This is the kind of thing
I have seen these in just one aircraft: a Cessna 400 (TTX), at least 10 years ago.
Is it worth doing? Obviously this is a Major Mod which practically speaking will need an STC.
I have a feeling that prop at fine pitch + engine at idle will have a lot more braking effect than this contraption.
Peter wrote:
I have seen these in just one aircraft: a Cessna 400 (TTX), at least 10 years ago.
Mooney as well.
Most long body Mooney have them, I think turbo (Bravo, Ovation, Ultra, Acclaim) will surely need them as they tend to clock +190kts in -4deg pitch with idle, they are useful for those who get crunched by radar ATC that keep one high & fast before going down at 190kts: it’s one way to descend with warm engines, although on latter Mooney models one can fly with the gear extended at 160kts as well…
In NA 4 cylinders short & mid bodies, one does not need them at all, but there are few STC for anyone who fancy them and fail to make FL/2 = TOD NM, it’s a fetish object and people just love them without a good user case, they look cool if you can afford higher GPH
Those who fly high performance gliders would tend to think airbreaks/spoilers, retractable gears, glass cockpits, airframe drag chutes, tailwheels…are “normal”, only aeroplane pilots who think these are very special to fork load of AMU 
Cool idea, but I would not bother – because, any speed brakes for a GA SEP, which are approved, will have an only mediocre effect to increase drag. When I test flew a Mooney so equipped, I was underwhelmed. The truth about their very moderate effect came to me when the left speed brake would not retract when I selected it so. So I flew the rest of the left extended, right retracted, landed that way, and really did not notice much asymmetric effect.
Other (non SEP types) which are equipped with speed brakes probably are better thought out than GA SEP systems are/would be, and so more useful. To get authority approval of a retrofit system would be: a) Every type tested and approved (no STC AML), so very costly to approve. And, b) Viewed by the authority with such nervousness about failure (as above) and/or misuse, that anything more than “benign” would require huge failure modes test and analysis, so, again, costly.
Good descent planning is lower cost, less maintenance cost, and does not require complex/costly approval.
Most pilots who fly jets take pride in planning their decent to avoid using the speed brakes…….. but they don’t have engine shock cooling to deal with.
Good descent planning is lower cost, less maintenance cost, and does not require complex/costly approval.
Of course but planning is not a luxury for IFR when mixing with fast aircrafts, I flew the Ovation in Paris TMA between Paris Orly & CharlesDeGaulle (it’s a slaughter when it comes to ATC), you stay at FL70 above Paris then you need to lose 7kft in 15nm while keeping some speed, the gear is draggy and engine is normally aspirated but I am glad it had airbreaks…
Away from these places, one can drop an aircraft like a brick while keeping engine warm on power by flying on the drag side of the power curve (STC: use whole wings as airbreak) but it’s not compatible with ATC & IFR/IMC
At slow speeds, they are not effective, you can go-around or climb +1500fpm with airbreaks open, it seems to me there is a small user case for them in one single scenario the rest of the obsession is just pilot fitishism and/or lazy planning…
Didn’t the Jodel 120 Paris—Nice have airbrakes?
I don’t think it had flaps though.
Had the speedbrakes on the Mooney M20K 252, it was a factory installed option and I did not use them as much – I too considered it poor descent planning if I deployed them. Still they are wonderful to have, you could lose 20 kts or double your rate of descent without increasing airspeed.
Cool idea, but I would not bother – because, any speed brakes for a GA SEP, which are approved, will have an only mediocre effect to increase drag. When I test flew a Mooney so equipped, I was underwhelmed. The truth about their very moderate effect came to me when the left speed brake would not retract when I selected it so. So I flew the rest of the left extended, right retracted, landed that way, and really did not notice much asymmetric effect.
The principales of airbrakes is effective at high speed but not really at low speed, i’m not surprise that you can land with it and even that you noticed it. It doesn’t mean it’s not effective, but you have to go high speed to have an effect and indeed in case of asymetric deployment, you have ot reduce speed to prevent its effect.
Once on the CJ1, we went on high speed approach keeping 260kn ias until 5N final/2000 ft, and cut power and deploy speed brake at this moment. We lost speed very effectivement until 170kn, where flaps and gear takes the most drag effect. Deploying speebrakes only at 120kias has barely an effect, and CJ speedbrakes are bigger.
These SEP speedbrakes are only here to incease descend rate at high speed when close to VNE/VNO to insert in IFR arrival. I would not qualify these as a solution of poor descent planning. Actually even the best pilot cannot guess and be prepared to all event that can happen. It allows some more flexibility that could be welcome in some cases. Of course, the best pilots doesn’t need it, as well as emergency landing gear actually, gear always deploys :lol.
