Porpoising leads to gear collapse accident

[bradp]

I always retract flaps as soon as all three wheels are firmly planted. I guess it's how we were taught. My CFI told me about other CFI's who disagreed with him but he didn't see any reason not to clean up the plane rolling out after landing. So that's the way I learned and what I practice

There are some models (some of the early Bo's for example), in which the flap switch and gear switches are eerily similar in form factor and have resulted in some snafus.  We have the benefit of human factors and ergonomic design in all the Mooney models in which the flaps and gear switches are notably dissimilar.  This is the reason why some CFIs teach don't touch anything until clear of the runway.  

[Shadrach]

8 hours ago, donkaye said:

If you really want to know the Pitch/Power relationship, the camaraderie of many like minded people, precision much greater than that required of the Instrument Rating, then acquiring the skill to fly formation should be on your agenda.  One hour of formation flying is like 4 hours of hand flying alongside  the most demanding instructor you have ever had.  Bring a large towel to wipe the sweat from your brow when a practice flight is over and debriefed.  Leave your ego at the door.

I've never questioned the usefulness, challenge or skill involved in formation work.  I have done some very limited formation flying, always with dissimilar aircraft, and it's not an exercise in comfort flying.  I'm sure some would come with the experience that I don't have.  I have seen the proverbial no flap, 90kt landing mentioned here several times and was curious about it as a practical matter...I big thanks to Mike for answering the question.  It appears the high speed landings are more a function of "caravan" missions than formation flying.  Outside of those conditions, I don't think the procedure has much virtue.  On the whole, Mooney pilot's are better at depositing their aircraft in the weeds at the end of the runway than they are at coming up short.

Edited February 10, 2018 by Shadrach

[Bob_Belville]

14 minutes ago, Shadrach said:

I've never questioned the usefulness, challenge or skill involved in formation work.  I have done some very limited formation flying, always with dissimilar aircraft, and it's not an exercise in comfort flying.  I'm sure some would come with the experience that I don't have.  I have seen the proverbial no flap, 90kt landing mentioned here several times and was curious about it as a practical matter...I big thanks to Mike for answering the question.  It appears the high speed landings are more a function of "caravan" missions than formation flying.  Outside of those conditions, I don't think the procedure has much virtue.  On the whole, Mooney pilot's are better at depositing their aircraft in the weeds than they are at coming up short.

There are those here with more Caravan experience and insight into the reason for no flaps, 90k on final than I have but I believe the main reason is to simplify the mixing of M20Cs, etc., and long body Mooneys in the air. Speeds are chosen for cruise (120k) and pattern (90k) that are well within the envelope of everyone. Also, bear in mind that routinely we're flying half way down the runway (to the dot) before touchdown which gives everyone time to bleed off to a reasonable, normal no flaps landing speed. We're not touching down at 90k. (Some long body jocks use one notch of flaps at that 90k final to fit in with our short bodies.)

It's really not that different from maintaining speed and landing long on a 10,000' runway to mix in as well as possibly at a airline hub drome. 

[triple8s]

9 hours ago, jetdriven said:

Having to “push real hard” on a go-around to avoid a stall is an inherently unsafe condition. It requires you to do something unnatural to prevent a stall. Airplanes are designed to fly approach speed while trimmed and to require light and normal forces to correct the flight path or land, or go around.  By trimming it full up to avoid pulling the nose up in the the flare, you defeat this safe, stable condition.  Should you get startled and firewall it, say to prevent hitting a deer, or do a normal style go-around and your seat slides back, you now have an airplane trying to kill you.  

Exactly how I feel, I always trim the rudder right in the TO position, and trim pitch so that it requires holding back to keep the nose up so if I need to go around it doesn't take lots of effort to maintain control. I am one who likes to plan and know ahead of time what to expect. I know ahead of time when I am in the pattern and start trimming in right rudder that I will need to use a bit of left rudder pressure to stay coordinated but I know that ahead of time, same with the pitch trim, I know as I trim it that I may have a bit of control pressure to over come to hold the nose off on landing but I know and am expecting it and am comfortable with it. What I don't want is holding the yoke forward with both hands or a knee and getting a big surprise on a go around. In flight or cruise yes trim all the forces off for hands free flight it's the most efficient and less fatigue for the pilot but on landing I plan for the unexpected go around.

