the other thread on the procedure turn. It is OK with me also that you remind us on that experience level gap between you and most of us. But if you don't mind I won't put a cockpit on fire just so I can experience it and I also will not kill my engine so I can make a real power off landing. Just kidding.

Anyways about getting down faster. My >>>vote<<< would be that if you compare descent with or without flaps, the result would be that you can get down faster without flaps. You can do a lot more than 2000 fpm if you dive 30 degrees nose down. I always thought flaps are there to slow you down while you descend. But than I am not experienced nor do I have facts to back it up but if I think (try to use common sense) of a plane going nose down 90 degrees, and another nose down 90 degrees with flaps... probably the one with flaps down will "arrive" later.

The original thread started as an "emergency descent" not as an "engine fire" thread although I admit we have always been thought to get it down fast if we have a fire, as long we can't extinguish it. I myself can't think of a single reason why I would want to have the 172RG... ohhh wait!... the mighty PA44 down in a hurry other than mother in law in the right seat (not true actually I like my molo... lately) but I guess when we will “move on to better equipment”... like in 10-20 years... then I will figure it out. Until then I just do what the flight school and the FAA wants me to do.

 

[Alchemy]

Most flaps are designed to allow you to descend at a steeper angle without increasing your airspeed (when fully or most of the way extended). If you want to descend with a relatively high sink rate without redlining (eg landing approach) you should use full flaps, pull the power to idle, and consider a forward slip.

The flaps up, gear up, and Vne method will probably give you a faster sink rate in most planes. You will travel a greater distance forward (descent angle will be shallower) than the full flaps method, but measured in time, you would probably reach the ground faster.