[gsxrpilot]

2 hours ago, Bob_Belville said:

Paul, @gsxrpilot, I had not heard that the change, which I like, was final... (The MooneyCaravan website does not show 2018 schedule yet.)

I'm trying to get it posted today. We've been sorting out some other minor details, but it's definitively Saturday this year.

[gsxrpilot]

1 hour ago, Shadrach said:

I've never questioned the usefulness, challenge or skill involved in formation work.  I have done some very limited formation flying, always with dissimilar aircraft, and it's not an exercise in comfort flying.  I'm sure some would come with the experience that I don't have.  I have seen the proverbial no flap, 90kt landing mentioned here several times and was curious about it as a practical matter...I big thanks to Mike for answering the question.  It appears the high speed landings are more a function of "caravan" missions than formation flying.  Outside of those conditions, I don't think the procedure has much virtue.  On the whole, Mooney pilot's are better at depositing their aircraft in the weeds than they are at coming up short.

@201er and @donkaye both explained the reason for it very well.  I only mention it to point out that it's possible to land well without bouncing or proposing at much higher speeds. 

The problem is trying to force an airplane on to the runway before it's ready. Obviously a higher speed will require a longer runway. And along with that, the shorter the runway, the slower the approach and landing should be. There is an obvious limit to how slow an approach can be flown, and likely an upper limit as well. But with sufficient runway length, the upper limit somewhere over 90 knots.

I like to be able to set up the approach and landing for any conceivable or possible landing scenario. So at my home airport of 84R there is a taxiway at 750 ft from the threshold of 17. It's fun to practice coming in absolutely as slow as possible and making that taxiway. It's good practice using the AOA. But also when landing 17L at KAUS where the GA ramp is at the far end of the runway and Southwest is number 2 behind me, I know I can fly it all the way in, roll it on and ride the mains all the way to the ramp without disrupting the flow anymore than necessary. 

It's fun and useful to know how to land well in any and all configurations and conditions...

BTW... the Missile in search of a wing had nothing to do with landing speed. I know the owner and met with him after the accident. I won't go into the detail here as that's for him to explain.

[LANCECASPER]

2 hours ago, bradp said:

 

There are some models (some of the early Bo's for example), in which the flap switch and gear switches are eerily similar in form factor and have resulted in some snafus.  We have the benefit of human factors and ergonomic design in all the Mooney models in which the flaps and gear switches are notably dissimilar.  This is the reason why some CFIs teach don't touch anything until clear of the runway.  

In July 1986, five months after getting my private I took some friends and flew to Mackinac Island. After we landed and were waiting for transportation (horse drawn carriage, since airplanes are the only motorized vehicles on the island) we saw on V-tail bonanza on final. He was way too fast and after 3/4 of the runway was used up he went around. He did the same thing again and then on the third try after bouncing it a couple times and getting into a porpoise situation and then attempting another go-around he lifted the gear instead of the flaps and skidded off into the grass. We ran down there to see if he needed help getting out of the airplane but he was already getting his luggage out and headed toward us when we got there. He had owned the airplane less than a week. The airplane was still there when we took off in a couple days. Not only were the gear and flap switch similar but they were in the opposite places that you would find them in most airplanes. 99% of the time you would think and get it right, but under pressure muscle memory kicks in. Hence the need for transition training to re-train your brain.

[Shadrach]

On 2/10/2018 at 9:49 AM, gsxrpilot said:

@201er and @donkaye both explained the reason for it very well.  I only mention it to point out that it's possible to land well without bouncing or proposing at much higher speeds. 

The problem is trying to force an airplane on to the runway before it's ready. Obviously a higher speed will require a longer runway. And along with that, the shorter the runway, the slower the approach and landing should be. There is an obvious limit to how slow an approach can be flown, and likely an upper limit as well. But with sufficient runway length, the upper limit somewhere over 90 knots.

I like to be able to set up the approach and landing for any conceivable or possible landing scenario. So at my home airport of 84R there is a taxiway at 750 ft from the threshold of 17. It's fun to practice coming in absolutely as slow as possible and making that taxiway. It's good practice using the AOA. But also when landing 17L at KAUS where the GA ramp is at the far end of the runway and Southwest is number 2 behind me, I know I can fly it all the way in, roll it on and ride the mains all the way to the ramp without disrupting the flow anymore than necessary. 

It's fun and useful to know how to land well in any and all configurations and conditions...

BTW... the Missile in search of a wing had nothing to do with landing speed. I know the owner and met with him after the accident. I won't go into the detail here as that's for him to explain.

I read the NTSB report and understood the detail therein. If one does not stop nor elect to go around in 3300ish feet of available runway then I find it hard to believe that touch down speed wasn’t a contributing factor.  I’m not beating up on the pilot. I’ve been lucky in that most of my misdeeds have only bent my ego...at least in aviation.

Edited November 9, 2018 by Shadrach

[gsxrpilot]

3 minutes ago, Shadrach said:

I read the NTSB report and understood the detail therein. If one does not stop nor elect to go around in 3300ish feet of available runway then I find it hard to believe that touch down speed wasn’t a contributing factor.  I’m not beating up on the pilot. I’ve been lucky in that most of misdeeds have only bent my ego...at least in aviation.

I'm happy to explain in a private message, but speed had nothing to do with it.

[Shadrach]

2 hours ago, Bob_Belville said:

There are those here with more Caravan experience and insight into the reason for no flaps, 90k on final than I have but I believe the main reason is to simplify the mixing of M20Cs, etc., and long body Mooneys in the air. Speeds are chosen for cruise (120k) and pattern (90k) that are well within the envelope of everyone. Also, bear in mind that routinely we're flying half way down the runway (to the dot) before touchdown which gives everyone time to bleed off to a reasonable, normal no flaps landing speed. We're not touching down at 90k. (Some long body jocks use one notch of flaps at that 90k final to fit in with our short bodies.)

It's really not that different from maintaining speed and landing long on a 10,000' runway to mix in as well as possibly at a airline hub drome. 

I read 90kt touch down speed. At MGW there’s an 11kt delta in Vso between the oldest, slowest and newest, fastest M20. The delta between planes can be more or less depending on load (I seem to remember a great video from a few years back of a fully loaded E model landing at OSH, quite a panel in that bird ). My thought was always that no Mooney needed to touch down at 90kts so why not have the slowest just speed up to the fastest’s SOP. Mike’s sensible explanation that it’s due to spacing and aircraft on approach makes sense to me.

[Shadrach]

52 minutes ago, gsxrpilot said:

The problem is trying to force an airplane on to the runway before it's ready. 

Short of approaching with a load of ice, landing any Mooney at a speed in excess of 90kts is an exercise in forcing the airplane to the runway before it’s ready. Doing it well just means the pilot has sufficiently finessed the process. 

[mike_elliott]

12 hours ago, Shadrach said:

The biggest fattest members of the breed stall at 59knots at MGW

The VG's on a M20V allowed me to stall it at 53. It was a loaded plane. I really didnt think they would help that much on a FIKI Acclaim and was surprised.

9 hours ago, M016576 said:

the best results come from realizing that the key is remaining humble, approachable, and credible.

Well said and so true

[Shadrach]

41 minutes ago, mike_elliott said:

The VG's on a M20V allowed me to stall it at 53. It was a loaded plane. I really didnt think they would help that much on a FIKI Acclaim and was surprised.

In reviewing the TN’s stall speed of 61kts, I’m wondering why the factory doesn’t install them if they’re good for an 8kt stall reduction. I wouldn’t think they’d have a significant drag penalty.

[carusoam]

VGs have an interesting task...

They are needed down low during landing...

They are unwanted up high in cruise...

until, they can become retractable....

On a TN’d plane, cruise can be in very thin air, making VGs almost invisible to the windstream...

Laws of nature actually working with the Pilot. 

Best regards,

-a-

[exM20K]

42 minutes ago, Shadrach said:

In reviewing the TN’s stall speed of 61kts, I’m wondering why the factory doesn’t install them if they’re good for an 8kt stall reduction. I wouldn’t think they’d have a significant drag penalty.

The salesforce would revolt: they couldn't sit on the wing at OSH.

[mike_elliott]

4 minutes ago, exM20K said:

The salesforce would revolt: they couldn't sit on the wing at OSH.

and Dmax would have to walk around the wing to get in the cockpit. At least thats what he said about them after he installed them on N252PT

[Bob_Belville]

2 hours ago, Shadrach said:

I read 90kt touch down speed. At MGW there’s an 11kt delta in Vso between the oldest, slowest and newest, fastest M20. The delta between planes can be more or less depending on load (I seem to remember a great video from a few years back of a fully loaded E model landing at OSH, quite a panel in that bird ). My thought was always that no Mooney needed to touch down at 90kts so why not have the slowest just speed up to the fastest’s SOP. Mike’s sensible explanation that it’s due to spacing and aircraft on approach makes sense to me.

Naw, I don't touch down at 90k and I doubt anyone does. I've done the Caravan arrival at KOSH twice and I've flown in 3 MAG clinics as well as some formation landing at Madison where Caravan assembles. I'd say we're aiming for a normal spot on the runway and about the threshold we're holding off and slowing to touch down well down the runway at a pretty normal no flap speed. I'm busy watching the element lead and not looking at the ASI, or even the runway but I suppose that's about 70k. The throttle is used to maintain position relative to lead. 

[exM20K]

47 minutes ago, Shadrach said:

In reviewing the TN’s stall speed of 61kts, I’m wondering why the factory doesn’t install them if they’re good for an 8kt stall reduction. I wouldn’t think they’d have a significant drag penalty.

serious answer: reports on this forum and mooney mailing list are that there is a significant speed loss.  Take a FIKI M20TN, which is 5-10 KTAS under book and knock another 5-10 ktas off for VG's, and now you've got a TN- Bonanza that doesn't carry as much.  I am based at a short field and would like the capability to take 1.3x 6 knots off my approach speed, but it's uninteresting if the speed penalty is so high.  I'd be interested in any recent PIREPS on the speed loss.

-dan

[Shadrach]

2 minutes ago, exM20K said:

serious answer: reports on this forum and mooney mailing list are that there is a significant speed loss.  Take a FIKI M20TN, which is 5-10 KTAS under book and knock another 5-10 ktas off for VG's, and now you've got a TN- Bonanza that doesn't carry as much.  I am based at a short field and would like the capability to take 1.3x 6 knots off my approach speed, but it's uninteresting if the speed penalty is so high.  I'd be interested in any recent PIREPS on the speed loss.

-dan

Dropping to 1.2Vso is free and easy and gets you to nearly the same approach speed and likely shorter roll outs! 

[exM20K]

4 minutes ago, Shadrach said:

Dropping to 1.2Vso is free and easy and gets you to nearly the same approach speed and likely shorter roll outs! 

For sure, and being on the back side of the power curve makes it easy to bleed off excess energy 

I have a cheat sheet in my plane that tells me at a glance what my landing weight is, given people/bags and landing fuel, and what Vso, 1.3*Vso and 1.2*Vso are.

The sheet also has the liftoff and 50' speeds at different rates.  In the TN, there is a significant spread for low - high weights: 65/75 @ 2700# up to 77/84 at MTOM.  I don't remember the 231 being so sensitive to weight on takeoff, but that was 10 years ago.  Of course, now that I have the 310HP STC, all the takeoff charts are excessively pessimistic. Or, looked at another way: if the book says it's do-able at 280HP, I'm highly, highly confident it can be done at 310HP.

-dan

[carusoam]

Oops...

[carusoam]

57 minutes ago, exM20K said:

serious answer: reports on this forum and mooney mailing list are that there is a significant speed loss.  Take a FIKI M20TN, which is 5-10 KTAS under book and knock another 5-10 ktas off for VG's, and now you've got a TN- Bonanza that doesn't carry as much.  I am based at a short field and would like the capability to take 1.3x 6 knots off my approach speed, but it's uninteresting if the speed penalty is so high.  I'd be interested in any recent PIREPS on the speed loss.

-dan

Dan,

Lets Ask Erik... @aviatoreb 

He recently added a few go slow penalties to his Rocket that didn’t seem to slow him down....

Slow me down, but don’t slow me down, list...

• Four blade prop 
• TKS anti ice on the leading edges
• VGs

The VGs got recently remounted with a really snazzy paint job....

 

Of course, I have no added resistance on my plane.... I would have gone to a two blade prop if it didn’t make the T/O run so long....  

PP Thinking out loud...

-a-

[Shadrach]

1 hour ago, exM20K said:

For sure, and being on the back side of the power curve makes it easy to bleed off excess energy 

I have a cheat sheet in my plane that tells me at a glance what my landing weight is, given people/bags and landing fuel, and what Vso, 1.3*Vso and 1.2*Vso are.

The sheet also has the liftoff and 50' speeds at different rates.  In the TN, there is a significant spread for low - high weights: 65/75 @ 2700# up to 77/84 at MTOM.  I don't remember the 231 being so sensitive to weight on takeoff, but that was 10 years ago.  Of course, now that I have the 310HP STC, all the takeoff charts are excessively pessimistic. Or, looked at another way: if the book says it's do-able at 280HP, I'm highly, highly confident it can be done at 310HP.

-dan

Agreed on the back side of power curve, but that's a riskier proposition.  1.2 Vso can be done power off.   I commend you on knowing your Vso for a given weight...It is the key to good airspeed management.  

Edited February 10, 2018 by Shadrach

[N9201A]

6 hours ago, Shadrach said:

Short of approaching with a load of ice, landing any Mooney at a speed in excess of 90kts is an exercise in forcing the airplane to the runway before it’s ready. Doing it well just means the pilot has sufficiently finessed the process. 

As others have explained, there is a difference between flying 90 KIAS on final (or even into the flare) and actually LANDING at 90 knots.  Given that Caravan (and B2Osh, others) SOP is to ROTATE @ 70 kts, it would be pretty hard actually to try to actually LAND 20 knots faster, at 90!  A safe lead will fly final and gradually reduce speed into the flare, landing well down the runway.  It is also SOP to use only long runways that permit these types of operations, and to keep taxi speed to the end of the runway as if there were 15, 20 or 50 planes coming in behind you...because there might be!  We use a standard procedure so everyone is proficient and there are minimal, non-material changes in techniques and procedures wherever and whenever we fly together. 

The purpose of keeping speed up is not only for a Caravan mass arrival, it is for ANY form work. There are several good reasons. In an element landing, Lead must always give wing either a power or drag advantage.  To prevent wing from overtaking, Lead must keep speed up.  This is especially true for Mooneys, which are relatively slippery and slow down more gradually than draggier types.  So pulling the throttle all the way out does not yield the deceleration achieved in a chunkier airframe, which amplifies the need for Lead to keep up speed.  Lead must also land further down the runway to accommodate following aircraft sharing that runway.  Slowing to get a "squeaker" or trying to just "kiss" the mains is great .... when flying alone.  In the front or middle of a formation recovery, it reduces built-in safety margins and compresses following aircraft, forcing following pilots to try to maneuver,  S-turn or go-around, since they cannot slow down and remain airborne if the aircraft in front of them is executing a stall-warning squeaker.  These effects are exacerbated the further back one goes.  In a "mass" (6+, 12+, or as at OSH last year 51 aircraft) formation, it needlessly jeopardizes safety.  Since we train the same techniques and procedures for newbies so that when they progress they'll have mastered what they need for more advanced work, we fly 90 as SOP.  

If you are too fast for the runway length, you are on too short a runway for form work.  If you cannot reliably transition your Mooney from 90 knots in the flare to a safe landing and fast taxi, you should not be flying formation until you can.  These sharpened stick-and-rudder skills will help you every time you fly your Mooney.  And while we have found that Js and below work best with no flaps, many K and later pilots opine that their aircraft warrant take-off flaps, which is fine.  

Come out and try it and you might like it.  But if you don't like it, or don't think you will, don't force it.  Some don't like water landings or helicopters, multis, aerobatics or gliders.  Pick what you like and be the best you can be at it.  Each of us should improve our own situation, and respect that others may not like what we do, just as we may not get what they do.  It's a big tent. 

[Shadrach]

12 hours ago, N9201A said:

As others have explained, there is a difference between flying 90 KIAS on final (or even into the flare) and actually LANDING at 90 knots.  Given that Caravan (and B2Osh, others) SOP is to ROTATE @ 70 kts, it would be pretty hard actually to try to actually LAND 20 knots faster, at 90!  A safe lead will fly final and gradually reduce speed into the flare, landing well down the runway.  It is also SOP to use only long runways that permit these types of operations, and to keep taxi speed to the end of the runway as if there were 15, 20 or 50 planes coming in behind you...because there might be!  We use a standard procedure so everyone is proficient and there are minimal, non-material changes in techniques and procedures wherever and whenever we fly together. 

The purpose of keeping speed up is not only for a Caravan mass arrival, it is for ANY form work. There are several good reasons. In an element landing, Lead must always give wing either a power or drag advantage.  To prevent wing from overtaking, Lead must keep speed up.  This is especially true for Mooneys, which are relatively slippery and slow down more gradually than draggier types.  So pulling the throttle all the way out does not yield the deceleration achieved in a chunkier airframe, which amplifies the need for Lead to keep up speed.  Lead must also land further down the runway to accommodate following aircraft sharing that runway.  Slowing to get a "squeaker" or trying to just "kiss" the mains is great .... when flying alone.  In the front or middle of a formation recovery, it reduces built-in safety margins and compresses following aircraft, forcing following pilots to try to maneuver,  S-turn or go-around, since they cannot slow down and remain airborne if the aircraft in front of them is executing a stall-warning squeaker.  These effects are exacerbated the further back one goes.  In a "mass" (6+, 12+, or as at OSH last year 51 aircraft) formation, it needlessly jeopardizes safety.  Since we train the same techniques and procedures for newbies so that when they progress they'll have mastered what they need for more advanced work, we fly 90 as SOP.  

If you are too fast for the runway length, you are on too short a runway for form work.  If you cannot reliably transition your Mooney from 90 knots in the flare to a safe landing and fast taxi, you should not be flying formation until you can.  These sharpened stick-and-rudder skills will help you every time you fly your Mooney.  And while we have found that Js and below work best with no flaps, many K and later pilots opine that their aircraft warrant take-off flaps, which is fine.  

Come out and try it and you might like it.  But if you don't like it, or don't think you will, don't force it.  Some don't like water landings or helicopters, multis, aerobatics or gliders.  Pick what you like and be the best you can be at it.  Each of us should improve our own situation, and respect that others may not like what we do, just as we may not get what they do.  It's a big tent. 

I’d love to come out and try it. The year that date worked for me, the clinic at KMTB filled up so quickly that I missed my opportunity. 

I appreciate the detailed explanation. If you look back at my previous posts you’ll see that I took no issue with nor claimed any specific insight into formation flying, clinic flying or caravan flying. The basics of my post can be summed up in one question (1) and one statement (2).

1) Why is it standard operating  procedure in the formation clinic and the caravan to land at 90kts? To be clear the 90kt reference  made in this thread and others specifically stated landing as in touchdown, as in rolling on a flying airplane at 90Kts, not approaching. I simply wanted to know why as it seems a tad excessive.

2. Landing a Mooney significantly faster than stall speed does not require any special skill and my experience flying with other Mooney pilots is that it’s often the norm. I stand by my assertion that high speed landings have little to no utility outside of specialized operations. I believe that most mooney pilots would benifit from learning to slow down for approach and landing rather than learning to fly on to the runway at high speed.

 

 

Edited February 13, 2018 by Shadrach